Antibodies binding to constant domains of gamma delta t-cell receptors

Abstract

This invention relates to human antibodies and antigen-binding fragments thereof, including multispecific antibodies, that specifically bind to one or more constant domains of a gamma delta T- cell receptor (gdTCR) or a fragment or fragments thereof. The invention also relates to novel recombinant antigens, particularly novel recombinant and / or isolated antigens comprising one or more constant domains of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof and antibodies that bind said antigens. Further, this invention relates to methods employing said recombinant antigens to obtain said antibodies that specifically bind to and selectively target the constant regions of a gdTCR or fragment thereof. This invention additionally relates to methods for producing and purifying said antibodies and recombinant antigens. Additionally, this invention relates to polynucleotide molecules encoding said antibodies and said recombinant antigens. It also relates to vectors containing such polynucleotides and host cells comprising such polynucleotides and methods of producing said antibodies and antigen-binding fragments. The invention also relates to methods using said antibodies, such as methods of detecting, diagnosing and treating disease using said antibodies and medicaments comprising or derived from said antibodies.

Description

[0001]ANTIBODIES AND USES THEREOF FIELD OF THE INVENTION 5 In general, this invention relates to human antibodies and antigen-binding fragments thereof, including multispecific antibodies, that specifically bind to one or more constant domains of a gamma delta T- cell receptor (gdTCR) or a fragment or fragments thereof. The invention also relates to novel recombinant antigens, particularly novel recombinant and / or isolated antigens comprising one or more constant domains of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof 10 and antibodies that bind said antigens. Further, this invention relates to methods employing said recombinant antigens to obtain said antibodies that specifically bind to and selectively target the constant regions of a gdTCR or fragment thereof. This invention additionally relates to methods for producing and purifying said antibodies and recombinant antigens. Additionally, this invention relates to polynucleotide molecules encoding said antibodies and said recombinant antigens. It also relates to 15 vectors containing such polynucleotides and host cells comprising such polynucleotides and methods of producing said antibodies and antigen-binding fragments. The invention also relates to methods using said antibodies, such as methods of detecting, diagnosing and treating disease using said antibodies and medicaments comprising or derived from said antibodies. 20 BACKGROUND Gamma Delta T cell and T-cell receptor Classification Human gamma (g) delta (d) T-cell Receptors (gamma delta TCRs) are heterodimeric receptors comprising a gamma chain and a delta chain. Conventionally this class of receptors is classified into 25 sub-groups (sub-classes or sub-types) dependent on variable domain usage and the associated functionality / residency of gamma delta cells expressing said receptors. For example, one common classification system involves classifying the receptors via variable chain usage which can be summarized as follows: 30 Classification of receptor via variable chain usage: Human gamma delta TCRs containing a variable delta-one chain are often termed “delta-one” or “d1” or “VD1” TCRs as they comprise gamma delta TCRs encoded in part by the TRDV1 gene and comprise TRDV1 protein sequence. Typically, delta-one TCRs are predominantly expressed on gamma delta cells found in tissues and as such, cells positive for the delta-one TCR are sometimes termed ‘tissue- resident’ gamma delta T cells. Human gamma delta TCRs containing a variable delta-two chain are often termed “delta-two” or “d2” 5 or “VD2” TCRs as they comprise gamma delta TCRs encoded in part by the TRDV2 gene and comprise TRDV2 protein sequence. Typically, delta-two TCRs are predominantly expressed on gamma delta cells found in blood and as such, cells positive for the delta-two TCR are sometimes termed ‘blood-derived’ gamma delta T cells. 10 Human gamma delta TCRs containing a variable delta-three chain are often termed “delta-three” or “d3” or “VD3” TCRs as they comprise gamma delta TCRs encoded in part by the TRDV3 gene and thus comprise TRDV3 protein sequence. Delta-three TCRs are less well-studied and can be expressed on a smaller population of gamma delta T cells. They are likely a mixture of blood and tissue-resident (see also ‘non-delta two’ classification below). 15 Additional to the above delta-one, delta-two and delta-three receptor sub-classes, there are a number of ‘other’ human gamma-delta receptors; specifically “delta-four” or “d4” or “VD4” TCRs, “delta-five” or “d5” or “VD5” TCRs, “delta-six” or “d6” or “VD6” TCRs, “delta-seven” or “d7” or “VD7” TCRs, “delta- eight” or “d8” or “VD8” TCRs. Conventionally these ‘other’ classes are not considered ‘true’ gamma- 20 delta variable domains as they are also shared with alpha-beta TCRs. Additionally, the numbers of gamma delta cells expressing gamma delta TCRs containing VD4, VD5, VD6, VD7, and VD8 are typically small. Alongside the above classification, a more simplified classification system splits all gamma delta cells 25 between one of only two categories; those cells expressing delta-two TCRs and those which do not. In this approach gamma delta cells not expressing delta-two TCRs are termed ‘non-delta two’ gamma delta cells or ‘non-haematopoietic tissue-resident’ gamma delta cells (e.g. WO2017072367A1). In essence this classification approach is in recognition of the fact that in blood, the predominant class of cells are positive for delta-two containing TCRs cells whereas ‘non-delta two’ gamma delta cells 30 predominate elsewhere (in tissues etc). Finally, another somewhat enigmatic classification system defines one populations of gamma delta cells purely by what they are not – specifically gamma delta cells which are ‘non delta-one and non delta-two’ gamma delta cells have been classified as a single group previously (e.g. see Deniger et al Clin Cancer Res. 2014 Nov 15;20(22):5708-19. doi: 10.1158 / 1078-0432.CCR-13-3451). One might assume this class of cells is therefore instead positive for TCR delta-three, delta-four, delta-five, delta- six, delta-seven, and / or delta-eight. 5 An alternate way by which gamma delta TCRs and cells expressing said receptors are classified has been through their gamma-chain usage. Whilst there are at least 14 variable gamma genes (TRGV) it is assumed that only eight of these variable genes are functional. These belong to four different structural subgroups. However, only those sub-groups for which marked functional / residency differences are noted will be discussed below. 10 Human gamma delta TCRs containing a variable-four gamma chain are termed “gamma-four” or “g4” or “VG4” TCRs as they as they comprise gamma delta TCRs encoded in part by the TRGV4 gene and comprise TRGV4 protein sequence. This sub-class of TCR is of particular interest because cells expressing atypical levels or activity of gamma-four TCR can be associated with human gut 15 inflammation. Human gamma delta TCRs containing a variable-nine gamma chain are sometimes termed “gamma- nine” or “g9” or “VG9” TCRs as they as they comprise gamma delta TCRs encoded in part by the TRGV9 gene and comprise TRGV9 protein sequence. This sub-class of TCR is of particular interest because cells 20 expressing gamma-nine TCRs often present as a heterodimeric complex with delta-two chains and as such typically predominate in blood. Finally, it must be noted that the above example classification systems are not absolute and indeed there is overlap. For example, and as already mentioned, gamma-nine TCR positive cells are often 25 delta-two TCR positive too. New classification of receptor via constant chain usage: However often overlooked is the fact that all such gamma delta TCR comprise one of two variant heterodimeric constant domains. The present inventors therefore propose an alternate approach to 30 classifying both the gamma delta TCRs themselves as well as the cells expressing such TCRs. In humans, the delta chain constant domain of a gamma delta receptor is encoded by a single human TRDC gene and as such all gamma delta TCRs contains human TRDC protein sequence – termed T-cell receptor constant protein (e.g. see Uniprot B7Z8K6; TRDC_HUMAN) (SEQ ID NO: 1). 35 By contrast the human gamma constant chain of a gamma delta receptor is encoded by either; (i) the human TRGC1 gene and as such will contain the human TRGC1 protein - termed T-cell receptor constant protein 1 (see Uniprot P0CF51; TRGC1_HUMAN) (SEQ ID NO: 2) or; (ii) the human TRGC2 gene and as such contain the human TRGC2 protein – termed T-cell 5 receptor constant protein 2 (see Uniprot P03986; TRGC2_HUMAN) (SEQ ID NO: 3) Hence rather than classifying all gamma delta T cell sub-types by variable domain usage, one could instead consider classifying such receptors by constant domain usage. In doing so it is thus possible to divide all gamma delta cells into one of only 2 alternate sub-types as follows. 10 Human “GC1” receptors and cells expressing GC1 receptors This gamma delta TCR sub-class comprises TCRs containing the TRDC and TRGC1 constant domains. Hence it is proposed herein that TCRs of this sub-class are termed “GC1” TCRs. As such gamma delta cells expressing this sub-class of TCR can thus be abbreviated to “GC1” positive gamma delta cells. 15 Human “GC2” receptors and cells expressing GC2 receptors This gamma delta TCR sub-class comprises TCRs containing the TRDC and TRGC2 constant domains. Hence it is proposed herein that TCRs of this sub-class are termed “GC2” TCRs and as such gamma delta cells expressing this sub-class of TCR can thus be abbreviated to “GC2” positive gamma delta 20 cells. Whilst defining such cells in this manner is thus a novel possibility, without antibody tools able to distinguish these two sub-groups clearly and reliably it is little more than a theoretical academic exercise in most circumstances. Hence there is a need for better, more selective antibodies and to 25 develop such, there is first a need for better antigens to discover and characterise such antibodies. A sub-set of such antibodies may also be considered suitable as a novel class of therapeutic medicaments. One notable challenge in the provision of antigen tools to aid with discovery of antibodies capable of 30 selectively recognizing and binding GC1 and / or GC2 TCRs are the respective TRGC1 and TRGC2 constant domains. Whilst both human TRGC1 and TRGC2 domains share >90% amino acid sequence homology, they differ in marked and unique ways not observed in constant domains of conventional alpha beta TCRs. Specifically, whilst gamma delta GC1 TCRs comprising TRDC / TRGC1 heterodimers contain a canonical single interchain disulfide linkage, the GC2 TCRs comprise TRDC / TRGC2 heterodimers contains no such interchain disulfide linkage. This is unique amongst human T-cell Receptors and is because the TRGC2 gene segment contains no partner cysteine to pair with the cysteine present on cognate TRDC domains. Instead for the TRGC2 domain, this cysteine is replaced by a bulky hydrophobic tryptophan (Trp133, SEQ ID NO: 12) as shown in Figure 4. Alongside this 5 atypical ‘missing’ interchain linkage, the TRGC2 constant domain is also larger, exhibits multiply sized isoforms, and exhibits differing N-linked glycosylation patterning. The resulting differences in GC1 and GC2 TCR architectures makes the design and provision of authentic and representative antigens of this invention more challenging. 10 To summarize further, a comparison of the GC1 and GC2 TCRs is presented below in Table 1. TABLE 1 TCR Feature GC1 TCRs GC2 TCRs Overall Size Smaller relative to GC2 Multiple allelic variants, all larger than GC1 TRGC ‘Connecting’ Smaller relative to TRGC2 Larger relative to TRGC1 and due to at Region least one additional insert (or multiple inserts dependent on the allele) TRGC cysteine Yes, TRGC1 (Cys121; Uniprot No, cysteine replaced with a bulky employed in numbering of TRGC1_Human aromatic acid (Trp137; Uniprot interchain pairing P0CF51 (SEQ ID NO: 2; also see numbering of TRGC2_Human P03986 Cys117 SEQ ID NO:11) SEQ ID NO: 3, also see Trp133 SEQ ID 12 ) TRDC cysteine 110 is Yes No, instead it appears ‘orphaned’ paired Inter-chain disulfide Yes No bond formed between TRDC and TRGC heterodimer Potential TRDC 2 sites (N14 and N77 TRDC SEQ 2 Sites (N14 and N77 TRDC SEQ ID glycosylation sites ID NO: 1) NO: 1) Potential TRGC N- Four sites (N66, N120, N126, Five Sites (N66, N120, N136, N142, linked Glycosylation N135 Uniprot numbering of N151, Uniprot numbering of Sites (and positions) TRGC1_Human P0CF51 SEQ ID TRGC2_Human P03986 SEQ ID NO: 3) NO: 2) Therapeutic Human Monoclonal antibodies selective for specific Gamma Delta TCRs. To date, a number of discovery projects have been undertaken primarily to identify and isolate human or humanized therapeutic antibodies capable of binding and / or modulating and / or depleting and / or 5 activating cells expressing gamma delta TCRs. Typically, such discovery projects have focused on the discovery and use of antibodies as medicaments to selectively activate specific sub-sets of gamma delta cells such to ameliorate signs and symptoms of diseases including cancers and infections. Example of such projects are summarized in Table 2 below. 10 TABLE 2 Sub-Class of Example Project Possible use ? Possible Advantages ? gamma delta TCR targeted by antibody-based moieties Gamma nine WO2015156673 and de Medical treatment for the Targeting and Bruin et al 2018 treatment of cancer or an activation of gamma- Oncoimmunology; 7(1): infectious disease nine TCR positive cells e1375641 doi: predominantly found 10.1080 / 2162402X.2017.137 in blood 5641 Gamma four WO2021171002 Pharmaceutical Targeting and composition for the activation of gamma treatment of disease four TCR positive cells often displaying markers of gut tissue residency Delta one WO2021032960 Pharmaceutical Targeting and composition for the activation of ‘tissue- treatment of disease resident’ delta-one TCR positive cells Delta one WO2019147735 Medicament for use in Inhibiting the treating diseases activation of gamma delta T cells Delta two WO2015156673 and de Medical treatment for the Targeting and Bruin et al 2018 treatment of cancer or an activation of delta-two Oncoimmunology; 7(1): infectious disease TCR positive cells in e1375641 doi: blood 10.1080 / 2162402X.2017.137 5641 Delta three WO 2019099744 For creating Ex-vivo enrichment of pharmaceutical delta-three TCR composition comprising positive subset delta-three enriched gamma delta cells for the treatment of conditions including cancer and infectious diseases The use of antibodies as medicaments to modulate specific gamma delta T cells As outlined in Table 2, various strategies have been undertaken to date focused on the discovery of antibodies which selectively bind to, target, and / or modulate (typically through activation) certain sub- 5 sets of gamma delta T cells. Associated with such strategies, those skilled-in-the-art have typically outlined that the sub-set of gamma delta T cells they are activating is likely the most preferred sub- type. For example, it has been suggested that antibodies which selectively target and activate delta- two TCR positive cells are most desirable because (i) delta-two positive cells comprise 90-95% of peripheral blood gamma delta T cells; (ii) they consistently generate a pro-inflammatory cytotoxic T 10 cell population; (iii) they are able to present antigen and (iv) they are associated with good prognosis in cancer patients. In contrast, it is suggested that targeting the other major sub-set of gamma delta cells - namely the delta-one cell sub-set – is less desirable given (i) delta-one cells are infrequently present in blood and (ii) delta-one cells exhibit more variable prognosis profiles. However, other artisans suggest the converse - specifically that delta-one cells are a more preferred sub-set to activate and to use in the treatment of cancer. For example, some authors suggest that delta-one cells may be preferred whereas delta-two cells are (i) dysfunctional in some cancer patients 5 and (ii) susceptible to activation induced anergy and exhaustion. Finally, some investigators suggest that gamma delta cells are in fact undesirable and should be depleted rather than selectively activated during cancer treatment regimens. Indeed, these researchers – some associated with Nybo Therapeutics Inc (Boston, MA, USA) - consider killing or 10 depleting gamma delta cells, particularly delta-one TCR positive cells, as the best option and propose the use of selective antibodies to mediate dependent cellular cytotoxicity (ADCC) based depletion of gamma delta cells accordingly. This is because these investigators consider gamma delta cells, and more specifically delta-one TCR positive gamma delta cells, to be immunosuppressive, particularly in pancreatic cancer. 15 Alongside example antibody clinical trials as outlined above in Table 2, to date there have also been a significant number of example cell therapy products wherein delta two or delta one enriched populations of cells have been used as cell therapy medicaments. Such cell therapies typically comprise hundreds of millions of gamma delta cells per dose. Such medicines are highly complex, costly to 20 develop, store, distributed and administer – particularly to large numbers of patients. Hence there is a need for ways and means to increase the number of gamma delta cells in a patient in need of treatment without the need for such complex cell therapies. In summary, during the pursuit of antibody-based medicaments and cell therapies designed to harness 25 gamma delta T cells, numerous alternative strategies have been explored and described at length to date. The need for “pan-gd” medicines Whilst it is possible that all such approaches for the use of antibodies as medicaments to modulate 30 specific gamma delta T cells have merit, there is clearly a need to better understand and characterize this class of medicaments. Many approaches to date are narrow in focus which may result in less effective antibody medicaments. In many circumstances a selective, partisan choice of one sub-type of gamma delta cells to target is not always optimal since it ignores potential holistic benefits of activating multiple sub-classes of gamma delta cells. There is therefore a need for antibodies that are capable of recognising and binding specifically and selectively to multiple sub-classes of gamma delta TCR via one or more constant domains of a gdTCR (termed a “pan gamma delta” or “pan gd” antibody). Such antibodies are not restricted to binding only one sub-class of gamma delta TCR (for example a delta-one TCR) but can bind to multiple sub-classes of gamma delta TCR (for example delta-one, delta- 5 two and delta-three TCRs). For instance, researchers focused on the discovery of antibody-based medicaments selective for delta- one gamma delta cells with a more tissue-resident distribution may then consider use of such medicaments to ameliorate the signs and symptoms of tissue-derived cancers – so called solid tumors. 10 However, such antibody-based medicaments may prove sub-optimal for this purpose as they do not also target delta-three cells also reportedly present in tissues – and sometimes in greater numbers. Therefore antibody-based medicaments capable of activating both classes could be used to underpin more holistic treatment regimens wherein both blood and tissue resident gamma delta cells are activated resulting in a more systemic surveillance of both blood and tissue. 15 As another example, other investigators with a preference for developing antibodies specifically designed to activate blood-centric gamma-nine gamma delta cells may then focus on their use in the treatment of leukaemia or so called ‘liquid’ tumors of the blood and where delta-two gamma delta cells predominate. However primary liquid tumors of the blood can develop via metastasis to become 20 secondary tissue / solid tumors where gamma-nine gamma delta cells are less prevalent. In this instance, and once again, an ideal antibody-based medicaments might be one that is not only capable of selectively activating blood-centric gamma nine cells but also tissue-resident delta-one cells. Once again, treatment of cancer with such medicaments may better ensure a more wholistic, systemic activation of gamma delta cells and enhanced, systemic tumor surveillance. 25 The same point can also be made when considering antibodies designed to selectively activate gut resident gamma-four TCR positive gd-cells. For example, primary tumors of the gut metastasize to other tissues often via the blood and lymphatic system. Hence once again an ideal antibody-based medicament is one capable of activating more than just gut-resident, gamma-four TCR positive gamma 30 delta cells. To discover and fully characterise such antibody-based medicaments capable of selectively target multiple sub-classes of gd cells and induce proliferation in all sub-classes of gamma delta T cells – be they the delta one, delta two or delta three sub-class, a novel suite of antigens is needed. Provided herein are such a novel antigen tool set so designed to aid discovery of the new class of antibodies and antibody-based medicaments also provided herein. 5 These antibodies and antibody-based medicaments exhibit desirable characteristics and technical effects which enable better treatment of patients, providing engagers to enhance and direct the power of key cells of the innate and adaptive immune system, opening up attractive targets unsuitable for CD3 based engagers. Through the recognition of antigens common to multiple classes of gamma delta T cells these antibodies and antibody-based medicaments exhibit features which can be leveraged to 10 aid with more effective dosing regimens, more real-time patient monitoring, patient response and responsiveness rates, alongside improved patient stratification regimens. These antibodies can also be employed as superior tools to better understand the biology and character of gamma delta T cells and sub-classes thereof. The novel approaches, methods, and treatment regimens thereby conceptualized by the availability and characterization of these novel antibodies are also provided herein. 15 Anti-gamma delta TCR antibody based medicaments; measuring target engagement and accurately characterizing conferred effects. As outlined above, a variety of differing antibody-based medicaments targeting gamma delta TCRs have been prioritized and progressed to the clinic. To the best of our knowledge all such medicaments 20 in clinical development to date selectively bind and target a variable domain as summarized above. However, one seemingly overlooked consideration in developing such medicaments is the need to optimally characterize and measure gamma delta TCR target engagement and conferred functional effects. There is a need for better medicines and better methods to monitor gamma delta TCR engagement, in particular when targeting tissue resident gamma delta cells. 25 This need is particularly pressing in human and primate studies as this group of mammals are defined as ‘gamma delta low’ species (<5% of lymphocytes in blood). In contrast, certain other mammals such as ruminants are sometimes termed ‘gamma delta high’ species given significantly higher numbers (15%-60%) observed in immune compartments. 30 Consequently, whilst these cells are often considered fundamentally important for immune surveillance and catalysis, they form a very small number of immune cells in human blood. Furthermore, within the blood, the numbers of delta one positive and delta three positive gamma delta are even lower given their tissue preference / residency. Hence developing medicines which may target and activate delta one and delta three cells may be desirable but the very small numbers of delta one and delta three cells in blood make clinical development and patient triaging more challenging. In such situations perhaps the only alternative option is to measure effects via complex tissue biopsy which is highly invasive. 5 For further example and as described above, certain medicaments are known which selectively target and modulate gamma delta cells expressing TRDV1 (delta one, VD1) containing TCRs. This class of gamma delta cells are often found in tissues and solid tumors. When developing such antibodies as medicines one essential requirement during clinical development is the ability to characterize and 10 model target receptor engagement, occupancy and conferred technical effects. The industry-wide challenges in this space are manyfold but these challenges are further amplified given the predominant tissue-resident nature of delta one TCR expressing cells. For example, measuring target engagement and conferred effects of predominantly tissue resident immune cells is difficult without invasive, error prone, and time-consuming tissue biopsy. This is further confounded by the 15 requirement to ship the resected and often labile biopsied tissue samples to specialized laboratories for further processing. Additionally, given the anticipated rapid effects of antibody target engagement - such as TCR downregulation - one may be unable to accurately measure target engagement in such tissue biopsies as the target cells become ‘invisible’. As a consequence it may be very difficult to determine optimal dosing regimens, patient response rates and treatment regimens, or characterize 20 cause-and-effect mechanisms of action of such medicaments. In sum, developing effective patient regimens with antibody medicaments which engage tissue prominent or resident delta one or delta three gamma delta TCR positive cells in ‘gamma delta low’ environment is very difficult given the smaller numbers of cells for analysis in the blood. Consequently, 25 leveraging most desired and most robust ‘liquid biopsy’ strategies to aid guide treatment regimens may not be possible. Further, given TCR downregulation will further hamper an ability to detect target engagement of already small population better medicines are needed which are able to engage tissue resident cells alongside more prominent blood cells more readily measured and monitored. 30 The antigens as provided herein have been designed to aid in the discovery of new antibodies and antibody-based medicaments capable of binding to domains present on both blood and tissue resident cells. In turn such provisions have conceptualized and enabled more effective methods of treatment informed by the ability of such medicines to engage tissue resident targets whilst in parallel monitoring effects in the surrogate blood compartment. This allows for near real-time analysis of prevailing gamma delta two positive cells in the blood which can operate as a target engagement and response- rate surrogate for more difficult to access tissue resident gamma delta cells. Gamma delta T cells; ADCC, AIDC and non-ADCC mediated killing 5 Antibody-Dependent Cellular Cytotoxicity (ADCC) refers to a cell-mediated killing reaction whereby cytotoxic immune cells expressing IgG-Fc-receptor (FcγR or abbreviated to FcR herein) recognize and bind to the Fc domain of antibodies. The variable domain of said antibodies is free to recognise and bind to a target antigen expressed on a target cell. Upon such binding, Fc receptor signalling pathways of the cytotoxic immune cell are activated, resulting in immune cell activation and lysis of the target 10 cell via an ‘immunological synapse’ bridge between the Fc receptor / antibody Fc domain on the immune cell and the variable domain of the antibody bound to the target present on the cell to be killed. It is well established that gamma delta T cells are highly effective at ADCC mediated killing of target 15 cells. It is known gamma delta T-cell killing can be mediated by ADCC using both monospecific and bispecific antibodies targeting one or two antigens. In such examples the Fc domain of the antibody binds the gamma delta T-cell FcR (e.g. CD16) and triggers FcR activation, whilst the variable domain or domains bind the target antigens. 20 Conversely, it has previously been proposed that tool (e.g. rodent-derived) antibodies targeting the constant domain of gamma delta T cells actually induce gamma delta T-cell death (see Dutta et al 2017 “Apoptosis Induced via Gamma Delta T Cell Antigen Receptor “Blocking” Antibodies: A Cautionary Tale” Front Immunol.2017; 8: 776. doi: 10.3389 / fimmu.2017.00776). Given this finding, one might imagine anti-gamma delta TCR constant domain antibodies may be most useful for situations in which 25 killing a gamma delta T cell is desired, such as targeting Gamma delta (γδ) T-cell acute lymphoblastic leukemia / lymphoma (T-ALL). In such situations the TCR target can be considered a TAA (tumor associated antigen) and killing of the diseased T-ALL cells can be mediated via either activation induced cell death and / or by ADCC mediated effector cell ‘fratricide’ wherein two effectors cells engage and kill one another via antibody mediated ADCC. 30 It remains unclear if one can replace ADCC mediated killing with antibodies which instead engage the gamma delta T cell by selectively binding to the constant domain of the TCR in order to mediate killing of target cells by non-ADCC mechanisms. Although therapeutics that exploit ADCC can be useful, there are also downsides associated with such mechanisms, for example the possibility of off-target effects. 35 In some situations, an antibody may bind to a healthy cell instead of a target cell (since antigens are often expressed on multiple cell types), causing lysis of healthy cells once ADCC pathways are activated. Additionally, binding of Fc to FcR leads to activation of immune cells, which can lead to further off-target toxicity when activated immune cells kill innocent “bystander” cells as well as target cells. Additionally, reducing the FcR binding properties of antibodies helps to avoid effector cell to 5 effector cell fratricide whereby NK cell or gamma delta T-cells kill other gamma-delta T-cells which are bound by the human anti-constant domain antibody - as provided herein - by ADCC mediated reaction. The ADCC reaction is mediated by the effector cell FcR binding to the Fc domain of the antibody. For recombinant human antibodies, there are a number of established ways to reduce the Fc domain 10 binding to the FcR to reduce or disable ADCC functionality and prevent antibody mediated ADCC cytotoxicity toward the target cell. Figure 20 herein further outlines the distinctions between (i) antibody mediated killing via classical ADCC reactions mediated by FcR engagement of the gamma delta T-cell (ii) Activation induced cell15 death (AICD) reactions mediated by Fab variable domain engagement of the gamma delta effector T- cell and (iii) non-conventional, non-ADCC reactions mediated by antibody Fab variable domain engagement of the gamma delta effector cells wherein gamma delta T-cell FcR is not engaged. One class of antibodies of interest are termed bispecific antibodies. Such antibodies can be employed 20 to engage two targets. One approach employs bispecific antibody wherein a first antibody binding arms targets a CD3+ T-cell, and second antibody binding arm targets a disease associated antigen (DAA) or tumour associated antigen (TAA) present on a diseased or cancerous cell. Such antibodies are sometimes termed T-cell bispecific engagers. For example, conventional anti-CD3 T-cell bispecific engagers are designed such that the first binding arm binds the accessible CD3 component of the 25 CD3 / TCR complex present on T-cells and the second binding arm binds a DAA or TAA target. Said bispecific antibody engagers then mediate the co-joining of the T-cell to the target DAA or TAA positive cell and the killing of said target cell by the T-cell. However, current T-cell bispecific engagers such as these CD3 engagers are typically sub-optimal (e.g see Singh, A. et al (2021) doi.org / 10.1038 / s41416- 020-01225-5). For example, there are often significant side-effects associated with these molecules. 30 This has resulted in numerous such engager programs being terminated during non-clinical or clinical development. One reason for such failures is because CD3 bispecific engager can engage all T-cells (CD8, CD4, T-regs, etc.) and this can result in over-activation of the immune system and result in elevated treatment-related adverse events (AE). Some of these AEs may manifest in T-cell exhaustion and / or acute cytokine flares such as cytokine release syndrome (CRS) and immune effector cell- associated neurotoxicity syndrome (ICANS). Cytokines associated with CRS include IL-2, IL-6, IL-10, IL- 17A. Extremely elevated levels of cytokines can have unwanted gross effects on the immune system. Further, certain such cytokines may exhibit uniquely undesirable effects. For example, high levels of IL- 17A are associated with B-cell pathogenesis in autoimmune diseases (see Koga et al 2021 5 doi.org / 10.3389 / fimmu.2020.624971). IL-17A is also implicated in cancer progression and may be involved in the pathophysiology of cancer, from tumorigenesis, proliferation, angiogenesis, and metastasis, to adapting the tumour in its ability to confer upon itself both immune, and chemotherapy resistance (see Yang et al (2014) doi.org / 10.1155 / 2014 / 623759). Overall, targeted, modest or controlled induction of certain cytokines such as interferon-gamma (IFN-g) is considered beneficial 10 whereas the induction of high or uncontrolled levels of cytokine is typically considered detrimental. Consequently AE, CRS and ICANS is a continuing issue and concern with conventional CD3 engagers. Typically, these serious side effects are classified by an agreed harmonized grading system. For example, when measuring CRS and ICANS, a non-limiting example includes MedDRA version 26.0 system (see Lee DW et al. (2019) Apr;25(4):625-638. doi: 10.1016 / j.bbmt.2018.12.758.). Additional 15 concerns associated with this approach relate to the fact that such CD3 engagers mediate the destruction of all antigen-positive cells (on-target, off-disease). This is because “conventional” alpha- beta T-cells will kill or are less able to “spare” non-diseased, healthy cells expressing the target antigen once coupled to such cells by conventional CD3 engagers. This can result in significant immune- mediated damage of healthy tissues (e.g. see Harter, M.F et al (2024). Nat. Biomed. Eng 8, 345-360 20 doi.org / 10.1038 / s41551-023-01156-5). Another approach involves designing T-cell engagers comprising a first binding arm which targets the variable domain of a gamma delta T-cell variable domain (such as a gamma nine variable domain) and a second binding arm which targets a target TAA or DAA. It has previously been shown that antigen 25 binding to the variable domain of the gamma delta TCR can trigger receptor activation and may thereby enhance gamma delta T-cell cytotoxicity through selectively enhancing release of granzyme B and perforin. For example, a murine antibody (Clone 7A5) and highly selective only for TCR variable domain gamma-nine (TCR V gamma 9) has been used previously to design bispecific which mediate target cell killing by delta-two, gamma-nine positive T-cells - predominantly blood resident (Oberg et 30 al (2014) doi: 10.1158 / 0008-5472.CAN-13-0675). As such, antibodies which bind the variable domain may operate much like authentic antigens or ligands to trigger receptor activation. Therefore, anti- variable domain antibodies which trigger the gamma delta TCR may be considered ligand mimetics. However, whilst targeting the variable domain in this way may result in authentic receptor activation, they will only target a sub-class of gamma delta T-cells. For example, they may target predominantly blood resident cells (e.g. delta-two positive, or gamma 9 positive) or tissue resident T-cells (e.g. delta- one positive cells). Finally, and beyond impacting safety and tolerability, significant concerns have also been raised about 5 effector cell induced cytokines providing pro-survival signals to cancers and conferring resistance to effector cell killing. For example, in a clinical trial it was observed that the cytokines induced and associated with CAR-T engineered CD3+ effector T-cells targeting AML actually increased cancer cell resistance to T-cell mediated killing. Furthermore, the resulting cytokine-supported cancers conferred a more exhausted phenotype on effector T-cells. The authors thereby concluded that co-treatment 10 with cytokine signalling inhibitors may be needed, that induced cytokine pro-cancer signals may be a “blind spot” in current approaches, and that “immunotherapy may be undermined by the cytokines induced by these therapies” (Bhagwat et al (2024), DOI: 10.1038 / s41591-024-03271-5). Hence conventional approaches focused on activating a sufficient number of T-cells by conventional means may also generate a fizzing cocktail of cytokines which induce serious AE, exhaust the T-cells, and 15 support cancer cell survival / proliferation. There is a need for more effective bispecific T-cell engagers. A more preferred bispecific engager may be one which engages a sufficient number of a most preferred effector cells found in both blood and in tissue such to mediate and potently kill targeted cancers - whilst not being undermined by excessive 20 cytokine production and / or by immune-mediated damage of healthy tissues. SUMMARY OF THE INVENTION The present invention provides human antibodies and antigen-binding fragments thereof that 25 specifically (and selectively) bind to one or more constant domains of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof. Such antibodies may suitably be multispecific antibodies, such as bispecific antibodies, that also specifically bind to a second target antigen. The invention also relates to recombinant and / or isolated antigens comprising or consisting of one or more constant domains of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof. Therefore, the 30 present invention provides antibodies that selectively bind to the recombinant antigens defined herein. The constant domain may be TRDC or a fragment thereof and / or TRGC1 or a fragment thereof and / or TRGC2 or a fragment thereof. According to a first aspect of the invention, human antibodies or antigen-binding fragments thereof 35 are provided which specifically bind to human TRGC2 / TRDC heterodimeric constant domain antigen, wherein the antibodies are multispecific antibodies, optionally bispecific antibodies, and specifically bind to a second target antigen. In some embodiments, the antibody or antigen-binding fragment thereof does not bind to a variable domain of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof. Said antibodies may also specifically bind to recombinant antigens comprising one 5 or more constant domains of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof. In some embodiments, the antibodies or antigen-binding fragments thereof also specifically bind human TRGC1 / TRDC heterodimeric constant domain antigen. 10 In some embodiments, the antibodies or antigen-binding fragments thereof specifically bind the constant domain TRDC or a fragment thereof, optionally human TRDC or a fragment thereof. In some embodiments, the antibodies or antigen-binding fragments thereof specifically bind the 15 constant domain TRGC1 or a fragment thereof, optionally human TRGC1 or a fragment thereof. In some embodiments, the antibodies or antigen-binding fragments thereof specifically bind the constant domain TRGC2 or a fragment thereof, optionally human TRGC2 or a fragment thereof. 20 In some embodiments, the antibodies or antigen-binding fragments thereof selectively bind the constant domain TRDC or a fragment thereof and / or TRGC1 or a fragment thereof and / or TRGC2 or a fragment thereof, optionally wherein the constant domain(s) are human. In some embodiments, the antibodies or antigen-binding fragments thereof selectively bind the 25 constant domain TRGC1 or a fragment thereof and the constant domain TRGC2 or a fragment thereof, optionally wherein the constant domain(s) are human. In some embodiments the second target antigen may be a tumor associated antigen (TAA) such as EGFR, GPC3, CD19, CD20, CD123, CD33, 5T4, EpCAM or CAIX. 30 According to one aspect of the invention, there is provided an anti-constant gdTCR antibody or antigen- binding fragment thereof as defined by SEQ ID NO herein, for example those presented in Table 3. Also provided herein are methods of using said antibodies, including methods of treating a disease or disorder in a subject, comprising administering to the subject the antibody or antigen-binding fragment thereof provided herein, optionally wherein the disease is cancer or an autoimmune disease. 5 Also provided herein are recombinant antigens used to identify and develop antibodies of the invention. In one aspect the recombinant antigens may be monomeric and comprise or consist of, in a N-terminal to C-terminal direction: 10 a. optionally a leader sequence; b. one or more constant domains of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof; and c. a dimerization domain. 15 In another aspect the recombinant antigens may be dimeric and comprise or consist of a first sub-unit and a second sub-unit, wherein the first sub-unit comprises or consists of, in a N-terminal to C-terminal direction: a. optionally a leader sequence; b. one or more constant domains of a gamma delta T-cell receptor (gdTCR) or a fragment or 20 fragments thereof; and c. a dimerization domain; and the second sub-unit comprises or consists of, in a N-terminal to C-terminal direction: a. optionally a leader sequence; b. one or more constant domains of a gamma delta T-cell receptor (gdTCR) or a fragment or 25 fragments thereof; and c. a dimerization domain. In some embodiments the recombinant antigen is homodimeric. In some embodiments the recombinant antigen is heterodimeric. 30 Also provided herein are nucleic acids that encode a recombinant antigen as described herein. Also provided herein are nucleic acids that encode an antibody as described herein. Also disclosed are vectors comprising the nucleic acid as described herein. Also disclosed are host cells comprising the vector as described herein. Also provided herein is a method of producing an antibody or antigen binding fragment as defined herein, comprising culturing a vector as defined herein or a host cell as defined herein under conditions allowing expression of the antibody or fragment and recovering the antibody or fragment. 5 Also provided herein are antigen libraries comprising two or more recombinant antigens described herein. Also provided herein is the use an antigen as described herein in a method of obtaining an antibody. 10 Also provided herein are antibodies obtained or obtainable via a method as described herein. In one aspect there is provided a method of obtaining antibodies that specifically bind to the constant regions of a gdTCR or fragment thereof, the method comprising using at least two of the recombinant antigens as described herein. 15 In one aspect there is provided a method of obtaining antibodies that specifically bind to the constant regions of a gdTCR or fragment thereof, the method comprising: a. providing an antibody display library; b. employing sequential affinity screening of the antibody display library using at least two 20 of the recombinant antigens as described herein in any aspect or embodiment to identify candidate clones that specifically bind to the TRDC and / or TRGC regions of a gdTCR; c. obtaining antibodies specific to the TRDC and / or TRGC regions of a gdTCR. Also provided herein is the use of an antigen as described herein in a method of screening an antibody 25 library. Also provided herein is an isolated recombinant peptide comprising or consisting of the amino acid sequence of any one of SEQ ID NO: 33 to 50. 30 Also provided herein is the use of an antigen as described herein in a method of immunizing an animal. Also provided herein is a method of making an antigen as described herein. Also provided herein are antibodies which selectively and specifically bind to one or more of the antigens described herein. One primary goal of the antigens provided herein is the creation of a library of antigens suitable as 5 aids to help identify antibodies which selectively bind to GC1 and / or GC2 sub-classes of gamma delta TCR, or both. Such antibodies, and the antigens used to identify them, form part of the invention. Additionally conceived of, and provided herein, is a library of novel tool antibodies to aid identification and characterisation of a novel class of immune cells, to use as medicaments, to inform patient 10 treatment regimens or responsiveness, and to characterize sub-sets of gamma delta T cells which up until now have not been characterizable and poorly defined. BRIEF DESCRIPTION OF THE DRAWINGS 15 Figure 1: Constant Domain Guidance. (1A) Schematic summary of the gamma delta TCR and areas of notable variation. I = The variable domain (preferably not included in antigen); ii = The “constant” domain – also variable; variation conferred by TRGC gene usage; Exon 2 multiplication; Disulfide linkage; N-linked glycosylation profile (up to 20Kd);Final size / charge; iii =TRGC exon 2 encoded domain of various sizes due to insert multiplication; iv = The hyper variable CDR3 V(D)J domain (average length 20 increases with human age). The two greyed boxes indicate the structural domains of particular interest to this invention. The greyed boxes each comprise (canonical) beta-stranded IgG-like sub-unit of the gamma and delta constant domain respectively. These isolated sub-units are C-terminal of the hypervariable VDJ region and continue through to less structured regions. These greyed areas are of particular interest for inclusion into antigens as described herein. 25 (1B) Example Full Length Human Protein Sequence for TRDC, TRGC1 and TRGC2 proteins domains. Example human, cynomolgus and murine protein sequence shown for: Human TRDC sequence (B7Z8K6 TRDC_HUMAN uniprot.org also termed IMGT.org allele TRDC*01); Human TRGC1 sequence (P0CF51 TRGC1_HUMAN uniport.org also termed IMGT allele TRGC1*01); Human TRGC2 30 sequence (P03986 TRGC2_HUMAN uniport.org also termed IMGT allele TRGC2*06); Human TRGC2 sequence (alternate allele, GenBank: AAB63312.1); Cynomolgus TRDC (A0A7N9CA91_MACFA uniport.org); Cynomolgus TRGC (G7P2C2_MACFA uniport.org); murine TRDC (A0A0G2JEU3_MOUSE) uniprot.org; murine TRGC1 (A0A075B5Z0_MOUSE); murine TRGC2 (A0A075B5Z2_MOUSE) Figure 2: Cartoon adaption of a crystal structure of an example TCR of the “GC1” gamma delta TCR class. Cartoon of 1HXM gamma delta TCR crystal structure. This an example of a delta two, gamma nine TCR inclusive of constant domain and variable domain. Note cartoon does not depict a full length TCR as the components of regions encoded by TRDC and TRGC (C-terminal unstructured or connecting 5 region, the transmembrane domain, and cytoplasmic tail / stump) are not incorporated. Such TCRs are typically expressed on gamma delta cells predominant in blood and conventionally termed “delta two” TCRs. By the classification system as now proposed herein, this TCR is an example of a “GC1” class of TCR because the constant domain employed is the TRDC / TRGC1 variant. Location of the canonical beta strands found in the Ig-like constant TRGC1 and TRDC domains are indicated by brackets. Cartoon 10 sourced from www.rcsb.org / 3d-view / 1HXM. Figure 3: TRGC and TRDC domain structure and sequence including example antigen numbering scheme and key residues (3A) TRGC and TRDC domains in isolation and inclusive of unstructured regions, alpha helical transmembrane regions, and cytoplasmic tail / stumps. Cartoon structure 15 prediction of (i) TRDC, (ii) TRGC1 and (iii) TRGC2 domains in isolation and inclusive of the beta strands of the Ig-like domain (boxed), unstructured connecting regions, helical transmembrane domain and cytoplasmic stump. No N-terminal variable domains are shown. Cartoons adapted from AlphaFold (alphafold.com) - for TRDC see AlphaFold AF-B7Z8K6-F1; for TRGC1 see AF-P0CF51-F1; for TRGC2 see AF-P03986-F1. Cartoons adapted from screenshots and for illustrative purposes only (and not 20 necessarily to the same scale) (3B) TRDC domain structure. The full length TRDC sequence (SEQ ID NO: 1) is shown (amino acids 1-153) alongside an associated AlphaFold model (see also 3A). Highlighted (bold) is the area of particular interest when designing antigens as described herein (Ser1 to Cys110). Contained within this region is the B-strand structured sequence between and inclusive of residues Ser8 and His81. Beta strands (predicted by Uniprot KB) at position 8-14, 17-24, 26-28, 31-35, 37-42, 25 46-49, 53-63, 70-75 and 78-81 are underlined.-(3C) TRGC1 domain structure. The full length TRGC1 sequence (SEQ ID NO:2) is shown (amino acids 1-173) alongside an associated AlphaFold model (see also 3A). Highlighted (bold) is the area of particular interest when designing antigens as described herein (Asp5 to Cys121). Contained withing this region is the B-strand structured sequence between and inclusive of residues Lys11 through to Phe105. Beta strands (predicted by Uniprot KB) at positions 30 11-15, 19-25, 26-40, 43-48, 49-51,63-65,68-78, 79-81, 82-84, 86-91, 101-105 are underlined. (3D) TRGC2 domain structure. The full length TRGC2 sequence (SEQ ID NO: 3) is shown (amino acids Asp1 to Ser190) alongside an associated AlphaFold model (see also 3A). Highlighted (bold) is the area of particular interest when designing antigens as described herein (Asp5 to Phe105). Contained withing this region is the B-strand structured sequence between and inclusive of residues Lys11 through to Phe105. Beta strands (predicted by UniProtKB, plus an additional as modelled by alphafold for 11-15) at positions 11-15, 24-26, 28-39, 42-51, 66-77,89-92, and 101-105 are underlined. Further detail of TRDC, TRGC1 and TRGC2 domain structure / sequence respectively. (3E) The beta strand intervening loops of TRDC1, TRGC1 and TRGC2 (bold, underlined). 5 Figure 4: Protein sequence alignment of human TRDC and TRGC domains. Alignment of different TRGC1 and TRGC2 constant domain sequences (BLOSUM 62 scoring matrix). Consensus sequence shaded. Two variant TRGC2 alleles are shown to highlight single or double inserts for one example alternative TRGC2 allele. Only a TRGC1 single insert and TRGC2 double insert allele examples are 10 shown herein. However reportedly additional multiplications have been observed in certain other TRGC2 variants (see Buresi et al., 1989;29(3):161-72. doi: 10.1007 / BF00373641). Position of the Cys of TRDG1 which pairs with cys contained in the TRDC domain is indicated by box. Also highlighted in the same box is the TRGC2 trp at this position – no interchain cysteine is unique amongst all human TCR constant domains. 15 Figure 5: Example antigen sequence inclusive of an example downstream junction (5A) Schematic cartoon of an example heterodimeric (left) and homodimeric (middle and right) antigens. Optionally, heterodimerisation can be encouraged with aid of knob-in-hole Fc domains. (5B) Example heterodimeric sequence guide. Example junction shown between antigen and associated 20 purification / dimerization domain. In this example, the underlined sequence comprises IgG-like domain of the TRDC and TRGC1 constant domains incorporated into the antigen. Note the dual identity of cysteine at the junction of the gamma delta constant domain and the Ig Fc domain. This Cys can be numbered either as the first cysteine of the Fc sequence (220 / 233; Eu or Kabat numbering respectively) or equally as cysteine 110 of TRDC (SEQ ID NO:1) and cysteine 121 (SEQ ID NO:2) of TRGC1 25 respectively. When present these cysteines can form an interchain disulfide bridge in antigens as provided herein. Full length IGHG1 sequence not shown. Figure 6: Example library of TRGC1 / TRDC heterodimeric human (SEQ ID No: 33 & 34), cyno (SEQ ID No: 35 & 36) and murine (SEQ ID No: 37 & 38) antigens. Note for each antigen sub-unit, a cleavable 30 leader (SEQ ID No: 21) can be included at the N-terminus to encourage secretion in mammalian cells such as CHO and HEK293. Also note each sub-unit contains a C-terminal knob or hole Fc domain (SEQ 24 or 25 respectively) to encourage heterodimerization. Figure 7: Example library of TRGC2 / TRDC heterodimeric human antigens. The first antigen (SEQ ID No: 39 & 34) comprises human TRGC2 and TRDC authentic or wild-type sequence and as such no interchain disulfide bond can form between TRGC2 and TRDC chains - the TRDC Cys110 cannot form a disulfide bridge with TRGC2 partner chain which naturally lack a cysteine at the orthologous position. 5 Hence in this antigen, the TRDC Cys110 is present but principally unpartnered. The second antigen (SEQ ID No:40 & 34) comprises TRGC2 sequence with a Trp137Cys change such to allow the TRGC2 chain to form a disulfide bond between TRGC2137Cys and TRDC Cys110. The third antigen (SEQ ID No: 39 & 41) comprises wild-type TRGC2 sequence (Trp137, no cysteine) and TRDC sequence with Cys110Ser modification such to ensure there is no unpartnered Cys in the TRDC sub-unit. Note for each 10 antigen sub-unit, a cleavable leader (SEQ ID No: 21) can be included at the N-terminus to encourage secretion in mammalian cells such as CHO and HEK293. Also note each sub-unit contains a C-terminal knob or hole Fc domain (in this example SEQ 24 or 25 respectively) to encourage heterodimerization. Figure 8: Example library of TRDC, TRGC1 and TRGC2 homodimeric human antigens. Note these are15 homodimers antigens comprising two identical sub-unit with wild-type Fc fusion domains at their C- termini. Also note for each antigen sub-unit, a cleavable leader (SEQ ID No: 21) can be included at the N-terminus to encourage secretion in mammalian cells such as CHO and HEK293. Figure 9: Example library of human heterodimeric antigens comprising both constant domain 20 sequence AND variable domain sequence of Table 7. For Antigen CytAnt10 (SEQ ID No:45 and 46), the 1HXM variable domain (and CDR3) sequences are employed. For Antigen CytAnt11 (SEQ ID No:47 and 48), the 6G7D variable (and CDR3) sequences are employed. For Antigen CytAnt12 (SEQ ID No:49 and 50), the 7LLI variable (and CDR3) sequences are employed. Note for each antigen sub-unit, a cleavable leader (SEQ ID No: 21) can be included at the N-terminus to encourage secretion in 25 mammalian cells such as CHO and HEK293. Also note each sub-unit contains a C-terminal knob or hole Fc domain (SEQ 24 or 25 respectively) to encourage heterodimerization. Figure 10: Reduced and Non-reduced analysis of antigens described herein. Example non-reduced and reduced (suffixed as ‘r’ ) SDS-PAGE analysis of purified gamma delta constant domain antigens 30 against M Protein Standard Marker (Bio-Rad Laboratories Ltd, Hertfordshire UK. A) Example analysis of purified heterodimeric antigens; Lane order: 1= CytAnt01, 2 = CytAnt02, 3= CytAnt03, 4 = CytAnt04, 5 = CytAnt05,6 = CytAnt06, 10 = CytAnt10, 11 = CytAnt11, 12 = CytAnt12 B) Example analysis purified homodimeric antigens Lane Order 7 = CytAnt7, 8 = CytAnt8, 9= CytAnt9. Figure 11: Example stepwise library screening cascade using the TRDC / TRGC antigens. Initial antibody library sequences can be derived from either a naive or immunized source to generate the initial repertoire of antibodies (or fragments thereof such as scFV and Fab based sequences). Screening can be undertaken in parallel or in series as shown here. For further detail of strategies employed 5 herein (A, B, C and D) – see Figure 12. Figure 12: A summary of four different antigen / library discovery strategies. The strategies presented herein used human scFV phage display libraries N05, N06, S01, S02 to discover the human anti-TRDC and anti-TRGC antibodies provided herein. Strategy A, B, C and D are presented in Figure 12 A, B, C and10 D respectively. See Table 6 for further information on the antigens described herein. (A): Focus on anti- TRDC selective antibodies. (B): Focus on TRGC1 and TRGC2 selective antibodies. (C): Focus on TRGC1 and TRGC2 selective antibodies (alternate approach to (B)). (D): Focus on TRGC2 selective antibodies. Figure 13: A summary of master-plated scFV phage outputs in the “primary screen” ELISA assays 15 against the antigens as indicated. Also indicated is the library and screening strategy employed to generate said outputs. Figure 14: A summary of the cross-reactivity of the 29 clones in the second screen ELISA assays against the antigens as indicated. (A): Results presented for 29 clones in a tabulated form. Also20 indicated is the library and screening strategy employed to generate said clones. For these secondary- screen ELISA assays, the antigens were either plate-captured as biotinylated antigen (prefixed “Bio-”) with neutravidin or not biotinylated and plate-captured. The ELISA values are recorded and also grey- scaled heat maps created. Of note only clone 697 exhibited significant signal to background human IgG (last column). (B) Results for a subset of example clones exhibiting different target antigen 25 selectivity profiles presented in bar chart format. Examples include an antibody specific for TRGC2 containing antigens, an antibody which is specific for TRGC1 containing antigens, and an antibody cross reactive to both antigens – antibodies 1,2 and 3 respectively. Figure 15: Example analysis of fresh blood (PBMC purified) highlighting the relative abundance of 30 the three different subsets of gamma delta cells. The top three plots indicate a standard step-wise flow gating method from left to right comprising gating on forward / side scatter (to avoid debris) then singlets, then live cells. The lower three plots show subsequent analysis on CD3xVD1, CD3xVD2 and CD3xVD3. For this donor (arbitrarily selected) the delta two gamma delta cell content (middle lower plot) is clearly visible at approximately 2% of total CD3 positive immune cells, whilst the lower left plot (delta one) and the lower right plot (delta three) are less visible (both at less than 1% total CD3 positive cells). This aligns with the consensus view which often terms delta-two positive cells as ‘blood resident’ whilst delta-one and delta-three cells as more tissue-resident. 5 Figure 16: Example use of an antibody which selectively binds gamma delta one, delta two and delta three positive cells to increase the relative numbers of all three populations in blood PBMCs. Tabulated results on day zero (left hand table pre-incubation with antibody) and day 16 (right hand table) are shown. Significant increases as a proportion of total CD3+ cells is recorded. Plots below tables provide a visual guidance of the delta one (VD1), delta two (VD2) and delta three (VD3) gating 10 strategy and results. This gating was preceded by stepwise, forward / side, then singlet, then live, then CD3+ gating (also see Figure 15 for this pre-gating). Figure 17: Antibody which selectively binds gamma delta one, delta two and delta three positive cells induced down-regulation of gamma delta TCR with antibodies. All three sub-classes (delta one, 15 delta two and delta TCR positive gamma delta cells) exhibited a titratable TCR downregulation upon engagement with the two different antibody clones which recognize and bind all three sub-types. Figure 18: Summary of antibody sequences inclusive of Clone ID, domain, chain, and SEQ ID categorization 20 Figure 19: Cancer cell killing. Primary human PBMCs enriched for gamma delta cells were mixed with a human cancer cell line. Antibody clones were then titrated into the mix. OKT3 (anti-CD3) was used as a positive control. X / Y axis plots shown report antibody concentration versus antibody induced cell killing (as measured by increased bioluminescence). Absolute values shown on left-hand graph, 25 relative values versus base-line shown on right-hand graph. Figure 20: Schematic cartoon summary of Example antibody-mediated cell killing mechanisms. (A) Antibody dependant cell cytotoxicity (ADCC) mediated killing by gamma delta effector T cells. Antibody binds one or more targets expressed on the target cell or cells via Fab domains. The antibody also30 engages the FcR of the effector gamma delta T cell via Fc domains. FcR is triggered on the gamma- delta effector cell. The effector cell then kills the target cell via the immunological synapse or bridge formed by the antibody between the effector cell and target cell. (B) Antibody induced effector cell death (AICD). Antibody binds a selective target such as the gamma delta TCR constant domain via Fab domains. Upon binding, the activation of the TCR induces apoptosis of the effector gamma delta T cell. This killing may be further augmented by cross-linking or ADCC mediated fratricide by neighbouring effector cells (not shown for simplicity). This approach may be of use if one wants to target and kill gamma delta (γδ) T-cell acute lymphoblastic leukemia / lymphoma (T-ALL) cells (C) Non-ADCC killing by the gamma delta effector T-cell. Antibody is bound via Fc domain to a target cell which expresses 5 FcR. Antibody is then presented and selectively binds to a target on the effector cell (gamma delta T cell) via its Fab domain. In this instance the Fab target is the constant domain of a gamma delta T-cell receptor. Upon antibody engagement the gamma delta T cell is activated and then kills the target cell presenting the antibody. In this mechanism the FcR is not triggered on the gamma delta T cell, instead both activation and immune synapse formation is mediated by Fab domain engagement of the gamma 10 delta TCR constant domain. Figure 21: Leveraging non-ADCC mediated mechanisms using bispecific antibody formats. (A) Non- ADCC mediated killing; the starting point. This is a replicate of Figure 20(C). It is repeated here to reiterate that this mechanism requires no effector-cell (gamma delta T cell) FcR engagement by the 15 antibody to mediate target cell lysis (B) Non-ADCC target cell lysis with a bispecific antibody. A bispecific format can be designed whereby an anti-constant domain antibody is joined to an antibody targeting an antigen on a target cell (such as a tumor associated antigen). Optionally, and given no FcR engagement is needed, the resulting bispecific antibody can be designed with a deleted, disabled or attenuated Fc domain with reduced or no FcR binding capabilities. 20 Figure 22: Bispecific antibody examples. (A) Schematic cartoons of Bispecific 1 and Bispecific 2 as described in Example 15, not to scale. Bispecific Antibody 1 comprises a human anti-gamma delta TCR constant domain antibody as provided herein in a scFV format. This is linked to an anti-TAA (target 1) molecule also in a scFV format. Bispecific Antibody 2 comprises a full-length antibody containing 1 25 Vh / Vl Fab binding domain which binds the gamma delta TCR constant domain and 1 Vh / Vl Fab domain which binds a TAA (target 2). The IgG Fc domain contains ‘LAGA’ mutations to reduce FcR binding. (B) Mechanistic cartoon representation of non-ADCC mediated killing of Target 1 positive target cells using Bispecific Antibody 1 (C) Mechanistic cartoon representation of non-ADCC mediated killing of Target 2 positive target cells using Bispecific Antibody 2. 30 Figure 23: Anti-gamma delta constant domain x anti-TAA (GPC3) bispecific engagers; binding profile and conferred cytotoxicity effects on TAA-positive cancer cells. For all X / Y plots the bispecific molecule is represented by black circles and starting control anti-gamma delta constant domain antibody and anti-GPC3 antibody are represented by black triangles and black diamonds respectively (A) Schematic cartoon of the example bispecific molecule. The differing binding domains are shown as indicated (B) Binding profile on gamma delta enriched PBMCs. An X / Y plot summary showing % binding of test article to target cells vs. test article / concentration as indicated. (C) Binding profile on TAA positive (GPC3) cancer cells. An X / Y plot summary showing % binding of test article to target cells vs. 5 test article / concentration as indicated (D) Bispecific engager mediated killing of TAA (GPC3) positive cancer cells by gamma delta cells. An X / Y plot summary of a cytotoxicity assay comprising mixed co- culture of gamma delta cells and GPC3 positive cancer cells. Cancer cell death vs. test article / concentration as indicated. 10 Figure 24: Anti gamma-delta TCR constant domain antibody binding to gamma delta T-cells. X / Y plots of anti-constant domain antibody % binding to gated population vs titrated antibody concentration. Binding profile to alpha-beta negative gated, gamma delta enriched PBMCs (top plot, boxed). Binding profile to delta-one gated population (bottom left plot). Binding profile to delta-two gated populations (bottom middle plot). Binding profile to delta-three gated populations (bottom right plot). 15 Figure 25: Anti gamma-delta TCR constant domain antibody induction of delta T-cells proliferation. Bar chart summary of fold-change in gamma delta T-cell number overtime (mean; 2 donors) for exemplar anti-constant domain antibodies (labelled as CYT Ab1 and CYT Ab2) versus sub-type specific Comparators as indicated. Fold change in delta-one positive gamma delta T-cells (left hand bar chart), 20 in delta-two positive cells (middle bar chart), in delta-three positive cells (right bar chart). Figure 26: Anti gamma-delta TCR constant domain antibody induction of delta T-cells degranulation. X / Y plot measuring gamma delta T-cell CD107a levels vs titrated antibody concentration for two exemplar anti-constant IgG1 antibodies (CYT Ab1 or CYT Ab2) as described herein or non-binding 25 negative control IgG1 (as indicated). Analysis of delta-one gate (left hand plot), delta-two gate (middle plot) ad delta-three gate (right hand plot). Figure 27: Anti gamma-delta TCR constant domain antibody induced gamma delta T-cell killing of tumour cells. (A) Composition of gamma delta enriched PBMCs used in the co-incubation cytotoxicity 30 study (B) X / Y plots of the results of the gamma delta cell / cancer cell co-incubation; % live tumour cells vs titrated antibody test article (as indicated) after co-incubation. Left-hand plot highlights anti- constant domain antibody mediated effects for two exemplar antibodies as described and discovered herein (CYT Ab1 and CYT Ab2) versus a non-binding control IgG1. Right-hand plot compares the relative potency of these anti-constant domain antibodies to comparator sub-set specific antibodies as indicated. Figure 28: Conferred effects of anti-gamma delta constant domain bispecific EGFR engagers on 5 gamma delta enriched PBMCs co-incubated with EGFR positive tumours (A) X / Y plots summarising the levels of cell surface levels of CD107Aa on gated cell populations vs various titrated test articles (as indicated) (B) Bar chart summaries of induced Ki67 marker levels on gated populations vs various titrated test articles (as indicated) (C) X / Y plot summarising the measured levels of tumour cell killing vs various titrated test articles (as indicated) (D) X / Y plot summarising the measured levels of tumour 10 cell killing vs various titrated test articles (as indicated) as a simplified replicate of the data presented in Figure 28 (C) but with additional emphasis added for further guidance. (E) X / Y plots depicting the fold increase in adenylate kinase as a measure of tumour cell lysis. EGFR+ tumour cells (A375) were co-cultured in a 1:1 E:T ratio with enriched γδ T cells from PBMCs (62% γδ T, 27% αβT cells) for 24 hours in the presence of an anti-constant domain x anti-EGFR gamma delta engager (Cyt Engager B) or 15 an anti-CD3 x anti-EGFR ‘conventional’ engager comparator as indicated. Supernatants were collected and the level of adenylate kinase quantified. Left-hand plot shows increased titratable TAA targeted cancer cell killing is mediated by both the anti-constant domain engager and the conventional CD3 engager. Right-hand plot shows remarkably more controlled / reduced levels of cytokine induction when employing the anti-constant domain engager vs the conventional CD3 engager. (F) X / Y plots 20 depicting the fold increase in adenylate kinase as a measure of TAA targeted killing of diseased or healthy cell with titrated test articles (CYT B Engager or NT Engager as indicated). Left-hand plot demonstrates anti-constant domain dependant, TAA mediated killing of tumour cells by the enriched PBMCs when CYT B Engager is employed. Right-hand plot shows a very little such mediated killing is observed when cancer cells are replaced with a variety of healthy cells - even when very high levels of 25 target TAA (EGFR) are present on such healthy cells. Figure 29: Targeting CD19 or CD20 positive diseased cells (A) Analytical flow profiling of purified effector cell populations employed in this cytotoxicity study. Left-hand plot: starting alpha-beta effector T-cell employed; 95.69% alpha beta +ve as indicated. Right-hand plot: starting gamma-delta 30 effector T-cell population employed; 99% gamma delta +ve as indicated (B) Schematic cartoon and tabulated description of molecules employed in this controlled cytotoxicity study (C) Targeted killing of target / antigen positive diseased cells as indicated; X / Y plot summary of % target cells (Raji) killed vs titrated molecule. Upper half; alpha-beta T-cells employed as the effector cell population, right-hand plot, gamma delta T-cells employed as the effector cell population (D) Killing mechanism; additional characterization. Top half indicates that higher levels of the more pleiotropic granzyme B protease is more heavily associated in alpha-beta T-cell mediated killing. In contrast, bottom half highlights a more targeted, more discrete killing profile is mediated by gamma delta effector T-cells (E) Example CRS- related cytokines induced during cytotoxicity assay: X / Y plots summaries of cytokine quantities 5 measured vs titrated test article. Upper half summarizes the vast levels of cytokines induced when alpha-beta T-cells are employed in the cytotoxicity assay if CD3 engagers are employed. Lower half summarizes the reduced levels of cytokine induced when gamma delta T-cells are employed (F) Interferon gamma (IFN-g) and TNF-alpha (TNF-a) induction: X / Y plots summaries of IFN-g and TNF-a quantities measured vs titrated test article. Upper half summarizes the vast levels induced when alpha- 10 beta T-cells are employed in the cytotoxicity assay. Lower half summarizes that more controlled levels (of IFN-g) induced when gamma delta T-cells are instead employed. Note differing X-axis and excessive / uncontrolled IFN-g induction observed in the alpha-beta T-cell / CD3 engager arm only. Figure 30: Targeting CD123 or CD33 or 5T4 or EpCAM or CAIX positive diseased cells (A) Schematic 15 cartoon and tabulated description of example anti-gamma delta constant domain, anti-TAA bispecific molecules (i) = For one of the Fab domains, the starting Vh-CH1 and Vl-CL is swapped to generate a Fab comprising Vh-CL and Vl-CH1 such to ensure correct light chain pairing for each Fab domain during production. (ii) = Attenuated Fc domain to reduce binding to FcR. (iii) Reciprocal KiH mutations to favour Fc domain heterodimerization. (B) Schematic cartoon of targeted killing of diseased cells by 20 gamma delta T-cells mediated by such bispecific molecules. (C) Targeted killing of CD33 target / antigen positive THP-1 cancer cells co-incubated with primary human gamma delta T-cells. X / Y plot showing the titratable increased killing profile conferred by a bispecific which selectively binds both the constant domain of a gamma delta T-cell TCR and the CD33 disease-associated target antigen. (D) Targeted killing of CD123 target / antigen positive THP-1 cancer cells co-incubated with primary human 25 gamma delta T-cells. X / Y plot showing the titratable increased killing profile conferred by a bispecific which selectively binds both the constant domain of a gamma delta T-cell TCR and the CD123 disease- associated target antigen. (E) Targeted killing of 5T4 target / antigen positive A431 cancer cells co- incubated with primary human gamma delta T-cells. X / Y plot showing the titratable increased killing profile conferred by a bispecific which selectively binds both the constant domain of a gamma delta T- 30 cell TCR and the 5T4 disease-associated target antigen. (F) Targeted killing of EpCAM target / antigen positive HCT116 cancer cells co-incubated with primary human gamma delta T-cells. X / Y plot showing the titratable increased killing profile conferred by a bispecific which selectively binds both the constant domain of a gamma delta T-cell TCR and the EpCAM disease-associated target antigen. (G) Targeted killing of CAIX target / antigen positive A431 cancer cells co-incubated with primary human gamma delta T-cells. X / Y plot showing the titratable increased killing profile conferred by a bispecific which selectively binds both the constant domain of a gamma delta T-cell TCR and the CAIX disease- associated target antigen. 5 Figure 31: Targeted killing of CD19 target / antigen positive diseased Raji cells co-incubated with primary human gamma delta T-cells. X / Y plot showing the titratable increased killing profile conferred by bispecific which selectively bind both the constant domain of a gamma delta T-cell TCR and the CD19 disease-associated target antigen. 10 Figure 32: Same assay comparisons with differing anti-constant domain antibodies (A) Binding to PEER cells. Studies highlight that the TRGC1 / TRDC selective A10 anti-constant domain antibody does not bind PEER cells effectively (B) Binding to primary gamma delta T-cells gated on VD1 cells, VD2 cells and VD3. Studies shows that the TRGC2 / TRDC selective A03 anti-constant domain antibody exhibits a significant lower binding signal to VD2 cells whilst the anti-TRGC1 / TRDC selective A10 clone exhibits a 15 significantly lower binding profile for VD1 or VD3 cells. Finally, the A09, A12 and A14 clones which can selectively bind TRGC1 / TRDC and TRGC2 / TRDC bind all VD1, VD2 and VD3 subsets similarly (C) Cytotoxicity assays involving gamma delta cells co-incubated with THP-1 cells plus test antibodies as indicated. Lefthand study used gamma delta effector cells more enriched for VD1 cells as indicated in the upper bar chart. The righthand study used gamma delta effector cells similarly enriched for VD120 and VD2 cells, again see upper bar chart. Study shows that the more selective A03 and A10 anti- constant domain antibodies are inferior relative to true-pan binders able to bind all gamma delta cells similarly and that the degree of inferiority may be impacted by the VD1 / VD2 / VD3 ratio of the gamma delta effector cells employed in the assay. 25 Figure 33: AlphaFold modelling of antibody / antigen engagement: (A) A static model of the full length TCR / CD3 complex including the position of example loops located on the ‘shoulder’ TRGC / TRDC complex (B). Modelling approach undertaken to model antibody engagement with isolated Ig-like domains Vh: Vl: TRGC: TRDC engagement using AlphaFold (C) Model of isolated TRGC1 / TRDC Ig-like domain including position of BC / FG loop shoulder and more C-terminal G-sheet flanking regions.30Figure 34: Binding profile comparison of anti-TRGC1 / TRDC selective antibodies vs broader anti- TRGC1 / TRGC2 selective antibodies. In each graph, anti-TRGC1 / TRGC2 selective antibodies (black and dark grey coloured bars – A09 and A14)) flank the more anti-TRGC1 only biased antibody (light grey bars - A10) in the middle (A) Binding to primary gamma delta T-cells (left-hand bar chart) (B) Binding to human gamma delta TRGC2 positive PEER cell line (right-hand bar chart). Figure 35: Attempted TRGC1 / TRDC and TRGC2 / TRDC deglycosylation. Attempted native (non- 5 denaturing) deglycosylation of Ant01 and Ant04. Top row Ant01; bottom row Ant04. The major peak identified via LC-MS analysis is indicated by circle for each analysis. Left hand columns: LC-MS analysis of starting antigen. Middle column LC-MS analysis of control deglycosylated, denatured antigen: Right column LC-MS analysis of (attempted) deglycosylated, non-denatured antigen – only TRGC1 / TRDC antigen is successfully deglycosylated under more native or non-denaturing conditions thereby further 10 highlighting the differences between TRGC1 / TRDC and TRGC2 / TRDC antigens as provided herein and the importance of considering use of both such antigens in the methods of the invention. Figure 36: Comparative binding profile of antibodies against primary (mixed) gamma delta T-cells, or VD1, or VD2, or VD3 sub-gated populations. Bar chart summaries presented. TRGC1 biased clones 15 generated from a prior campaign (CYTA161, CYTA163 and CYTA165) and TRGC1 and TRGC2 ‘true pan’ specific clones (CYTA115 and R10) identified using antigens provided herein. Bar chart orientation: binding to mixed human gamma delta enriched PBMCs (top, far left), VD1 positive sub-gate (top, second from left VD2), VD2 positive sub-gate (top, far right), VD3 sub-gate (bottom, left), and alpha- beta sub-gate (bottom, right). Figure highlights that the TRGC1-biased clones underperform when 20 targeting VD1 and VD3 sub-gates thereby highlighting the preference of VD1 and VD3 cells for use of TRGC2. Figure 37: Example discovery campaign output: Lefthand flow diagram represents an example prior campaign employing antigens we believe comprised variable domains (represented by the 1HXM 25 crystal structure). In this campaign, all selected antibodies generated were characterized as either variable domain selective, or likely constant / part variable domain selective, or proven TRGC1 / TRDC- biased by research herein. Righthand flow diagram represents our example campaign which employs antigens not containing variable domain. Via this constant domain centric approach, all selected binders discovered are not selective for the variable domain and a most preferred subset exhibit 30 significantly less TRGC1 or TRGC2 bias. As such this class can be termed true-pan or universal binders given they are characterized as selective for human TRGC1 containing TCRs and human TRGC2 containing TCRs (and cynomolgus TCR). Figure 38: Example of TRGC2 / TRDC selective bias or binding profile: Sequences and alignment highlights the extended Vh CDR3 of A03 inclusive of non-canonical cysteines. Also shown are three daughter molecules (A037, A038 and A039) wherein these non-canonical cysteines are removed by different mutational strategies. Also included in this study is an anti-RSV antibody as a negative control. 5 The X / Y plots below the alignment show titration (X axis) of the A03 antibody or mutated daughter molecules against primary gamma delta cells (mixed ‘pan’ population) or VD1 or VD2 or VD3 gated subsets as indicated Y axis indicated MFI as measured by flow-based analysis (with aid of a secondary labelling anti-Ig antibody). First, these results further highlight the finding that the A03 molecule exhibits a very significant binding bias towards VD1 and VD3 subsets – these subsets typically contain 10 more TRGC2+ve TCRs. Second it demonstrates that all attempts to remove the non-canonical cysteines failed and ablated all binding. DETAILED DESCRIPTION OF THE INVENTION 15 Before the various embodiments are described, it is to be understood that this disclosure is not limited to the particular embodiments described, and as such can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present teachings will be limited only by the appended claims. 20 The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described in any way. While the present teachings are described in conjunction with various embodiments, it is not intended that the present teachings be limited to such embodiments. On the contrary, the present teachings encompass various alternatives, modifications, 25 and equivalents, as will be appreciated by those of skill in the art. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the 30 practice or testing of the present disclosure, some exemplary methods and materials are now described. As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which can be 35 readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present teachings. Any recited method can be carried out in the order of events recited or in any other order which is logically possible. All patents and publications, including all sequences disclosed within such patents and publications, referred to herein are expressly incorporated by reference. 5 Numeric ranges are inclusive of the numbers defining the range. Unless otherwise indicated, nucleic acids are written left to right in 5' to 3' orientation; amino acid sequences are written left to right in amino to carboxy orientation, respectively. 10 Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Still, certain terms are defined below for the sake of clarity and ease of reference. It must be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and 15 “the” include plural referents unless the context clearly dictates otherwise. For example, the term “a antigen” refers to one or more antigens, i.e., a single antigen and multiple antigens. It is further noted that the claims can be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation. 20 The term “about” as used herein includes up to and including 10% greater and up to and including 10% lower than the value specified, suitably up to and including 5% greater and up to and including 5% lower than the value specified, especially the value specified. The term “between”, includes the values of the specified boundaries. 25 ANTIBODIES OF THE INVENTION The present invention provides an antibody or antigen-binding fragment thereof that specifically binds to one or more constant domains of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments 30 thereof. In preferred embodiments the antibody is a human antibody. In a first aspect, the invention provides an antibody or antigen-binding fragment thereof that specifically binds to human TRGC2 / TRDC heterodimeric constant domain antigen, wherein the antibody or antigen-binding fragment thereof is a human antibody or antigen-binding fragment 35 thereof and the antibody is a multispecific antibody, optionally a bispecific antibody, and specifically binds to a second target antigen. In some embodiments, the antibodies or antigen-binding fragments thereof also specifically binds to human TRGC1 / TRDC heterodimeric constant domain antigen. The term “antibody” as used herein may be used interchangeably with term “immunoglobulin” or “Ig” 5 and means an immunoglobulin molecule that recognizes and specifically binds to a target, such as a protein, polypeptide, peptide, carbohydrate, polynucleotide, lipid, or combinations of the foregoing through at least one antigen recognition site within the variable region of the immunoglobulin molecule. As used herein, the term “antibody” encompasses intact polyclonal antibodies, intact monoclonal antibodies, antibody fragments (such as Fab, Fab', F(ab')2, and Fv fragments), single chain 10 Fv (scFv) mutants, chimeric antibodies, fully human antibodies, humanized antibodies, fusion proteins comprising an antigen determination portion of an antibody, and any other modified immunoglobulin molecule comprising an antigen recognition site so long as the antibodies exhibit the desired biological activity. The term “antibody” can also refer to a Y-shaped glycoprotein with a molecular weight of approximately 150 kDa that is made up of four polypeptide chains: four polypeptide chains: two heavy 15 (H) chains and two light (L) chains. Each chain is divided into a constant region and a variable domain. The heavy (H) chain variable domains are abbreviated herein as VH, and the light (L) chain variable domains are abbreviated herein as VL. These domains, domains related thereto and domains derived therefrom, may be referred to herein as immunoglobulin chain variable domains. The VH and VL domains (also referred to as VH and VL regions) can be further subdivided into regions, termed 20 “complementarity determining regions” (“CDRs”), interspersed with regions that are more conserved, termed “framework regions” (“FRs”). The framework and complementarity determining regions have been precisely defined (Kabat et al. Sequences of Proteins of Immunological Interest, Fifth Edition U.S. Department of Health and Human Services, (1991) NIH Publication Number 91-3242). There are also alternative numbering conventions for CDR sequences, for example those set out in Chothia et al. 25 (1989) Nature 342: 877-883 or as summarized by IMGT.org. For guidance, antibody CDRs herein are defined by Kabat. However these CDR sequences are non-limiting. An ordinarily skilled person will be able to define CDRs by alternative standard definitions. Open-access freeware such as provided by abysis.org and the like can be routinely employed to aid with such definitions. Typically by alternate definitions, a specific CDR may be the same, or marginally longer or shorter by sequence length. An 30 ordinarily skilled person will readily recognize that regardless of which convention is employed to define a CDR, it is essentially the same CDR. In a conventional antibody, each VH and VL is composed of three CDRs and four FRs, arranged from amino-terminus to carboxy-terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. The conventional antibody tetramer of two heavy immunoglobulin chains and two light immunoglobulin chains is formed with the heavy and the light immunoglobulin chains inter-connected by e.g. disulphide bonds, and the heavy chains similarly connected. The whole antibody thus comprises two Fabs, each Fab comprising a VH-VL domain pair. The heavy chain constant region includes three domains, CH1, CH2 and CH3. The light chain constant region is comprised of one domain, CL. The variable domain of the heavy chains and the variable 5 domain of the light chains are binding domains that interact with an antigen. The constant regions of the antibodies typically mediate the binding of the antibody to host tissues or factors, including various cells of the immune system (e.g. effector cells) and the first component (C1q) of the classical complement system. This also includes antibodies comprising an Fc region that has been engineered to contain antigen-binding loops in its CH3 domain - this modified Fc region is termed an "Fcab" (Fc 10 with antigen binding). Antibodies may be oligoclonal, polyclonal, monoclonal (including full-length monoclonal antibodies), camelised, chimeric, CDR-grafted, single-domain, catalytic, chimeric, humanized, anti-idiotypic, including antibodies that can be labelled in soluble or bound form as well as fragments, variants or derivatives thereof, either alone or in combination with other amino acid sequences provided by known techniques. An antibody may be from any species. A “human antibody” 15 or “fully human antibody” refers to antibodies derived from human germline immunoglobulin sequences. Human antibodies provoke less cross-species antibody responses when administered to a human subject. The CDR, framework and / or constant region of the antibody or antigen-binding fragment thereof may be derived from a human Ig sequence, in particular a human IgG sequence. Human antibodies may include some amino acid residues not encoded by human germline 20 immunoglobulin sequences (e.g. mutations introduced by random or site-specific mutagenesis or by somatic mutation). However, the term is not intended to include antibodies in which CDR sequences derived from the germline of another mammalian species, such as a mouse, have been grafted onto human framework sequences. An advantage of using human antibodies is that they are low or non- immunogenic in humans. 25 Antibodies or antigen-binding fragments thereof can be naked or conjugated to other molecules such as toxins, radioisotopes, etc. “EU numbering” refers to a numbering convention used for the numbering of amino acid residues in 30 antibodies. Each residue of the antibody is assigned a number to allow comparison of antibodies. Where a variant antibody contains a residue that was not present in the wildtype antibody (e.g. an insertion mutation) decimals are used to indicate the insertion. For example, if a residue was inserted between the residues designated numbers 1 and 2, the new residue would be given the EU number 1.1. EU numbering is an alternative numbering scheme to others such as Kabat, (Kabat et al. Sequences of Proteins of Immunological Interest, Fifth Edition U.S. Department of Health and Human Services, (1991) NIH Publication Number 91-3242). Chothia (Chothia et al. (1989) Nature 342: 877-883) or as summarized by IMGT.org. wherein EU numbering is presented with further cross reference to Edelman, G.M. et al., Proc. Natl. Acad. USA, 63, 78-85 (1969). (10.1073 / pnas.63.1.78). 5 The term “epitope” as used herein refers to a localised region of the antigen or target which is specifically bound by the antibody or antigen-binding fragment thereof. Epitopes usually consist of chemically active surface groupings of molecules such as amino acids or sugar side chains and have specific three-dimensional structural characteristics as well as specific charge characteristics. Epitopes 10 found on protein targets may be defined as “linear epitopes” or “conformational epitopes”. Linear epitopes are formed by a continuous or semi-continuous sequence of amino acids in a protein antigen. Conformational epitopes are formed of amino acids that are discontinuous in the protein sequence, but which are brought together upon folding of the protein into its three-dimensional structure. Epitopes may also be referred to as “antigenic determinants”. An antibody binds “essentially the same 15 epitope” as another antibody when they both recognize and bind identical or sterically overlapping epitopes. Commonly used methods to determine whether two antibodies bind to identical or overlapping epitopes are competition assays, which can be configured in a number of different formats (e.g. well plates using radioactive or enzyme labels, or flow cytometry on antigen-expressing cells) using either labelled antigen or labelled antibody. An antibody binds “the same epitope” as another 20 antibody when they both recognize and bind identical epitopes (i.e. all contact points between the antigen and the antibody are the same). Various techniques are known in the art to establish which epitope is bound by an antibody. Exemplary techniques include, for example, routine cross-blocking assays, antibody “binning”, alanine scanning mutational analysis, peptide blot analysis, peptide cleavage analysis crystallographic studies and NMR analysis. In addition, methods such as epitope 25 excision, epitope extraction and chemical modification of antigens can be employed. Another method that can be used to identify the amino acids within a polypeptide with which an antibody interacts is hydrogen / deuterium exchange detected by mass spectrometry. In general terms, the hydrogen / deuterium exchange method involves deuterium-labelling the protein of interest, followed by binding the antibody to the deuterium-labelled protein. Next, the protein / antibody complex is 30 transferred to water and exchangeable protons within amino acids that are protected by the antibody complex undergo deuterium-to-hydrogen back-exchange at a slower rate than exchangeable protons within amino acids that are not part of the interface. As a result, amino acids that form part of the protein / antibody interface may retain deuterium and therefore exhibit relatively higher mass compared to amino acids not included in the interface. After dissociation of the antibody, the target protein is subjected to protease cleavage and mass spectrometry analysis, thereby revealing the deuterium-labelled residues which correspond to the specific amino acids with which the antibody interacts. 5 A “Fab region” as used herein refers to a portion of an antibody (or constructs that contain said portion) comprising a VH-VL domain pair providing an antigen-binding site (also known as a CDR based antigen binding site). The Fab region may further comprise the CL and CH1 domains. A conventional antibody with two heavy and two light chains thus comprises two Fabs, each Fab comprising a VH-VL domain pair. 10 The term “crossmab” or “CL-CH1 switching” as used herein refers to modifications to multispecific antibodies wherein a heavy chain and light chain have their respective CL and CH1 domains or portions thereof switched (replaced with each other) in one binding arm such to encourage correct light-chain / heavy-chain pairing and / or reduce wrong light-chain / heavy-chain pairing (also termed mispairing). 15 Examples of this approach are further described by Schaefer, W. et al., PNAS, 108 (2011) 11187-1191 DOI: 10.1073 / pnas.1019002108 The term “charge steering” “charge switching” or “polarity swapping” as employed in “light chain charge steering” and as used herein refers to modification to multispecific antibodies where a heavy 20 chain / light chain pair in one binding arm incorporate charge-complimentary amino acid modifications such to encourage correct light chain / heavy chain pairing and / or reduce wrong light chain / heavy chain pairing (also termed mispairing). Examples such heavy chain / light pair modifications are further described in EP2543680A1 25 A “Fc region” (fragment crystallizable region, also known as “Fc domain”), as used herein refers to a portion of an antibody (or constructs that contain said portion) comprising the CH2 and CH3 domains, optionally including hinge region too. The Fc region is the C-terminal region of an immunoglobulin heavy chain, including wild-type-sequence Fc regions and modified Fc regions. An Fc region is dimeric and thus comprises paired heavy chain constant regions each comprising a CH2 and CH3 domain. Fc 30 regions of antibodies are recognised by “Fc Receptors” (IgG-Fc-receptor, FcγR or FcR) that are expressed on the surface of certain immune cells. Fc-gamma receptor and reduced binding Fc domains As outlined above, ADCC is an immune reaction leading to the lysis of antibody-coated target cells by immune effector cells such gamma delta T-cells, NK cells etc. This reaction is mediated by the effector cell FcR binding to the C region or Fc domain of the antibody. For recombinant human antibodies, there are a number of established ways to reduce the Fc domain binding to the FcR to reduce or disable 5 ADCC functionality and prevent antibody mediated ADCC cytotoxicity toward the target cell. Non limiting examples include: ^ Choice of isotype - For example, wild-type and / or further modified IgG4 isotypes typically bind a number of FcR with reduced affinity versus IgG1 isotypes. Hence one can reduce ADCC 10 mediated effects by use of antibodies of IgG4 isotype or chimeric IgG (e.g. IgG1 / IgG4 wherein select residues from IgG4 are incorporated into, for example, an IgG1 Fc backbone) in order to reduce FcR binding and ADCC functionality. This approach is well summarised in Dumet et al 2019 (MAbs.2019 Nov-Dec; 11(8): 1341–1350) ^ Glycosylation modification: Human IgG1 Asn297 (EU numbering) positioned in the CH2 15 domain is heavily glycosylated. However, mutation of this position (e.g. N297A) results in aglycosylated antibodies with reduced FcR binding and reduced ADCC activity. ^ Mutation of critical residues in the hinge / CH2 domain of an IgG: There are a variety of established ways by which one can mutate an IgG to reduce FcR binding and ADCC activity. A non-exhaustive list of examples is provided in WO2021234402. For further guidance 20 incorpor ated herein are adapted examples from this application. Table A includes examples of therapeutic lgG antibodies which include combinations of mutations in the Fc region that may reduce binding to Fc-gamma-Receptors and / or C1q. WHO INN name for each molecule also included. Adapted from WO2021234402, Table 2. 25 TABLE A Mutations in the Fc regionabelacimab D265A, P329A anifrolumab L234F, L235E, P331S anrukinzumab L234A, G237A bimagrumab L234A, L235A cemiplimab L234A, L235A cergutuzumab L234A, L235A, P329G, Y349C, T366S, L368A, Y407V L235R, G236R, S239K, A327G, A330S, P331S, M428L, crovalimab durvalumab L234F, L235E, P331S foralumab L234A, L235E lodelcizumab L234A, L235A olendalizumab L234F, L235E, P331S perakizumab L234A, L235A prolgolimab L234A, L235A refanezumab L234A, L235A Table B includes Examples of individual mutations in the Fc region of human lgG1 considered to result in reduced binding to FcyR. Amino acid residues are listed according to the single letter code and numbered according to the EU system. These mutations are typically incorporated in combination into 5 an IgG1 Fc domain to ensure significant reduction in FcR binding. Variants reported in this table are included if they were reported as giving reduced binding to all FC-gamma receptor or were reported as giving less than 50% binding to FC gamma RI, FC gamma RIIA and Fc gamma RI when co mpare d to the wild-type IgG1 Fc domain. Adapted from W O 2021234402, Table 1. 10 TABLE B: EU num- Wild- Variants showing reduced binding ber type (either alone or more typically combination) Adapted from W O 2 021 23 4 402 Study 1 P K P H,Q,T A,D,E,G,H,K,Q,R,I,S,T A D,G,H Delet ed F,L,M,N,P,R R K,L,N,P AA K R F,H,YF,G ,HA A H,YS R HA R 38 AH H,P,T KA A R R H A R RA A KA L,N,P,R,S P332 I K,R Table A and B th e r e fo r e p r o v i d e a n u m b e r o f non-limiting ways by human antibody Fc domains can be modified resulting in an antibody with reduced binding to FcR or FcRs. 5 In some embodiments of the invention, the antibodies disclosed herein may be Fc disabled. As used herein, “Fc disabled” or “hinge disabled” refers to an antibody that does not comprise a Fc region or comprises a modified Fc region with reduced functionality. A modified Fc region is one that has been disabled by mutation or otherwise. Fc disabled antibodies demonstrate attenuated Fc function, such as reduced binding to FcR. For example, reduced binding of an Fc disabled antibody to FcR may refer 10 to a decrease in affinity of an antibody Fc region to an FcR as measured by SPR relative to a starting wild-type IgG1 Fc domain. Reduced binding also encompasses complete loss of binding, e.g. reduction of affinity of an antibody Fc region to an FcR to zero (or below detection limit of the analytical method). The Fc disabled antibody may comprise human IGHC heavy chain sequences that have been constructed, engineered or modified to reduce binding to one or more Fc gamma receptors. For 15 example, via IGHC hinge mutation or by construction of an antibody comprising heavy chain constant domains which are chimeric or hybrid for IgG1 / IgG2A or IgG1 / IgG4 IGHC sequences, or via any of the mutations shown in Tables A and B herein. In some embodiments of the invention, the antibodies disclosed herein may be Fc functional (i.e. 20 comprise a functional Fc domain). Thus, in some embodiments of the invention, the antibodies disclosed herein are able to bind FcR through the functional Fc domain. In some embodiments, the functional Fc domain may be any of IgG1, IgG2, IgG3 or IgG4 functional Fc domains. In some embodiments of the invention, the antibodies disclosed herein exhibit reduced ADCC relative to a wild type IgG1 antibody when measured by the same or substantially the same method. A subset of antibodies with reduced Fc receptor binding also exhibit measurably reduced ability to mediate 5 ADCC reactions. “Reduced ADCC” refers to a level of ADCC that is lower than exhibited by a wild type IgG1 antibody (Fc enabled) as measured, for example, by an ADCC reporter bioassay (Promega). For example, it is well known that Fc domain mutations which reduce engagement with Human Fc gamma RIIIA / CD16a result in antibodies with reduced ADCC activity. In some embodiments of the invention, the antibodies disclosed herein exhibit reduced CD16a binding relative to a wild type IgG1 antibody 10 when measured by the same or substantially the same method. Antibodies with reduced ADCC activity as referred to herein includes antibody that have reduced affinity to FcR relative to human wild-type IgG1 resulting in reduced capacity to mediate ADCC reactions relative to wild-type IgG1. In some embodiments of the invention, the antibodies disclosed herein do not exhibit ADCC. Antibodies that do not exhibit ADCC refers to antibodies in which ADCC activity has been reduced to zero (or below 15 detection limit of the analytical method) i.e. complete abolishment of ADCC functionality such that an antibody is incapable of triggering ADCC. ADCC activity can be measured by any suitable method known in the art, for example, by an ADCC reporter bioassay (Promega). The term “specificity” as used herein is the ability of an antibody or antibody binding domain to 20 recognise a particular antigen as a unique molecular entity and distinguish it from another. Specificity therefore refers to the number of different types of antigens or antigenic determinants to which a particular antibody or antigen-binding fragment thereof can bind. An antibody that “specifically binds” to an antigen or an epitope is a term well understood in the art. A molecule is said to exhibit “specific binding” if it reacts more frequently, more rapidly, with greater duration and / or with greater affinity 25 with a particular target antigen or epitope, than it does with alternative targets. An antibody that specifically binds to a particular epitope over another epitope may also be said to “selectively bind” to the first epitope. An antibody “specifically binds” to a target antigen or epitope if it binds with greater affinity, avidity, more readily, and / or with greater duration than it binds to other substances. In one embodiment, the extent of binding of an antibody to an unrelated target is less than about 10% of the 30 binding of the antibody to the target as measured, e.g. by a radioimmunoassay (RIA) or ELISA. As described above, gamma (g) delta (d) T-cell Receptors (gamma delta TCRs) are heterodimeric receptors comprising a gamma chain and a delta chain. The gamma chain and the delta chain each comprise a variable region and a constant region, and the classification of the various chains is explained in detail above in the section headed “Gamma Delta TCRs”. An antibody “fragment” (also referred to as “antigen-binding fragment”) refers to a part of an antibody 5 that binds to the intended target even though it is not a full immunoglobulin chain. For example, the following non-exhaustive list includes examples of antigen-binding fragments of an antibody: d. (i) a Fab fragment (a monovalent fragment consisting of the VL, VH, CL and CH1 domains); (ii) a F(ab')2 fragment (a bivalent fragment consisting of two Fab fragments linked by a disulphide bridge at the hinge region); 10 e. (iii) a Fd fragment (consisting of the VH and CH1 domains); (iv) a Fv fragment (consisting of the VL and VH domains of a single arm of an antibody); (v) a single chain variable fragment, scFv (consisting of VL and VH domains joined, using recombinant methods, by a synthetic linker that enables them to be made as a single protein chain in which the VL and VH regions pair to form monovalent molecules); 15 (vi) a VH (an immunoglobulin chain variable domain consisting of a VH domain); (vii) a VL (an immunoglobulin chain variable domain consisting of a VL domain); (viii) a domain antibody (dAb, consisting of either the VH or VL domain); (ix) a minibody (consisting of a pair of scFv fragments which are linked via CH3 domains); and (x) a diabody (consisting of a noncovalent dimer of scFv fragments that consist of a VH domain 20 from one antibody connected by a small peptide linker a VL domain from another antibody). In some embodiments, the antigen-binding fragment is not a VHH domain or single domain antibody. Antibodies or antigen-binding fragments thereof of the invention may be of any class. For example, 25 they may be IgG, IgA, IgM, IgE, IgD or isotypes thereof. Antibodies and antigen-binding fragments thereof of the invention may comprise a kappa light chain or a lambda light chain. In some embodiments, the antibody or antigen-binding fragment thereof is an IgG antibody, such as an IgG2, IgG3, IgG4 or preferably an IgG1 antibody. 30 In some embodiments, the antibody or antigen-binding fragment thereof comprises a hinge disabled Fc region. In some embodiments, the antibody or antigen-binding fragment thereof comprises L235A and G237A mutations (according to Eu numbering). In some embodiments, the antibody or antigen-binding fragment thereof of the invention comprises a VH and VL domain. In some embodiments, the CDRs (as defined by any applicable scheme such as for example Kabat, Eu, 5 IMGT, Chothia) of the antibody or antigen-binding fragment thereof of the invention do not comprise a cysteine. In some embodiments, the antibody or antigen-binding fragment does not comprise a non-canonical cysteine-cysteine bridge or disulfide bond. 10 In some embodiments, the constant domain bound by the antibody or antigen-binding fragment is TRDC or a fragment thereof and / or TRGC1 or a fragment thereof and / or TRGC2 or a fragment thereof. 15 In some embodiments, the constant domain bound by the antibody or antigen-binding fragment thereof is TRDC or a fragment thereof. The constant domain may be human TRDC, or cyno TRDC, or murine TRDC, preferably human TRDC. In some embodiments, the constant domain bound by the antibody or antigen-binding fragment 20 thereof is TRGC1 or a fragment thereof. The constant domain may be human TRGC1, or cyno TRGC, or murine TRGC1, preferably human TRGC1. In some embodiments, the constant domain bound by the antibody or antigen-binding fragment thereof is TRGC2 or a fragment thereof. The constant domain may be human TRGC2, or cyno TRGC, or 25 murine TRGC2, preferably human TRGC2. In some embodiments, the constant domains bound by the antibody or antigen-binding fragment thereof are TRGC1 or a fragment thereof and TRGC2 or a fragment thereof. In some embodiments, the constant domains bound by the antibody or antigen-binding fragment thereof are TRGC1 or a fragment 30 thereof and TRGC2 or a fragment thereof and not TRDC. The constant domains may be human TRGC1, or cyno TRGC, or murine TRGC1, and human TRGC2, or cyno TRGC, or murine TRGC2, preferably human TRGC1 and human TRGC2. In some embodiments, the antibody or antigen-binding fragment thereof specifically binds to a first antigen wherein a first subunit of the first antigen comprises the amino acid sequence of SEQ ID NO: 10; and the second sub-unit of the first antigen comprises the amino acid sequence of SEQ ID NO: 11 and the antibody or antigen-binding fragment thereof specifically binds to a second antigen wherein 5 a first subunit of the second antigen comprises the amino acid sequence of SEQ ID NO: 10; and the second sub-unit of the first antigen comprises the amino acid sequence of SEQ ID NO: 12. In some embodiments, the antibody or antigen-binding fragment thereof binds a human constant domain or fragment thereof, or a cyno constant domain or fragment thereof, or a murine constant 10 domain or fragment thereof. The term “human constant domain” or “cyno constant domain” or “murine constant domain” refers to the constant domain of a gdTCR derived from humans, cynomolgus monkeys or mice, respectively. In some embodiments, the antibody or antigen-binding fragment thereof bind to a human constant domain or fragment thereof and does not bind to a murine constant domain or fragment thereof. In some embodiments, the antibody or antigen-binding 15 fragment thereof binds to a human constant domain and is “cross-reactive” with a cyno constant domain. As used herein, “cross-reactive” means the antibody or antigen-binding fragment thereof binds to a human constant domain or fragment thereof and a corresponding cyno constant domain or fragment thereof. Cross-reactivity is useful in providing antibodies that can be used for pre-clinical evaluation, for example in in vivo animal studies, which is an important step in medicine development. 20 In some embodiments, the antibody or antigen-binding fragment thereof binds to corresponding human and cyno constant domains, for example the delta constant domain or the gamma constant domains. In some embodiments the antibody or antigen-binding fragment thereof binds to human TRDC or fragment thereof and cyno TRDC or fragment thereof. In some embodiments, the antibody or antigen-binding fragment thereof binds human TRGC1 or fragment thereof and cyno TRGC or fragment 25 thereof. In some embodiments, the antibody or antigen-binding fragment thereof binds human TRGC2 or fragment thereof and cyno TRGC or fragment thereof. In some embodiments, the antibody or antigen-binding fragment thereof binds human TRGC1 or fragment thereof, human TRGC2 or fragment thereof, and cyno TRGC or fragment thereof. 30 In some embodiments, the antibody or antigen-binding fragment thereof does not bind to a variable domain of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof. In some embodiments, antibodies or antigen-binding fragments thereof specifically bind to; a. antigens comprising gdTCR constant domain sequences (SEQ ID NOs: 1 to 20) which do not also contain any V-D-J region sequence or sequences as outlined in Table 7 (SEQ ID NOs: 66 to 83) and; b. antigens comprising gdTCR constant domain sequence (SEQ ID NOs: 1 to 20) which do also contain V-D-J region sequence or sequences as outlined in Table 7 (SEQ ID NOs: 66 to 83); but which do not specifically bind; f. c. antigens containing gdTCR V-D-J sequence or sequences as outlined in Table 7 (SEQ ID 5 Nos: 66 to 83) which do not also comprise gdTCR constant domain sequence (SEQ ID NOs: 1 to 20) In this embodiment therefore the antibody or antigen-binding fragment thereof identified specifically binds only to the constant domain and does not bind to any sequence in the variable region. 10 In some embodiments, the antibody or antigen-binding fragment thereof is able to specifically bind to more than one constant domain. In some embodiments, the antibody or antigen-binding fragment thereof specifically binds to both TRGC1 and TRGC2. In some embodiments, the antibody or antigen- binding fragment thereof specifically binds to TRGC1 and TRGC2 and TRDC. In some embodiments, the 15 antibody or antigen-binding fragment thereof specifically binds to both TRGC1 and TRDC. In some embodiments, the antibody or antigen-binding fragment thereof specifically binds to both TRGC2 and TRDC. In some embodiments, the antibody or antigen-binding fragment thereof specifically binds to both TRGC1 and TRGC2 and not TRDC. 20 In some embodiments, the antibody or antigen-binding fragment thereof specifically binds to an antigen comprising or consisting of SEQ ID NO: 3 (optionally a fragment thereof comprising residues Lys11 to Phe105 of SEQ ID NO: 3). In some embodiments, the antibody or antigen-binding fragment thereof specifically binds to an antigen comprising or consisting of SEQ ID NO: 2 (optionally a fragment thereof comprising residues Lys11 to Phe105 of SEQ ID NO: 3). 25 In some embodiments, the antibody or antigen-binding fragment thereof preferentially binds to one constant domain over another, or may specifically bind to only one constant domain. In some embodiments, the antibody or antigen-binding fragment thereof preferentially binds to 30 TRGC1 over TRGC2. As used herein, “preferentially binds” means the antibody or antigen-binding fragment binds more specifically to TRGC1 than it does to TRGC2. In some embodiments, the antibody or antigen-binding fragment thereof has an affinity for TRGC1 antigen that is 2-fold; or 5-fold; or 10- fold; or 50-fold; or 100-fold; or 500-fold; or 1000-fold greater than the affinity for TRGC2 antigen when measured under the same or substantially the same conditions. In some embodiments, the antibody or antigen-binding fragment thereof has an affinity for TRGC1 antigen that is 10-fold greater than the affinity for TRGC2 antigen when measured under the same or substantially the same conditions. Affinity can be measured by any method know in the art, for example as measured using surface plasmon resonance. In some embodiments, the antibody or antigen-binding fragment thereof 5 specifically binds to TRGC1 and does not specifically bind to TRGC2. In some embodiments, the antibody or antigen-binding fragment thereof preferentially binds to TRGC2 over TRGC1. As used herein, “preferentially binds” means the antibody or antigen-binding fragment binds more specifically to TRGC2 than it does to TRGC1. In some embodiments, the antibody10 or antigen-binding fragment thereof has an affinity for TRGC2 antigen that is 2-fold; or 5-fold; or 10- fold; or 50-fold; or 100-fold; or 500-fold; or 1000-fold greater than the affinity for TRGC1 antigen when measured under the same or substantially the same conditions. In some embodiments, the antibody or antigen-binding fragment thereof has an affinity for TRGC2 antigen that is 10-fold greater than the affinity for TRGC1 antigen when measured under the same or substantially the same conditions. 15 Affinity can be measured by any method know in the art, for example as measured using surface plasmon resonance. In another embodiment, the antibody or antigen-binding fragment thereof of specifically binds to TRGC2 and does not specifically bind to TRGC1. The antibodies or antigen-binding fragments thereof of this invention are capable of selectively 20 recognising constant domains structures present in authentic heterodimeric GC1 and GC2 TCRs expressed on the surface of a T cell. Said antibodies are not dependent on contact points found elsewhere in either the N-terminal variable and VDJ domains of the receptor, or in less structured, more varied sequence found in the more C-terminal section of the constant domain. Known antibodies that bind to gamma delta TCRs may therefore be inferior in this regard. For example, it has previously 25 been demonstrated that rodent-generated so-called pan antibodies such as IMMU510 partially compete with rodent generated so-called anti-VD1 specific antibodies such as TS8.2 (eg see Figure 6 of WO17197347). Logically such competition is only possible if these two antibodies are at least partially dependent and competing for space or contact points in the intervening J- region. The presently provided antibodies are not dependent on nor do they bind to the J region. Hence in one 30 embodiment antibodies as provided herein can still bind TRDC or TRGC constant domain sequence in the presence of IMMU510. In one embodiment antibodies provided herein do not compete with IMMU510. In some embodiments, the antibody or antigen-binding fragment thereof preferentially binds to TRDC over TRGC1 or TRGC2. As used herein, “preferentially binds” means the antibody or antigen-binding fragment binds more specifically to TRDC than it does to TRGC1 or TRGC2. In some embodiments, the antibody or antigen-binding fragment thereof has an affinity for TRDC antigen that is 2-fold; or 5-fold; 5 or 10-fold; or 50-fold; or 100-fold; or 500-fold; or 1000-fold greater than the affinity for TRGC1 antigen or TRGC2 antigen when measured under the same or substantially the same conditions. In some embodiments, the antibody or antigen-binding fragment thereof has an affinity for TRDC antigen that is 10-fold greater than the affinity for TRGC1 antigen or TRGC2 antigen when measured under the same or substantially the same conditions. Affinity can be measured by any method know in the art, 10 for example as measured using surface plasmon resonance. In one embodiment, the antibody or antigen-binding fragment thereof specifically binds to TRDC and does not bind specifically to TRGC1 or TRGC2. 15 In some embodiments, the antibodies or antigen-binding fragments thereof bind to protein sequences common to both human TRDC / TRGC1 and human TRDC / TRGC2 heterodimeric complexes. For example, a TRDC sequence or a sequence that appears in both TRGC1 and TRGC2. See Figure 4 which shows alignment and identities of TRGC domains. 20 In some embodiments, the antibodies or antigen-binding fragments thereof specifically bind to (i) human TRGC2 / TRDC heterodimeric constant domain antigen, (ii) human TRGC1 / TRDC heterodimeric constant domain antigen and cynomolgus TRGC / TRDC constant domain antigen. In some embodiments, the antibodies or antigen-binding fragments thereof specifically bind to (i) 25 glycosylated recombinant human TRGC2 / TRDC heterodimeric constant domain antigen, (ii) glycosylated recombinant human TRGC1 / TRDC heterodimeric constant domain antigen and glycosylated recombinant cynomolgus TRGC / TRDC constant domain antigen. In some embodiments, the invention provides an antibody or antigen-binding fragment thereof that 30 specifically binds to one or more constant domains of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof and does not specifically bind to a variable domain of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof, wherein the antibody or antigen-binding fragment thereof is a human antibody or antigen-binding fragment thereof. In some embodiments, the antibody or antigen-binding fragment thereof specifically binds human TRDC or a fragment thereof and does not specifically bind to a variable domain of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof. In some embodiments, the antibody or antigen-binding fragment thereof specifically binds human TRGC1 or a fragment thereof and does not specifically bind to a variable domain of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof. In some 5 embodiments, the antibody or antigen-binding fragment thereof specifically binds human TRGC2 or a fragment thereof and does not specifically bind to a variable domain of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof. In some embodiments, the antibodies or antigen-binding fragments thereof do not specifically bind 10 to: ^ a Fc region ^ a gdTCR transmembrane sequence; ^ TRDC peri transmembrane sequence located C-terminal of position valine129 (SEQ ID NO:1); ^ TRGC1 peri transmembrane sequence located C-terminal of position alanine138 (SEQ ID 15 NO:2); ^ TRGC2 peri transmembrane sequence located C-terminal of alanine154 (SEQ ID NO:3); ^ ‘connecting region’ of the gdTCR antigen located downstream and C-terminal of position Ser109 (for TRDC antigen), position Asn120 (for TRGC1) or position Asn136 (TRGC2) in the respective TRDC, TRGC1 or TRGC2 antigens; 20 ^ the C-terminal constant domain sequences downstream of Ser109 (for TRDC antigen), position Asn120 (for TRGC1) or position Asn136 (TRGC2) and the alpha-helix transmembrane. Such regions may be poorly recognised by antibodies, which should bind to the constant domain of the gdTCR only. 25 In some embodiments, the antibody or antigen-binding fragment is isolated. The term “isolated” as used herein means an antibody that has been removed from its original environment. An isolated antibody may be used to denote an antibody that is substantially free of other antibodies that bind to different antigens. For example an isolated antibody that specifically binds one or more gamma 30 constant domains is substantially free of antibodies that bind an antigen that is not a gamma constant domain. The term “isolated” may also be used to refer to preparations where the isolated antibody is sufficiently pure to be administered therapeutically when formulated as an active ingredient of a pharmaceutical composition, or at least 70-80% (w / w) pure, more preferably, at least 80-90% (w / w) pure, even more preferably, 90-95% pure; and, most preferably, at least 95%, 96%, 97%, 98%, 99%, or 100% (w / w) pure. Functional properties of antibodies of the invention 5 The antibodies or antigen binding fragments of the present invention may have an advantageous functional profile. For example, antibodies or antigen-binding fragments thereof of the invention may selectively activate and / or induce proliferation of gamma delta T cells. Antibodies or antigen-binding fragments thereof of the invention may induce downregulation of gamma delta TCRs. Antibodies or antigen-binding fragments thereof of the invention may induce, promote or increase gamma delta T 10 cell mediated killing. As used herein “activation” of a gamma delta T cell refers to a change in the behaviour or morphology of the gamma delta T cell resulting from exposure to an activating factor. For example, in vivo a T cell may be activated or stimulated by physical interaction of the TCR with an activating factor that is a 15 cognate peptide presented by the major histocompatibility complex molecule expressed on the surface of an antigen-presenting cell. A gamma delta T cell can also be activated or stimulated by the physical interaction of the TCR with another activating factor, such as an antibody or antigen-binding fragment of the present invention. Changes in behaviour and morphology displayed during activation include TCR downregulation, growth and proliferation of T cells and / or effector functions such as 20 cytokine secretion, cytotoxicity, degranulation, initiation of the cell based functions of the immune system or enzyme secretion. Activation of gamma delta T cells can be measured by any suitable method known in the art, for example quantification of T cell activation markers such as CD107a, CD25, CD69 or Ki67 via flow cytometry. 25 As used herein, “proliferation” of gamma delta T cells refers to an increase, growth or expansion of the number of gamma delta T cells as a result of cell division. Proliferation of gamma delta T cells can be measured by any suitable method known in the art that demonstrates a change in cell number over time, for example using a haemocytometer counting chamber, using a multi-mode cell imager or assays that measure the change in metabolic activity of cells. 30 As used herein, “downregulation” of gamma delta TCRs refers to the process in which activated TCRs are internalised by the T cell and retained or degraded as part of the T cell activation process. The TCRs are therefore no longer displayed on the cell surface. TCR downregulation may be a marker of T cell activation. TCR downregulation may be measured by any suitable method known in the art, such as measuring TCR expression using median fluorescence intensity measured by flow cytometry. As used herein, “gamma delta T cell mediated cell killing” refers to direct killing of tumor or cancer 5 cells by gamma delta T cells, for example via cytotoxic functions such as secretion of perforin or granzymes by a gamma delta T cell that has recognised a tumor or cancer cell. This is distinct from ADCC (antibody-dependent cell-mediated cytotoxicity) which refers to a cell-mediated process of killing which occurs when an immune effector cell recognises cell bound antibodies and triggers lysis and death of the target cell, typically mediated via Fc-Fcγ interactions. Antibodies or antigen-binding 10 fragments thereof of the invention may induce, promote or increase gamma delta T cell mediated killing upon binding to a gamma delta T cell. Such gamma delta T cell mediated killing does not occur via ADCC cell-mediated mechanisms. Gamma delta T cell mediated killing can be measured by any suitable method known in the art, for example target cells (such as cancer or tumor cells) may be incubated with gamma delta T cells in the presence of the antibody or antigen-binding fragment 15 thereof of the invention. After incubation, the cell culture can be stained with a dye to distinguish between target cells that are dead or alive and the proportion of dead cells can then be measured, for example by flow cytometry methods. In some embodiments, the antibody or antigen-binding fragment thereof of the invention specifically 20 binds to multiple different delta chains of the gamma delta TCR, for example delta 1 positive, delta 2 positive, delta 3 positive, delta 4 positive, delta 5 positive, delta 6 positive, delta 7 positive and / or delta 8 positive gamma delta TCRs. In some embodiments, the antibody or antigen-binding fragment thereof of the invention specifically binds to delta 1 positive and delta 2 positive and delta 3 positive gamma delta TCRs. In some embodiments, the antibody or antigen-binding fragments of the invention 25 downregulates delta 1 positive and delta 2 positive and delta 3 positive gamma delta TCRs. In some embodiments, the antibody or antigen-binding fragments of the invention selectively activates and / or induces proliferation of delta 1 positive and delta 2 positive and delta 3 positive gamma delta cells. The proliferation and / or downregulation may occur in all three cell subtypes concurrently, meaning delta 1 positive and delta 2 positive and delta 3 positive gamma delta cells can all be activated in 30 parallel by antibodies of the invention. In some embodiments, the antibody or antigen-binding fragment thereof of the invention specifically binds to multiple different gamma chains of the gamma delta TCR. In some embodiments, the antibody or antigen-binding fragment thereof of the invention specifically binds gamma 4 positive and gamma 9 positive gamma delta TCRs. In some embodiments, the antibody or antigen-binding fragment thereof of the invention selectively activates and / or induces proliferation of gamma 4 positive and gamma 9 positive gamma delta T cells. In some embodiments, the antibody or antigen-binding fragment thereof of the invention selectively activates and / or induces proliferation of blood resident 5 gamma delta cells, optionally gamma 9 positive gamma delta cells or delta 2 positive gamma delta cells; and also selectively activates and / or induces proliferation of tissue resident gamma delta cells, optionally delta one positive gamma delta cells or delta 3 positive gamma delta cells. In some embodiments, the antibody or antigen-binding fragment thereof of the invention binds delta 10 1 positive and delta 2 positive and delta 3 positive gamma delta TCRs derived from peripheral blood mononuclear cells (PBMCs). In some embodiments, the antibody or antigen-binding fragment thereof of the invention binds to immortalized cells expressing TRGC2 containing TCR (for example PEER cells). 15 In some embodiments, the antibody or antigen-binding fragment thereof of the invention binds to PEER cells expressing TRGC2 containing TCR. PEER cells are identified by catalogue number ACC 6 in DSMZ, Leibniz Institute, Germany. 20 In some embodiments, the antibody or antigen-binding fragment thereof of the invention induces proliferation and / or TCR downregulation of gamma constant 1 positive cells but not gamma constant 2 positive cells. For example, an anti-TRGC1 antibody will bind to TRGC1 and not to TRGC2 leading to TCR downregulation of TCRs comprising TRGC1 and not those comprising TRGC2 and / or proliferation 25 of cells comprising TRGC1 positive TCRs and not those comprising TRGC2 positive TCRs. In some embodiments, the antibody or antigen-binding fragment thereof of the invention induces proliferation and / or TCR downregulation of gamma constant 2 positive cells but not gamma constant 1 positive cells. For example, an anti-TRGC2 antibody will bind to TRGC2 and not to TRGC1 leading to 30 TCR downregulation of TCRs comprising TRGC2 and not those comprising TRGC1 and / or proliferation of cells comprising TRGC2 positive TCRs and not those comprising TRGC1 positive TCRs. In some embodiments, the antibody or antigen-binding fragment thereof of the invention induces a greater than 150-fold, 200-fold, 300-fold, 450-fold or 460-fold proliferation in the number of gamma delta T cells. In some embodiments, the antibody or antigen-binding fragment thereof of the invention induces a greater than 150-fold, 200-fold, 300-fold, 450-fold or 460-fold proliferation in the number of Vδ3 gamma delta T cells. 5 The TCR downregulation, T cell activation and / or T cell proliferation may take place when the antibodies or antigen-binding fragments of the invention are administered to gamma delta T cells in human blood, a human blood sample or derived cells or when administered to a patient. The antibodies or antigen-binding fragments of the invention target all γδ T cells, both blood and tissue 10 resident. This differentiated technology enables circumvention of heterogeneity and fully enables γδ T cell activity across the broadest range of patients. Blood resident γδ T cells (typically Vδ2 enriched) are activated by antibodies of the invention, which may trigger cytokine release, immune licensing and migration of these γδ T cells out of blood circulation and into tumours. Tissue / tumour resident γδ T cells (typically Vδ1 and Vδ3 enriched that may be tissue adapted e.g. to hypoxia) are also activated by 15 antibodies of the invention, which may also trigger cytokine release, immune licensing and migration of these γδ T cells out of the tissues and into tumours. In some embodiments, the antibody or antigen-binding fragment thereof of the invention is an IgG1 antibody or fragment thereof and induces proliferation of gamma delta T cells. 20 In some embodiments, the antibody or antigen-binding fragment thereof of the invention is an IgG1 antibody or fragment thereof and activates gamma delta T-cells to kill THP-1 cells in a co-culture assay. Sequences of antibodies and antigen-binding fragments thereof provided herein 25 A summary of some of the antibodies and antigen-binding fragments thereof provided by the present invention is provided below with reference to the SEQ ID NO corresponding to the accompanying sequence listing. Sequences are provided in the attached sequence listing and the accompanying Figures. In the case of any discrepancy between the sequences in the sequence listing and those in 30 Figure 18, the sequences in Figure 18 should prevail. Table 3 provides a summary of antibodies of the invention and their SEQ ID Nos. It is to be understood that any of the antibodies described in Table 3 can be formatted as a monospecific, bispecific or multispecific antibody. In any aspect, the heavy chain constant domain of the antibody or antigen-binding fragment thereof may comprise or consist of the amino acid sequence of SEQ ID NO: 326 or 389. 5 TABLE 3 Full Full Clone name VH VL HCDR1 HCDR2 HCDR3 LCDR1 LCDR2 LCDR3 heavy light chain chain Clone 6 94 95 152 153 154 155 156 157 329 330 Clone 38 96 97 158 159 160 161 162 163 331 332 Clone 128 98 99 164 165 166 167 168 169 333 334 Clone 205 100 101 170 171 172 173 174 175 335 336 Clone 228 102 103 176 177 178 179 180 181 337 338 Clone 303 104 105 182 183 184 185 186 187 339 340 Clone 325 106 107 188 189 190 191 192 193 341 342 Clone 332 108 109 194 195 196 197 198 199 343 344 Clone 487 110 111 200 201 202 203 204 205 345 346 Clone 489 112 113 206 207 208 209 210 211 347 348 Clone 525 114 115 212 213 214 215 216 217 349 350 Clone 545 116 117 218 219 220 221 222 223 351 352 Clone 567 118 119 224 225 226 227 228 229 353 354 Clone 578 120 121 230 231 232 233 234 235 355 356 Clone 641 122 123 236 237 238 239 240 241 357 358 Clone 676 124 125 242 243 244 245 246 247 359 360 Clone 680 126 127 248 249 250 251 252 253 361 362 Clone 697 128 129 254 255 256 257 258 259 363 364 Clone 717 130 131 260 261 262 263 264 265 365 366 Clone 731 132 133 266 267 268 269 270 271 367 368 Clone 734 134 135 272 273 274 275 276 277 369 370 Clone 745 136 137 278 279 280 281 282 283 371 372 Clone 759 138 139 284 285 286 287 288 289 373 374 Clone 811 140 141 290 291 292 293 294 295 375 376 Clone 894 142 143 296 297 298 299 300 301 377 378 Clone 953 144 145 302 303 304 305 306 307 379 380 Clone 957 146 147 308 309 310 311 312 313 381 382 Clone 1125 148 149 314 315 316 317 318 319 383 384 Clone 1171 150 151 320 321 322 323 324 325 385 386 Clone 6 (CYTA001): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 152; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 5 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 153; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 154; and / or 10 a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 155; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 15 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 156; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 157. 20 In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 152, 153 and 154, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID Nos: 155, 156 and 157, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an 25 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 94 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 95, such that any sequence variations occur outside the CDR regions. 30 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 94 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 95. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or 5 consisting of the amino acid sequence of SEQ ID NO: 94 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 95. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human 10 heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may 15 be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain 20 comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 329 and / or an amino 25 acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 330. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 329 and SEQ ID NO: 330. 30 Clone 38 (CYTA002): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 158; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 5 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 159; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 160; and / or 10 a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 161; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 15 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 162; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 163. 20 In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 158, 159 and 160, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 161, 162 and 163, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an 25 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 96 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 97, such that any sequence variations occur outside the CDR regions. 30 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 96 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 97. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or 5 consisting of the amino acid sequence of SEQ ID NO: 96 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 97. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human 10 heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may 15 be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain 20 comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 331 and / or an amino 25 acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 332. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 331 and SEQ ID NO: 332. 30 Clone 128 (CYTA003): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 164; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 5 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 165; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 166; and / or 10 a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 167; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 15 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 168; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 169. 20 In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 164, 165 and 166, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 167, 168 and 169, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an 25 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 98 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 99, such that any sequence variations occur outside the CDR regions. 30 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 98 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 99. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or 5 consisting of the amino acid sequence of SEQ ID NO: 98 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 99. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human 10 heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may 15 be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain 20 comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 333 and / or an amino 25 acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 334. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 333 and SEQ ID NO: 334. 30 In some embodiments of this aspect, the antibody or antigen-binding fragment thereof specifically binds to human TRGC2 / TRDC heterodimeric constant domain antigen. In some embodiments of this aspect, the antibody or antigen-binding fragment thereof specifically binds to human TRGC2 / TRDC heterodimeric constant domain antigen and specifically binds to cynomolgus TRGC / TRDC heterodimeric constant domain antigen. 5 In some embodiments of this aspect, the antibody or antigen-binding fragment thereof promotes gamma delta T cell mediated killing (optionally THP-1 cell killing in co-culture assay). In some embodiments of this aspect, the antibody or antigen-binding fragment thereof binds to PEER cells expressing TRGC2 positive TCRs. 10 In some embodiments of this aspect, the antibody or antigen-binding fragment thereof specifically binds to delta 1 positive and delta 3 positive gamma delta TCRs. In some embodiments of this aspect, the antibody or antigen-binding fragment thereof 15 downregulates delta 1 positive and delta 3 positive gamma delta TCRs In some embodiments of this aspect, the antibody or antigen-binding fragment thereof selectively activates and / or induces proliferation of delta 1 positive and delta 3 positive gamma delta cells. 20 Clone 205 (CYTA004): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 25 least 99% or 100% identity to SEQ ID NO: 170; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 171; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 30 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 172; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 173; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 5 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 174; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 175. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 170, 171 and 172, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 173, 174 and 175, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an 15 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 100 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 101, such that any sequence variations occur outside the CDR regions. 20 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 100 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at 25 least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 101. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 100 and a VL comprising or consisting of the 30 amino acid sequence of SEQ ID NO: 101. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may 5 be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain 10 comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 335 and / or an amino 15 acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 336. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 335 and SEQ ID NO: 336. 20 Clone 228 (CYTA005): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 25 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 176; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 177; and 30 a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 178; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 179; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 5 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 180; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 181. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 176, 177 and 178, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 179, 180 and 181, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an 15 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 102 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 103, such that any sequence variations occur outside the CDR regions. 20 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 102 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at 25 least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 103. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 102 and a VL comprising or consisting of the 30 amino acid sequence of SEQ ID NO: 103. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may 5 be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain 10 comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 337 and / or an amino 15 acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 338. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 337 and SEQ ID NO: 338. 20 Clone 303 (CYTA006): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 25 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 182; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 183; and 30 a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 184; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 185; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 5 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 186; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 187. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 182, 183 and 184, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 185, 186 and 187, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an 15 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 104 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 105, such that any sequence variations occur outside the CDR regions. 20 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 104 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at 25 least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 105. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 104 and a VL comprising or consisting of the 30 amino acid sequence of SEQ ID NO: 105. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may 5 be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain 10 comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 339 and / or an amino 15 acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 340. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 339 and SEQ ID NO: 340. 20 Clone 325 (CYTA007): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 25 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 188; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 189; and 30 a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 190; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 191; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 5 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 192; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 193. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 188, 189 and 190, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 191, 192 and 193, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an 15 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 106 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 107, such that any sequence variations occur outside the CDR regions. 20 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 106 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at 25 least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 107. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 106 and a VL comprising or consisting of the 30 amino acid sequence of SEQ ID NO: 107. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may 5 be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain 10 comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 341 and / or an amino 15 acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 342. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 341 and SEQ ID NO: 342. 20 Clone 332 (CYTA008): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 25 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 194; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 195; and 30 a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 196; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 197; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 5 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 198; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 199. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 194, 195 and 196, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 197, 198 and 199, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an 15 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 108 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 109, such that any sequence variations occur outside the CDR regions. 20 In this aspect the antibody or antigen-binding fragment thereof may a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 108 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at 25 least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 109. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 108 and a VL comprising or consisting of the 30 amino acid sequence of SEQ ID NO: 109. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may 5 be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain 10 comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 343 and / or an amino 15 acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 344. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 343 and SEQ ID NO: 344. 20 Clone 487 (CYTA009): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 25 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 200; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 201; and 30 a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 202; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 203; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 5 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 204; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 205. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 200, 201 and 202, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 203, 204 and 205, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an 15 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 110 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 111, such that any sequence variations occur outside the CDR regions. 20 In this aspect the antibody or antigen-binding fragment thereof may a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 110 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at 25 least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 111. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 110 and a VL comprising or consisting of the 30 amino acid sequence of SEQ ID NO: 111. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may 5 be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain 10 comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 345 and / or an amino 15 acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 346. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 345 and SEQ ID NO: 346. 20 In some embodiments of this aspect, the antibody or antigen-binding fragment thereof specifically binds to human TRGC2 / TRDC heterodimeric constant domain antigen and specifically binds to human TRGC1 / TRDC heterodimeric constant domain antigen. 25 In some embodiments of this aspect, the antibody or antigen-binding fragment thereof specifically binds to human TRGC2 / TRDC heterodimeric constant domain antigen, specifically binds to human TRGC1 / TRDC heterodimeric constant domain antigen and specifically binds to cynomolgus TRGC / TRDC heterodimeric constant domain antigen. 30 In some embodiments of this aspect, the antibody or antigen-binding fragment thereof promotes gamma delta T cell mediated killing (optionally THP-1 cell killing in co-culture assay). In some embodiments of this aspect, the antibody or antigen-binding fragment thereof binds to PEER cells expressing TRGC2 positive TCRs. In some embodiments of this aspect, the antibody or antigen-binding fragment thereof specifically binds to delta 1 positive and delta 2 positive and delta 3 positive gamma delta TCRs. 5 In some embodiments of this aspect, the antibody or antigen-binding fragment thereof downregulates delta 1 positive and delta 2 positive and delta 3 positive gamma delta TCRs In some embodiments of this aspect, the antibody or antigen-binding fragment thereof selectively activates and / or induces proliferation of delta 1 positive and delta 2 positive and delta 3 positive 10 gamma delta cells. Clone 489 (CYTA010): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: 15 a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 206; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 20 least 99% or 100% identity to SEQ ID NO: 207; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 208; and / or a light chain variable region comprising: 25 a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 209; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 30 least 99% or 100% identity to SEQ ID NO: 210; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 211. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 206, 207 and 208, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 209, 210 and 211, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an 5 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 112 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 113, such that any sequence variations occur outside the CDR regions. 10 In this aspect the antibody or antigen-binding fragment thereof may a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 112 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at 15 least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 113. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 112 and a VL comprising or consisting of the 20 amino acid sequence of SEQ ID NO: 113. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino 25 acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the 30 antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 347 and / or an amino 5 acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 348. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 347 and SEQ ID NO: 348. 10 In some embodiments of this aspect, the antibody or antigen-binding fragment thereof specifically binds to human TRGC1 / TRDC heterodimeric constant domain antigen. In some embodiments of this aspect, the antibody or antigen-binding fragment thereof specifically 15 binds to human TRGC1 / TRDC heterodimeric constant domain antigen and specifically binds to cynomolgus TRGC / TRDC heterodimeric constant domain antigen. In some embodiments of this aspect, the antibody or antigen-binding fragment thereof promotes gamma delta T cell mediated killing (optionally THP-1 cell killing in co-culture assay). 20 In some embodiments of this aspect, the antibody or antigen-binding fragment thereof specifically binds to delta 2 positive gamma delta TCRs. In some embodiments of this aspect, the antibody or antigen-binding fragment thereof 25 downregulates delta 2 positive gamma delta TCRs In some embodiments of this aspect, the antibody or antigen-binding fragment thereof selectively activates and / or induces proliferation of delta 2 positive gamma delta cells. 30 Clone 525 (CYTA011): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 212; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 5 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 213; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 214; and / or 10 a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 215; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 15 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 216; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 217. 20 In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 212, 213 and 214, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 215, 216 and 217, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an 25 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 114 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 115, such that any sequence variations occur outside the CDR regions. 30 In this aspect the antibody or antigen-binding fragment thereof may a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 114 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 115. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or 5 consisting of the amino acid sequence of SEQ ID NO: 114 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 115. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human 10 heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may 15 be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain 20 comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 349 and / or an amino 25 acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 350. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 349 and SEQ ID NO: 350. 30 Clone 545 (CYTA012): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 218; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 5 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 219; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 220; and / or 10 a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 221; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 15 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 222; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 223. 20 In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 218, 219 and 220, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 221, 222 and 223, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an 25 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 116 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 117, such that any sequence variations occur outside the CDR regions. 30 In this aspect the antibody or antigen-binding fragment thereof may a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 116 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 117. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or 5 consisting of the amino acid sequence of SEQ ID NO: 116 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 117. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human 10 heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may 15 be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain 20 comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 351 and / or an amino 25 acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 352. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 351 and SEQ ID NO: 352. 30 In some embodiments of this aspect, the antibody or antigen-binding fragment thereof specifically binds to human TRGC2 / TRDC heterodimeric constant domain antigen and specifically binds to human TRGC1 / TRDC heterodimeric constant domain antigen. In some embodiments of this aspect, the antibody or antigen-binding fragment thereof promotes gamma delta T cell mediated killing (optionally THP-1 cell killing in co-culture assay). In some embodiments of this aspect, the antibody or antigen-binding fragment thereof binds to PEER 5 cells expressing TRGC2 positive TCRs. In some embodiments of this aspect, the antibody or antigen-binding fragment thereof specifically binds to delta 1 positive and delta 2 positive and delta 3 positive gamma delta TCRs. 10 In some embodiments of this aspect, the antibody or antigen-binding fragment thereof downregulates delta 1 positive and delta 2 positive and delta 3 positive gamma delta TCRs In some embodiments of this aspect, the antibody or antigen-binding fragment thereof selectively activates and / or induces proliferation of delta 1 positive and delta 2 positive and delta 3 positive 15 gamma delta cells. Clone 567 (CYTA013): 20 In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 224; 25 a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 225; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 30 least 99% or 100% identity to SEQ ID NO: 226; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 227; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 228; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 5 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 229. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 224, 225 and 226, respectively, and 10 a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 227, 228 and 229, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 118 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at 15 least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 119, such that any sequence variations occur outside the CDR regions. In this aspect the antibody or antigen-binding fragment thereof may a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at 20 least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 118 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 119. 25 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 118 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 119. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant 30 domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. 5 In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 10 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 353 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 354. Any sequence variation may occur outside the CDR regions or outside the 15 VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 353 and SEQ ID NO: 354. Clone 578 (CYTA014): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising 20 a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 230; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 25 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 231; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 232; and / or 30 a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 233; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 234; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 5 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 235. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 230, 231 and 232, respectively, and 10 a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 233, 234 and 235, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 120 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at 15 least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 121, such that any sequence variations occur outside the CDR regions. In this aspect the antibody or antigen-binding fragment thereof may a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at 20 least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 120 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 121. 25 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 120 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 121. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant 30 domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. 5 In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 10 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 355 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 356. Any sequence variation may occur outside the CDR regions or outside the 15 VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 355 and SEQ ID NO: 356. In some embodiments of this aspect, the antibody or antigen-binding fragment thereof specifically binds to human TRGC2 / TRDC heterodimeric constant domain antigen and specifically binds to human 20 TRGC1 / TRDC heterodimeric constant domain antigen. In some embodiments of this aspect, the antibody or antigen-binding fragment thereof specifically binds to human TRGC2 / TRDC heterodimeric constant domain antigen, specifically binds to human TRGC1 / TRDC heterodimeric constant domain antigen and specifically binds to cynomolgus TRGC / TRDC 25 heterodimeric constant domain antigen. In some embodiments of this aspect, the antibody or antigen-binding fragment thereof promotes gamma delta T cell mediated killing (optionally THP-1 cell killing in co-culture assay). 30 In some embodiments of this aspect, the antibody or antigen-binding fragment thereof binds to PEER cells expressing TRGC2 positive TCRs. In some embodiments of this aspect, the antibody or antigen-binding fragment thereof specifically binds to delta 1 positive and delta 2 positive and delta 3 positive gamma delta TCRs. In some embodiments of this aspect, the antibody or antigen-binding fragment thereof downregulates delta 1 positive and delta 2 positive and delta 3 positive gamma delta TCRs 5 In some embodiments of this aspect, the antibody or antigen-binding fragment thereof selectively activates and / or induces proliferation of delta 1 positive and delta 2 positive and delta 3 positive gamma delta cells. Clone 641 (CYTA015): 10 In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 236; 15 a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 237; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 20 least 99% or 100% identity to SEQ ID NO: 238; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 239; 25 a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 240; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 30 least 99% or 100% identity to a SEQ ID NO: 241. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 236, 237 and 238, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 239, 240 and 241, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 122 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at 5 least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 123, such that any sequence variations occur outside the CDR regions. In this aspect the antibody or antigen-binding fragment thereof may a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at 10 least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 122 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 123. 15 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 122 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 123. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant 20 domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise 25 or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. 30 In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 357 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 358. Any sequence variation may occur outside the CDR regions or outside the 5 VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 357 and SEQ ID NO: 358. Clone 676 (CYTA016): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising 10 a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 242; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 15 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 243; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 244; and / or 20 a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 245; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 25 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 246; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 247. 30 In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 242, 243 and 244, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 245, 246 and 247, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 124 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% 5 sequence identity to SEQ ID NO: 125, such that any sequence variations occur outside the CDR regions. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 10 124 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 125. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or 15 consisting of the amino acid sequence of SEQ ID NO: 124 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 125. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human 20 heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may 25 be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain 30 comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 359 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 360. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise 5 the amino acid sequences of SEQ ID NO: 359 and SEQ ID NO: 360. Clone 680 (CYTA017): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: 10 a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 248; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 15 least 99% or 100% identity to SEQ ID NO: 249; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 250; and / or a light chain variable region comprising: 20 a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 251; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 25 least 99% or 100% identity to SEQ ID NO: 252; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 253. 30 In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 248, 249 and 250, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 251, 252 and 253, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 126 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 127, such that any sequence variations occur outside the CDR regions. 5 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 126 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at 10 least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 127. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 126 and a VL comprising or consisting of the 15 amino acid sequence of SEQ ID NO: 127. In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino 20 acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the 25 antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light 30 chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 361 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 362. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 361 and SEQ ID NO: 362. 5 Clone 697 (CYTA018): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 10 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 254; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 255; and 15 a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 256; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 20 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 257; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 258; and 25 a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 259. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 30 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 254, 255 and 256, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 257, 258 and 259, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 128 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 129, such that any sequence variations occur outside the CDR regions. 5 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 128 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% 10 sequence identity to SEQ ID NO: 129. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 128 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 129. 15 In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may 20 comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or 25 SEQ ID NO: 326 and SEQ ID NO: 328. In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or 30 antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 363 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 364. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 363 and SEQ ID NO: 364. 5 Clone 717 (CYTA019): In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 10 least 99% or 100% identity to SEQ ID NO: 260; a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 261; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 15 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 262; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 20 least 99% or 100% identity to SEQ ID NO: 263; a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 264; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 25 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to a SEQ ID NO: 265. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 260, 261 and 262, respectively, and 30 a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 263, 264 and 265, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 130 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 131, such that any sequence variations occur outside the CDR regions. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an 5 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 130 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 131. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 130 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 131. 15 In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC 20 human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. 25 In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 30 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 365 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 366. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 365 and SEQ ID NO: 366. Clone 731 (CYTA020): 5 In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 266; 10 a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 267; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 15 least 99% or 100% identity to SEQ ID NO: 268; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 269; 20 a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 270; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 25 least 99% or 100% identity to a SEQ ID NO: 271. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 266, 267 and 268, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 269, 270 and 30 271, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 132 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 133, such that any sequence variations occur outside the CDR regions. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an 5 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 132 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 133. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 132 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 133. 15 In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC 20 human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. 25 In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 30 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 367 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 368. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 367 and SEQ ID NO: 368. Clone 734 (CYTA021): 5 In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 272; 10 a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 273; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 15 least 99% or 100% identity to SEQ ID NO: 274; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 275; 20 a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 276; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 25 least 99% or 100% identity to a SEQ ID NO: 277. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 272, 273 and 274, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 275, 276 and 30 277, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 134 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 135, such that any sequence variations occur outside the CDR regions. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an 5 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 134 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 135. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 134 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 135. 15 In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC 20 human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. 25 In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 30 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 369 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 370. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 369 and SEQ ID NO: 370. Clone 745 (CYTA022): 5 In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 278; 10 a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 279; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 15 least 99% or 100% identity to SEQ ID NO: 280; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 281; 20 a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 282; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 25 least 99% or 100% identity to a SEQ ID NO: 283. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 278, 279 and 280, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 281, 282 and 30 283, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 136 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 137, such that any sequence variations occur outside the CDR regions. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an 5 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 136 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 137. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 136 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 137. 15 In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC 20 human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. 25 In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 30 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 371 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 372. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 371 and SEQ ID NO: 372. Clone 759 (CYTA023): 5 In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 284; 10 a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 285; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 15 least 99% or 100% identity to SEQ ID NO: 286; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 287; 20 a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 288; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 25 least 99% or 100% identity to a SEQ ID NO: 289. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 284, 285 and 286, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 287, 288 and 30 289, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 138 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 139, such that any sequence variations occur outside the CDR regions. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an 5 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 138 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 139. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 138 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 139. 15 In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC 20 human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. 25 In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 30 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 373 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 374. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 373 and SEQ ID NO: 374. Clone 811 (CYTA024): 5 In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 290; 10 a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 291; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 15 least 99% or 100% identity to SEQ ID NO: 292; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 293; 20 a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 294; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 25 least 99% or 100% identity to a SEQ ID NO: 295. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 290, 291 and 292, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 293, 294 and 30 295, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 140 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 141, such that any sequence variations occur outside the CDR regions. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an 5 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 140 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 141. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 140 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 141. 15 In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC 20 human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. 25 In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 30 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 375 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 376. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 375 and SEQ ID NO: 376. Clone 894 (CYTA025): 5 In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 296; 10 a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 297; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 15 least 99% or 100% identity to SEQ ID NO: 298; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 299; 20 a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 300; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 25 least 99% or 100% identity to a SEQ ID NO: 301. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 296, 297 and 298, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 299, 300 and 30 301, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 142 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 143, such that any sequence variations occur outside the CDR regions. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an 5 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 142 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 143. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 142 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 143. 15 In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC 20 human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. 25 In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 30 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 377 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 378. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 377 and SEQ ID NO: 378. Clone 953 (CYTA026): 5 In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 302; 10 a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 303; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 15 least 99% or 100% identity to SEQ ID NO: 304; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 305; 20 a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 306; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 25 least 99% or 100% identity to a SEQ ID NO: 307. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 302, 303 and 304, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 305, 306 and 30 307, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 144 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 145, such that any sequence variations occur outside the CDR regions. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an 5 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 144 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 145. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 144 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 145. 15 In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC 20 human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. 25 In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 30 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 379 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 380. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 379 and SEQ ID NO: 380. Clone 957 (CYTA027): 5 In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 308; 10 a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 309; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 15 least 99% or 100% identity to SEQ ID NO: 310; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 311; 20 a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 312; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 25 least 99% or 100% identity to a SEQ ID NO: 313. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 308, 309 and 310, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 311, 312 and 30 313. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 146 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 147, such that any sequence variations occur outside the CDR regions. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an 5 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 146 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 147. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 146 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 147. 15 In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC 20 human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. 25 In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 30 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 381 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 382. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 381 and SEQ ID NO: 382. Clone 1125 (CYTA028): 5 In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 314; 10 a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 315; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 15 least 99% or 100% identity to SEQ ID NO: 316; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 317; 20 a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 318; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 25 least 99% or 100% identity to a SEQ ID NO: 319. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 314, 315 and 316, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 317, 318 and 30 319, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 148 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 149, such that any sequence variations occur outside the CDR regions. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an 5 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 148 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 149. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 148 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 149. 15 In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC 20 human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. 25 In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 30 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 383 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 384. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 383 and SEQ ID NO: 384. Clone 1171 (CYTA029): 5 In one aspect of the invention an antibody or antigen-binding fragment thereof is provided, comprising a heavy chain variable region comprising: a VHCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 320; 10 a VHCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 321; and a VHCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 15 least 99% or 100% identity to SEQ ID NO: 322; and / or a light chain variable region comprising: a VLCDR1 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 323; 20 a VLCDR2 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identity to SEQ ID NO: 324; and a VLCDR3 comprising or consisting of an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at 25 least 99% or 100% identity to a SEQ ID NO: 325. In this aspect the antibody or antigen-binding fragment thereof may comprise a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 320, 321 and 322, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 323, 324 and 30 325, respectively. The antibody or antigen-binding fragment thereof may comprise a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 150 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 151, such that any sequence variations occur outside the CDR regions. In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising an 5 amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 150 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 151. 10 In this aspect the antibody or antigen-binding fragment thereof may comprise a VH comprising or consisting of the amino acid sequence of SEQ ID NO: 150 and a VL comprising or consisting of the amino acid sequence of SEQ ID NO: 151. 15 In this aspect the antibody or antigen-binding fragment thereof may comprise a heavy chain constant domain and a light chain constant domain. The heavy chain constant domain may be an IGHG1 human heavy chain constant domain. The heavy chain constant domain may comprise or consist of the amino acid sequence of SEQ ID NO: 326. In this aspect the antibody or antigen-binding fragment thereof may comprise a light chain constant domain. The light chain constant domain may be either a kappa (IGKC 20 human) or a lambda (IGLC1 human) constant domain. The light chain constant domain may comprise or consist of the amino acid sequence SEQ ID NO: 327 or 328. The heavy chain constant domain may be paired with either a kappa or a lambda light chain constant domain so the constant domains of the antibody or antigen-binding fragment thereof may comprise SEQ ID NO: 326 and SEQ ID NO: 327 or SEQ ID NO: 326 and SEQ ID NO: 328. 25 In this aspect the antibody or antigen-binding fragment thereof may comprise a full length heavy chain comprising a heavy chain variable region and a heavy chain constant region and / or a full length light chain comprising a light chain variable region and a light chain constant region. The antibody or antigen-binding fragment thereof may comprise an amino acid sequence having at least 70%, at least 30 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 385 and / or an amino acid sequence having at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 386. Any sequence variation may occur outside the CDR regions or outside the VH or VL regions. In one embodiment the antibody or antigen-binding fragment thereof may comprise the amino acid sequences of SEQ ID NO: 385 and SEQ ID NO: 386. Multispecific antibodies of the invention 5 It is to be understood that any of the antibodies of the invention can be formatted as a monospecific, bispecific or multispecific antibody that specifically binds to a first target antigen and a different second target antigen. In such embodiments the first target antigen is one or more constant domains of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof, and all description of antibodies that bind to one or more constant domains of a gamma delta T-cell receptor (gdTCR) or a 10 fragment or fragments thereof can be applied to multispecific antibodies in which one or more constant domains of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof are the first target antigen. In some embodiments, the antibodies of the present invention are multispecific antibodies or antigen- 15 binding fragments thereof. Any of the antibodies described herein can be formulated as multispecific antibodies. A “multispecific antibody” is an antibody that can recognise and specifically bind to a plurality of different antigens or epitopes. This binding occurs via a plurality of different binding domains, as compared to a monospecific antibody which only specifically binds to one antigen or epitope. In some embodiments, the antibodies of the present invention are bispecific antibodies or 20 antigen-binding fragments thereof. A “bispecific antibody” is an antibody that can recognise and specifically bind to two different antigens or epitopes. Therefore bispecific antibodies can recognise and specifically bind to two different epitopes present on two different antigens via two different binding domains. This includes simultaneous or sequential binding to the different antigens or epitopes. 25 Bispecific antibodies of the invention can suitably be made in any format providing the bispecific antibodies or antigen-binding fragments thereof has two specificities. The bispecific antibodies may comprise two binding domains, a first binding domain and a second binding domain. Preferably the bispecific antibodies are human antibodies. In some embodiments, the antibodies or antigen-binding 30 fragments thereof specifically bind to a first antigen via a first binding domain and specifically bind to a second different antigen via a second binding domain. Examples of multispecific antibody formats include, but are not limited to Knobs-in-holes (KIH), Knobs- in-holes (common light chain), Charge pair, Fab-arm exchange, SEEDbody, Triomab, LUZ-Y, Fcab, CrossMab, DAF (two-in-one), DAF (four-in-one), DutaMab, DT-IgG, orthogonal Fab, DVD-IgG, IgG(H)- scFv, scFv-(H)IgG, IgG(L)-scFv, scFv-(L)IgG, IgG(L,H)-Fv, IgG(H)-V, V(H)-IgG, IgG(L)-V, V(L)-IgG, KIH IgG- scFab, 2scFv-IgG, IgG-2scFv, scFv4-Ig, Zybody, DVI-IgG(four-in-one), Nanobody, Nanoby-HAS, BiTE, Diabody, DART, TandAb, scDiabody, scDiabody-CH3, Diabody-CH3, Triple Body, Morrison formats, 5 Miniantibody, Minibody, TriBi minibody, scFv-CH3 KIH, Fab-scFv, scFv-CH-CL-scFv, F(ab’)2, F(ab)2-scFv2, scFv-KIH, Fab-scFv-Fc, Tetravalent HCAb, scDiabody-Fc, Diabody-Fc, Tandem scFv-Fc, Intrabody, Dock and Lock, ImmTAC, HSAbody, scDiabody-HAS, Tandem scFv-Toxin, IgG-IgG, ov-X-Body, duobody, mab2and scFv1-PEG-scFv2. 10 In some embodiments of the invention, the bispecific antibody comprises one copy of the first binding domain and one copy of the second binding domain. In some embodiments of the invention, the bispecific antibody comprises two copies of the first binding domain and one copy of the second binding domain. In some embodiments of the invention, the bispecific antibody comprises two copies of the first binding domain and two copies of the second binding domain. In embodiments of the 15 invention the first antigen is one or more constant domains of a gamma delta T-cell receptor or a fragment or fragment thereof (as described elsewhere herein) and the second antigen is a second target antigen. It is envisioned that any antibody described herein, by sequence or otherwise, could also be formatted as a multispecific or bispecific antibody that also binds to a second different antigen via a second binding domain. The first and second target antigens are different from each other. 20 Therefore all embodiments that describe antibodies of the invention apply equally to multispecific or bispecific antibodies of the invention. In some embodiments the second target antigen may be a tumor associated antigen (TAA). The term “tumor associated antigen” or “TAA” refers to an antigen that is typically expressed on a tumor or 25 cancer cell but not on a healthy, non-cancerous cell. In some embodiments the second target antigen may be a disease associated antigen (DAA). The term “disease associated antigen” or “DAA” refers to an antigen that is typically expressed on a diseased cell but not on a healthy cell. The disease may be cancer, therefore TAAs can also be classified as DAAs. In cases where the disease is cancer, the DAA may also be a TAA. “TAA” and “DAA” may therefore be used interchangeably herein, within this 30 framework, depending on the disease in question. It will therefore be und...

Claims

CLAIMS 1. An antibody or antigen-binding fragment thereof that specifically binds human TRGC2 / TRDC heterodimeric constant domain antigen or a fragment thereof, wherein the antibody or antigen-binding fragment thereof is a human antibody or antigen-binding fragment thereof and the antibody is a multispecific antibody, optionally a bispecific antibody, and specifically binds to a second target antigen.

2. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen- binding fragment thereof also specifically binds: TRGC1 / TRDC heterodimeric constant domain antigen or a fragment thereof, optionally human TRGC1.

3. The antibody or antigen-binding fragment thereof of any previous claim, wherein the antibody or antigen-binding fragment thereof also specifically binds to the corresponding cynomolgus constant domain antigen (cyno TRGC / TRDC) or fragment thereof.

4. The antibody or antigen-binding fragment thereof of any previous claim, wherein the constant domain specifically bound by the antibody or antigen-binding fragment thereof comprises or consists of the amino acid sequence of any one of SEQ ID NOs: 1 to 9.

5. The antibody or antigen-binding fragment thereof of any previous claim, wherein the constant domain or fragment thereof specifically bound by the antibody or antigen-binding fragment thereof comprises an amino acid sequence that is at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99% or is 100% identical to any one of SEQ ID NOs: 10 to 20.

6. The antibody or antigen-binding fragment thereof of any previous claim, which does not specifically bind to a variable domain of a gamma delta T-cell receptor (gdTCR) or a fragment or fragments thereof.

7. The antibody or antigen-binding fragment thereof of any previous claim, wherein the constant domain fragment specifically bound by the antibody or antigen-binding fragment thereof comprises an Ig-like domain wherein the Ig-like domain comprises or consists of: (a) the canonical beta strands defined by residues 1 to 110 of SEQ ID NO: 1; (b) the canonical beta strands defined by residues 5 to 105 of SEQ ID NO: 2 (optionally residues 5 to 121); or (c) the canonical beta strands defined by residues 5 to 105 of SEQ ID NO: 3; (d) residues 11 to 105 of SEQ ID NO: 3; or (e) residues 11 to 105 of SEQ ID NO: 2.

8. The antibody or antigen-binding fragment thereof of any previous claim, wherein, the antibody or antigen-binding fragment thereof binds to immortalized cells expressing TRGC2 positive TCRs (for example PEER cells expressing TRGC2 positive TCRs).

9. The antibody or antigen-binding fragment thereof of any previous claim, comprising: a. a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 164, 165 and 166, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 167, 168 and 169, respectively; b. a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 200, 201 and 202, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 203, 204 and 205, respectively; c. a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 218, 219 and 220, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 221, 222 and 223, respectively; d. a VHCDR1, a VHCDR2 and a VHCDR3 comprising the amino acid sequences of SEQ ID NO: 230, 231 and 232, respectively, and a VLCDR1, a VLCDR2 and a VLCDR3 comprising the amino acid sequences of SEQ ID NOs: 233, 234 and 235, respectively.

10. The antibody or antigen-binding fragment thereof of any previous claim, wherein the antibody or antigen-binding fragment thereof does not comprise a cysteine residue in any of VHCDR1, VHCDR2, VHCDR3, VLCDR1, VLCDR2 and VLCDR3.

11. The antibody or antigen-binding fragment thereof of any previous claim, comprising: a. a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 98 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 99; b. a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 110 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 111; c. a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least99% or 100% sequence identity to SEQ ID NO: 116 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 117; d. a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 120 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO:

121.

12. The antibody or antigen-binding fragment thereof of any of claims 9 to 11, further comprising a heavy chain constant domain and a light chain constant domain, wherein the heavy chain constant domain comprises or consists of the amino acid sequence of SEQ ID NO: 326 or 389 and the light chain constant domain comprises or consists of the amino acid sequence of SEQ ID NO: 327 or SEQ ID NO:

328.

13. The antibody or antigen-binding fragment thereof of any previous claim, comprising the amino acid sequences of: a. SEQ ID NO: 333 and SEQ ID NO: 334; b. SEQ ID NO: 345 and SEQ ID NO: 346; c. SEQ ID NO: 351 and SEQ ID NO: 352; d. SEQ ID NO: 355 and SEQ ID NO:

356.

14. The antibody or antigen-binding fragment thereof of any previous claim, wherein the antibody is isolated and / or the antibody or antigen-binding fragment thereof is an scFv, Fab, Fab’, F(ab')2, Fv, variable domain (e.g. VH and / or VL), diabody, minibody or full length antibody.

15. The antibody or antigen-binding fragment thereof of any previous claim, wherein the antibody induces proliferation of gamma delta T cells, optionally a greater than 460-fold proliferation of gamma delta T cells (for example greater than 460-fold proliferation of gamma delta 3 TCR positive cells), and / or downregulation of gamma delta TCRs and / or promotes gamma delta T cell mediated killing (optionally THP-1 cell killing in co-culture assay).

16. The antibody or antigen-binding fragment thereof of any previous claim, wherein the antibody is Fc disabled and / or does not exhibit ADCC.

17. The antibody or antigen-binding fragment thereof of any previous claim, wherein the antibody: a. specifically binds to delta 1 positive and delta 2 positive and delta 3 positive gamma delta TCRs;b. downregulates delta 1 positive and delta 2 positive and delta 3 positive gamma delta TCRs; c. selectively activates and / or induces proliferation of delta 1 positive and delta 2 positive and delta 3 positive gamma delta cells; and / or d. induces proliferation and / or TCR downregulation of gamma constant 2 positive cells but not gamma constant 1 positive cells.

18. The antibody or antigen-binding fragment thereof of any previous claim, wherein the second target antigen is a tumor associated antigen.

19. The antibody or antigen-binding fragment thereof of claim 18, wherein the second target antigen is EGFR, GPC3, CD19, CD20, CD123, CD33, 5T4, EpCAM or CAIX.

20. The antibody or antigen-binding fragment thereof of claim 19, comprising a. a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 393 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 394; b. a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 387 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 388; c. a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 402 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 403; d. a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 435 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, atleast 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 436; e. a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 437 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 438; f. a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 439 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 440; g. a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 479 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 480; h. a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 477 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 478; i. a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 481 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 482; j. a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least99% or 100% sequence identity to SEQ ID NO: 483 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 484; or k. a VH comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 485 and a VL comprising an amino acid sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO:

486.

21. The antibody or antigen-binding fragment thereof of claim 19 or 20, comprising: a. a VH comprising the amino acid sequence of SEQ ID NO: 120; b. a VL comprising the amino acid sequence of SEQ ID NO: 121; c. a VH comprising the amino acid sequence of SEQ ID NO: 393; d. a VL comprising the amino acid sequence of SEQ ID NO: 394; and e. a constant domain comprising the amino acid sequence of SEQ ID NO: 389; or comprising: f. a VH comprising the amino acid sequence of SEQ ID NO: 120; g. a VL comprising the amino acid sequence of SEQ ID NO: 121; h. a VH comprising the amino acid sequence of SEQ ID NO: 402; i. a VL comprising the amino acid sequence of SEQ ID NO: 403; and j. a constant domain comprising the amino acid sequence of SEQ ID NO:

389.

22. The antibody or antigen-binding fragment thereof of claim 19 or 20, comprising: a. a VH comprising the amino acid sequence of SEQ ID NO: 120; b. a VL comprising the amino acid sequence of SEQ ID NO: 121; c. a VH comprising the amino acid sequence of SEQ ID NO: 387; d. a VL comprising the amino acid sequence of SEQ ID NO: 388; and e. a constant domain comprising the amino acid sequence of SEQ ID NO: 389; or comprising: f. a VH comprising the amino acid sequence of SEQ ID NO: 120; g. a VL comprising the amino acid sequence of SEQ ID NO: 121; h. a VH comprising the amino acid sequence of SEQ ID NO: 402; i. a VL comprising the amino acid sequence of SEQ ID NO: 403.

23. The antibody or antigen-binding fragment thereof of claim 19 or 20, comprising the amino acid sequence of SEQ ID NO: 390 and SEQ ID NO:

391.

24. A pharmaceutical composition comprising the antibody or antigen-binding fragment thereof as defined in any one of claims 1 to 23 and a pharmaceutically acceptable diluent or carrier.

25. A kit comprising the antibody or antigen-binding fragment thereof of any one of claims 1 to 23, or the pharmaceutical composition of claim 24, optionally further comprising an additional therapeutically active agent.

26. The antibody or antigen-binding fragment thereof of any one of claims 1 to 23 or the pharmaceutical composition of claim 24 or the kit of claim 25 for use in a method of treating a disease or disorder in a subject, optionally wherein the disease is cancer or an autoimmune disease.

27. A method of treating a disease or disorder in a subject, comprising administering to the subject the antibody or antigen-binding fragment thereof of any one of claims 1 to 23, or the pharmaceutical composition of claim 24, optionally wherein the disease or disorder is cancer or an autoimmune disease.

28. A method of determining whether a patient is a suitable recipient of an anti-gamma delta antibody medicament, the method comprising: a. measuring the level of a constant domain biomarker (TRDC, TRGC1 or TRGC2) in a blood sample that has been obtained from a patient; b. determining the level of this biomarker is above a suitable threshold; c. recommending the patient for treatment with an antibody medicament which binds the constant domain of a gamma delta TCR positive immune cell.

29. A method of assessing a treatment regimen without a tissue biopsy is provided, the method comprising a. providing a blood sample that has been obtained from a patient to whom an antibody of the invention (an anti-TRDC, an anti-TRGC1 or an anti-TRGC2 antibody) has been administered; b. analysing the Vδ2+ gamma delta cells in the blood sample to confirm the administered antibody has engaged with the gamma delta cells; c. using this analysis to inform the treatment regimen for the patient.

30. The method of claim 28, wherein the level of biomarker is measured using an antibody of any one of claims 1 to 23.

31. The method of claim 28, wherein the antibody medicament is an anti-TRDC antibody, an anti- TRGC1 antibody or an anti-TRGC2 antibody, optionally wherein the antibody medicament is an antibody of any one of claims 1 to 23.

32. A nucleic acid that encodes an antibody or antigen binding fragment as defined in any of claims 1 to 23.

33. A vector comprising the nucleic acid as defined in claim 32, optionally wherein the vector is a CHO vector or HEK293 vector.

34. A host cell comprising the vector as defined in claim 33, optionally wherein the host cell is a CHO cell or HEK293 cell.

35. A method of producing an antibody or antigen binding fragment as defined in any of claims 1 to 23, comprising culturing the vector of claim 33 or the host cell of claim 34 under conditions allowing expression of the antibody or fragment and recovering the antibody or fragment.

36. An antibody or antigen-binding fragment of claims 1-23 comprising a hinge disabled Fc region, optionally comprising L235A, G237A mutations (according to Eu numbering).

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