Chimeric antigen receptor (CAR) T cells

Abstract

The present invention relates to chimeric antigen receptor (CAR)-T cells, particularly, but not exclusively, to anti-T cell receptor (TCR) V-β CARs, their use in immunotherapy and for the treatment, prevention or amelioration of cancers such as T cell lymphomas, various microbial infections such as HIV and TB, and autoimmune diseases. The present invention relates to the use of CAR-engineered mucosal-associated invariant T (MAIT) cells, and novel methods for stimulating, isolating and expanding highly purified MAIT cells, which can then be engineered into such CAR-MAIT cells. The present invention extends to the genetic constructs themselves, and their use in the generation of CAR-MAIT cells, and to the transduced CAR-MAIT cells themselves. The present invention also extends to various medical uses of the constructs and transduced CAR-MAIT cells, and to pharmaceutical compositions comprising these constructs and CAR-MAIT cells.

Description

[Technical field]

[0001] The present invention relates to chimeric antigen receptor (CAR)-T cells, particularly, but not exclusively, to anti-T cell receptor (TCR) V-β CARs, their use in immunotherapy and for the treatment, prevention or amelioration of cancers such as T cell lymphomas, various microbial infections such as HIV and TB, and autoimmune diseases. The present invention relates to the use of CAR-engineered mucosal-associated invariant T (MAIT) cells, and novel methods for stimulating, isolating and expanding highly purified MAIT cells, which can then be engineered into such CAR-MAIT cells. The present invention extends to the genetic constructs themselves, and their use in the generation of CAR-MAIT cells, and to the transduced CAR-MAIT cells themselves. The present invention also extends to various medical uses of the constructs and transduced CAR-MAIT cells, and to pharmaceutical compositions comprising these constructs and CAR-MAIT cells. [Background technology]

[0002] T-cell lymphomas are a heterogeneous group of clinically aggressive diseases that include peripheral T-cell lymphomas (PTCLs), such as adult T-cell leukemia / lymphoma (ATL), caused by human T-lymphotropic virus type I (HTLV-1), and cutaneous T-cell lymphomas (CTCLs), such as Sézary syndrome (SS). T-cell malignancies are more difficult to treat than B-cell malignancies. ATL and SS are rare and often aggressive forms of T-cell lymphoma, and not enough patients have been enrolled in randomized trials to establish treatment standards. As a result, the general first-line therapies used are the same as those used to treat other types of T-cell lymphoma. For example, currently approved drugs for treating T-cell malignancies include chemotherapeutic agents, biological response modifiers (e.g., interferon, bexarotene, and HDAC inhibitors), monoclonal antibodies (alemtuzumab, mogamulizumab, brentuximab), hematopoietic stem cell transplantation (HSCT), and extracorporeal photopheresis (ECP). However, no single treatment regimen is known to be superior to the others in terms of its overall response rate or duration of response. Although allogeneic (HSCT) has been the only potentially curative regimen, a significant number of patients may not be eligible for HSCT due to advanced age and comorbidities in addition to the mortality associated with HSCT. Thus, more effective treatments are needed, as the median survival with current treatments for ATL is only 8 months (Katsuya et al., 2015).

[0003] The recently FDA-approved chimeric antigen receptor (CAR)-based T-cell therapy (CAR-T) is considered one of the most important breakthroughs in the treatment of B-cell malignancies by targeting the CD19 antigen achieving nearly 100% remission (Park et al., 2018). However, despite the efficacy of CAR-T therapy for B-cell malignancies, a similar approach to target T-cell-derived malignancies is not well established. Similar to most B-cell malignancies that contain identical rearrangements of immunoglobulin genes (i.e., clones) and express pan-B-cell markers such as CD19, the majority (>95%) of ATL and CTCL are derived from dominant T-cell clones that express defined T-cell receptor (TCR) genes (i.e., clonal TCR-Vβ chains) and the pan-T helper cell marker CD4. Thus, targeting pan-T-cell markers such as CD4 or TCR-Vb chains with monoclonal antibodies (mAbs) for the treatment of T lymphomas has been tested, but has only resulted in partial regressions in small-scale clinical trials.

[0004] Current CAR-T therapy is mainly based on conventional αβ T cells. However, the antigen recognition of αβ T cells is significantly restricted by MHC, which makes them suitable for autologous therapy but very difficult for allogeneic adoptive transfer. Furthermore, due to inadequate tumor infiltration of αβ T cells, conventional CAR-T therapy shows low efficacy in solid tumors such as CTCL, but shows promising potential in liquid tumor therapy. However, conventional CAR-T cell therapy has several major drawbacks that limit its further application. For example, current CAR-T therapy is (i) limited by autologous transfusion due to graft-versus-host disease (GVHD), (ii) limited by on-target / off-tumor toxicity with cytokine release syndrome, and (iii) disadvantages of autologous CAR-T, such as variability of patient T cell function, standardization and cost of products.

[0005] Thus, there is a need to provide improved immunotherapies for the treatment of T-cell malignancies such as T-cell lymphomas, including PTCL and CTCL, and microbial infections such as HIV and TB.

[0006] To treat T-cell malignancies, we focused on mucosal-associated invariant T cells (MAIT cells), a subset of T cells of the immune system that display natural effector-like properties. MAIT cells are defined by the invariant use of the T-cell receptor chain Vα7.2, restricted by the major histocompatibility complex (MHC)-Ib-related protein MR1, and display high expression of the C-type lectin CD161 and IL18 receptor. In humans, MAIT cells are found in the blood, liver, lungs, and mucosa, where they defend against microbial activity and infection. The MHC class I-like protein MR1 is responsible for presenting bacterially produced vitamin B metabolites, such as 5-OP-RU, to MAIT cells. After presentation of foreign antigens by MR1, MAIT cells can secrete pro-inflammatory cytokines and lyse bacterially infected cells.

[0007] Current MAIT cell expansion methods require the use of human allogeneic feeder cells to support the expansion of MAIT cells in in vitro culture, which is difficult for large-scale production and quality control for adaptive immunotherapy in humans. In addition, MAIT cells generated using these known methods contain a certain proportion of other cell subsets (e.g., conventional CD4+T cells and CD8+T cells, etc.), thus making the resulting MAIT isolates completely unsuitable for their use in allogeneic adoptive transfer, since those cell subsets cause graft-versus-host disease (GvHD).

[0008] Therefore, there is also a need for improved methods for stimulating and isolating pure MAIT cell cultures without the need for allogeneic feeder cells to scale up MAIT cell production, and therefore for use in allogeneic adoptive transfer.

[0009] As described in the Examples, the inventors have developed novel methods for stimulating and isolating highly pure cultures of MAIT cells from human PBMCs. The inventors have also developed several novel genetic constructs and vectors (referred to herein as "CART4" and "CARTVb7.1"), each encoding a chimeric antigen receptor (CAR), which are then transduced into pure MAIT cells, thereby producing CAR-MAIT cells that specifically target either the CD4 molecule (using "CART4") or the TCR-Vβ7.1 chain (using "CARTVb7.1") on T cells. This was achieved by generating novel genetic constructs containing scFvs of either (i) anti-CD4 mAb (e.g., Hu5A8) or (ii) anti-TCR-Vb7.1 mAb (e.g., 3G5), with a CD28 / 4-1BB / CD3ζ chain signaling portion to form a third generation CAR. These CARs were then transduced into MAIT cells purified from peripheral blood mononuclear cells (PBMCs) to generate the resulting CAR-MAIT cells that target either CD4 on T cells or the TCR-Vβ7.1 chain on T cells. The inventors surprisingly demonstrated that these CAR-MAIT cells exhibited comparable, and even superior, anti-T lymphoma activity to conventional CAR-T cells. [Prior art documents] [Non-patent literature]

[0010] [Non-Patent Document 1] Katsuya et al., 2015 [Non-Patent Document 2] Park et al., 2018 Summary of the Invention

[0011] Thus, in a first aspect of the present invention, there is provided a mucosal-associated invariant T (MAIT) cell expressing a chimeric antigen receptor (CAR).

[0012] As discussed herein, MAIT cells are non-conventional innate-like T cells expressing an invariant T cell receptor (TCR) that is highly conserved during mammalian evolution, recognizes microbial antigens presented by MR1 protein, is present in human blood, and maintains tissue homeostasis due to its broad antimicrobial responsiveness. Moreover, advantageously, the antigen recognition mechanism of MAIT cells is MHC-independent, which makes them an exciting candidate for allogeneic T cell killing therapy, so as not to be limited to autologous therapy as in current T cell therapies that are MHC-dependent. In other words, MAIT cells have low alloreactivity and are less prone to induce graft-versus-host disease (GVHD) in humans, thus representing an ideal T cell subset for allogeneic CAR-T therapy. In comparison, the CART-MAIT cells of the present invention and the resulting cell therapy can be easily allogeneically transferred, and the endogenous properties of MAIT cells make them promising candidates to infiltrate peripheral tissues for solid tumor treatment. Thus, CAR-MAIT cells can effectively infiltrate solid tumors, making MAIT cell-based cell therapy a promising treatment for solid as well as liquid tumors.

[0013] Advantageously, the CAR-MAIT cells of the invention can be used to treat T-cell malignancies, such as adult T-cell leukemia / lymphoma (ATL) and cutaneous T-cell lymphoma (CTCL), e.g., Sézary syndrome, caused by human T-lymphotropic virus type I (HTLV-1). It will be appreciated that T-cell malignancies are a heterogeneous group of clinically aggressive diseases and are significantly more difficult to treat than B-cell malignancies. Advantageously, CAR-MAIT therapy is expected to show increased efficacy against solid tumors and to be allogeneic, thereby obviating the need for autologous transplantation, thus positioning it as an off-the-shelf therapy.

[0014] Preferably, in one embodiment, the CAR-MAIT cells express a CAR that targets the CD4 antigen on T cells. Thus, preferably, the CAR is specific for the CD4 antigen on T cells. It will be understood that the CD4 antigen is a glycoprotein found on the surface of immune cells such as T helper cells, monocytes, macrophages, and dendritic cells (T cell surface glycoprotein CD4 [Homo sapiens] UniProt No. P01730.1; NCBI Reference Sequence NP_000607.1). One embodiment of the polypeptide sequence of the CD4 antigen is represented herein as SEQ ID NO: 1, as follows:

[0015] MNRGVPFRHL LLVLQLALLP AATQGKKVVL GKKGDTVELT CTASQKKSIQ FHWKNSNQIK ILGNQGSFLT KGPSKLNDRA DSRRSLWDQG NFPLIIKNLK IEDSDTYICE VEDQKEEVQL LVFGLTANSD THLLQGQSLT LTLESPPGSS PSVQCRSPRG KNIQGGKTLS VSQLELQDSG TWTCTVLQNQ KKVEFKIDIV VLAFQKASSI VYKKEGEQVE FSFPLAFTVE KLTGSGELWW QAERASSSKS WITFDLKNKE VSVKRVTQDP KLQMGKKLPL HLTLPQALPQ YAGSGNLTLA LEAKTGKLHQ EVNLVVMRAT QLQKNLTCEV WGPTSPKLML SLKLENKEAK VSKREKAVWV LNPEAGMWQC LLSDSGQVLL ESNIKVLPTW STPVQPMALI VLGGVAGLLL FIGLGIFFCV RCRHRRRQAE RMSQIKRLLS EKKTCQCPHR FQKTCSPI [SEQ ID No:1] Thus, preferably, the CAR is specific for the CD4 antigen comprising an amino acid sequence substantially as set forth in SEQ ID NO:1, or a variant or fragment thereof.

[0016] Preferably, in another embodiment, the CAR-MAIT cells express a CAR that targets the T cell receptor (TCR) beta chain variable region (Vβ) on T cells. It will be understood that the T cell receptor (TCR) is a protein complex found on the surface of T cells or T lymphocytes that is responsible for recognizing fragments of antigens as peptides bound to major histocompatibility complex (MHC) molecules. The TCR is composed of two different protein chains. In humans, in 95% of T cells, the TCR is composed of an alpha (α) chain encoded by TRA and a beta (β) chain encoded by TRB.

[0017] Table 1 below lists Vβ regions on T cells along with the associated encoding genes, any one or more of which may be targeted by a CAR on a CAR-MAIT cell of the present invention.

[0018] [Table 1]

[0019] CAR-MAIT cells may express CARs that target multiple T cell receptor (TCR) β chain variable regions (Vβ) on a T cell. Preferably, the multiple Vβ regions may be selected from the group of Vβ regions shown in Table 1. For example, CAR-MAIT cells may express CARs that target at least two, or at least three, or at least four T cell receptor (TCR) β chain variable regions (Vβ) on a T cell, preferably as listed in Table 1. CAR-MAIT cells may express CARs that target at least five, or at least six, or at least seven T cell receptor (TCR) β chain variable regions (Vβ) on a T cell, preferably as listed in Table 1. The multiple TCR Vβ regions may be the same or different Vβ regions.

[0020] The following Vb families are believed to be frequently associated with T cell lymphomas: Vb 1, Vb 2, Vb 3, Vb 5.1, Vb 7.1, Vb 8, Vb 12, Vb 13.1, Vb 17, and Vb 20. Thus, in a preferred embodiment, the CAR-MAIT cells express a CAR that targets one or more TCR Vβ regions on T cells selected from the group consisting of the following Vβ regions: Vb 1, Vb 2, Vb 3, Vb 5.1, Vb 7.1, Vb 8, Vb 12, Vb 13.1, Vb 17, and Vb 20. Preferably, the CAR-MAIT cells express a CAR that targets at least two or three TCR Vβ regions on a T cell selected from the group consisting of the following Vβ regions: Vb 1, Vb 2, Vb 3, Vb 5.1, Vb 7.1, Vb 8, Vb 12, Vb 13.1, Vb 17, and Vb 20.

[0021] Thus, preferably, the CAR is specific for at least one or more TCR Vβ regions on T cells, most preferably the TCR-Vβ7.1 chain. One embodiment of the polypeptide sequence of the TCR Vβ7.1 region (H. sapiens rearranged TCR Vβ7.1 UniProtKB / Swiss-Prot:A0A577.1) is represented herein as SEQ ID NO:2, as follows:

[0022] MGCRLLCCAVLCLLGAVPIDTEVTQTPKHLVMGMTNKKSLKCEQHMGHRAMYWYKQKAKKPPELMFVYSYEKLSINESVPSRFSPECPNSSLLNLHLHALQPEDSALYLCASSQ [SEQ ID No:2] Thus, preferably, the CAR is specific for at least one or more TCR Vβ regions (and more preferably the TCR-Vβ7.1 chain) comprising an amino acid sequence substantially as set forth in SEQ ID NO:2, or a variant or fragment thereof.

[0023] Preferably, the CAR-MAIT cells are configured to directly kill targeted T cells by inducing apoptosis.

[0024] Preferably, the CAR-MAIT cells comprise one or more coding sequences that allow for the controllably or inducibly elimination of the CAR-MAIT cells, for example in the event of an adverse patient reaction. The one or more coding sequences may be known to those skilled in the art as so-called "suicide genes."

[0025] Thus, in one embodiment, the one or more coding sequences may code for epidermal growth factor receptor (EGFR) or truncated epidermal growth factor receptor (tEGFR) (refs) (UniProt No. P00533; NCBI Reference Sequence NP_001333826.1). Expression of tEGFR can be controlled by anti-EGFR mAb (cetuximab) for monitoring or depletion of CAR-T cells in patients. It will be appreciated that EGFR is a transmembrane protein that is known as HER1 in humans and is the receptor for the epidermal growth factor (EGF) member of the extracellular protein ligands (UniProt No. P01133; NCBI Reference Sequence NP_001171601.1).

[0026] In another embodiment, the one or more coding sequences may encode inducible caspase-9 (iC9) (Mol. Therapy, Diaconu et al., 580, 25, 3, March 2017). iC9 is a modified human caspase-9 (UniProt No. P55211; NCBI Reference Sequence NP_001220.2) that is fused to human FK506 binding protein (UniProt No. P62942; NCBI Reference Sequence NP_000792.1) to allow conditional dimerization with a chemical inducer of dimerization (caspase-inducing drug (CID), Rimiducid) to trigger apoptosis of CAR-T cells expressing the fusion protein.

[0027] Preferably, the CAR-MAIT cells comprise coding sequences encoding a truncated epidermal growth factor receptor (tEGFR) and / or inducible caspase-9 (iC9). More preferably, the CAR-MAIT cells comprise coding sequences encoding a truncated epidermal growth factor receptor (tEGFR) and inducible caspase-9 (iC9).

[0028] It will be understood that CAR-MAIT cells are produced by transducing a nucleic acid or gene construct encoding a CAR into MAIT cells. In order to produce T cell-specific and active CAR-MAIT cells, it is important that a highly purified culture of MAIT cells is used in the CAR transduction step. Therefore, the present inventors have developed an effective method for isolating purified MAIT cells from human peripheral blood mononuclear cells (PBMCs) by combining magnetic activated cell sorting (MACS) and fluorescence activated cell sorting (FACS) methods, and the resulting method results in a large amount of MAIT cells with a high expansion fold.

[0029] Thus, preferably, MAIT cells are isolated from human peripheral blood mononuclear cells (PBMCs). Preferably, MAIT cells are isolated from PBMCs by magnetic activated cell sorting (MACS) and / or fluorescence activated cell sorting (FACS), more preferably by both MACS and FACS. The inventors consider that their MAIT isolation method is novel per se.

[0030] Thus, in a second aspect, there is provided a method for isolating MAIT cells, comprising the steps of: (i) providing peripheral blood mononuclear cells (PBMCs); (ii) subjecting the PBMCs to magnetic activated cell sorting (MACS) and / or fluorescence activated cell sorting (FACS) to isolate MAIT cells therefrom; Includes.

[0031] Preferably, the method of the present invention results in the isolation of pure ex vivo MAIT cells. In one embodiment, the method comprises subjecting PBMCs to either MACS or FACS to isolate MAIT cells therefrom. However, preferably, the method comprises subjecting PBMCs to both MACS and FACS to isolate MAIT cells therefrom. Preferably, PBMCs are first subjected to MACS and then to FACS. Preferably, the method comprises isolating TCR Vα7.2+ cells from PBMCs by MACS and then subjecting the cells to FACS by MR1-5-OP-RU tetramer staining to isolate MAIT cells.

[0032] The MACS procedure (step (ii)) may involve harvesting the PBMCs and then washing the cells with binding buffer. The supernatant is discarded and the resulting cell pellet is resuspended in MACS buffer (e.g., 1×10 7 The solution may be contacted with phycoerythrin (PE) anti-human TCR Vα7.2 antibody (e.g., at a ratio of 1:100). The solution may be mixed and then incubated (e.g., on ice for 30 minutes). The cells may be washed with MACS buffer (e.g., by centrifugation at 300×g for 5 minutes). The cells may be washed with MACS buffer (e.g., by centrifugation at 10 7 The suspension may be contacted with anti-PE microbeads, which may then be incubated (e.g., on ice for 20 minutes). The cells may be washed (e.g., 10 volumes of MACS buffer). The solution may be centrifuged (e.g., at 300×g for 5 minutes). The cells may be resuspended (e.g., in 1 ml of MACS buffer). The MS column may be prewashed with MACS buffer and assembled on the magnet. The cells may be applied to the column and MACS may be performed. The column may then be washed one or more times (e.g., each time with MACS buffer). The column may be removed from the magnet and the bound cells may be eluted from the column (e.g., in MACS buffer).

[0033] The FACS procedure (in step (ii)) may involve collecting the magnet-separated cells, followed by centrifugation (e.g., at 300×g for 5 min). The cells may be resuspended (e.g., at 10 7 At a concentration of 100 μl / 100 μl). The solution can be contacted with BV421-labeled human 5-OP-RU MR1 tetramer (e.g., at a ratio of 1:500) and APC-H7 conjugated anti-human CD3 (e.g., at a ratio of 1:200). The solution can then be incubated (e.g., on ice for 20 minutes). The cells can be washed (e.g., 10 volumes of FACS buffer). The solution can be centrifuged (e.g., at 300×g for 5 minutes). The cells can be resuspended (e.g., in 2 ml of FACS buffer). The cell sample can then be loaded onto a FACS sorter (e.g., a BD Prodigy Sorter) and FACS can be performed.

[0034] Prior to transducing the isolated MAIT cells with a nucleic acid encoding a CAR, the MAIT cells are preferably activated in a subsequent step after step (ii) in the method of the second aspect. Thus, the method further comprises activating the isolated MAIT cells with an anti-CD3 antibody, preferably in vitro. The method comprises activating the isolated MAIT cells with an anti-CD28 antibody, preferably in vitro. Preferably, the isolated MAIT cells are activated with both an anti-CD3 antibody and an anti-CD28 antibody, substantially simultaneously or sequentially. Sequential activation may comprise contacting the MAIT cells first with an anti-CD3 antibody, followed by contacting with an anti-CD28 antibody, or first with an anti-CD28 antibody, followed by contacting with an anti-CD3 antibody. Contact with the antibodies may be for at least 1 day, 2 days, or 3 days.

[0035] The MAIT cell activation procedure may include recovering the sorted MAIT cells by centrifugation (e.g., 300 x g for 5 min). The supernatant may be discarded, and the pellet may be resuspended (e.g., 10 µL in R10 medium). 6cells / ml). The solution may be contacted with Dynabeads Human T-Activator CD3 / CD28 (e.g., by vortexing for 30 seconds). The desired volume of Dynabeads may be transferred to a tube. An equal volume of buffer may be added to the tube and this may be mixed (e.g., by vortexing for 5 seconds). The tube may be placed on a magnet (e.g., for 1 minute) and the supernatant may be discarded. The tube may be removed from the magnet and the washed Dynabeads may be resuspended (e.g., in R10 medium). The desired volume of Dynabeads may be contacted with a cell suspension (e.g., to obtain a bead to cell ratio of approximately 1:1 at 100 IU / ml IL-2 in a 24-well plate in a 37° C. incubator).

[0036] The method can then include transducing the isolated and activated MAIT cells with a nucleic acid encoding a CAR.

[0037] MAIT cells express CD3 that recognize the MHC class I-like molecule MR1. + TCR Va 7.2 + CD161 + MAIT cells are a subset of natural T cells defined as CAR-based T cells. Previous studies have shown that MAIT cells can be expanded in vitro, but require the presence of allogeneic feeder cells. However, the problem with this method is that large-scale production and quality control are difficult. As described in Example 10 and shown in Figure 15, the inventors have now developed a surprisingly effective method for in vitro expansion of MAIT cells by first stimulating PBMCs with antigen (5-OP-RU)-loaded MR1 tetramer beads or 5-OP-RU (alone) in the presence of various cytokine combinations for up to 6 days. MAIT cells were then isolated by MACS or FACS sorting, and then further expanded by anti-CD3 / CD28 beads for CAR-based therapy, as described above.

[0038] Thus, in a preferred embodiment, the method may comprise stimulating the PBMCs before being subjected to the MACS and / or FACS step (i.e. step ii). Preferably, this initial stimulating step comprises contacting the PBMCs with (a) an antigen comprising either MR1 / 5-OP-RU or 5-OP-RU and / or (b) a cytokine. Preferably, the stimulating step comprises contacting the PBMCs with (a) an antigen comprising either MR1 / 5-OP-RU or 5-OP-RU and (b) a cytokine. The stimulating step may comprise contacting the PBMCs with the antigen and / or cytokine for at least 1, 2 or 3 days. The stimulating step may last for at least 4, 5 or 6 days. Preferably, the stimulating step comprises contacting the PBMCs with the antigen and / or cytokine in an in vitro culture.

[0039] MR1 / 5-OP-RU and 5-OP-RU are described in WO 2015 / 149130, the entire contents of which are incorporated herein by reference. Thus, preferably, the antigen comprises either MR1 / 5-OP-RU or 5-OP-RU, as described in WO 2015 / 149130 (PCT / AU2015 / 050148).

[0040] The cytokine may be any interleukin. However, preferably, the cytokine may be one or more interleukins selected from the group consisting of IL-2, IL-7, IL-12, IL-15, IL-18 and IL-23, or any combination thereof. The concentration of the interleukin may be at least 5, 10 or 20 ng / ml, preferably at least 30, 40 or 50 ng / ml.

[0041] For example, the one or more interleukins may be: (i) IL-2 only (condition 1 in Figure 15); (ii) IL-12 and IL-18 (condition 11 in Figure 15); (iii) IL-2, IL-12 and IL-18 (condition 3 in Figure 15); (iv) IL-12, IL-18 and IL-23 (condition 12 in Figure 15); (v) IL-2, IL-12, IL-18 and IL-23 (condition 13 in Figure 15); or (vi) IL-7, IL-15, IL-12 and IL-18 (condition 8 in Figure 15).

[0042] Most preferably, the one or more interleukins may comprise a combination of IL-12, IL-18 and IL-23.Thus, preferably, the stimulating step comprises contacting the PBMCs with (a) an antigen comprising either MR1 / 5-OP-RU or 5-OP-RU, and (b) a combination of IL-12, IL-18 and IL-23.

[0043] The inventors believe that they have devised a novel method for stimulating MAIT cells in cultures of PBMCs.

[0044] Thus, in another aspect, a method of stimulating MAIT cells in a culture of PBMCs, the method comprising contacting the culture of PBMCs with (a) an antigen comprising MR1 / 5-OP-RU or 5-OP-RU, and / or (b) one or more interleukins selected from the group consisting of IL-2, IL-7, IL-12, IL-15, IL-18 and IL-23, or any combination thereof.

[0045] Preferably, the one or more interleukins are IL-12, IL-18 and / or IL-23. More preferably, the one or more interleukins are IL-12, IL-18 and IL-23.

[0046] The inventors believe that their method of generating CAR-MAIT cells is also novel in itself.

[0047] Thus, in a third aspect, there is provided a method of making a CAR-MAIT cell, the method comprising: (i) providing peripheral blood mononuclear cells (PBMCs); (ii) subjecting the PBMCs to MACS and / or FACS to isolate MAIT cells therefrom; (iii) activating the isolated MAIT cells, optionally by contacting them with an anti-CD3 antibody and / or an anti-CD28 antibody; (iv) transducing the activated MAIT cells with a nucleic acid encoding a CAR, thereby generating CAR-MAIT cells; Includes.

[0048] Steps (i), (ii) and / or (iii) of the method of the third aspect may be the same as those described herein with respect to the method of the second aspect, and therefore these method steps are interchangeable. Furthermore, preferably, the method comprises stimulating the PBMCs before subjecting them to the MACS and / or FACS step (i.e. step ii). Preferably, this initial stimulating step comprises contacting the PBMCs with (a) an antigen comprising either MR1 / 5-OP-RU or 5-OP-RU and / or (b) a cytokine. Preferably, the stimulating step comprises contacting the PBMCs with (a) an antigen comprising either MR1 / 5-OP-RU or 5-OP-RU and (b) a cytokine. The cytokine may be an interleukin as described in relation to the second aspect, preferably one or more interleukins selected from the group consisting of IL-2, IL-7, IL-12, IL-15, IL-18 and IL-23, or any combination thereof, as described above.

[0049] Most preferably, the one or more interleukins may comprise a combination of IL-12, IL-18 and IL-23.Thus, preferably, the stimulating step comprises contacting the PBMCs with (a) an antigen comprising either MR1 / 5-OP-RU or 5-OP-RU, and (b) a combination of IL-12, IL-18 and IL-23.

[0050] Preferably, the MAIT cells are activated in step (iii) before the isolated MAIT cells are transduced with a nucleic acid encoding a CAR in step (iv). The isolated MAIT cells may be activated with an anti-CD3 antibody, preferably in vitro. The isolated MAIT cells may be activated with an anti-CD28 antibody, preferably in vitro. Preferably, the isolated MAIT cells are activated with both an anti-CD3 antibody and an anti-CD28 antibody, substantially simultaneously or sequentially, as described in connection with the method of the second aspect.

[0051] The MAIT cell transduction procedure (i.e. step (iv)) may comprise transducing the MAIT cells with a nucleic acid encoding a CAR. The transduction step may comprise viral transduction. Preferably, the MAIT cell transduction procedure comprises retrovirally transducing the MAIT cells with a nucleic acid encoding a CAR. The MAIT cells may be transduced with any nucleic acid encoding a CAR according to the fifth aspect or a vector according to the sixth aspect as described herein. The nucleic acid may encode a CAR that targets the CD4 antigen or at least one or more TCR Vβ regions on T cells. Preferably, the nucleic acid may encode a CAR that targets one or more TCR Vβ regions (and more preferably the TCR-Vβ7.1 chain) as shown in Table 1 on T cells. The nucleic acid can encode a CAR that targets one or more TCR Vβ regions on a T cell selected from the group consisting of the following Vβ regions: Vb 1, Vb 2, Vb 3, Vb 5.1, Vb 7.1, Vb 8, Vb 12, Vb 13.1, Vb 17, and Vb 20.

[0052] Preferably, transduction is performed at least 34 hours, 36 hours or 48 hours after MAIT cell activation. Prior to transduction (e.g., about 1 day before), a retronectin-coated plate can be prepared. Retronectin (e.g., about 15 μg) can be contacted with PBS (e.g., about 1 ml) to form a solution. The method can include introducing the solution into one well of a non-tissue culture-treated 24-well plate. The plate can be wrapped (e.g., with an adhesive film) and stored at about 4° C. (e.g., overnight in the refrigerator). On the day of transduction, unbound retronectin is removed from the wells. The wells can be washed (e.g., once or twice with 2 ml of PBS). Preferably, the wells are not allowed to dry out. The retroviral supernatant can be thawed (e.g., in a water bath at 37° C.). The viral supernatant is preferably transferred to each well of the retronectin-coated plate (e.g., about 1 ml). The plate can be wrapped by an adhesive film. The plate can be centrifuged (e.g., 1000×g, 32° C. for 2 hours). During centrifugation, the activated MAIT cells can be collected. The collected cells can be resuspended (e.g., in fresh R10 medium containing 100 IU / ml IL-2 to a concentration of 1×106 / ml). Once centrifugation is complete, the supernatant can be discarded from the plate. A cell suspension (e.g., 1 ml) can be added to each well. The plate can be centrifuged (e.g., 500×g for 10 minutes). The plate can then be incubated (e.g., in a 37° C. incubator). If necessary, the transduction process can be repeated to achieve higher transduction efficiency. The transduction efficiency can be detected by flow cytometry about 48 hours after transduction.

[0053] The method of the invention preferably comprises a step of expanding the CAR-MAIT cells in a subsequent step after step (iv) in the method of the third aspect. The CAR-MAIT cell expansion step may comprise harvesting the transduced CAR-MAIT cells one or two days after transduction, preferably using a retrovirus or virus. The harvested cells may be counted (e.g. by hemocytometer). The harvested cells are then plated into wells (e.g. 1×10 7 The cells can then be transferred to a well of a Grex6 M-well plate. The harvested cells can then be contacted with an interleukin. For example, the interleukin can be IL-2 (e.g., about 100 IU / ml) in an appropriate medium such as R10 medium (e.g., 130 ml). The plate can then be returned to the incubator. The IL-2 can then be refreshed (e.g., every 3 days to a final concentration of 100 IU / ml). CAR-MAIT cells can be harvested after 8-12 days of culture. The expanded CAR-MAIT cells may be used for phenotypic testing, functional assays, and / or may be frozen (e.g., in liquid nitrogen) for subsequent use.

[0054] Advantageously, as described in the Examples, 11 days of culture resulted in a 100-fold expansion level of CAR-MAIT cells with a transduction efficiency of over 50%. The inventors observed that CAR-MAIT cells surprisingly exhibited cytotoxic potency at least equivalent to conventional CAR-expressing CD8+ T cells.

[0055] In a fourth aspect, there is provided a CAR-MAIT cell obtained or obtainable by the method of the third aspect.

[0056] As described herein, isolated MAIT cells obtained using the method of either the second or third aspect can be activated and ultimately transduced with a nucleic acid construct encoding a CAR to generate CAR-MAIT cells of the first or fourth aspect. As discussed herein, the inventors have developed novel genetic constructs and recombinant vectors encoding CARs that specifically target either the CD4 molecule on T cells (in this case the constructs and vectors are referred to herein as "CART4") or one or more TCR-Vβ regions, such as the TCR-Vβ7.1 chain (in this case the constructs and vectors are referred to herein as "CARTVb7.1"). Any of these constructs and vectors can be used to transduce MAIT cells in the method of the third or fourth aspect.

[0057] The genetic construct comprises scFv of either (i) anti-CD4 mAb (e.g., Hu5A8) or (ii) anti-TCR-Vb mAb, such as anti-TCR-Vb7.1 mAb (e.g., 3G5), with a CD28 / 4-1BB / CD3-zeta chain signaling moiety to form a third generation CAR. The CAR-encoding construct further comprises at least one safety switch encoded by a so-called suicide gene, such as truncated epidermal growth factor receptor (tEGFR) and / or inducible caspase-9 (iC9), allowing for elimination of the resulting CAR-T cells if desired, thus providing an elegant monitoring system or safety mechanism when using the CAR-T cells therapeutically. Expression of tEGFR can be recognized by anti-EGFR mAb (e.g., Cetuximab) to monitor or deplete CAR-T cells, and iC9 is a modified human Caspase-9 fused to human FK506 binding protein, allowing conditional dimerization using a chemical inducer of dimerization (e.g., Rimiducid) to trigger apoptosis of CAR-T cells expressing the fusion protein. The inventors believe that the CAR-encoding nucleic acid construct they have developed is novel in itself. Referring to Figure 1A (1 and 2), a schematic diagram is shown showing the functional elements included in two embodiments of the CAR-encoding construct according to the present invention, namely, "CART4" is shown in Figure 1A (1) and "CARTVb7.1" is shown in Figure 1A (2). However, it will be understood that "CARTVb7.1" having anti-TCR-Vb7.1 targeting the Vβ7.1 family is purely exemplary and that any Vβ region can be targeted by the CAR, for example any of the Vβs shown in Table 1, particularly Vb 1, Vb 2, Vb 3, Vb 5.1, Vb 7.1, Vb 8, Vb 12, Vb 13.1, Vb 17 and Vb 20.

[0058] Thus, in a fifth aspect, there is provided a nucleic acid construct comprising a promoter operably linked to a first coding sequence encoding either an anti-CD4 chimeric antigen receptor (CAR) or an anti-T cell receptor (TCR) V-β CAR.

[0059] The promoter may be any suitable promoter, including a constitutive promoter, an activatable promoter, an inducible promoter, or a tissue-specific promoter.

[0060] A constitutive promoter allows a heterologous gene (also called a transgene) to be constitutively expressed in a host cell. Exemplary constitutive promoters contemplated herein include, but are not limited to, cytomegalovirus (CMV) promoter, human elongation factor-1 alpha (hEFla), ubiquitin C promoter (UbiC), phosphoglycerokinase promoter (PGK), simian virus 40 early promoter (SV40), and chicken β-actin promoter coupled with CMV early enhancer (CAGG). Inducible promoters belong to the category of regulated promoters. Inducible promoters can be induced by one or more conditions, such as physical conditions, the microenvironment of the engineered immune effector cells, or the physiological state of the engineered immune effector cells, an inducer (i.e., an inducer), or a combination thereof. In some embodiments, the induction conditions do not induce expression of endogenous genes in the engineered mammalian cells and / or in the subject receiving the pharmaceutical composition. In some embodiments, the inducing condition is selected from the group consisting of an inducer, irradiation (e.g., ionizing radiation, light), temperature (e.g., heat), redox conditions, the tumor environment, and the activation state of an engineered mammalian cell.

[0061] In one embodiment, the promoter may be the PGK promoter (EMBL number: A19297.1). In one embodiment, the PGK promoter is referred to herein as SEQ ID NO:3, as follows:

[0062] GGGTAGGGGAGGCGCTTTTCCCAAGGCAGTCTGGAGCATGCGCTTTAGCAGCCCGCTGGGCACTTGGCGCTACACAAGTGGCCTCTGGCCTCGCACACATTCCACATCCACCGGTAGGCGCCAA CCGGCTCCGTTCTTTGGTGGCCCCTTCGCGCCACCTTCTACTCCTCCCTAGTCAGGAAGTTCCCCCCCGCCCCGCAGCTCGCGTCGTGCAGGACGTGACAAATGGAAGTAGCACGTCTCACTAG TCTCGTGCAGATGGACAGCACCGCTGAGCAATGGAAGCGGGTAGGCCTTTGGGGCAGCGGCCAATAGCAGCTTTGCTCCTTCGCTTTCTGGGCTCAGAGGCTGGGAAGGGGTGGTCCGGGGGCG GGCTCAGGGGCGGGCTCAGGGGCGGGGCGGGCGCCCGAAGGTCCTCCGGAGGCCCGGCATTCTGCACGCTTCAAAAGCGCACGTCTGCCGCGCTGTTCTCCTCTTCCTCATTCTCCGGGCCTTTCG [SEQ ID No:3] Thus, preferably, the promoter may comprise a nucleotide sequence substantially as shown in SEQ ID NO: 3, or a fragment or variant thereof.

[0063] The nucleic acid construct may comprise a nucleotide sequence encoding a signaling peptide. Advantageously, the signaling peptide is configured to direct the CAR (i.e., a fusion protein) to the T cell outer membrane. Preferably, the sequence encoding the signaling peptide is located 3' to the promoter. Preferably, the signaling peptide is an Igκ signaling peptide. In one embodiment, the signaling peptide may have an amino acid sequence referred to herein as SEQ ID NO: 4, as follows:

[0064] METDTLLLWVLLLWVPGSTGD [SEQ ID No:4] Thus, preferably, the construct comprises a nucleotide sequence encoding a signalling peptide having the amino acid sequence substantially as shown in SEQ ID NO: 4, or a fragment or variant thereof.

[0065] In one embodiment, the nucleotide sequence encoding the signaling peptide is referred to herein as SEQ ID NO:5, as follows.

[0066] ATGGAGACAGACACACTCCTGCTATGGGTGCTGCTGCTCTGGGTTCCAGGTTCCACAGGTGAC [SEQ ID No:5] Thus, preferably the construct comprises a nucleotide sequence substantially as shown in SEQ ID NO:5, or a fragment or variant thereof.

[0067] Preferably, the first coding sequence is located 3' to the sequence encoding the signaling peptide. In a first embodiment of the nucleic acid construct, the first coding sequence encodes an anti-CD4 chimeric antigen receptor (CAR). Preferably, the CAR is specific for the CD4 antigen comprising an amino acid sequence substantially as set forth in SEQ ID NO: 1, or a variant or fragment thereof.

[0068] As shown in Figure 1A(1) ("CART4"), the first coding sequence can encode an scFv region that can include a VL (variable light chain) sequence and a VH (variable heavy chain) sequence. Preferably, the VL sequence is upstream (i.e., 5') of the VH sequence. However, in some embodiments, the VH sequence can be upstream of the VL sequence.

[0069] In one embodiment, the VL and VH sequences may be the light chain variable region and heavy chain variable region of Hu5A8 (i.e., the hybridoma clone name of the anti-CD4 monoclonal antibody) for binding to the CD4 antigen on T cells.

[0070] Thus, in one embodiment, the first coding sequence, which may encode a VL sequence for binding to CD4, encodes the amino acid sequence referred to herein as SEQ ID NO:6, as follows:

[0071] DIVMTQSPDSLAVSLGERVTMNCKSSQSLLYSTNQKNYLAWYQQKPGQSPKLLIYWASTRESGVPDRFSGSGSGTDFTLTISSVQAEDVAVYYCQQYYSYRTFGGGTKLEIK [SEQ ID No:6] Thus, preferably, the first coding sequence comprises a nucleotide sequence encoding the amino acid sequence substantially as shown in SEQ ID NO: 6, or a fragment or variant thereof.

[0072] In one embodiment, the first coding sequence, which may encode a VL sequence for binding to CD4, comprises the nucleotide sequence referred to herein as SEQ ID NO:7, as follows: GACATTGTGATGACTCAGAGCCCCGACAGCCTGGCCGTCTCACTGGGCGAAAGGGTGACCATGAATTGTAAATCTTCTCAGAGCCTGCTGTACAGTACAAACCAGAAAAATTACCTGGCCTGGTATCAGCAGAAACCCGGCCAGAGCCCTAAGCTGCTGATCTATTGG GCAAGTACCCGAGAGTCAGGAGTGCCAGACAGATTCTCCGGGTCTGGAAGTGGCACAGACTTCACCCTGACAATTAGCTCCGTGCAGGCGAGGACGTGGCTGTCTACTATTGCCAGCAGTACTATAGCTACCGAACTTTCGGCGGGGGAACCAAACTGGAAATCAAG [SEQ ID No:7] Thus, preferably, the first coding sequence comprises a nucleotide sequence substantially as shown in SEQ ID NO: 7, or a fragment or variant thereof.

[0073] In one embodiment, the first coding sequence, which may encode a VH sequence for binding to CD4, encodes an amino acid sequence referred to herein as SEQ ID NO:8, as follows:

[0074] QVQLQQSGPEVVKPGASVKMSCKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDEKFKGKATLTSDTSTSTAYMELSSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSS [SEQ ID No:8] Thus, preferably, the first coding sequence comprises a nucleotide sequence encoding the amino acid sequence substantially as shown in SEQ ID NO:8, or a fragment or variant thereof.

[0075] In one embodiment, the first coding sequence, which may encode a VH sequence for binding to CD4, comprises the nucleotide sequence referred to herein as SEQ ID NO:9, as follows: CAGGTGCAGCTGCAGCAGTCCGGACCAGAGGTGGTCAAACCCGGCGCTAGCGTCAAATGTCCTGTAAGGCATCTGGCTACACTTTCACCTCTTATGTGATTCACTGGGTCAGACAGAAGCCTGGGCAGGGACTGGACTGGATCGGGTACATTAACCCATATAATGATGGAACTGACTACGAT GAAAAGTTTAAAGGCAAGGCCACACTGACTTCCGACACCTCAACAAGCACTGCTTATATGGAGCTGTCTAGTCTGAGGTCTGAAGACACAGCAGTGTACTATTGCGCCCGCGAGAAGGATAACTACGCCACTGGCGCTTGGTTTGCATATTGGGGCCAGGGGACCCTGGTGACAGTCTCATCC [SEQ ID No:9] Thus, preferably, the first coding sequence comprises a nucleotide sequence substantially as shown in SEQ ID NO: 9, or a fragment or variant thereof.

[0076] Preferably, the VH (e.g., SEQ ID NO: 9) and VL (e.g., SEQ ID NO: 7) sequences are separated by a linker sequence when in either orientation, in one embodiment, the linker sequence may be the G4S linker sequence, referred to herein as SEQ ID NO: 10, as follows.

[0077] GGGGSGGGGSGGGGS [SEQ ID No:10] Thus, preferably, the first coding sequence comprises a nucleotide sequence encoding the amino acid sequence substantially as shown in SEQ ID NO: 10, or a fragment or variant thereof.

[0078] In one embodiment, the linker sequence may be encoded by the nucleotide sequence referred to herein as SEQ ID NO:11, as follows:

[0079] GAGGAGGAGGCAGTGGCGGAGGAGGGTCAGGAGGAGGAGGAAGC [SEQ ID No:11] Thus, preferably, the linker sequence comprises a nucleotide sequence substantially as shown in SEQ ID NO: 11, or a fragment or variant thereof.

[0080] However, in a second embodiment of the nucleic acid construct ("CARTVb7.1"), the first coding sequence encodes an anti-T cell receptor (TCR) V-β region CAR. It will be understood that any Vβ region can be targeted by the CAR. For example, any of the Vβ regions listed in Table 1 can be targeted by the CAR encoded by the first coding sequence.

[0081] The first coding sequence may encode multiple T cell receptor (TCR) β chain variable region (Vβ) CARs. Preferably, the multiple Vβ regions may be selected from the group of Vβ regions shown in Table 1. It is also possible to combine two or more Vβ region-targeted CARs on the same construct. For example, the construct may comprise a coding sequence encoding at least two, or at least three, or at least four T cell receptor (TCR) β chain variable region (Vβ)-targeted CARs, preferably as listed in Table 1. The construct may comprise a coding sequence encoding at least five, or at least six, or at least seven T cell receptor (TCR) β chain variable region (Vβ)-targeted CARs, preferably as listed in Table 1. The multiple TCR Vβ regions may be the same or different Vβ regions.

[0082] The following Vb families are believed to be frequently associated with T cell lymphomas: Vb 1, Vb 2, Vb 3, Vb 5.1, Vb 7.1, Vb 8, Vb 12, Vb 13.1, Vb 17, and Vb 20. Thus, in a preferred embodiment, the construct comprises a coding sequence encoding at least one CAR that targets one or more TCR Vβ regions on a T cell selected from the group consisting of the following Vβ regions: Vb 1, Vb 2, Vb 3, Vb 5.1, Vb 7.1, Vb 8, Vb 12, Vb 13.1, Vb 17, and Vb 20. Preferably, the construct comprises a coding sequence encoding at least one CAR that targets at least two or three TCR Vβ regions on a T cell selected from the group consisting of the following Vβ regions: Vb 1, Vb 2, Vb 3, Vb 5.1, Vb 7.1, Vb 8, Vb 12, Vb 13.1, Vb 17, and Vb 20.

[0083] Thus, preferably, a nucleic acid construct is provided that comprises a promoter operably linked to a first coding sequence encoding multiple anti-T cell receptor (TCR) V-β CARs, where different V-β regions on a T cell are targeted.

[0084] Preferably, the CAR is specific for a TCR Vβ region (preferably the TCR-Vβ7.1 chain) comprising an amino acid sequence substantially as set forth in SEQ ID NO:2, or a variant or fragment thereof.

[0085] As shown in Figure 1A(2), the first coding sequence may encode an scFv region that may include a VL (variable light chain) sequence and a VH (variable heavy chain) sequence. Preferably, the VL sequence is upstream (i.e., 5') of the VH sequence. However, in some embodiments, the VH sequence may be upstream of the VL sequence. Preferably, the VH and VL coding sequences in either orientation are separated by a linker sequence, such as a G4S linker sequence.

[0086] The VL and VH sequences may in one embodiment be the 3G5 (i.e., hybridoma clone name of the anti-TCR Vβ7.1 monoclonal antibody) light chain variable region and heavy chain variable region for binding to the TCR V-β7.1 antigen.

[0087] In one embodiment, the first coding sequence, which may encode a VL sequence for binding to a TCR V-β, preferably the TCR-Vβ7.1 chain, encodes the amino acid sequence referred to herein below as SEQ ID NO: 12.

[0088] QVQLQQPGAELVKPGASVKMSCKASGYTFTRYWITWVKQRPGQGLEWIGDIYPGSGFTKYNEKFKSKATLTVDTSSSTAYMQLSSLTSEDSAVYYCAREGGNYWYFDVWGTGTTVTVSS [SEQ ID No:12] Thus, preferably, the first coding sequence comprises a nucleotide sequence encoding the amino acid sequence substantially as shown in SEQ ID NO: 12, or a fragment or variant thereof.

[0089] In one embodiment, the first coding sequence (which may encode a VL sequence for binding to a TCR V-β, preferably a TCR-Vβ7.1 chain) comprises the nucleotide sequence referred to herein below as SEQ ID NO: 13.

[0090] CAAGTTCAGCTGCAACAGCCTGGCGCCGAGCTTGTGAAACCTGGCGCCTCTGTGAAGATGAGCTGCAAGGCCTCCGGCTACACCTTCACCAGATACTGGATCACCTGGGTCAAGCAGAGGCCTGGACAGGGACTCGAGTGGATCGGCGATATCTATCCTGGCTCCGGCTTCACCAAGT ACAACGAGAAGTTCAAGAGCAAGGCCACACTGACCGTGGACACCAGCAGCAGCACAGCCTACATGCAGCTGTCTAGCCTGACCAGCGAGGACAGCGCCGTGTACTACTGTGCTAGAGAAGGCGGCAACTACTGGTACTTCGACGTGTGGGGCACCGGCACCACAGTGACAGTTAGTTCT [SEQ ID No:13] Thus, preferably, the first coding sequence comprises a nucleotide sequence substantially as shown in SEQ ID NO: 13, or a fragment or variant thereof.

[0091] In one embodiment, the first coding sequence, which may encode a VH sequence for binding to a TCR V-β, preferably the TCR-Vβ7.1 chain, encodes the amino acid sequence referred to herein below as SEQ ID NO: 34.

[0092] DIQMTQSPSSLSASLGGKVTLTCKASQDINKYIAWYQHKPGKGPRLLIHYTSTLQPGIPSRFSGSGSGRDYSFSISNLEPEDVATYYCLQYDNLRTFGGGTKLEIKRTD [SEQ ID No:34] Thus, preferably, the first coding sequence comprises a nucleotide sequence encoding the amino acid sequence substantially as shown in SEQ ID NO: 34, or a fragment or variant thereof.

[0093] In one embodiment, the first coding sequence (which may encode a VH sequence for binding to a TCR V-β, preferably a TCR-Vβ7.1 chain) comprises the nucleotide sequence referred to herein below as SEQ ID NO: 35.

[0094] GACATCCAGATGACACAGAGCCCTAGCAGCCTGTCTGCCTCTCGGCGGAAAAGTGACCCTGACATGCAAGGCCAGCCAGGACATCAACAAGTATATCGCCTGGTATCAGCACAAGCCCGGCAAGGGACCTAGACTGCTGATCCACTACACCAGCACACTGC AGCCTGGCATCCCCAGCAGATTTTCTGGCAGCGGCTCCGGCAGAGACTACAGCTTCAGCATCAGCAACCTGGAACCTGAGGACGTGCCACCTACTACTGCCTGCAGTACGACAACCTGCGGACCTTTGGCGGCGGAACAAAGCTGGAAATCAAGCGGACAGAT [SEQ ID No:35] Thus, preferably, the first coding sequence comprises a nucleotide sequence substantially as shown in SEQ ID NO: 35, or a fragment or variant thereof.

[0095] Preferably, the VH (e.g. SEQ ID NO: 35) and VL (e.g. SEQ ID NO: 13) sequences are separated by a linker sequence when in either orientation. In one embodiment, the linker sequence may be a G4S linker sequence which may comprise or consist of an amino acid sequence substantially as set out in SEQ ID NO: 10, or a fragment or variant thereof. Thus, preferably, the linker sequence comprises a nucleotide sequence substantially as set out in SEQ ID NO: 11, or a fragment or variant thereof.

[0096] The nucleic acid construct may comprise a nucleotide sequence encoding a CD8a hinge and transmembrane (TM) structural domain. Advantageously, the hinge and TM domain are configured for the display and anchoring of the CAR to the CAR-T cell. Preferably, the sequence encoding the hinge and TM domain is located 3' of the first coding sequence.

[0097] In one embodiment, the amino acid sequence of the CD8a hinge and transmembrane domain is referred to herein as SEQ ID NO:14, as follows.

[0098] FVPVFLPAKPTTTPAPRPPTPAPTIASQPLSLRPEACRPAAGGAVHTRGLDFACDIYIWAPLAGTCGVLLLSLVITLYCNHRN [SEQ ID No:14] Thus, preferably the construct comprises a nucleotide sequence encoding the amino acid sequence substantially as shown in SEQ ID NO: 14, or a fragment or variant thereof.

[0099] In one embodiment, the nucleotide sequence encoding the CD8a hinge and transmembrane domain is referred to herein as SEQ ID NO:15, as follows.

[0100] TTCGTGCCGGTCTTCCTGCCAGCGAAGCCCACCACGACGCCAGCGCCGCGACCACCAACACCGGCGCCCACCATCGCGTCGCAGCCCCTGTCCCTGCGCCCAGAGGCGTGCCGGCCAGCGGCGG GGGCGCAGTGCACACGAGGGGGCTGGACTTCGCCTGTGATATCTACATCTGGGCGCCCTTGGCCGGGACTTGTGGGGTCCTTCTCCTGTCACTGGTTATCACCCTTTACTGCAACCACAGGAAC [SEQ ID No:15] Thus, preferably the construct comprises a nucleotide sequence substantially as shown in SEQ ID NO: 15, or a fragment or variant thereof.

[0101] The nucleic acid construct may comprise a nucleotide sequence encoding an intracellular domain, which may comprise the signaling domain of CD28, the signaling domain of 4-1BB and / or the CD3 zeta chain, more preferably the signaling domain of CD28, the signaling domain of 4-1BB and the CD3 zeta chain. It will be understood that these components form the basis of a third generation CAR and are necessary to trigger an intracellular signaling pathway. Preferably, the intracellular domain is located 3' to the sequence encoding the hinge and transmembrane domain. The signaling domain of CD28 may be 5' to the signaling domain of 4-1BB. The signaling domain of 4-1BB may be 5' to the CD3 zeta chain.

[0102] One embodiment of a CD28 signaling domain can have the amino acid sequence as follows, referred to herein as SEQ ID NO:16.

[0103] RSKRSRLLHSDYMNMTPRRPGPTRKHYQPYAPPRDFAAYRS [SEQ ID No:16] Thus, preferably the construct comprises a nucleotide sequence encoding the amino acid sequence substantially as shown in SEQ ID NO: 16, or a fragment or variant thereof.

[0104] In one embodiment, the CD28 signaling domain can be encoded by the nucleic acid sequence referred to herein as SEQ ID NO:17, as follows:

[0105] AGGAGTAAGAGGAGCAGGCTCCTGCACAGTGACTACATGAACATGACTCCCCGCCGCCCCGGGCCCACCCGCAAGCATTACCAGCCCTATGCCCCACCACGCGACTTCGCAGCCTATCGCTCC [SEQ ID No:17] Thus, preferably the construct comprises a nucleotide sequence substantially as shown in SEQ ID NO: 17, or a fragment or variant thereof.

[0106] One embodiment of a 4-1BB signaling domain can have the amino acid sequence as follows, referred to herein as SEQ ID NO:18.

[0107] RFSVVKRGRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEEGGCEL [SEQ ID No:18] Thus, preferably the construct comprises a nucleotide sequence encoding the amino acid sequence substantially as shown in SEQ ID NO: 18, or a fragment or variant thereof.

[0108] In one embodiment, the 4-1BB signaling domain can be encoded by the nucleic acid sequence referred to herein as SEQ ID NO:19, as follows:

[0109] CGTTTCTCTGTTGTTAAACGGGGCAGAAAGAAGCTCCTGTATATATTCAAACAACCATTTATGAGACCAGTACAAACTACTCAAGAGGAAGATGGCTGTAGCTGCCGATTTCCAGAAGAAGAAGAAGGAGGATGTGAACTG [SEQ ID No:19] Thus, preferably the construct comprises a nucleotide sequence substantially as shown in SEQ ID NO: 19, or a fragment or variant thereof.

[0110] One embodiment of the CD3 zeta chain can have the amino acid sequence referred to herein as SEQ ID NO:20, as follows:

[0111] RVKFSRSADAPAYQQGQNQLYNELNLGRREEYDVLDKRRGRDPEMGGKPRRKNPQEGLYNELQKDKMAEAYSEIGMKGERRRGKGHDGLYQGLSTATKDTYDALHMQALPPR [SEQ ID No:20] Thus, preferably the construct comprises a nucleotide sequence encoding the amino acid sequence substantially as shown in SEQ ID NO: 20, or a fragment or variant thereof.

[0112] In one embodiment, the CD3 zeta chain can be encoded by the nucleic acid sequence referred to herein as SEQ ID NO:21, as follows:

[0113] AGAGTGAAGTTCAGCAGGAGCGCAGACGCCCCCGCGTACCAGCAGGGCCAGAACCAGCTCTATAACGAGCTCAATCTAGGACGAAGAGAGGAGTACGATGTTTTGGACAAGAGACGTGGCCGGGACCCTGAGATGGGGGAAAGCCGAGAAGGAAGAACCCTCAGGAA GGCCTGTACAATGAACTGCAGAAAGATAAGATGGCGGAGGCCTACAGTGAGATTGGGATGAAAGGCGAGCGCCGGAGGGGCAAGGGGCACGATGGCCTTTACCAGGGTCTCAGTACAGCCACCAAGGACACCTACGACGCCCTTCACATGCAGGCCCTGCCCCCTCGC [SEQ ID No:21] Thus, preferably the construct comprises a nucleotide sequence substantially as shown in SEQ ID NO: 21, or a fragment or variant thereof.

[0114] Preferably, the nucleic acid construct comprises a second coding sequence encoding at least one suicide protein, more preferably at least two suicide proteins. The construct of the present invention is advantageous in that the presence of the second coding sequence encoding at least one suicide protein means that the resulting CAR-T cells transduced with the construct can be controllably or inducibly detected or eliminated, for example in the event of an adverse patient reaction.

[0115] Thus, preferably, in one embodiment there is provided a nucleic acid construct comprising a promoter operably linked to a first coding sequence encoding an anti-CD4 chimeric antigen receptor (CAR) and a second coding sequence encoding at least one suicide protein, more preferably at least two suicide proteins.

[0116] Preferably, in another embodiment, a nucleic acid construct is provided that comprises a promoter operably linked to a first coding sequence encoding an anti-T cell receptor (TCR) V-β CAR and a second coding sequence encoding at least one suicide protein, more preferably at least two suicide proteins.

[0117] In yet another embodiment, a nucleic acid construct is provided that comprises a promoter operably linked to a first coding sequence encoding multiple anti-T cell receptor (TCR) V-β CARs, preferably targeted to different V-β regions on a T cell, and a second coding sequence encoding at least one suicide protein, more preferably at least two suicide proteins.

[0118] In one embodiment, the second coding sequence may encode epidermal growth factor receptor (EGFR) or truncated epidermal growth factor receptor (tEGFR) (UniProt No. P00533; NCBI Reference Sequence NP001333826.1). Expression of tEGFR may be controlled by anti-EGFR mAb (cetuximab) for monitoring or depletion of CAR-T cells in patients. In one embodiment, the amino acid sequence of tEGFR may be referred to herein as SEQ ID NO: 22, as follows.

[0119] MLLLVTSLLLCELPHPAFLLIPRKVCNGIGIGEFKDSLSINATNIKHFKNCTSISGDLHILPVAFRGDSFTHTPPLDPQELDILKTVKEITGFLLIQAWPENRTDLHAFENLEIIRGRTKQHGQFSLAVVSLNITSLGLRSLKEISDGDVIISGNKNLCYANTINWKKLFGTSGQKTK IISNRGENSCKATGQVCHALCSPEGCWGPEPRDCVSCRNVSRGRECVDKCNLLEGEPREFVENSECIQCHPECLPQAMNITCTGRGPDNCIQCAHYIDGPHCVKTCPAGVMGENNTLVWKYADAGHVCHLCHPNCTYGCTGPGLEGCPTNGPKIPSIATGMVGALLLLLVVALGIGLFM [SEQ ID No:22] Thus, preferably the construct comprises a nucleotide sequence encoding the amino acid sequence substantially as shown in SEQ ID NO: 22, or a fragment or variant thereof.

[0120] In one embodiment, tEGFR can be encoded by the nucleic acid sequence referred to herein as SEQ ID NO:23, as follows:

[0121] [SEQ ID No:23] Thus, preferably the construct comprises a nucleotide sequence substantially as shown in SEQ ID NO: 23, or a fragment or variant thereof.

[0122] In another embodiment, the second coding sequence may code for inducible caspase-9 (iC9). iC9 is a modified human caspase-9 (UniProt No. P55211; NCBI Reference Sequence NP_001220.2) that allows conditional dimerization with a dimerization chemical inducer (caspase-inducing drug (CID), Rimiducid) fused to human FK506 binding protein (UniProt No. P62942; NCBI Reference Sequence NP_000792.1) to induce apoptosis of CAR-T cells expressing the fusion protein. In one embodiment, the amino acid sequence of iC9 may be referred to herein as SEQ ID NO: 24, as follows.

[0123] MLEGVQVETISPGDGRTFPKRGQTCVVHYTGMLEDGKKVDSSRDRNKPFKFMLGKQEVIRGWEEGVAQMSVGQRAKLTISPDYAYGATGHPGIIPPHATLVFDVELLKLESGGGSGVDGFGDVGALESLRGNADLAYILSMEPCGHCLIINNVNFCRESGLRTRTGSNIDCEKLRRRFSSLHFMVEVKGDLTAKKMVLALLELAQQD HGALDCCVVVILSHGCQASHLQFPGAVYGTDGCPVSVEKIVNIFNGTSCPSLGGKPKLFFIQACGGEQKDHGFEVASTSPEDESPGSNPEPDATPFQEGLRTF DQLDAISSLPTPSDIFVSYSTFPGFVSWRDPKSGSWYVETLDDIFEQWAHSEDLQSLLLRVANAVSVKGIYKQMPGCFNFLRKKLFFKTSVDYPYDVPDYALD* [SEQ ID No:24] Thus, preferably the construct comprises a nucleotide sequence encoding the amino acid sequence substantially as shown in SEQ ID NO: 24, or a fragment or variant thereof.

[0124] In one embodiment, iC9 can be encoded by the nucleic acid sequence referred to herein as SEQ ID NO:25, as follows:

[0125] [SEQ ID No:25] Thus, preferably the construct comprises a nucleotide sequence substantially as shown in SEQ ID NO: 25, or a fragment or variant thereof.

[0126] Preferably, the nucleic acid construct of the invention comprises a coding sequence encoding EGFR or truncated epidermal growth factor receptor (tEGFR) and / or inducible caspase-9 (iC9). Having one suicide gene provides robust control over the expression of CAR and CAR-MAIT cells (for detection and / or elimination) when used therapeutically.

[0127] More preferably, however, the nucleic acid construct comprises coding sequences encoding both a truncated epidermal growth factor receptor (tEGFR) and an inducible caspase-9 (iC9). Advantageously, having two suicide genes provides even tighter control over the expression of CAR and CAR-MAIT cells (for detection and / or elimination) when used therapeutically.

[0128] Preferably, the nucleic acid construct comprises a nucleotide sequence encoding a peptide spacer configured to be digested (or self-cleaved), thereby producing the polypeptides encoded on either side of the spacer as separate molecules, e.g., the intracellular domain and the suicide gene-encoded protein (which may be tEGFR and / or iC9). Thus, the peptide spacer may be known as a self-cleaving peptide.

[0129] Preferably, the spacer sequence comprises or encodes a viral peptide spacer sequence, more preferably a viral 2A peptide spacer sequence (Furler S, Paterna JC, Weibel M and Bueler H Recombinant AAV vectors containing the foot and mouth disease virus 2A sequence confer efficient bicistronic gene expression in cultured cells and rat substantia nigra neurons Gene Ther. 2001, vol. 8, PP: 864-873).

[0130] Preferably, a spacer sequence encoding a 2A peptide sequence connects the sequence encoding the intracellular domain to the sequence encoding the suicide protein. In an embodiment in which the construct encodes two suicide proteins (e.g., EGFR / tEGFR and iC9), the nucleic acid construct comprises a first spacer sequence disposed between the sequence encoding the intracellular domain and the sequence encoding the first suicide protein, and a second spacer sequence disposed between the sequence encoding the first suicide protein and the sequence encoding the second suicide protein. The first suicide protein may be EGFR / tEGFR and the second suicide protein may be iC9. In another embodiment, the first suicide protein may be iC9 and the second suicide protein may be EGFR / tEGFR.

[0131] The 2A spacer sequence may be any known variant, including sequences designated E2A, F2A, P2A and T2A, as disclosed in Wang Y et al. Scientific Reports 2015,5. Preferably, the self-cleaving peptide is P2A. In one embodiment, the P2A spacer has the amino acid sequence designated herein as SEQ ID NO:26 below.

[0132] GSGATNFSLLKQAGDVEENPGP [SEQ ID No:26] Thus, preferably the construct comprises a nucleotide sequence encoding the amino acid sequence substantially as shown in SEQ ID NO: 26, or a fragment or variant thereof.

[0133] In one embodiment, the 2A spacer can be encoded by the nucleic acid sequence referred to herein as SEQ ID NO:27, as follows:

[0134] GGATCCGGAGCCACGAACTTCTCTCTGTTAAAGCAAGCAGGAGACGTGGAAGAAAACCCCGGTCCT Thus, preferably the construct comprises a nucleotide sequence substantially as shown in SEQ ID NO: 27, or a fragment or variant thereof.

[0135] In a further embodiment, the construct may further comprise a nucleotide sequence encoding a Woodchuck Hepatitis Virus Post-transcriptional Regulatory Element (WPRE) that enhances expression of the transgene. Preferably, the WPRE coding sequence is located 3' to the sequence encoding the suicide protein. In particular, the WPRE sequence is preferably 3' to the iC9 coding sequence.

[0136] One embodiment of the WPRE is 592 bp in length, including the gamma-alpha-beta element, as follows, and is referred to herein as SEQ ID NO:28.

[0137] AATCAACCTCTGGATTACAAAATTTGTGAAAGATTGACTGGTATTCTTAACTATGTTGCTCCTTTTACGCTATGTGGATACGCTGCTTTAATGCCTTTGTATCATGCTATTGCTTCCCGTATGGCTTTCATTTTCTCCTCCTTGTATA AATCCTGGTTGCTGTCTCTTTATGAGGAGTTGTGGCCCGTTGTCAGGCAACGTGGCGTGGTGTGCACTGTGTTTGCTGACGCAACCCCCACTGGTTGGGGCATTGCCACCACCTGTCAGCTCCTTTCCGGGACTTTCGCTTTCCCCCT CCCTATTGCCACGGCGGAACTCATCGCCGCCTGCCTTGCCCGCTGCTGGACAGGGGCTCGGCTGTTGGGCACTGACAATTCCGTGGTGTTGTCGGGGAAGCTGACGTCCTTTCCATGGCTGCTCGCCTGTGTTGCCACCTGGATTCTG CGCGGGACGTCCTTCTGCTACGTCCCTTCGGCCCTCAATCCAGCGGACCTTCCTTCCCGCGGCCTGCTGCCGGCTCTGCGGCCTCTTCCGCGTCTTCGCCTTCGCCCTCAGACGAGTCGGATCTCCCTTTGGGCCGCCTCCCCGCCTG [SEQ ID NO:28] Preferably, the nucleic acid comprises a nucleic acid sequence substantially as shown in SEQ ID NO: 28, or a fragment or variant thereof.

[0138] Preferably, the construct comprises a left (i.e., 5') and / or a right (i.e., 3') long terminal repeat (LTR). Preferably, each LTR is located at the 5' and / or 3' end of the construct.

[0139] In a preferred embodiment, the nucleic acid construct comprises, in this designated order, a 5' promoter, a sequence encoding an scFv specific for a CD4 or TCR V-β region; and a 3' sequence encoding an intracellular domain. The use of 5' and 3' indicates that a feature is either upstream or downstream, and is not intended to indicate that a feature is necessarily a terminal feature.

[0140] In a preferred embodiment, the nucleic acid construct comprises, in this specified order: a 5' promoter; a sequence encoding an scFv specific for a CD4 or TCR V-β region; a sequence encoding an intracellular domain; and a 3' sequence encoding at least one suicide protein.

[0141] In a more preferred embodiment, the nucleic acid construct comprises, in this specified order: a 5' promoter (preferably, a PGK promoter); a sequence encoding an scFv specific for CD4 or one or more TCR V-β regions (preferably, the VL domain and / or the VH domain); a sequence encoding an intracellular domain (preferably, CD28, 4-1BB and / or CD3 zeta chain); and a 3' sequence encoding at least one suicide protein (preferably, EGFR / EGFRt and / or iC9).

[0142] In an even more preferred embodiment, the nucleic acid construct comprises, in this specified order, a 5' promoter (preferably a PGK promoter); a sequence encoding a signaling peptide (SP); a sequence encoding an scFv specific for CD4 or one or more TCR V-β regions (preferably the VL and VH domains separated by a G4S linker); a sequence encoding the CD8a hinge and transmembrane domain; a sequence encoding an intracellular domain (preferably CD28, 4-1BB and CD3 zeta chain); a 3' sequence encoding at least one suicide protein (preferably EGFR / EGFRt and iC9), optionally with a self-cleaving peptide spacer between the sequence encoding the intracellular domain and the sequence encoding the suicide protein.

[0143] In a first most preferred embodiment (known as "CART4"), the nucleic acid construct comprises, in this specified order, a 5' PGK promoter; a sequence encoding a signaling peptide (SP); a sequence encoding the VL and VH domains of an scFv specific for CD4 (preferably separated by a G4S linker); a sequence encoding the CD8a hinge and transmembrane domain; a sequence encoding the intracellular domains CD28, 4-1BB and CD3 zeta chain; a sequence encoding a first self-cleaving peptide spacer; a sequence encoding EGFR / EGFRt; a sequence encoding a second self-cleaving peptide spacer; and a 3' sequence encoding iC9.

[0144] In a second most preferred embodiment (known as "CARTVb7.1"), the nucleic acid construct comprises, in this specified order, a 5' PGK promoter; a sequence encoding a signaling peptide (SP); a sequence encoding the VL and VH domains of an scFv specific for one or more TCR V-β regions, preferably the TCR-Vβ7.1 chain (preferably separated by a G4S linker); a sequence encoding the CD8a hinge and transmembrane domain; a sequence encoding the intracellular domains CD28, 4-1BB and CD3ζ chains; a sequence encoding a first self-cleaving peptide spacer; a sequence encoding EGFR / EGFRt; a sequence encoding a second self-cleaving peptide spacer; and a 3' sequence encoding iC9.

[0145] Thus, one preferred embodiment of the nucleic acid construct (known as "CART4") has the amino acid sequence as follows, referred to herein as SEQ ID NO:29.

[0146] [SEQ ID No:29] Thus, preferably the construct comprises a nucleotide sequence encoding the amino acid sequence substantially as shown in SEQ ID NO: 29, or a fragment or variant thereof.

[0147] Preferably, an embodiment of the nucleic acid construct (known as "CART4") has the nucleotide sequence as follows, referred to herein as SEQ ID NO:30.

[0148] [SEQ ID No:30] Thus, preferably the construct comprises a nucleotide sequence substantially as shown in SEQ ID NO: 30, or a fragment or variant thereof.

[0149] Thus, a second preferred embodiment of the nucleic acid construct (known as "CARTVb7.1") has the amino acid sequence as follows, referred to herein as SEQ ID NO:31.

[0150] [SEQ ID No:31] Thus, preferably the construct comprises a nucleotide sequence encoding the amino acid sequence substantially as shown in SEQ ID NO: 31, or a fragment or variant thereof.

[0151] Preferably, an embodiment of the nucleic acid construct (known as "CARTVb7.1") has the nucleotide sequence as follows, referred to herein as SEQ ID NO:32.

[0152] [SEQ ID No:32] Thus, preferably the construct comprises a nucleotide sequence substantially as shown in SEQ ID NO: 32, or a fragment or variant thereof.

[0153] It will therefore be appreciated that isolated MAIT cells obtained using the methods of either the second or third aspect may be activated and ultimately transduced with a nucleic acid construct according to the fifth aspect encoding a CAR, thereby generating a CAR-MAIT cell of the first or fourth aspect.

[0154] In a sixth aspect, there is provided an expression vector encoding the nucleic acid construct of the fifth aspect.

[0155] Preferably, the vector is recombinant. Preferably, the vector is a viral vector, more preferably a retroviral vector. Maps showing the characteristics of two preferred embodiments of the vector of the present invention are shown in Figures 9 and 10.

[0156] In one embodiment (CART4:CAR4-tEGFR-iC9; see Figure 9), the vector has the nucleic acid sequence as follows, referred to herein as SEQ ID NO: 33.

[0157] GGTCCAGGCTCTAGTTTTGACTCAACAATATCACCAGCTGAAGCCTATAGAGTACGAGCCATAGATAAAATAAAAGATTTTATTTAGTCTCCAGAAAAAAGGGGGGAA [SEQ ID NO:33] Preferably, the vector comprises a nucleic acid sequence substantially as shown in SEQ ID NO: 33, or a fragment or variant thereof.

[0158] In one embodiment (CARTVb7.1:CARTVb7.1-tEGFR-iC9; see Figure 10), the vector has the nucleic acid sequence as follows, referred to herein as SEQ ID NO:36.

[0159] AGTTTTGACTCAACAATATCACCAGCTGAAGCCTATAGAGTACGAGCCATAGATAAAATAAAAGATTTTATTTAGTCTCGAAAAAAAGGGGGGAA [SEQ ID NO:36] Preferably, the vector comprises a nucleic acid sequence substantially as shown in SEQ ID NO: 36, or a fragment or variant thereof.

[0160] It will therefore be appreciated that isolated MAIT cells obtained using the methods of either the second or third aspect may be activated and ultimately transduced with an expression vector of the sixth aspect encoding a CAR, thereby generating a CAR-MAIT cell of the first or fourth aspect.

[0161] In an eleventh aspect, there is provided a T cell comprising a construct according to the fifth aspect or a vector according to the sixth aspect, optionally expressing an anti-CD4 chimeric antigen receptor (CAR) or an anti-Vβ CAR.

[0162] Preferably, the T cells are mucosal-associated invariant T (MAIT) cells.

[0163] In a seventh aspect there is provided a pharmaceutical composition comprising a T cell according to the eleventh aspect, preferably a MAIT cell according to the first or fourth aspect, and a pharma- ceutically acceptable excipient.

[0164] Preferably, the pharmaceutical composition comprises a plurality of T cells or MAIT cells of the invention. For example, the composition may comprise at least 100, 1000 or 10,000 T cells or MAIT cells. Preferably, the composition comprises at least 100,000, or at least 1,000,000, or at least 10,000,000 T cells or MAIT cells.

[0165] In an eighth aspect, there is provided a T cell of the eleventh aspect, or a MAIT cell of the first or fourth aspect, or a pharmaceutical composition of the seventh aspect, for use in therapy.

[0166] In a ninth aspect, there is provided a T cell according to the eleventh aspect, or a MAIT cell according to the first or fourth aspect, or a pharmaceutical composition according to the seventh aspect, for use (i) in immunotherapy, (ii) for treating, preventing or ameliorating cancer, (ii) for treating, preventing or ameliorating a microbial infection, or (iv) for treating, preventing or ameliorating an autoimmune disease.

[0167] In a tenth aspect, the present invention provides a method for (i) treating, preventing or ameliorating a disease in a subject by immunotherapy, (ii) treating, preventing or ameliorating cancer, (iii) treating, preventing or ameliorating a microbial infection in a subject, or (iv) treating, preventing or ameliorating an autoimmune disease in a subject, comprising administering, or having administered, to a patient in need of such treatment a therapeutically effective amount of a T cell of the eleventh aspect, or a MAIT cell of the first aspect or the fourth aspect, or a pharmaceutical composition of the seventh aspect.

[0168] Preferably, the T cells, MAIT cells or pharmaceutical composition are for use in the treatment, prevention or amelioration of a T cell malignancy, which may be a solid or liquid tumour.

[0169] The T-cell malignancy can be peripheral T-cell lymphoma (PTCL) or cutaneous T-cell lymphoma (CTCL).

[0170] Peripheral T-cell lymphoma (PTCL) comprises a diverse group of rare and aggressive diseases in which a patient's T cells become cancerous. PTCL is divided into three categories: nodal, extranodal, and leukemic, each of which is encompassed by the present invention.

[0171] The PTCL may be a PTCL subtype selected from the group consisting of adult T-cell acute lymphoblastic lymphoma or leukemia (ATL); enteropathy-associated lymphoma; hepatosplenic lymphoma; subcutaneous panniculitis-like T-cell lymphoma (SPTCL); precursor T-cell acute lymphoblastic lymphoma or leukemia; and angioimmunoblastic T-cell lymphoma (AITL).

[0172] Adult T-cell acute lymphoblastic lymphoma or leukemia (ATL) is more common in Japan and Mexico than in the United States and is associated with the human T-cell leukemia virus-1 (HTLV-1). Enteropathy-associated lymphoma is associated with celiac disease, a chronic intestinal disorder caused by hypersensitivity to gluten proteins found in wheat, rye, and barley. Symptoms usually include stomach pain, weight loss, gastrointestinal bleeding, or intestinal perforation. Treatment for patients with enteropathy-associated T-cell lymphoma includes anthracycline-based chemotherapy regimens, nutritional supplements, and a gluten-free diet when appropriate. Hepatosplenic lymphoma is an extremely rare and aggressive disease that begins in the liver or spleen and usually affects young adults in their 20s and 30s. Treatment for patients with hepatosplenic T-cell lymphoma includes anthracycline-based chemotherapy and possibly stem cell transplantation.

[0173] Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is the least common and least well-defined of the T-cell lymphomas. This lymphoma occurs primarily in subcutaneous adipose tissue, where it forms nodules. Symptoms include fever, chills, weight loss, and oral mucosal ulcers. SPTCL can be either rapidly aggressive or indolent (slow-growing). Treatment includes anthracycline-based combination chemotherapy or local radiation. Precursor T-cell acute lymphoblastic lymphoma or leukemia can be diagnosed as leukemia or lymphoma or both. This cancer is seen in both children and adults, and is most commonly diagnosed in adolescent and adult males. Treatment of newly diagnosed patients with precursor T-cell acute lymphoblastic lymphoma or leukemia is aggressive chemotherapy and radiation therapy. Nelarabine (Arranon®) is approved for the treatment of relapsed or refractory precursor T-cell acute lymphoblastic lymphoma or leukemia in adults and children.

[0174] Angioimmunoblastic T-cell lymphoma (AITL) is an example of a neoplasm characterized by strong inflammatory and immune responses, as evidenced by its clinical, pathological, cellular, and biological characteristics. The tumor cells phenotypically resemble follicular helper T (Tfh) cells and are therefore thought to function somewhat similarly to non-neoplastic Tfh cells found in reactive follicular hyperplasia. However, follicles are not hyperplastic but rather depleted or destroyed in the majority of AITL cases. AITL was recently reported to account for 36.1% of PTCL.

[0175] Cutaneous T-cell lymphoma (CTCL) constitutes approximately 70-75% of primary cutaneous lymphomas. CTCL can be a CTCL subtype selected from the group consisting of: mycosis fungoides (MF); Sézary syndrome (SS); and CD4+ small-medium pleomorphic T-cell lymphoproliferative disorder.

[0176] Mycosis fungoides (MF) is the most common subtype. Sézary syndrome (SS) is a more aggressive type of CTCL. Patients with SS have erythroderma (i.e., a rash affecting >80% of the body surface area [BSA]), lymphadenopathy, and large numbers of circulating neoplastic CD4+ T cells in the peripheral blood.

[0177] In other embodiments, the T cells, MAIT cells or pharmaceutical compositions may be used to treat, prevent or ameliorate viral (e.g., HIV, HBV, HTLV, EBV, HPV), bacterial (e.g., TB) or fungal infections.

[0178] In other embodiments, the T cells, MAIT cells or pharmaceutical compositions may be used to treat, prevent or ameliorate an autoimmune disease, such as systemic lupus erythematosus, rheumatoid arthritis or myasthenia gravis.

[0179] Preferably, the method comprises inducing a sequence encoding a suicide protein. Thus, in an embodiment in which the nucleic acid construct comprises a sequence encoding EGFR or tEGFR, the method preferably comprises administering an anti-EGFR antibody to the subject. For example, the anti-EGFR antibody can be the monoclonal antibody Cetuximab. The administration of the antibody allows for monitoring or depletion of CAR-T cells in the subject.

[0180] In embodiments in which the nucleic acid construct comprises a sequence encoding iC9, the method can include administering to the subject a caspase-inducing drug (CID). For example, the CID can comprise Rimiducid. Administration of the CID allows for conditional dimerization of caspases, which causes apoptosis of CAR-T cells expressing the fusion protein and consequent depletion of CAR-T cells in the subject.

[0181] In the most preferred embodiment, the construct encodes two suicide proteins, including both iC9 and tEGFR, and thus the use of an anti-EGFR antibody and a CID allows for exquisite control of the lifespan of the CAR-T or CAR-MAIT cells in the subject undergoing treatment.

[0182] It will be appreciated that the CAR-T cells or CAR-MAIT cells according to the invention (collectively referred to herein as "agents") may be used in monotherapy (e.g., use of T cells or CAR-MAIT cells alone), for therapy, preferably immunotherapy, to (i) treat, ameliorate or prevent cancer or T-cell malignancies, or (ii) treat, prevent or ameliorate microbial infections, or (iii) treat, prevent or ameliorate autoimmune diseases. Alternatively, the CAR-T cells or CAR-MAIT cells according to the invention may be used as an adjunct to or in combination with known immunotherapies, or to treat microbial infections as well as cancer or autoimmune diseases.

[0183] The agent according to the present invention can be combined in a composition having many different forms, particularly depending on the manner in which the composition is used.Thus, for example, the composition can be a powder, tablet, capsule, liquid, ointment, cream, gel, hydrogel, aerosol, spray, micelle solution, transdermal patch, liposomal suspension, or any other suitable form that can be administered to the person or animal in need of treatment.It will be understood that the vehicle of the pharmaceutical according to the present invention must be well tolerated by the subject to which it is given.

[0184] The pharmaceutical agent containing the agent of the present invention can be used in several ways. For example, oral administration may be required, in which case the agent can be contained in a composition that can be taken orally, for example, in the form of a tablet, capsule or liquid. The composition containing the agent and pharmaceutical agent of the present invention can be administered by inhalation (e.g., intranasally). The composition can also be formulated for topical use. For example, a cream or ointment can be applied to the skin.

[0185] The drugs and medicaments according to the present invention may also be incorporated into sustained or delayed release devices. Such devices may, for example, be inserted above or below the skin, and the medicament may be released over a period of weeks or months. The device may be placed at least adjacent to the treatment site. Such devices may be particularly advantageous when long-term treatment with the drugs used according to the present invention is required, which would normally require frequent administration (e.g., at least daily injections).

[0186] In a preferred embodiment, the agents and medicaments according to the invention may be administered to a subject by injection into the bloodstream or directly into the site requiring treatment. Injection may be intravenous (bolus or infusion) or subcutaneous (bolus or infusion) or intradermal (bolus or infusion).

[0187] It will be understood that the amount of gene construct or vector (i.e., drug) required will be determined by its biological activity and bioavailability, which will depend on the mode of administration, the physicochemical properties of the drug, and whether it is used as a monotherapy or in a combination therapy. The frequency of administration will also be affected by the half-life of the drug in the subject being treated. The optimal dosage to be administered can be determined by one skilled in the art and will vary depending on the particular drug being used, the strength of the pharmaceutical composition, the mode of administration, and the progression of the disease being treated, such as cancer, T-cell malignancy, microbial infection, or autoimmune disease. Additional factors that depend on the particular subject being treated, including the subject's age, weight, sex, diet, and time of administration, will result in the need to adjust the dosage.

[0188] Generally, a daily dose of the agents according to the invention of 0.001 μg / kg body weight to 10 mg / kg body weight can be used for therapy, particularly for treating, ameliorating or preventing cancer, T-cell malignancies, microbial infections or autoimmune diseases, depending on the agent. More preferably, the daily dose of the agent is 0.01 μg / kg body weight to 1 mg / kg body weight, more preferably 0.1 μg / kg body weight to 100 μg / kg body weight, most preferably about 0.1 μg / kg body weight to 10 μg / kg body weight.

[0189] Alternatively, the dose administered to the subject is 0.5×10 7 ~5×10 12 More preferably, the dose administered to the subject is 0.5×10 8 ~5×10 11 Most preferably, the dose administered to the subject is 0.5×10 9 ~5×10 10 It can be TU / kg body weight.

[0190] The drug may be administered before, during or after the onset of cancer, T-cell malignancy, microbial infection or autoimmune disease. The daily dose may be given as a single administration (e.g., one injection per day). Alternatively, the drug may require administration more than once per day. By way of example, the drug may be administered as a dose of 0.07 μg to 700 mg (i.e., assuming a body weight of 70 kg) twice a day (or more depending on the severity of the disease being treated, e.g., cancer). The patient undergoing treatment may take a first dose upon waking and then a second dose in the evening (in the case of a two-dose regimen), or at 3- or 4-hour intervals thereafter. Alternatively, the drug may require administration once a week or even once a month. Alternatively, a sustained release device may be used to provide the patient with an optimal dose of the drug according to the invention without the need to administer repeated doses. Known procedures, such as those conventionally used by the pharmaceutical industry (e.g., in vivo experiments, clinical trials, etc.), can be used to formulate the specific formulation of the agent according to the invention and the exact treatment regimen (e.g., daily dose and frequency of administration of the agent).

[0191] The pharmaceutical composition of the present invention is preferably an immunotherapy treatment composition, or an autoimmune disease treatment composition, or an anti-infectious composition, or an anti-cancer composition, i.e. a pharmaceutical preparation used for the therapeutic amelioration, prevention or treatment of cancer in a subject.

[0192] The present invention also provides, in an eleventh aspect, a process for producing a pharmaceutical composition according to the seventh aspect, comprising combining a therapeutically effective amount of MAIT cells according to the first or fourth aspect with a pharma- ceutically acceptable vehicle.

[0193] A "subject" may be a vertebrate, a mammal, or a livestock animal. Thus, the medicaments according to the invention may be used to treat any mammal, such as livestock (e.g., horses), pets, or for other veterinary purposes. Most preferably, the subject is a human.

[0194] A "therapeutically effective amount" of a genetic construct or vector is any amount that, when administered to a subject, is the amount of drug that produces the necessary or desired effect to treat the disease being treated, e.g., cancer.

[0195] For example, the therapeutically effective amount of the gene construct or vector used may be about 0.001 ng to about 1 mg, preferably about 0.01 ng to about 100 ng. The amount of the gene construct or vector is preferably about 0.1 ng to about 10 ng, most preferably about 0.5 ng to about 5 ng.

[0196] A "pharmaceutically acceptable vehicle" as referred to herein is any known compound or combination of known compounds known to those skilled in the art to be useful in formulating a pharmaceutical composition.

[0197] In one embodiment, the pharma- ceutically acceptable vehicle may be solid and the composition may be in the form of a powder or tablet. The solid pharma- ceutically acceptable vehicle may contain one or more substances that may also act as flavoring agents, lubricants, solubilizers, suspending agents, dyes, fillers, glidants, compression aids, inert binders, sweeteners, preservatives, dyes, coatings or tablet disintegrating agents. The vehicle may also be an encapsulating material. In powders, the vehicle is a finely divided solid mixed with the finely divided active agent according to the present invention. In tablets, the active agent may be mixed with a vehicle having the necessary compression properties in the appropriate proportions and compressed into the desired shape and size. Powders and tablets preferably contain up to 99% of the active agent. Suitable solid vehicles include, for example, calcium phosphate, magnesium stearate, talc, sugar, lactose, dextrin, starch, gelatin, cellulose, polyvinylpyrrolidine, low melting waxes and ion exchange resins. In another embodiment, the pharmaceutical vehicle may be a gel, the composition may be in the form of a cream, or the like.

[0198] However, the pharmaceutical vehicle may be liquid and the pharmaceutical composition is in the form of a solution. Liquid vehicles are used in the preparation of solutions, suspensions, emulsions, syrups, elixirs and pressurized compositions. The active agent according to the invention may be dissolved or suspended in a pharma- ceutically acceptable liquid vehicle, such as water, an organic solvent, a mixture of both or a pharma- ceutically acceptable oil or fat. The liquid vehicle may contain other suitable pharmaceutical additives, such as solubilizers, emulsifiers, buffers, preservatives, sweeteners, flavorings, suspending agents, thickeners, colorants, viscosity adjusters, stabilizers or osmolality adjusters. Suitable examples of liquid vehicles for oral and parenteral administration include water (partially containing additives as described above, such as cellulose derivatives, preferably sodium carboxymethylcellulose solution), alcohols (including monohydric and polyhydric alcohols, such as glycols) and their derivatives, and oils (e.g., fractionated coconut oil and peanut oil). For parenteral administration, the vehicle may be an oily ester, such as ethyl oleate and isopropyl myristate. Sterile liquid vehicles are useful in sterile liquid form compositions for parenteral administration. The liquid vehicle for pressurized compositions can be halogenated hydrocarbon or other pharma- ceutically acceptable propellant.

[0199] Liquid pharmaceutical compositions that are sterile solutions or suspensions can be utilized by, for example, intramuscular, intrathecal, epidural, intraperitoneal, intravenous, and especially subcutaneous injection. The agents can be prepared as sterile solid compositions that can be dissolved or suspended at the time of administration using sterile water, saline, or other appropriate sterile injectable medium.

[0200] The agents and compositions of the present invention may be orally administered in the form of a sterile solution or suspension containing other solutes or suspending agents (e.g., sufficient saline or glucose to make the solution isotonic), bile salts, acacia, gelatin, sorbitan monooleate, polysorbate 80 (oleic acid ester of sorbitol and its anhydrides copolymerized with ethylene oxide), and the like. The agents used according to the present invention may also be orally administered in either liquid or solid composition form. Compositions suitable for oral administration include solid forms such as pills, capsules, granules, tablets, and powders, and liquid forms such as solutions, syrups, elixirs, and suspensions. Forms useful for parenteral administration include sterile solutions, emulsions, and suspensions.

[0201] It will be understood that the present invention extends to any nucleic acid or peptide comprising substantially the amino acid or nucleic acid sequence of any of the sequences referred to herein (including variants or fragments thereof), or variants, derivatives or analogues thereof. The terms "substantially amino acid / nucleotide / peptide sequence", "variant" and "fragment" may refer to a sequence having at least 40% sequence identity with the amino acid / nucleotide / peptide sequence of any one of the sequences referred to herein, such as 40% sequence identity with the sequences identified as SEQ ID NOs: 1-36.

[0202] Also envisaged are amino acid / polynucleotide / polypeptide sequences having greater than 65%, more preferably greater than 70%, even more preferably greater than 75%, even more preferably greater than 80% sequence identity with any of the sequences mentioned. Preferably, the amino acid / polynucleotide / polypeptide sequence has at least 85% identity, more preferably at least 90% identity, even more preferably at least 92% identity, even more preferably at least 95% identity, even more preferably at least 97% identity, even more preferably at least 98% identity, and most preferably at least 99% identity with any of the sequences mentioned herein.

[0203] Those skilled in the art will understand how to calculate the identity percentage between two amino acid / polynucleotide / polypeptide sequences. To calculate the identity percentage between two amino acid / polynucleotide / polypeptide sequences, the alignment of the two sequences must first be prepared, and then the sequence identity value must be calculated. The identity percentage of two sequences can take different values ​​depending on:-(i) the method used to align sequences, such as ClustalW, BLAST, FASTA, Smith-Waterman (implemented in different programs), or structural alignment from 3D comparison; (ii) the parameters used by the alignment method, such as local vs. global alignment, the pair score matrix used (e.g., BLOSUM62, PAM250, Gonnet, etc.), and gap penalties, such as function form and constants.

[0204] There are many different ways to calculate the percent identity between two sequences after alignment. For example, the number of identities can be divided by: (i) the length of the shortest sequence; (ii) the length of the alignment; (iii) the average length of the sequences; (iv) the number of non-gap positions; or (v) the number of equivalent positions excluding overhangs. Furthermore, it will be appreciated that the percent identity is also strongly length-dependent. Thus, the shorter the sequence pair, the higher the sequence identity that is expected to occur by chance.

[0205] It will therefore be appreciated that accurate alignment of protein or DNA sequences is a complex process. The popular multiple alignment program ClustalW (Thompson et al., 1994, Nucleic Acids Research, 22, 4673-4680; Thompson et al., 1997, Nucleic Acids Research, 24, 4876-4882) is the preferred method for generating protein or DNA multiple alignments according to the present invention. Suitable parameters for ClustalW may be as follows: for DNA alignment: gap opening penalty = 15.0, gap extension penalty = 6.66, and matrix = Identity. for protein alignment: gap opening penalty = 10.0, gap extension penalty = 0.2, and matrix = Gonnet. for DNA and protein alignment: ENDGAP = -1, and GAPDIST = 4. Those skilled in the art will recognize that it may be necessary to vary these and other parameters for optimal sequence alignment.

[0206] Preferably, the calculation of the identity percentage between two amino acid / polynucleotide / polypeptide sequences can then be calculated from the alignment as (N / T)*100, where N is the number of positions where the sequences share the same residue, and T is the total number of positions to be compared, including gaps and including or excluding overhangs.Preferably, overhangs are included in the calculation.Thus, the most preferred method for calculating the identity percentage between two sequences includes (i) preparing a sequence alignment, for example as described above, using the ClustalW program with appropriate parameter set, and (ii) inserting the values ​​of N and T into the following formula:-sequence identity=(N / T)*100.

[0207] Alternative methods for identifying similar sequences are known to those skilled in the art. For example, substantially similar nucleotide sequences are encoded by sequences that hybridize to DNA sequences or their complements under stringent conditions. By stringent conditions, we mean nucleotide hybridization to filter-bound DNA or RNA in 3x sodium chloride / sodium citrate (SSC) at about 45°C, followed by at least one wash in 0.2x SSC / 0.1% SDS at about 20-65°C. Alternatively, substantially similar polypeptides may differ from, for example, the amino acid sequences shown in SEQ ID NO:1 to SEQ ID NO:36 by at least one, 5, 10, 20, 50 or less than 100 amino acids.

[0208] Due to the degeneracy of the genetic code, it is clear that any nucleic acid sequence described herein can be altered or modified without substantially affecting the sequence of the protein encoded thereby to provide a functional variant thereof. Suitable nucleotide variants are those that have a sequence altered by substitution of different codons that code for the same amino acid in the sequence, thus resulting in a silent (synonymous) change. Other suitable variants are those that have a homologous nucleotide sequence, but contain all or a portion of the sequence altered by substituting a different codon that codes for an amino acid with a side chain of similar biophysical properties to the amino acid it replaces, resulting in a conservative change. For example, small non-polar hydrophobic amino acids include glycine, alanine, leucine, isoleucine, valine, proline, and methionine. Large non-polar hydrophobic amino acids include phenylalanine, tryptophan, and tyrosine. Polar neutral amino acids include serine, threonine, cysteine, asparagine, and glutamine. Positively charged (basic) amino acids include lysine, arginine, and histidine. Negatively charged (acidic) amino acids include aspartic acid and glutamic acid. Thus, it will be understood which amino acids can be replaced with amino acids having similar biophysical properties, and one of skill in the art will know the nucleotide sequences that code for these amino acids.

[0209] Every feature described in this specification (including the accompanying claims, abstract, and drawings), and / or every step of any method or process so disclosed, may be combined with any of the above aspects in any combination, except combinations in which at least some of such features and / or steps are mutually exclusive.

[0210] For a better understanding of the present invention, and to show how embodiments thereof may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which: [Brief description of the drawings]

[0211] [Figure 1]Illustrates the generation of third generation CD4-targeted T cells according to one embodiment of the present invention. A(1). The diagram depicts the functional elements included in one embodiment of a CAR construct according to the present invention (known as "CART4"). An scFv derived from monoclonal antibody Hu5A8 was fused to the CD8 transmembrane domain (TM), CD28 endodomain, 4-1BB endodomain and CD3 zeta chain. Gene sequences for tEGFR (truncated epidermal growth factor receptor) and iC9 (inducible caspase-9) were tagged to the rear of the CAR via a self-cleaving 2A linker. A(2). The diagram depicts the functional elements included in another embodiment of a CAR construct according to the present invention (known as "CARTVb7.1"). An scFv derived from monoclonal antibody 3G5 was fused to the CD8 transmembrane domain (TM), CD28 endodomain, 4-1BB endodomain and CD3 zeta chain. Gene sequences for tEGFR (truncated epidermal growth factor receptor) and iC9 (inducible caspase-9) were tagged behind the CAR via a self-cleaving 2A linker. B. Transduced T cells were stained by anti-mouse IgG F(ab)'2 and anti-EGFR antibodies. Cells were grown on CD3+ single lymphocytes and the numbers indicate the percentage of CAR+ / tEGFR+ cells. C. After retroviral transduction of CAR, primary T cells were sampled daily and stained for surface markers including CD3 and tEGFR. Blue histograms were the results of untransduced cells. The percentage of cells positive for CAR and markers is shown in the plot. D. Viability was defined as the ratio of EGFR positive (A) or EGFR high (B) percentages from untreated and dimerization chemical inducer (CID, rimizucide)-treated conditions after 24 hours of exposure to the indicated doses of CID. E. The mean fluorescence intensity of EGFR expression in viable cells is shown. Data reflect typical results from three replicates from separate donors. Each sample was performed in triplicate. Data are presented as mean ± SEM. Statistically significant differences between groups were determined by two-tailed unpaired Student's t-test. **=p<0.01; *=p<0.05. [Diagram 2]Figure 1 shows in vitro functional validation of one embodiment of CART4 T cells according to the invention. A. PBMCs were activated with Dynabeads Human T-Activator and IL7 / IL15. Activated PBMCs contained two subsets of T cells, CD4+ and CD8+ (left). Cells were transduced with CART20 (middle) or CART4 (right) retroviral particles. Starting from day 3 post-transduction, cells were stained with anti-CD4 and anti-CD8 antibodies and analyzed by flow cytometry. Statistics of CD4+ ratios are summarized in B. Data reflect typical results from 5 healthy individuals. C. Primary CD4+ T cells (left) or CD20+ B cells (right) were co-cultured with either autologous CART4 cells, CART20 cells, or non-transduced CD8+ T cells for 4 hours. Absolute amount of viable target cells was counted using Countbright beads by flow cytometry analysis. D. Two T cell lines, CEM-ss cells, Jurkat cells and one B cell line were stained with anti-CD4 antibody. CD4 expression levels were assessed by flow cytometry analysis. Representative results of CART4 cells killing ET tumor cells. Each sample was performed in triplicate. Data reflect typical results from three independent experiments. F. Intracellular cytokine expression of CART4 cells co-cultured with different target cells. Each sample was performed in triplicate. Data reflect typical results from three independent experiments. [Diagram 3] Figure 1: CART4 cells specifically kill CD4+ T tumor cells. A vial of PBMCs from an ATLL patient was revived from liquid nitrogen and rested overnight in an incubator before flow cytometry analysis and co-culture experiments. A. PBMCs were stained with anti-CD4, CD8 and specific TCR Vβ. After two washes with PBS, flow cytometry was performed. Regenerated ATLL (B) or CTCL (C) PBMCs were co-cultured with allogeneic CART4 or CART20 cells for 4 hours before flow cytometry analysis. Each condition was repeated three times. Data are presented as mean ± SEM. [Figure 4]Figure 2: CART4 cells efficiently mediate anti-leukemic effects in vivo. A. NRG immunodeficient mice were injected with 1x105 Gluc / GFP transduced CEM-ss cells followed by an additional injection of 4x106 T cells via retro-orbital route. NTD n=5, CART4 n=7. B. 50 μl of peripheral blood was collected from each mouse and plasma was used to measure luciferase activity. Serial measurements of luciferase activity demonstrated inhibition of CD4+ leukemia by CART4 T cells but not NTD CD8+ T cells. C. Overall survival of mice treated with the indicated CART4 or control NTD T cells by Kaplan-Meier survival analysis. D. At endpoint, mice were dissected. Spleen and bone marrow were crushed and stained by anti-CD4 mAb and DAPI to detect residual tumor cells. Tumor cells were identified as DAPI-CD4+GFP+. E. CD4 expression levels of residual tumor cells in the spleen. Grey line - cultured CEMss cells, black line - CEMss cells from NTD control mice, red line - CEMss cells from CART4-treated mice. F. Spleen cells were co-cultured with CART4 or NTD T cells at a 1:5 ratio for 4 h and then analyzed by flow cytometry. Data are presented as mean ± SEM. Two-tailed unpaired Student's t test was used for significance analysis. *=p<0.05. [Diagram 5] Figure 1. Development of a GMP-compliant CAR-T cell manufacturing method. A. Time course of CAR-T cell manufacturing. Human PBMCs are activated in flasks with CD3 / CD28 Dynabeads and IL7 / IL15 prior to retroviral transduction of CAR. Two days after transduction, transduced cells are transferred to G-Rex plates (1 x 106 / m2). Cytokines are replenished every 2-3 days until day 12. B. Cell proliferation during the manufacturing procedure. Representative flow plots of CAR transduction ratio (C) and differentiation state (D) on day 12. Statistics of ET cell differentiation. CM, central memory; EM, effector memory. Each sample was performed in triplicate. Each sample was performed in triplicate. Data are expressed as mean ± SEM. Data reflect typical results from 4 healthy individuals. [Figure 6]Generation and functional validation of CARTVb7.1. A. Transduced T cells were stained with anti-EGFR antibody to detect CAR expression. Cells were grown on CD3+ single lymphocytes and numbers indicate the percentage of tEGFR+ cells. B. Endogenous TCRVb7.1+ population detection 5 days after CAR transduction. C. TCRVb7.1+ primary ATL samples were stained with CFSE and mixed with different numbers of effector CAR-T cells. After 6 hours of incubation, cells were harvested and stained with DAPI, 3G5 and CD3 antibodies for 15 minutes. A fixed volume of 5uL Countbright beads was added to each sample. Samples were loaded into a flow cytometer for absolute quantification. Representative results of CARTVb7.1 cells killing DT tumor cells. Each sample was performed in triplicate. [Figure 7] Figure 1. Generation of MAIT-CART cells. A. Representative flow cytometry examples of MAIT cell staining. PBMCs were stained with BV421 MR1-5-OP-RU tetramer and PE anti-TCR Vα7.2 antibody for 20 min. Cells were washed twice with PBS and then characterized by flow cytometry. B. Gating strategy for flow cytometric sorting of MAIT cells. TCR Vα7.2+ cells were isolated from PBMCs by magnetic separation and then stained with BV421 MR1-5-OP-RU tetramer and PE anti-CD3 antibody for 20 min. Cells were washed twice with PBS and then loaded onto the Melody cell sorter. MR1-5-OP-RU tetramer positive populations were sorted and cultured. C. Growth curves of in vitro cultured MAIT cells and CD8+ T cells as controls. D. After 12-14 days of culture, more than 90% of expanded MAIT cells were MR1-5-OP-RU tetramer specific. E. CAR-transduced CD8+ T cells and MAIT cells were stained with anti-EGFR flow antibody to detect transduction efficiency. [Figure 8]Expanded MAIT and CD8 T cells were co-cultured with the CFSE-stained CD4+ cell line CEMss at E:T 0:1, 1:1, 3:1 and 5:1. Co-cultures were harvested after 20 hours of incubation. The absolute amount of viable tumor cells was counted using Countbright beads by flow cytometry analysis. (A) Flow cytometry diagram of 3:1 E:T condition. (B) Statistical results of cytotoxicity. Data are expressed as mean ± SEM. [Figure 9] 1 is a map showing a first embodiment of the expression vector "CART4" used to transduce MAIT cells. [Figure 10] 1 is a map showing a second embodiment of the expression vector "CARTVb7.1" used to transduce MAIT cells. [Figure 11] Detection of human MAIT cells from peripheral blood mononuclear cells (PBMCs): Lymphocytes were gated and MAIT cells were identified by expression of CD3 and reactivity with 5-OP-RU / MR1 tetramer (A) or expression of CD161 and TCRVα7.2 (B). [Figure 12] Isolation of human MAIT cells from peripheral blood mononuclear cells (PBMCs). After magnetic bead-mediated separation by Vα7.2 expression, the Vα7.2 positive cell population was enriched from 2.2% (A) to >97%. MAIT cells were sorted by reactivity with 5-OP-RU / MR1 tetramer (B). [Figure 13] Figure 1. Generation of CAR-MAIT cells. After 12-14 days of culture, more than 90% of the expanded MAIT cells were MR1-5-OP-RU tetramer-specific (A). CAR-transduced CD8+ T cells and MAIT cells were stained with anti-EGFR flow antibody to detect transduction efficiency (B). [Figure 14] Figure 1: CAR-MAIT4 cells exhibit efficient anti-leukemic function in vivo. A. NSG immunodeficient mice were injected iv with 1x106 Gluc / GFP transduced CEM-ss cells followed by another iv injection of 4x106 CAR transduced cells.

[0212] Bioluminescence imaging was performed twice weekly until day 45 after tumor injection. B. Overall survival of mice treated with the indicated CAR-transduced cells by Kaplan-Meier survival analysis. C. Bioluminescence imaging (BLI) of mice at day 40 after tumor injection. D. Radiance of individual mice at day 40. n=5 or 6 mice / group. *P<0.05 by Student's t-test. Ph, photons; sr, steradians [Figure 15] Enrichment of MAIT cells in PBMCs. PBMCs were stimulated for 6 days with either MR1 / 5-OP-RU complex beads at a 1:1 bead-to-cell ratio or 5-OP-RU antigen at 10 nM in the presence of different cytokines as indicated in the table. Fold MAIT cell expansion was calculated by dividing the frequency of viable MAIT (CD3+Va7.2+CD161+) cells on day 6 by the original frequency of MAIT cells on day 0. The top 5 groups are highlighted in orange (i.e., conditions 1, 3, 11, 12 and 13). The combination of IL-12, IL-18 and IL-23 gives the highest fold increase of MAIT cells in PBMCs. EXAMPLES

[0213] Chimeric antigen receptor (CAR)-based T cell therapy has achieved great success in treating B cell malignancies by targeting pan-B cell specific antigens. However, a similar strategy for T cell lymphoma has not been realized so far, mainly due to the potential severe toxicity due to global T cell exhaustion and dysfunction / low frequency of normal T cells in T lymphoma compared to B cell malignancies. To overcome these limitations, we engineered two novel CAR constructs, the first CAR construct is called "CART4" that is specific for a pan-T cell marker (CD4) and the second CAR construct is called "CARTVb7.1" that is specific for the TCR-Vb isotype chain. Both CAR constructs incorporate one or two safety switches selected from truncated epidermal growth factor receptor (tEGFR) and inducible caspase-9 (iC9). However, both safety switches are shown as shown in Figure 1. We investigated whether mucosal-associated invariant T (MAIT) cells, which have low alloreactivity, exhibit similar antitumor killing activity as conventional T cells after being transduced with a CAR construct.

[0214] Furthermore, MAIT cells express CD3 that recognizes the MHC class I-like molecule MR1. + TCR Va 7.2 + CD161 +MAIT cells are known to be a subset of natural T cells defined as CAR-based T cells. Previous studies have shown that MAIT cells can be expanded in vitro but require the presence of allogeneic feeder cells, but this method is difficult for large-scale production and quality control. In this study, we developed an effective method to expand MAIT cells in vitro by first stimulating PBMCs with antigen (5-OP-RU)-loaded MR1 tetramer beads or 5-OP-RU alone for up to 6 days in in vitro culture, both in the presence of a combination of various cytokines (IL-2, IL-7, IL-15, IL-12, IL-18 and IL-23). ​​The resulting MAIT cells were then isolated by MACS or FACS sorting as described in the previous examples and further expanded by anti-CD3 / CD28 beads for CAR-based therapy.

[0215] Materials and Methods Construction of CAR plasmid DNA fragments encoding scFvs of Hu5A8 and Leu16 and human Igκ leading sequences were synthesized by Genewiz. These fragments as well as the MSCV CAR expression retroviral vector were cleaved using NcoI and NotI. The MSCV CAR expression vector was modified from the MSCV-IRES-GFP vector (Addgene) by replacing the IRES-GFP region with human CD8 transmembrane domain and third generation CAR intracellular signaling domains (CD28 and 4-1BB costimulatory domains, CD3ζ signaling domain). The sequence of tEGFR was obtained from US Patent No. 8,802,347, which deleted domains I and II of the extracellular portion and intracellular domain of the human EGFR protein. tEGFR was synthesized by Genewiz with the self-cleaving T2A sequence and the leader peptide of the human granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor. The DNA sequence of iC9 was kindly provided by Prof. Lishan Su (University of North Carolina, Chapel Hill). The iC9 DNA fragment consists of a truncated form of caspase-9, containing the large and small subunits of the caspase molecule, linked to a single 12 kDa human FK506-binding protein (FKBP12) via a short Gly-Gly-Gly-Ser (GGGS) flexible linker.

[0216] Construction of retroviral vectors Plat-GP cells (Cellbiolabs) were transfected with MSCV-retroviral plasmid and pCMV-VSVG vector (Addgene) via 7ul of X-tremeGENE HP transfection reagent (Roche) to generate virus with a VSV envelope. To produce high titer CAR-encoding retroviral supernatant, a stable virus-producing cell line was subsequently performed, including PG-13 (ATCC). PG-13 cells were transduced with virus supernatant from Plat-GP containing 8ug / ml polybrene (Sigma). Plates were wrapped in cling film and centrifuged at 1000g, 32°C for 2 hours. To produce high titer viral particles, confluent cells were passaged in duplicate by trypsinization. Supernatants were harvested after 24 hours. The medium was aliquoted and centrifuged at 300g for 5 minutes before being stored at -80°C.

[0217] Primary T cells and tumor cells Peripheral blood mononuclear cells (PBMCs) from healthy donors were isolated by Ficoll-Paque PLUS density gradient centrifugation (GE Healthcare) for engineering CAR-T cells. T lymphoma cell lines generated from ATL or CTCL patients were cultured in D10 medium (DMEM containing 10% fetal bovine serum, 100 IU / mL penicillin, 100 μg / mL streptomycin, and 2 mM L-glutamine), and T leukemia cell lines (Jurket or CEM) were maintained in R10 medium (RPMI1640 containing 10% fetal bovine serum, 100 IU / mL penicillin, 100 μg / mL streptomycin, and 2 mM L-glutamine).

[0218] Isolation and expansion of MAIT cells MAIT cells were isolated from healthy PBMCs by a two-step method using anti-human TCR Vα7.2 antibody (Biolegend, Cat. No. 351724) MicroBeads (Miltenyi, Cat. No. 130-090-485) followed by BV421 MR1-5-OP-RU tetramers kindly provided by Prof Jim McCluskey (University of Melbourne, Australia). Briefly, TCR Vα7.2+ T cells were isolated from PBMCs using biotinylated anti-human TCR Vα7.2 antibody and anti-biotin MicroBeads kit according to the manufacture's procedure (Miltenyi). MAIT cells were then isolated from TCR Vα7.2+ T cells by staining with BV421 MR1-5-OP-RU tetramers and FACS sorting using a FACSMelody Cell Sorter (BD).

[0219] MAIT cells were isolated from PBMCs by a two-step method. PBMC cells were counted and diluted to 1 × 10 in PBS / EDTA buffer in a 15 mL tube. 8 Dilute to cells / mL: 10 8 Add 5 μL of Biotin Anti-Human TCR Vα7.2 antibody (Biolegend, Cat. No. 351724) per cell and incubate for 20 min at 4° C. Wash the cells by adding 10 volumes of PBS / EDTA buffer and centrifuge at 300×g for 10 min. Aspirate the supernatant completely. 10 total cells were collected. 8 Add 800 μL of PBS / EDTA buffer and 200 μL of Anti-Biotin MicroBeads (Miltenyi, Cat. No. 130-090-485) per cell. Mix well and incubate at 4° C. for 15 min. Wash cells by adding 10 volumes of PBS / EDTA buffer and centrifuge at 300×g for 10 min. Aspirate the supernatant completely. 8Resuspend cells in 1 mL PBS / EDTA buffer. Place MS column (Miltenyi) in the magnetic field of an appropriate MACS separator. Prepare column by rinsing with 500 μL PBS / EDTA buffer. Apply cell suspension to column. Wash column with 3×500 μL PBS / EDTA buffer. Elute retained cells outside the magnetic field by adding 1 mL PBS / EDTA buffer. Harvest TCR Vα7.2+ cells and stain with APC anti-human CD3 (Biolegend) and BV421 MR1-5-OP-RU tetramer (1:500) for 30 min at 4°C. Wash cells by adding 10 volumes of PBS / EDTA buffer and centrifuge at 300×g for 10 min. Aspirate supernatant completely. Add 1 mL PBS / EDTA buffer per 108 total cells. The CD3+MR1-5-OP-RU+ cell population is flow sorted using a FACSMelody Cell Sorter (BD).

[0220] Activation and expansion of MAIT cells Count sorted MAIT cells and resuspend in R10 medium (90% RPMI + 10% FBS + 1% penicillin / streptomycin + 2 mM L-glutamine) to 106 / mL. Activate cells with Dynabeads Human T-Activator CD3 / CD28 (Life Technologies) to obtain a 1:1 bead-to-cell ratio with 100 IU / mL IL-2 in a 24-well plate in a 37 °C incubator. Two days after transduction, harvest cells and transfer cells to 6-well plates. Add R10 to 0.5–1 × 10 6 Refresh the cells with R10 medium every 2-3 days.

[0221] Generation of CAR-T cells or CAR-MAIT cells Purified PBMC or MAIT cells were stimulated with Dynabeads Human T-Activator CD3 / CD28 (Life Technologies) in R10 medium containing 100 IU / mL IL-2 for 48 h. Activated cells were then transfected with retroviruses encoding CAR constructs and cultured in R10 for an additional 48 h. CAR-T or CAR-MAIT cells were maintained in G-Rex 6-well plates (Wilsonwolf) in the presence of recombinant IL7 and IL15 (Miltenyi) for an additional 7 days before harvesting.

[0222] Generation of CAR-T cells or CAR-MAIT cells Retroviral transduction was performed 48 hours after T cell activation. If necessary, the transduction process was repeated 24 hours later to achieve higher transduction efficiency. 6 Cells were transferred and further cultured in G-Rex 6-well plates (Wilsonwolf) containing 110 mL of R10 medium. Cytokine IL7 / 15 was replenished every 2 or 3 days. Cells were harvested after 1 week of culture in G-Rex.

[0223] Co-culture cytotoxicity assay This non-radioactive killing assay was performed as previously reported (Rowan et al., 2014). Briefly, target cells were stained with 1 uM CFSE (Biolegend) for 15 min at 37°C. After washing three times with PBS, 100,000 target cells were mixed with CAR-T or CAR-MAIT cells at a ratio of 1:1, 1:3, or 1:5. 200 ul co-cultures were incubated for 4 hours in a 37°C incubator. 1 ul DAPI and 5 ul Countbright beads (BD Biosciences) were added to the samples. Samples were acquired by flow cytometry at a constant rate. The number of viable target cells was calculated as cells in tube = (cells collected / beads collected) x total beads added to the tube.

[0224] Intracellular cytokine staining CART4 or CART20T cells were co-cultured with specific target cells in 96-well bottom plates. All cells were cultured at 2 × 10 5 T cells were seeded at 1000 x 1000 cells / well. T cells cultured alone as negative control and T cells cultured with a combined stimulation of 10ug / ml PMA and 10ug / ml ionomycin (Biolegend) were included as positive control. 10ug / mL Brefeldin A (Biolegend) was added to all wells after 1 hour incubation. The co-cultures were incubated for a further 5 hours and then harvested. Cells were stained for surface markers using antibodies for 30 minutes in the dark. After washing with PBS, cells were fixed with 4% paraformaldehyde solution (Biolegend) for 15 minutes at room temperature. After further washing with fixation buffer, cells were resuspended with a mixture containing intracellular staining antibodies. Cells were incubated for 30 minutes at 4°C and then washed with fixation buffer. They were analyzed by flow cytometry with fluorescence minus one (FMO) controls to determine the expression levels of IFN-γ and TNF-α.

[0225] In vitro suicide assay CART4 with or without iC9 cells were generated using retroviral transduction with CART4 or CART4 without iC9 constructs. CAR-T cells were continued to expand for 5-7 days after transduction. Caspase-inducing drug (CID), B / B homodimerizer AP20187 (Clontech Laboratories), was added to T cell cultures at various concentrations. Induction of apoptosis induced by CID was assessed after 24 h using Annexin-v / 7-AAD (BD Biosciences) staining and flow cytometry analysis. Viable cells were quantified by counting beads (BD Biosciences). The survival index was calculated as follows: live tEGFR in untreated control samples vs. live tEGFR in untreated control samples. + Number of cells / live tEGFR + Number of cells.

[0226] In vivo mouse xenograft experiments Six to eight week old NRG mice (Jackson Laboratory) were used for in vivo experiments with T leukemia cell lines (0.5 × 10 cells) co-expressing Gaussia luciferase and EGFP. 6 CEM-ss cells were injected into mice via the posterior orbit. Mice were then randomized prior to T cell injection. PBMCs from healthy donors were activated and transduced to generate CART4 T cells or non-transduced T cells. On the day of transfusion, CART4 CD8 T cells were transduced by using the Uncontacted Microbeads Human CD8 T Cell Kit (Miltenyi) according to the manufacturer's instructions. + T cells and non-transduced CD8 + T cells were negatively isolated from CART4 T cells or non-transduced T cells. 4 × 10 6 The isolated cells were washed twice by PBS, resuspended in 100 μl and injected into xenografted mice by retro-orbital injection. 30-50 μl of peripheral blood was collected via the tail vein once a week. After centrifugation at 500g for 5 min, plasma was separated to detect luciferase activity according to the manufacturer's equipment (Thermo Fisher Scientific). After red blood cell lysis, cells were resuspended in 100ul antibody master mix for surface marker staining including human CD45, mouse CD45, human CD3, human CD8, human EGFR and live / dead dye. The composition of cell subsets was analyzed using flow cytometry (BD AriaIII). Mice were closely monitored throughout all described studies. Mice were euthanized when they showed one of the following symptoms: loss of more than 20% of initial body weight, significant lethargy, crouching posture, severe diarrhea or severe dermatitis.

[0227] statistical analysis Statistical analysis was performed by using GraphPad Prism software version 6.0 (GraphPad Software). Two-tailed unpaired Student's t test was used to compare data between two groups. *P<0.05, **P<0.01, ***P<0.001. All data with error bars are presented as mean ± standard error of the mean (SEM). P values ​​less than 0.05 were considered significant. Data were analyzed using GraphPad Prism software (version 8).

[0228] 1. Detailed Method 1.1.Detection of MAIT cells 1.1.1. Preparation of human peripheral blood mononuclear cells (PBMCs) 1.1.1.1. Transfer 5 mL of peripheral blood from a volunteer donor into a heparinized tube.

[0229] 1.1.1.2. Dilute whole blood with an equal volume of PBS.

[0230] 1.1.1.3. Place 5 mL of Histopaque-1077 in a 15 ml centrifuge tube. Carefully and gently add 10 ml of the diluted blood solution along the wall of the tube on top of the Histopaque-1077; do not disrupt the liquid interface.

[0231] 1.1.1.4. Centrifuge at 400 x g for 30 minutes at room temperature.

[0232] NOTE: Ensure that the brakes and acceleration are on the lowest settings on the centrifuge, as vigorous braking and acceleration can affect layer separation.

[0233] After centrifugation, carefully aspirate the top layer with a Pasteur pipette to within 0.5 cm of the opaque interface containing the mononuclear cells. Discard the top layer.

[0234] 1.1.1.6. Wash harvested PBMCs twice with 10 ml of PBS by centrifugation at 250 x g for 10 minutes.

[0235] 1.1.1.7. Resuspend the PBMC pellet using RPMI 1640 medium.

[0236] 1.1.2. Preparation of BV421-labeled 5-OP-RU / MR1 tetramer 1.1.2.1. Dilute 6.8 μl of 0.5 mg / ml streptavidin-BV421 in 10.2 μl of PBS and mix well.

[0237] Add 1.1.2.2.1 / 10 streptavidin-BV421 solution (1.7 μl) to 18 μl of MR1-5-OP-RU solution (5 μg) every 10 min, mix with a pipette and incubate at room temperature in the dark between steps.

[0238] 1.1.2.3. Keep the BV421-labeled 5-OP-RU / MR1 solution at 4°C.

[0239] The tetramer should be titrated for use; typically a 1:500 dilution is sufficient.

[0240] 1.1.3. Detection of human MAIT cells by flow cytometry Human MAIT cells can be detected by flow cytometry using MR1 tetramers loaded with 5-OP-RU or by co-staining with antibodies against CD161 and the TCR Vα7.2 chain. In general, MAIT cells represent 0.1-10% of CD3+ T cells in peripheral blood.

[0241] 1.1.3.1. 1 x 10 cells per 100 µl FACS staining buffer 6 Resuspend the PBMCs at a cell concentration of 1:1.

[0242] 1.1.3.2. Add FACS antibody and / or 5-OP-RU / MR1 tetramer to the sample.

[0243] For the detection of human MAIT cells, two methods can be used.

[0244] a) Tetramer staining: using BV421-labeled human 5-OP-RU MR1 tetramer (1:500) and APC-H7-conjugated anti-human CD3 (1:200).

[0245] b) Substitution marking: PE-conjugated anti-human TCR Va7.2 (1:200), APC-H7-conjugated anti-human CD3 (1:200), and FITC-conjugated anti-human CD161 (1:200).

[0246] 1.1.3.3. Incubate in the dark at 4 °C for 30 minutes.

[0247] 1.1.3.4. Wash the cells with FACS stain buffer by centrifugation at 300 x g for 5 minutes at 4°C and resuspend in 300 µl of FACS stain buffer.

[0248] 1.1.3.5. Analyze MAIT cells by flow cytometry (see Figure 11).

[0249] 1.2.Isolation of MAIT cells 1.2.1.Magnetic bead isolation of Vα7.2+ cells.

[0250] 1.2.1.1. Harvest PBMCs and wash the cells with binding buffer. Discard the supernatant and pellet the cells at 1 x 10 7 Resuspend in MACS buffer at a concentration of 1:100 / 100 μl. Add PE anti-human TCR Vα7.2 antibody (1:100). Mix thoroughly and incubate on ice for 30 min.

[0251] 1.2.1.2. Wash the cells once with MACS buffer by centrifugation at 300 x g for 5 minutes.

[0252] 1.2.1.3. Cells were diluted with MACS buffer for 10 min. 7 Resuspend at a concentration of 10 / 80 μl. 7 Add 20 μl of anti-PE microbeads per cell and incubate on ice for 20 min.

[0253] 1.2.1.4. Wash cells once with 10 volumes of MACS buffer. Centrifuge at 300 x g for 5 minutes. Resuspend in 1 ml of MACS buffer.

[0254] 1.2.1.5. Pre-wash the MS column with 1 ml of MACS buffer and assemble it on the magnet. Apply the cells to the column and wash the column 3 times with 1 ml of MACS buffer each time.

[0255] 1.2.1.6. Remove the column from the magnet and elute the bound cells in 1 ml of MACS buffer.

[0256] 1.2.2.Flow sorting of MAIT cells 1.2.2.1. Collect the cells separated by magnet and centrifuge at 300 x g for 5 minutes.

[0257] 1.2.2.2. Cells were diluted with MACS buffer for 10 min. 7 Resuspend at a concentration of 1:100 / 100 μl. Add BV421-labeled human 5-OP-RUMR1 tetramer (1:500) and APC-H7 conjugated anti-human CD3 (1:200). Incubate on ice for 20 minutes.

[0258] 1.2.2.3. Wash cells once with 10 volumes of MACS buffer. Centrifuge at 300 x g for 5 minutes. Resuspend in 2 ml of MACS buffer.

[0259] 1.2.2.4. Turn on the BD Prodigy sorter and load the cell sample. Select the CD3+ tetramer+ cell population (see Figure 12).

[0260] 1.3.Isolation of MAIT cells 1.3.1. Harvest sorted MAIT cells and centrifuge at 300 x g for 5 minutes.

[0261] 1.3.2. Discard the supernatant and transfer to R10 medium for 10 min. 6 Resuspend at 200 cells / ml.

[0262] 1.3.3.Resuspend Dynabeads Human T-Activator CD3 / CD28 by vortexing for 30 seconds.

[0263] 1.3.4. Transfer the desired volume of Dynabeads to a tube.

[0264] 1.3.5. Add an equal volume of buffer and mix by vortexing for 5 seconds. Place the tube on the magnet for 1 minute and discard the supernatant.

[0265] 1.3.6. Remove the tube from the magnet and resuspend the washed Dynabeads in R10 medium.

[0266] 1.3.7. Add the desired volume of Dynabeads to the cell suspension to obtain a 1:1 bead to cell ratio at 100 IU / ml IL-2 in a 24-well plate in a 37° C. incubator.

[0267] 1.4. Retroviral transduction of MAIT cells 1.4.1. Retroviral transduction was performed 48 hours after MAIT cell activation.

[0268] 1.4.2. One day prior to transduction, prepare Retronectin coated plates: Add 15 μg Retronectin to 1 ml PBS. Mix well and add to one well of a non-tissue culture treated 24-well plate.

[0269] 1.4.3. Wrap the plate in film and store in the refrigerator at 4°C overnight.

[0270] 1.4.4. On the day of transfection, remove unbound RetroNectin from the wells. Wash twice with 2 ml of PBS. Avoid letting the wells dry out.

[0271] 1.4.5. Thaw the retroviral supernatant in a water bath at 37 °C. Transfer 1 ml of viral supernatant to each well of the RetroNectin-coated plate.

[0272] 1.4.6. Wrap the plate in film and centrifuge the plate at 1000 x g, 32°C for 2 hours.

[0273] 1.4.7. Harvest the activated MAIT cells by centrifugation. Resuspend the cells to a concentration of 1×106 / ml with fresh R10 medium containing 100 IU / ml IL-2.

[0274] 1.4.8. Once the spin is complete, discard the supernatant from the plate. Add 1 ml of cell suspension to each well.

[0275] 1.4.9. Centrifuge the plate at 500 x g for 10 minutes.

[0276] 1.4.10. Return the plate to the 37°C incubator.

[0277] 1.4.11. If necessary, repeat the transduction process to achieve higher transduction efficiency.

[0278] NOTE: Transduction efficiency can be detected by flow cytometry 48 h after transduction.

[0279] 1.5.Expansion of CAR-MAIT cells 1.5.1. Two days after retroviral transduction, harvest the cells and count the cells by hemocytometer.

[0280] 1.5.2.1×10 7 The cells are transferred to one well of a Grex 6 M-well plate. 130 ml of fresh R10 medium containing 100 IU / ml IL-2 is added and the plate is returned to the incubator.

[0281] 1.5.3. Refresh IL-2 every 3 days to a final concentration of 100 IU / ml.

[0282] 1.5.4. CAR-MAIT cells can be harvested after 8-12 days of culture (see Figure 13).

[0283] NOTE: Expanded CAR-MAIT cells can be used for phenotypic testing, functional assays, or frozen in liquid nitrogen.

[0284] result Example 1 - Generation of CD4-targeted T cells and TCR Vβ7.1-targeted T cells Referring to Figures 1A(1) and (2), a schematic diagram showing the functional elements contained in two different embodiments of a CAR construct according to the invention is shown.

[0285] In each embodiment, the construct is flanked by upstream and downstream long terminal repeats (LTRs). The 5' promoter is located downstream of the 5' LTR and can be a PGK promoter. 3' to the promoter is located an SP, an Igκ signaling peptide, for directing the fusion protein to the T cell outer membrane. 3' to the SP is provided an scFv region that includes an upstream VL (variable light chain) sequence, a central G4S sequence, and a downstream VH (variable heavy chain) sequence. The VL and VH sequences can be, in one embodiment (as shown in FIG. 1A(1)), Hu5A8 light and heavy chain variable regions for binding to the CD4 antigen. In another embodiment (as shown in FIG. 1A(2)), the VL and VH sequences can be, in one embodiment (as shown in FIG. 1A(3)), 3G5 light and heavy chain variable regions for binding to TCR-Vb7.1.

[0286] 3' of the scFv region is a CD8a hinge and transmembrane (TM) domain structural domain for display and anchoring of the CAR. 3' of the hinge and TM provides an intracellular domain including the signaling domains of CD28, 4-1BB and CD3 zeta chain to trigger intracellular signaling pathways. A P2A self-cleaving peptide is placed 3' of the zeta chain and 5' of the truncated EGFR (EGFRt), which tracks it and acts as a first safety switch. A second P2A self-cleaving peptide is placed 3' of the EGFRt and 5' of inducible caspase-9 (iC9), which acts as a second safety switch. The construct contains a woodchuck hepatitis control element (WPRE) (see plasmids in Figures 9 and 10) that enhances expression, and finally a terminal 3' LTR.

[0287] The DNA sequence of humanized 5A8 (Hu5A8) murine IgG antibody with immunospecificity for human CD4 was found in CN103282385. Hu5A8, also known as TNX-355 or ibalizumab, has been extensively evaluated in phase I and II clinical trials for inhibiting HIV entry by blocking the HIV binding site on the CD4 molecule. As a control, the VH and VL chains of anti-CD20 monoclonal antibody (Leu16) were also synthesized and evaluated for their efficacy in preclinical and clinical CAR-T studies. The scFv fragment was cloned in frame with the CD8 transmembrane domain, CD28 endodomain, 4-1BB endodomain and CD3 ζ chain into the backbone of a third generation CAR plasmid. The third generation CAR was used for studies to demonstrate its superiority over first and second generation CARs. The utility of tEGFR was investigated as a selection, in vivo tracking marker for the elimination of engineered CAR-T cells, and as a first safety switch. Therefore, this remaining tEGFR sequence was linked to the CAR sequence by a T2A-ribosomal skip sequence.

[0288] CAR-T cells can remain in patients, sometimes for decades, as in the case of anti-CD19 and anti-HIV CAR trials. Unlike B-cell aplasia, long-term CD4 +T cell hypoplasia is life-threatening. Therefore, it is necessary to establish a safe method to remove the CART4 cells of the present invention from patients after tumor or viral depletion, or in emergency cases due to severe side effects during CAR-T therapy. The dimerization drug-induced caspase-9 (iC9) suicide switch is based on the fusion of human caspase-9 to a mutant human FK506 binding protein (FKBP), which allows conditional dimerization in the presence of the small chemical molecule drug AP20187, called caspase-inducing drug (CID). The use of iC9 has already been proven safe and effective in clinical trials of haploidentical HSC transplantation. Therefore, a gene fragment containing CD4 CAR, tEGFR and iC9 was then synthesized (Figure 1A.1) and inserted into a retroviral MSCV (murine stem cell virus) vector (shown in Figure 9; 10,348 bp). A gene fragment containing TCR Vβ7.1 CAR, tEGFR and iC9 was then synthesized (Figure 1A.2) and inserted into a retroviral MSCV (murine stem cell virus) vector (shown in Figure 10; 10,347 bp).

[0289] To demonstrate co-expression of CAR and tEGFR, human PBMCs were activated with Dynabeads human T-activator and engineered to express the CAR / tEGFR / iC9 genetic construct by retroviral transduction of the plasmids shown in Figures 9 and 10. Indeed, the expression levels of CAR and tEGFR were found to be closely correlated, as shown by the detection of double-positive cell populations upon surface staining with mouse scFv-specific anti-mouse IgG F(ab')2 antibodies in combination with EGFR-specific antibodies (Figure 1B). Together with T cell proliferation, tEGFR + The cell population maintained its proportion of approximately 50% of the total cells (Figure 1C).

[0290] To evaluate the efficiency of the iC9 safety switch in vitro, a CART4 mutant without the iC9 gene (CART4 without iC9) was cloned as a control. T cells transduced with CART4 or CART4 without iC9 constructs were exposed to increasing concentrations of the CID AP20187 (0.1 nM to 100 nM) for 24 h. Cell death was assessed by flow cytometry analysis with 7AAD and Annexin V. The tEGFR positive percentage in the surviving population decreased with increasing concentrations of CID. 69.1% of tEGFR high cells were eliminated after a single dose of 100 nM CID (Figure 1D). Consistent with observations from other studies, cells escaping death were those expressing low levels of the transgene, which showed a 50% decrease in mean fluorescence intensity (MFI) of tEGFR after CID (Figure 1E). Thus, non-responsive T cells expressed insufficient iC9 for functional activation of the CID. For clinical applications, CAR-T cells may need to be selected for sufficient transgene expression prior to administration.

[0291] Example 2 - Functional validation of CART4 T cells in vitro Within 4 days after CAR transduction, CD4 + T cells were almost completely depleted compared to non-transduced (NTD) and CART20 controls where approximately 45% of cells remained CD4 positive (Figure 2A). These data demonstrated the robust activity of CART4 cells against CD4 during T cell expansion.

[0292] Co-cultures were established for autologous primary healthy donor PBMCs. CFSE-labeled autologous PBMCs were cultured with CD8 + The CD4 / 20 cells were co-cultured with either CART4 or CART20 cells. In both settings, CART4 / 20 cells mediated high levels of cytotoxicity against the respective target cells. + 94% of cells were lysed by CART4 cells at an E:T ratio of 3:1 during 4 h of coculture. However, compared with NTD T cells, CD20 + There was no specific T cell cytotoxicity in response to CART4 cells (Fig. 2C).

[0293] To further evaluate the function of CART4 cells, we tested the antitumor effect of CART4 cells using Jurkat and CEM-ss cell lines. Jurkat and CEM-ss cell lines were T cell lines originally established from peripheral blood of patients with T cell leukemia or human T4 lymphoblastic leukemia. Both cell lines express CD4, while CEM-ss cell line expresses higher levels of CD4 (Figure 2D). Indeed, CART4 cells targeted T tumor cell lines based on CD4 expression levels. After a short incubation, CART4 cells successfully eliminated CEM-ss cells at an E:T (effector:target) ratio of 5:1. As a control, CART4 cells were also tested for their activity against CD4- lymphoma cells, a human B cell line (BCL) that does not express CD4 (Figure 2D). Flow cytometry analysis demonstrated that CART4 cells were unable to target BCL (Figure 2E). + CART4 cells cultured with tumor cells showed significant IFN-γ and TNF-α responses by intracellular cytokine staining (FIG. 2F). Thus, these data demonstrated a strong dose-dependent response of CART4 to CD4 expression. No killing effect was observed when CART4 cells were incubated with CD4-negative cells. Thus, these results indicate that CART4 cell ablation is CD4 specific.

[0294] Example 3 - CART4 cells are CD4 + Specific killing of T-tumor cells To investigate the function of CART4 on patient samples, PBMCs from ATLL patients were thawed and phenotyped. All samples had CD4 expression ranging from 67.4% to 97.7%. + Most of the cells expressed one unique β chain of the T cell receptor (TCR Vβ), indicating clonal development of T cell leukemia202-204 (Figure 3A). Co-culture of ATLL patient samples with CART4 cells for 4 h resulted in the proliferation and differentiation of CD4 +This resulted in rapid and complete disappearance of the malignant tumor. Consistent with the disappearance of blast T cell lines shown previously (Figure 3B), a disappearance of approximately 80% was observed for all ATLL cocultures. Tests were also performed with samples from six CTCL patients. Similarly, a strong cytotoxicity of CART4 cells against freshly thawed primary CTCL cells was observed, resulting in a reduction of approximately 60%-80% of malignant T cells after 4 h of coculture (Figure 3C). Thus, CART4 cells were able to effectively suppress aggressive CD4 T cells isolated directly from patient samples. + These results suggest that CD4 T cells efficiently eliminated CD4 T malignancies. + These results suggest that IFN-γ is a promising therapeutic target for T malignancies.

[0295] Example 4 - CART4 cells efficiently mediate anti-leukemic effects in vivo To evaluate in vivo antitumor activity, we developed a xenogeneic mouse model using the Gaussia luciferase-expressing CEM-ss cell line. They first administered a single dose (4 × 10 6 We tested the ability of CART4 cells to delay the emergence of leukemia in NRG mice using a 3-cell mouse model. Prior to injection, approximately 50% of the cells expressed the anti-CD4 CAR, as demonstrated by flow cytometry analysis. Mice received retro-orbital injections of CEM-ss cells. Four days after tumor engraftment, mice were injected with CART4 cells or NTDCD8 cells. + A single dose of retro-orbital injection of T cells was administered to leukemia-bearing mice (Figure 4A). Tumor burden was monitored by weekly measurement of luciferase activity in peripheral blood. Injected CART4 cells provided robust protection against leukemia progression (Figure 4B) and significantly extended the median survival of mice (38 days in the control group vs. 60 days in the CART4 group, P = 0.026 by Mantel-Cox log-rank test) (Figure 4C). Indeed, by endpoint, eGFP + Tumor progression was dramatically delayed in the spleen and bone marrow by flow cytometric analysis (FIG. 4D).

[0296] Although recurrent tumor cells retained CD4 expression, the expression level was reduced to approximately 40% MFI compared to the control group (Figure 4E). However, this downregulation was insufficient to impair the ability of CART4 cells to eliminate recurrent tumors (Figure 4F). This result indicated that lack of CAR-T cell persistence, rather than antigen escape, was the main reason for tumor recurrence.

[0297] Example 5 - Development of a GMP-compliant method for producing CAR-T cells To evaluate scalability and simplify CAR-T cell manufacturing, we established an optimized standard operating procedure using a gas-permeable static cell culture system (G-Rex) for CAR-T manufacturing (Figure 5A). The G-Rex system contains a silicone membrane at the bottom of the plate. Gas exchange, including O2 and CO2, across the membrane allows for increasing the depth of the culture medium, providing more nutrients and diluting waste products. PBMCs were activated, transduced, and cultured at 10 × 10 6 Cells were transferred and further cultured in G-Rex 6-well plates. Cells were supplemented with cytokines IL-7 and IL-15 every 2-3 days. Cells were cultured at an initial number of 2 × 10 6 From cells 3 × 10 8 The cells expanded beyond 100% and increased 150-fold in 15 days (Figure 5B). We next confirmed the transduction efficiency of the final product after T cell expansion in the G-Rex system. The final transduction efficiency of CART4 was 57.6% ± 7.1%, as shown in Figure 5C, similar to cells produced from conventional flasks (53.7% ± 5.3%). As expected, endogenous CD4 + The population was completely depleted in the final product, demonstrating the anti-CD4 activity of CAR-T cells.

[0298] Interestingly, CAR-T cells produced in G-Rex showed differentiation preference towards a central memory phenotype. Evaluation of memory markers CD45RO and CD62L showed a higher CD45RO CD62L double positive population percentage (77% ± 7.1% vs. 41% ± 5.5%) compared to cells cultured in conventional culture flasks (Figure 5D). CD45RO CD62L double positive cells are thought to be central memory T cells and necessary for long-term persistence in vivo. Thus, this bioprocess optimization method increased cell output and the percentage with a central memory phenotype while decreasing the number and cost of technical interventions in CAR-T manufacturing.

[0299] Example 6 - Generation of TCR Vβ7.1-specific CAR-T cells T-cell malignancies usually arise from one monoclonal cancerous cell expressing a unique TCR. A broad range of antibodies against the variable (V) region of the TCR β (Vβ) chain are now available in a direct conjugate multicolor format that allows the assessment of 22 of the 25 Vβ families, covering 75% of the normal circulating T-cell repertoire. Therefore, we consider TCR Vβ to be a potential target for CAR-T therapy against T-cell malignancies. To develop TCR Vβ targeting CAR-T (CARTVb7.1) cells, we cloned the scFv region of hybridoma cell 3G5, which produces a monoclonal antibody specific for human TCR Vβ7.1 (Dr Margret Callam in Andrew's lab, Oxford), into a CAR construct, as shown in Figure 1A(2). Five days after CAR transduction, the endogenous TCR Vβ7.1+ population was almost completely depleted compared to the CART20 control, where approximately 1.2% of cells remained TCR Vβ7.1 positive (Figure 6B). These data demonstrated the robust activity of CAR-T cells against TCR Vβ7.1 during T cell expansion.

[0300] To further evaluate the function of CARTVb7.1 cells, we tested their antitumor effect using tumor cells isolated from ATL patients diagnosed with TCR Vβ7.1 positive tumors. Indeed, co-culture of ATL patient samples with CARTVb7.1 cells for 6 hours significantly increased the CD4 + This resulted in rapid and complete disappearance of the malignant tumors. Approximately 60% disappearance was observed for all ATL cocultures (Figure 6C, Figure 6D). These results indicate that TCR Vβ is a promising therapeutic target for T malignancies.

[0301] Example 7 - Development of CAR-MAIT cells Currently, most CAR-T therapies utilize autologous conventional CD3+ T cells. However, immune cells from cancer patients may be poorly functional or present in low numbers. In particular, it would be dangerous to expand and genetically modify PBMCs of patients with T malignancies, as tumor cells can be engineered with CARs. It is therefore desirable to develop immunotherapies that can produce third-party allogeneic cells. Here, we developed a two-step method to isolate mucosal-associated invariant T cells (MAIT cells) from PBMCs by a combination of magnetic separation and flow cytometry sorting. After the first step of separation based on TCR Vα7.2 expression, the MAIT cell percentage increased from 0.74% to 33.3% (Figure 7A, Figure 7B). The next step of flow sorting could further increase MAIT purity to 95%. Sorted cells were activated with Dynabeads Human T-Activator CD3 / CD28 and expanded in the presence of a cocktail of cytokines (IL-2, IL-7 and IL-15). The expansion method resulted in approximately 100-fold expansion within 12–14 days (Figure 7C). Upon recovery, 90.9% of the expanded cells maintained specificity for the MR1-5-OP-RU tetramer (Figure 7D). Moreover, the expanded MAIT cells could be successfully engineered with a CAR gene by retroviral transduction (Figure 7E). CAR-transduced MAIT (CAR-MAIT) cells have comparable cytotoxicity capacity to conventional CAR-T cells (Figure 8).

[0302] Example 8 - CAR-MAIT cells efficiently mediate anti-leukemia effects in vivo To evaluate the antitumor function of CAR-MAIT cells in vivo, we tested the ability of anti-CD4 CAR-MAIT (CAR-MAIT4) cells to delay leukemia progression in NSG mice with a single dose of CAR cells (4×106). Mice received retro-orbital injection of CEM-ss cells. Four days after tumor engraftment, a single dose of intravenous injection of CAR-MAIT4 or CART4 cells was administered to leukemia-bearing mice (FIG. 14A). Anti-CD20 CAR-MAIT (CAR-MAIT-Ctrl) or anti-CD20 CART (CART-Ctrl) cells were administered as control groups. Tumor burden was monitored by measuring luciferase activity weekly. Injected CAR-MAIT4 and CART4 cells provided comparable protection against leukemia progression (FIG. 14C and FIG. 14D) and significantly extended the survival of tumor-bearing mice (FIG. 14B).

[0303] Example 9 - Detection, isolation, expansion and manipulation of human MAIT cells Using the methods described herein, human MAIT cells were detected, isolated, expanded and manipulated.

[0304] As shown in FIG. 11, human MAIT cells were analyzed by flow cytometry.

[0305] As shown in FIG. 12, MAIT cells were flow sorted.

[0306] The MAIT cells were then activated and transduced with a CAR expression vector to generate CAR-MAIT cells, which were then expanded as shown in Figure 13.

[0307] Example 10 - Proliferation of MAIT cells by stimulating PMBCs MAIT cells express CD3 that recognize the MHC class I-like molecule MR1. + TCR Va 7.2 + CD161 +MAIT cells are a subset of natural T cells defined as CAR-based T cells. Previous studies have shown that MAIT cells can be expanded in vitro but require the presence of allogeneic feeder cells, but this method is difficult for large-scale production and quality control. In this study, we developed a highly novel and effective method to expand MAIT cells in vitro by first stimulating PBMCs with antigen (5-OP-RU)-loaded MR1 tetramer beads or 5-OP-RU alone for up to 6 days in in vitro culture, both in the presence of a combination of various cytokines (IL-2, IL-7, IL-15, IL-12, IL-18 and IL-23). ​​The resulting MAIT cells were then isolated by MACS or FACS sorting as described in the previous examples and further expanded by anti-CD3 / CD28 beads for CAR-based therapy.

[0308] Materials and Methods 1. PBMC Isolation PBMCs were isolated from buffy coats of healthy blood donors via centrifugation on a Ficoll-Hypaque density gradient. Aliquots of isolated PBMCs were frozen and stored in liquid nitrogen until use. Before starting the experiment, frozen PBMC stocks were thawed and incubated at 37°C in RPMI medium supplemented with 10% FBS.

[0309] 2. Preparation of MR1 / 5-OP-RU Composite Beads MR1 / 5-OP-RU tetramer coated beads were generated by using M-280 dynabeads containing streptavidin and biotinylated MR1 monomer from ThermoFisher. 5-OP-RU loaded MR1 monomer was kindly provided by Dr Jim McCluskey (University of Melbourne, Australia). The beads were mixed and incubated on a rocker for 12 hours at 4°C with 5-OP-RU loaded MR1 monomer (5ug / 3x10 7The beads were coated with 100 mM tetramer (MDMA) and 100 mM glycerol (MDMA) (beads). Excess unbound protein was removed by two 10-minute washes in PBS. The prepared MR1 tetramer-coated beads were resuspended in PBS and stored at 4° C. until use.

[0310] 3. Enrichment of MAIT Cells in PBMCs PBMCs (2 x 10 per well 5 Cells) were cultured in 96-well plates containing R10 medium (90% RPMI + 10% FBS + 1% penicillin / streptomycin + 2mM L-glutamine) in a 37°C incubator and stimulated with either MR1 / 5-OP-RU complex-coated beads or purified 5-OP-RU antigen (10 nM) (provided by Dr Jeffrey Mak, University of Queensland, Australia) at a 1:1 bead-to-cell ratio in combination with different cytokines for 6 days in vitro. Cytokines IL-2 (100 IU / ml) (Roche), IL-7 (50 ng / ml) (Miltenyi), IL-15 (50 ng / ml) (Miltenyi), IL-12 (50 ng / ml) (Miltenyi), IL-18 (50 ng / ml) (ThermoFisher) and IL-23 (50 ng / ml) (Miltenyi) were added in 15 different combinations numbered 1 to 15 as shown in the table in Figure 15. On day 6, expanded cells were harvested and analyzed to determine the percentage of MAIT cells by flow cytometry as described below.

[0311] 4. FACS Analysis of MAIT Cell Frequency in PBMCs Expanded PBMCs were stained for surface markers using antibodies for 30 min in the dark. Cells were labeled with FITC-conjugated CD3 (clone BW264 / 56, Miltenyi), PE-conjugated Va7.2 (clone 3C10, Biolegend), and APC-conjugated CD161 (clone DX12, BD) at 1:100. MAIT cells were stained with CD3 + Va7.2 + CD161 +Dead cells were defined as cells that were not stained with LIVE / DEAD™ Fixable Aqua Dead Cell Stain Kit (ThermoFisher). Stained cells were washed with 5–10 volumes of PBS, centrifuged at 500 × g for 5 min, and resuspended in 200 μl of PBS prior to flow cytometry analysis. Flow cytometry results were analyzed by FlowJo.

[0312] result Referring to Figure 15, the results of enriching MAIT cells in PBMCs are shown. PBMCs were stimulated with either (i) MR1 / 5-OP-RU complex beads at a bead to cell ratio of 1:1 or (ii) 5-OP-RU antigen at 10 nM for 6 days in the presence of different cytokines (IL-2, IL-7, IL-15, IL-12, IL-18 and IL-23) as shown in the table. For example, condition 1 corresponds to IL-2 only, condition 2 corresponds to IL-7 and IL-15, condition 3 corresponds to IL-2, IL-12 and IL-18, etc.

[0313] The fold increase in MAIT cells was calculated by dividing the number of viable MAIT (CD3 + Va7.2 + CD161 + ) cells divided by the original frequency of MAIT cells on day 0. The top five groups are highlighted in orange (i.e., conditions 1, 3, 11, 12, and 13).

[0314] As can be seen, for MR1 / 5-OP-RU complexed beads (for donor 1), cytokine combinations of 1, 13, 12, 3 and 11 gave the greatest fold increase in MAIT cells in PBMCs. For MR1 / 5-OP-RU complexed beads (for donor 2), cytokine combinations of 12, 13, 1, 11 and 3 gave the greatest fold increase in MAIT cells in PBMCs.

[0315] As can be seen, for 5-OP-RU (for donor 1), cytokine combinations of 3, 1, 12, 13 and 11 gave the greatest fold increase in MAIT cells in PBMCs. For 5-OP-RU (for donor 2), cytokine combinations of 8, 13, 12, 11 and 3 gave the greatest fold increase in MAIT cells in PBMCs.

[0316] Based on these data, it is clear that different cytokines and cytokine combinations (IL-2, IL-7, IL-15, IL-12, IL-18 and IL-23) provided different levels of stimulation and improved enrichment of MAIT cells in PBMCs. Overall, the combination of IL-12, IL-18 and IL-23 provided the greatest fold increase in MAIT cells in PBMCs.

[0317] Consideration Currently, no well-established treatments are available for T-cell lymphomas compared to B-cell malignancies, and the only potentially curative regimen is allogeneic hematopoietic stem cell transplantation (HSCT), which itself has significant treatment-related mortality. Because the majority (>95%) of T-cell lymphomas originate from dominant T-cell clones expressing defined T-cell receptor (TCR) genes (i.e., clonal TCR-Vb chain) and the pan-T help cell marker CD4, monoclonal antibodies targeting these markers have been explored for the treatment of T-cell lymphomas, and some have resulted in partial regressions in small clinical trials (d'Amore et al., 2010; Hagberg et al., 2005; Kim et al., 2007).

[0318] Although CAR-T is a highly effective treatment for B-cell malignancies by targeting the pan-B-cell marker CD19, this approach faces significant obstacles when applied to the treatment of T-cell lymphomas. First, unlike B-cell depletion, persistent T-cell aplasia, especially CD4 +T cell depletion would result in severe toxicity, such as opportunistic infections observed during chronic HIV infection. Secondly, the reduced number of normal T cells caused by T cell dysfunction and dominant T cell tumor growth associated with T cell lymphoma cannot be used to generate autologous CAR-T cells, and therefore allogeneic CAR-T cells are necessary for the treatment of T cell lymphoma. Finally, most T cell lymphomas are solid tumors associated with lymph node and skin tissues, which are difficult to treat by conventional CAR-T due to their lower tissue infiltration ability as well as the harsh tumor microenvironment.

[0319] To address these issues, we designed a CAR-targeted CD4 antigen (CART4) containing tEGFR and iC9 as a safety switch to selectively eliminate CART4-transduced T cells after eradicating tumor cells, and to selectively eliminate normal CD4 T cells from autologous hematopoietic stem cells or allogeneic HSCT. + This allowed the recovery of T cells. Trafficking depletion of CD4+ T cells has been shown to be safe and tolerable in the treatment of autoimmune diseases with anti-CD4 antibodies (Hagberg et al., 2005; Kim et al., 2007). CART4-transduced human T cells were able to kill CD4+ T cell lymphoma cell lines isolated from ATLL or CTCL patients in vitro and inhibit tumor growth in vivo in mouse xenograft models. More importantly, these CART4+ T cells co-express CAR with both tEGFR, detected by anti-EGFR antibodies, and iC9, determined by CID drug-induced apoptosis of CART4+ T cells in vitro and in vivo. Expression of tEGFR is associated with the increased expression of CART4. + To monitor T cell proliferation or in vivo using anti-EGFR antibodies, CART4 + Either can be used to eliminate T cells.

[0320] In general, normal T cells consist of a highly diverse TCR repertoire to maintain cellular immunity against pathogen infection. TCR consists of a heterodimer of a and b chains containing an N-terminal variable region and a C-terminal constant region. The TCR-Vb region (chain) is more polymorphic than TCR-Va and is often used to analyze the clonality of immune responses or T-cell malignancies. Currently, there are 22 mAbs specific for the TCR-Vb chain family, covering 75% of the TCR repertoire. Since most T-cell lymphomas originate from a single T-cell clone expressing the same TCR Vb chain, therefore, CART targeting the tumor clone-defined TCR-Vb chain while maintaining the remaining normal T-cell repertoire is an ideal approach to minimize opportunistic infections and does not require removal of CART cells after transfusion.

[0321] As a proof-of-concept for anti-TCR-Vb-based immunotherapy, we engineered a CAR that specifically targets the TCR-Vb7.1 chain (CARTVb7.1) and showed that CARTVb7.1-transduced T cells could effectively eliminate TCR-Vb7.1-positive tumor cells isolated from ATL patients, suggesting that anti-TCR-Vb CARs may provide an alternative immunotherapy for T-cell lymphoma.

[0322] Finally, we investigated whether MAIT cells could be used as effector cells for CAR-based therapy, as they have several advantages over conventional T cells: (1) low alloreactivity due to expressing an invariant TCR that is highly conserved during mammalian evolution (i.e., inducing graft-versus-host disease, GVHD); (2) regulatory functions, including inhibition of GVHD in mouse models; (3) activation-induced killing activity of GrB, perforin, and GrA; and (4) Tissue homing, such as distribution in the intestinal mucosa, skin and lungs.

[0323] As described herein, CAR-transduced MAIT cells (CAR-MAIT) demonstrated anti-tumor activity in vitro and in vivo at least equivalent to that exhibited by conventional CAR-T cells.

[0324] In conclusion, we have developed a novel CAR-MAIT-based immunotherapy for the effective treatment of T-cell malignancies by targeting either pan-T cell marker CD4 with switchable CAR-T to reduce on-target / off-tumor toxicity and cytokine release syndrome or specific TCR-Vb chain (intrinsic to malignant T cells to avoid global immunosuppression). More importantly, CAR-MAIT cells may have the potential to develop allogeneic CAR-based therapies required for the treatment of T-cell lymphoma. If produced consistently, i.e., large amounts of ex vivo expansion, they can be used for off-the-shelf development. We believe that CAR-MAIT may provide a new approach for effective treatment not only for T-cell malignancies but also for other non-immune cell type tumors.

[0325] conclusion Chimeric antigen receptor (CAR)-based T cell therapy has achieved great success in treating B cell malignancies by targeting pan-B cell specific antigens. However, a similar strategy for T cell lymphoma has not been realized so far, mainly due to the potential severe toxicity due to global T cell exhaustion and dysfunction / low frequency of normal T cells in T lymphoma compared to B cell malignancies. To overcome these limitations, we engineered novel CAR constructs specific for pan-T cell markers (CD4) or TCR-Vb isotype chain, incorporating two safety switches: truncated epidermal growth factor receptor (tEGFR) and inducible caspase-9 (iC9). We investigated whether mucosal-associated invariant T (MAIT) cells, which have low alloreactivity, exhibit similar antitumor killing activity as conventional T cells after being transduced with CAR constructs.

[0326] Surprisingly, CAR-transduced T cells not only showed specific killing of CD4+ T lymphoma cells or TCR-Vb-specific T leukemia clones isolated from patients, but also eliminated them upon treatment with inducers in vitro and in vivo. Furthermore, the inventors showed for the first time that CAR-MAIT cells can inhibit tumor growth as efficiently as conventional T cells in vitro and in vivo. This study provides a novel strategy for the treatment of T cell lymphoma.

[0327] Thus, the mucosal-associated invariant T (MAIT) cells of the present invention, a type of immune cell known for its involvement in a wide range of infectious and non-infectious diseases and for its unusual specificity for microbial riboflavin-derived antigens presented by the major histocompatibility complex (MHC) class I-like protein MR1, are developed into a novel form of immunotherapy to treat cancer patients by genetically modifying MAIT cells with chimeric antigen receptors (CARs) that enable them to specifically recognize and attack T lymphomas.

[0328] References d'Amore, F., Radford, J., Relander, T., Jerkeman, M., Tilly, H., Osterborg, A., Morschhauser, F., Gramatzki, M., Dreyling, M., Bang, B., & Hagberg, H. (2010). Phase II trial of zanolimumab(HuMax-CD4) in relapsed or refractory non-cutaneous peripheral T cell lymphoma.British Journal of Haematology,150(5),565-573.https: / / onlinelibrary.wiley.com / doi / full / 10.1111 / j.1365-2141.2010.08298.x Hagberg,H.,Pettersson,M.,Bjerner,T.,&Enblad,G.(2005).Treatment of a patient with a nodal peripheral T-cell lymphoma(Angioimmunoblastic T-cell lymphoma)with a human monoclonal antibody against the CD4 antigen(HuMax-CD4).Medical Oncology(Northwood,London,England),22(2),191-194.https: / / link.springer.com / article / 10.1385 / MO:22:2:191 Katsuya,H.,Ishitsuka,K.,Utsunomiya,A.,Hanada,S.,Eto,T.,Moriuchi,Y.,Saburi,Y.,Miyahara,M.,Sueoka,E.,Uike,N.,Yoshida,S.,Yamashita,K.,Tsukasaki,K.,Suzushima,H.,Ohno,Y.,Matsuoka,H.,Jo,T.,Amano,M.,Hino,R.,… Project,A.-P.I.(2015).Treatment and survival among 1594 patients with ATL.Blood,126(24),2570-2577.https: / / ashpublications.org / blood / article / 126 / 24 / 2570 / 34701 / Treatment-and-survival-among-1594-patients-with Kim,Y.H.,Duvic,M.,Obitz,E.,Gniadecki,R.,Iversen,L.,Osterborg,A.,Whittaker,S.,Illidge,T.M.,Schwarz,T.,Kaufmann,R.,Cooper,K.,Knudsen,K.M.,Lisby,S.,Baadsgaard,O.,&Knox,S.J.(2007).Clinical efficacy of zanolimumab(HuMax-CD4):two phase 2 studies in refractory cutaneous T-cell lymphoma.Blood,109(11),4655-4662.https: / / ashpublications.org / blood / article / 109 / 11 / 4655 / 23083 / Clinical-efficacy-of-zanolimumab-HuMaxCD4-two Park,J.H.,Riviere,I.,Gonen,M.,Wang,X.,Senechal,B.,Curran,K.J.,Sauter,C.,Wang,Y.,Santomasso,B.,Mead,E.,Roshal,M.,Maslak,P.,Davila,M.,Brentjens,R.J.,&Sadelain,M.(2018).Long-Term Follow-up of CD19 CAR Therapy in Acute Lymphoblastic Leukemia.New England Journal of Medicine.https: / / doi.org / 10.1056 / nejmoa1709919 Rowan, AG, Suemori, K., Fujiwara, H., Yasukawa, M., Tanaka, Y., Taylor, GP, & Bangham, CRM (2014). Cytotoxic T lymphocyte lysis of HTLV-1 infected cells is limited by weak HBZ protein expression, but non-specifically enhanced on induction of Tax expression.Retrovirology,11(1),112-116.https: / / retrovirology.biomedcentral.com / articles / 10.1186 / s12977-014-0116-6 Terms 1. Mucosal-associated invariant T (MAIT) cells expressing chimeric antigen receptors (CARs).

[0329] 2. The MAIT cell of clause 1, wherein the CAR-MAIT cell expresses a CAR that targets the CD4 antigen on T cells.

[0330] 3. The MAIT cell of clause 2, wherein the CAR is specific for a CD4 antigen comprising an amino acid sequence substantially as set forth in SEQ ID NO:1, or a variant or fragment thereof.

[0331] 4. The MAIT cell of any one of clauses 1 to 3, expressing a CAR that targets a T cell receptor (TCR) beta chain variable region (Vβ) on a T cell, preferably any one of the Vβ regions shown in Table 1.

[0332] 5. The MAIT cell of clause 4, wherein the CAR targets multiple T cell receptor (TCR) β chain variable regions (Vβ) on the T cell, preferably the multiple Vβ regions are selected from the group of Vβ regions set out in Table 1, and optionally the multiple TCR Vβ regions are the same or different Vβ regions.

[0333] 6. The MAIT cell of clause 4 or clause 5, wherein the CAR targets one or more TCR Vβ regions on a T cell selected from the group consisting of the following Vβ regions: Vb 1, Vb 2, Vb 3, Vb 5.1, Vb 7.1, Vb 8, Vb 12, Vb 13.1, Vb 17 and Vb 20.

[0334] 7. The MAIT cell of any one of clauses 4 to 6, wherein the CAR is specific for a TCR Vβ region comprising an amino acid substantially as set out in SEQ ID NO:2, or a variant or fragment thereof.

[0335] 8. The MAIT cell of any one of clauses 1-7, wherein the CAR-MAIT cell comprises one or more coding sequences that allow the CAR-MAIT cell to be controllably or inducibly eliminated.

[0336] 9. The MAIT cell of clause 8, wherein the one or more coding sequences encode epidermal growth factor receptor (EGFR) or truncated epidermal growth factor receptor (tEGFR).

[0337] 10. The MAIT cell of clause 8 or 9, wherein the one or more coding sequences encode inducible caspase-9 (iC9).

[0338] 11. MAIT cells according to any one of clauses 1 to 10, isolated from human peripheral blood mononuclear cells (PBMCs) by magnetic activated cell sorting (MACS) and / or fluorescence activated cell sorting (FACS), more preferably by both MACS and FACS.

[0339] 12. A nucleic acid construct comprising a promoter operably linked to a first coding sequence encoding either an anti-CD4 chimeric antigen receptor (CAR) or an anti-T cell receptor (TCR) V-β CAR.

[0340] 13. The construct of clause 12, wherein the promoter is a PGK promoter, optionally wherein the promoter comprises a nucleotide sequence substantially as set out in SEQ ID NO:3, or a fragment or variant thereof.

[0341] 14. The construct of clause 12 or 13, wherein the first coding sequence encodes an anti-CD4 chimeric antigen receptor (CAR), optionally wherein the CAR is specific for a CD4 antigen comprising an amino acid sequence substantially as set forth in SEQ ID NO:1, or a variant or fragment thereof.

[0342] 15. (i) the first coding sequence comprises a nucleotide sequence encoding an amino acid sequence substantially as set forth in SEQ ID NO:6, or a fragment or variant thereof; (ii) the first coding sequence comprises a nucleotide sequence substantially as set forth in SEQ ID NO:7, or a fragment or variant thereof; (iii) the first coding sequence comprises a nucleotide sequence encoding an amino acid sequence substantially as set forth in SEQ ID NO:8, or a fragment or variant thereof; and / or (iv) the first coding sequence comprises a nucleotide sequence substantially as set forth in SEQ ID NO:9, or a fragment or variant thereof; A construct as described in clause 14.

[0343] 16. The construct of clause 12 or 13, wherein the first coding sequence encodes an anti-T cell receptor (TCR) V-β region CAR, optionally any of the Vβ regions listed in Table 1.

[0344] 17. The construct of clause 16, wherein the first coding sequence encodes a plurality of T cell receptor (TCR) β chain variable region (Vβ) CARs, preferably the plurality of Vβ regions are selected from the group of Vβ regions shown in Table 1.

[0345] 18. The construct of clause 16 or 17, comprising a coding sequence encoding at least one CAR that targets one or more TCR Vβ regions on a T cell selected from the group consisting of the following Vβ regions: Vb 1, Vb 2, Vb 3, Vb 5.1, Vb 7.1, Vb 8, Vb 12, Vb 13.1, Vb 17, and Vb 20, and optionally comprising a coding sequence encoding at least one CAR that targets at least two or three TCR Vβ regions on a T cell selected from the group consisting of the following Vβ regions: Vb 1, Vb 2, Vb 3, Vb 5.1, Vb 7.1, Vb 8, Vb 12, Vb 13.1, Vb 17, and Vb 20.

[0346] 19. The construct of any one of clauses 16 to 18, wherein the CAR is specific for a TCR Vβ region (preferably the TCR-Vβ7.1 chain) comprising an amino acid sequence substantially as set forth in SEQ ID NO:2, or a variant or fragment thereof.

[0347] 20. (i) the first coding sequence comprises a nucleotide sequence encoding an amino acid sequence substantially as set forth in SEQ ID NO: 12, or a fragment or variant thereof; (ii) the first coding sequence comprises a nucleotide sequence substantially as set forth in SEQ ID NO: 13, or a fragment or variant thereof; (iii) the first coding sequence comprises a nucleotide sequence encoding an amino acid sequence substantially as set forth in SEQ ID NO: 34, or a fragment or variant thereof; and / or (iv) the first coding sequence comprises a nucleotide sequence substantially as set forth in SEQ ID NO: 35, or a fragment or variant thereof; 20. The construct according to any one of clauses 16 to 19.

[0348] 21. The construct according to any one of clauses 12 to 20, comprising a nucleotide sequence encoding the CD8a hinge and transmembrane (TM) structural domain, and optionally comprising a nucleotide sequence encoding an amino acid sequence substantially as set out in SEQ ID NO: 14, or a fragment or variant thereof, and / or comprising a nucleotide sequence substantially as set out in SEQ ID NO: 15, or a fragment or variant thereof.

[0349] 22. The construct according to any one of clauses 12 to 21, comprising a nucleotide sequence encoding an intracellular domain comprising the signalling domain of CD28, the signalling domain of 4-1BB and / or the CD3 zeta chain, more preferably the signalling domain of CD28, the signalling domain of 4-1BB and the CD3 zeta chain.

[0350] twenty three. (i) the construct comprises a nucleotide sequence encoding an amino acid sequence substantially as set forth in SEQ ID NO: 16, or a fragment or variant thereof; (ii) the construct comprises a nucleotide sequence substantially as set forth in SEQ ID NO: 17, or a fragment or variant thereof; (iii) the construct comprises a nucleotide sequence encoding an amino acid sequence substantially as set forth in SEQ ID NO: 18, or a fragment or variant thereof; (iv) the construct comprises a nucleotide sequence substantially as set forth in SEQ ID NO: 19, or a fragment or variant thereof; (v) the construct comprises a nucleotide sequence encoding an amino acid sequence substantially as set forth in SEQ ID NO: 20, or a fragment or variant thereof; and / or (vi) the construct comprises a nucleotide sequence substantially as set forth in SEQ ID NO: 21, or a fragment or variant thereof; A construct as described in clause 22.

[0351] 24. The construct according to any one of clauses 12 to 23, wherein the nucleic acid construct comprises a second coding sequence encoding at least one suicide protein, more preferably at least two suicide proteins.

[0352] 25. The construct of clause 24, wherein the second coding sequence encodes (i) epidermal growth factor receptor (EGFR) or truncated epidermal growth factor receptor (tEGFR), and / or (ii) inducible caspase-9 (iC9).

[0353] 26. A construct according to clause 25, wherein (i) the construct comprises a nucleotide sequence encoding the amino acid sequence substantially as set out in SEQ ID NO: 22, or a fragment or variant thereof, and optionally comprises a nucleotide sequence substantially as set out in SEQ ID NO: 23, or a fragment or variant thereof, and / or (ii) the construct comprises a nucleotide sequence encoding the amino acid sequence substantially as set out in SEQ ID NO: 24, or a fragment or variant thereof, and optionally the construct comprises a nucleotide sequence substantially as set out in SEQ ID NO: 25, or a fragment or variant thereof.

[0354] 27. A construct according to any one of clauses 12 to 26, comprising a nucleotide sequence encoding the amino acid sequence substantially as set out in SEQ ID NO: 29, or a fragment or variant thereof, and optionally comprising a nucleotide sequence substantially as set out in SEQ ID NO: 30, or a fragment or variant thereof.

[0355] 28. A construct according to any one of clauses 12 to 26, comprising a nucleotide sequence encoding the amino acid sequence substantially as set out in SEQ ID NO: 31, or a fragment or variant thereof, and optionally comprising a nucleotide sequence substantially as set out in SEQ ID NO: 32, or a fragment or variant thereof.

[0356] 29. An expression vector encoding the nucleic acid construct of any one of clauses 12 to 28, optionally comprising a nucleic acid sequence substantially as set out in SEQ ID NO: 33 or 36, or a fragment or variant thereof.

[0357] 30. A method for isolating MAIT cells, comprising: (i) providing peripheral blood mononuclear cells (PBMCs); (ii) subjecting the PBMCs to magnetic activated cell sorting (MACS) and / or fluorescence activated cell sorting (FACS) to isolate MAIT cells therefrom; A method for isolating MAIT cells, comprising:

[0358] 31. A method for producing CAR-MAIT cells, comprising: (i) providing peripheral blood mononuclear cells (PBMCs); (ii) subjecting the PBMCs to MACS and / or FACS to isolate MAIT cells therefrom; (iii) activating the isolated MAIT cells, optionally by contacting them with an anti-CD3 antibody and / or an anti-CD28 antibody; (iv) transducing the activated MAIT cells with a nucleic acid encoding a CAR, thereby generating CAR-MAIT cells; A method for producing CAR-MAIT cells, comprising:

[0359] 32. The method of clause 30 or 31, wherein the method comprises subjecting PBMCs to both MACS and FACS to isolate MAIT cells therefrom, optionally subjecting PBMCs to MACS and subsequently to FACS.

[0360] 33. The method of any one of clauses 30 to 32, wherein the isolated MAIT cells are activated with an anti-CD3 antibody and an anti-CD28 antibody.

[0361] 34. The method of any one of clauses 31-33, wherein step (iv) comprises virally or retrovirally transducing the MAIT cell with a nucleic acid encoding a CAR, preferably wherein the nucleic acid encodes a CAR that targets (i) the CD4 antigen, or (ii) at least one or more TCR Vβ regions on a T cell, preferably one or more TCR Vβ regions as set out in Table 1, or one or more TCR Vβ regions on a T cell selected from the group consisting of the following Vβ regions: Vb 1, Vb 2, Vb 3, Vb 5.1, Vb 7.1, Vb 8, Vb 12, Vb 13.1, Vb 17, and Vb 20.

[0362] 35. The method according to any one of clauses 30 to 43, wherein MAIT cells are transduced with a nucleic acid construct according to any one of claims 12 to 28 or with an expression vector according to claim 29.

[0363] 36. The method of any one of clauses 30 to 35, wherein the method comprises expanding the CAR-MAIT cells in a subsequent step after step (iv).

[0364] 37. A CAR-MAIT cell obtained or obtainable by the method according to any one of clauses 30 to 36.

[0365] 38. A pharmaceutical composition comprising the MAIT cells according to any one of clauses 1 to 11 or 37, and a pharma- ceutically acceptable excipient.

[0366] 39. A MAIT cell according to any one of clauses 1 to 11 or 37, or a pharmaceutical composition according to clause 38, for use in therapy.

[0367] 40. MAIT cells according to any one of clauses 1 to 11 or 37 or the pharmaceutical composition according to clause 38 for use in (i) immunotherapy, (ii) for the treatment, prevention or amelioration of cancer, (ii) for the treatment, prevention or amelioration of a microbial infection, or (iv) for the treatment, prevention or amelioration of an autoimmune disease.

[0368] 41. A MAIT cell according to any one of clauses 1 to 11 or clause 37 or a pharmaceutical composition according to clause 38 for use according to any one of clauses 39 or clause 40 in the treatment, prevention or amelioration of a T-cell malignancy, optionally a solid or liquid tumour.

[0369] 42. A MAIT cell according to any one of clauses 1 to 11 or 37, or a pharmaceutical composition according to clause 38, for use according to clause 41, wherein the T-cell malignancy is peripheral T-cell lymphoma (PTCL) or cutaneous T-cell lymphoma (CTCL).

[0370] 43. (i) The PTCL is a PTCL subtype selected from the group consisting of adult T-cell acute lymphoblastic lymphoma or leukemia (ATL); enteropathy-associated lymphoma; hepatosplenic lymphoma; subcutaneous panniculitis-like T-cell lymphoma (SPTCL); precursor T-cell acute lymphoblastic lymphoma or leukemia; and angioimmunoblastic T-cell lymphoma (AITL); (ii) the CTCL is a CTCL subtype selected from the group consisting of mycosis fungoides (MF); Sézary syndrome (SS); and CD4+ small-medium polymorphic T-cell lymphoproliferative disorder; The MAIT cell of any one of clauses 1 to 11 or 37 or the pharmaceutical composition of clause 38 for use as defined in clause 41.

[0371] 44. MAIT cells according to any one of clauses 1 to 11 or 37, or the pharmaceutical composition according to clause 38, for use according to any one of clauses 40 to 43 for treating, preventing or ameliorating a viral (e.g. HIV, HBV, HTLV, EBV, HPV), bacterial (e.g. TB) or fungal infection, or for treating, preventing or ameliorating an autoimmune disease, such as systemic lupus erythematosus, rheumatoid arthritis or myasthenia gravis.

[0372] 45. A MAIT cell according to any one of clauses 1 to 11 or 37, or a pharmaceutical composition according to clause 38, for use according to any one of clauses 40 to 44, wherein the use comprises triggering a sequence encoding a suicide protein, and optionally the method comprises administering to the subject an anti-EGFR antibody and / or a caspase-inducing drug (CID).

[0373] 46. ​​A process for producing a pharmaceutical composition as described in clause 38, comprising combining a therapeutically effective amount of MAIT cells as described in any one of clauses 1-11 or clause 37 with a pharma- ceutically acceptable excipient.

Claims

1. A mucosal-associated invariant T (MAIT) cell comprising a nucleic acid construct comprising a promoter operably linked to a first coding sequence encoding an anti-T cell receptor (TCR) V-β chimeric antigen receptor (CAR), or an expression vector encoding said nucleic acid construct.

2. (i) the promoter is a constitutive promoter, an activatable promoter, an inducible promoter, or a tissue-specific promoter; (ii) the promoter is a cytomegalovirus (CMV) promoter, a human elongation factor-1 alpha (hEFla), a ubiquitin C promoter (UbiC), a phosphoglycerokinase promoter (PGK), a simian virus 40 early promoter (SV40), or a chicken β-actin promoter (CAGG) coupled with a CMV early enhancer; (iii) the promoter is a PGK promoter, optionally wherein the promoter comprises a nucleotide sequence as set forth in SEQ ID NO:3, or a fragment or variant thereof having greater than 70% sequence identity to SEQ ID NO:3; (iv) the first coding sequence encodes an anti-T cell receptor (TCR) V-β region CAR, optionally any of the Vβ regions listed in Table 1; and / or (v) the first coding sequence encodes a plurality of T cell receptor (TCR) beta chain variable region (Vβ) CARs, and the plurality of Vβ regions may be selected from the group of Vβ regions shown in Table 1. (i) the construct comprises a coding sequence encoding at least one CAR that targets one or more TCR Vβ regions on a T cell selected from the group consisting of the following Vβ regions: Vb 1, Vb 2, Vb 3, Vb 5.1, Vb 7.1, Vb 8, Vb 12, Vb 13.1, Vb 17, and Vb 20; and / or wherein the construct comprises a coding sequence encoding at least one CAR that targets at least two or three TCR Vβ regions on a T cell selected from the group consisting of the following Vβ regions: Vb 1, Vb 2, Vb 3, Vb 5.1, Vb 7.1, Vb 8, Vb 12, Vb 13.1, Vb 17, and Vb 20; and / or (ii) The MAIT cell of claim 1, wherein the CAR is specific for a TCR-Vβ7.1 chain comprising the amino acid sequence shown in SEQ ID NO:2, or a functional variant or fragment having more than 70% sequence identity with SEQ ID NO:

2. (i) the first coding sequence comprises a nucleotide sequence encoding the amino acid sequence set forth in SEQ ID NO:12, or a functional fragment or variant having greater than 70% sequence identity to SEQ ID NO:12, and / or the first coding sequence comprises a nucleotide sequence set forth in SEQ ID NO:13, or a fragment or variant having greater than 70% sequence identity to SEQ ID NO:13; and / or (ii) the first coding sequence comprises a nucleotide sequence encoding the amino acid sequence set forth in SEQ ID NO: 34, or a functional fragment or variant having greater than 70% sequence identity to SEQ ID NO: 34, and / or the first coding sequence comprises a nucleotide sequence encoding the nucleotide sequence set forth in SEQ ID NO: 35, or a fragment or variant having greater than 70% sequence identity to SEQ ID NO:

35. The MAIT cell of claim 1, (i) comprising a nucleotide sequence encoding a CD8a hinge and transmembrane (TM) structural domain; The construct may comprise a nucleotide sequence encoding the amino acid sequence set forth in SEQ ID NO: 14, or a functional fragment or variant having greater than 70% sequence identity to SEQ ID NO: 14, and / or the construct may comprise a nucleotide sequence encoding the nucleotide sequence set forth in SEQ ID NO: 15, or a fragment or variant having greater than 70% sequence identity to SEQ ID NO: 15; (ii) the construct comprises a nucleotide sequence encoding an intracellular domain comprising the signaling domain of CD28, the signaling domain of 4-1BB and / or the CD3 zeta chain, more preferably the signaling domain of CD28, the signaling domain of 4-1BB and the CD3 zeta chain; The construct may comprise a nucleotide sequence encoding the amino acid sequence set forth in SEQ ID NO: 16, or a functional fragment or variant having greater than 70% sequence identity to SEQ ID NO: 16, and / or the construct may comprise a nucleotide sequence encoding the nucleotide sequence set forth in SEQ ID NO: 17, or a fragment or variant having greater than 70% sequence identity to SEQ ID NO: 17; (iii) the construct comprises a nucleotide sequence encoding the amino acid sequence set forth in SEQ ID NO: 18, or a functional fragment or variant having greater than 70% sequence identity to SEQ ID NO: 18, and / or the construct comprises a nucleotide sequence set forth in SEQ ID NO: 19, or a functional fragment or variant having greater than 70% sequence identity to SEQ ID NO: 19; (iv) The MAIT cell of claim 1, wherein the construct comprises a nucleotide sequence encoding the amino acid sequence set forth in SEQ ID NO: 20, or a functional fragment or variant having greater than 70% sequence identity to SEQ ID NO: 20, and / or the construct comprises a nucleotide sequence set forth in SEQ ID NO: 21, or a fragment or variant having greater than 70% sequence identity to SEQ ID NO:

21. (i) the nucleic acid construct comprises at least one suicide protein or a second coding sequence encoding at least two suicide proteins; The second coding sequence may encode (i) epidermal growth factor receptor (EGFR) or truncated epidermal growth factor receptor (tEGFR), and / or (ii) inducible caspase-9 (iC9); (ii) The MAIT cell of claim 1, encoding (i) epidermal growth factor receptor (EGFR) or truncated epidermal growth factor receptor (tEGFR), and (ii) inducible caspase-9 (iC9).

7. (i) the construct comprises a nucleotide sequence encoding the amino acid sequence set forth in SEQ ID NO:22, or a functional fragment or variant having greater than 70% sequence identity to SEQ ID NO:22, and / or the construct comprises a nucleotide sequence set forth in SEQ ID NO:23, or a fragment or variant having greater than 70% sequence identity to SEQ ID NO:23; and / or (ii) The MAIT cell of claim 1, wherein the construct comprises a nucleotide sequence encoding the amino acid sequence set forth in SEQ ID NO:24, or a functional fragment or variant having greater than 70% sequence identity to SEQ ID NO:24, and / or the construct comprises a nucleotide sequence encoding the nucleotide sequence set forth in SEQ ID NO:25, or a fragment or variant having greater than 70% sequence identity to SEQ ID NO:

25. (i) the construct comprises a nucleotide sequence encoding the amino acid sequence set forth in SEQ ID NO:31, or a functional fragment or variant having greater than 70% sequence identity to SEQ ID NO:31; (ii) the construct comprises the nucleotide sequence set forth in SEQ ID NO: 32, or a fragment or variant having greater than 70% sequence identity to SEQ ID NO: 32; and / or (iii) The MAIT cell of claim 1, comprising a nucleic acid sequence as set forth in SEQ ID NO: 36, or a fragment or variant having greater than 70% sequence identity to SEQ ID NO:

36.

9. A pharmaceutical composition comprising the MAIT cells of claim 1 and a pharma- ceutically acceptable excipient.

10. The MAIT cell according to any one of claims 1 to 8, or the pharmaceutical composition according to claim 9, for use in therapy.

11. The MAIT cell of any one of claims 1 to 8, or the pharmaceutical composition of claim 9, for use in (i) immunotherapy, (ii) for treating, preventing or ameliorating cancer, (ii) for treating, preventing or ameliorating microbial infection, or (iv) for treating, preventing or ameliorating an autoimmune disease.

12. MAIT cells according to any one of claims 1 to 8 or a pharmaceutical composition according to claim 9 for use according to claim 10 in the treatment, prevention or amelioration of a T-cell malignancy, optionally a solid or liquid tumor, The T-cell malignancy may be peripheral T-cell lymphoma (PTCL) or cutaneous T-cell lymphoma (CTCL); and / or (i) the PTCL may be a PTCL subtype selected from the group consisting of: adult T-cell acute lymphoblastic lymphoma or leukemia (ATL); enteropathy-associated lymphoma; hepatosplenic lymphoma; subcutaneous panniculitis-like T-cell lymphoma (SPTCL); precursor T-cell acute lymphoblastic lymphoma or leukemia; and angioimmunoblastic T-cell lymphoma (AITL); and / or (ii) The CTCL may be a CTCL subtype selected from the group consisting of mycosis fungoides (MF); Sézary syndrome (SS); and CD4+ small-medium polymorphic T-cell lymphoproliferative disorder.

13. The MAIT cell of any one of claims 1 to 8 or the pharmaceutical composition of claim 9 for use as claimed in claim 11 for treating, preventing or ameliorating (i) a viral infection, optionally HIV, HBV, HTLV, EBV or HPV, (ii) a bacterial infection, optionally TB, or (iii) a fungal infection, or for treating, preventing or ameliorating an autoimmune disease, such as systemic lupus erythematosus, rheumatoid arthritis or myasthenia gravis.

14. The MAIT cell of any one of claims 1 to 8 or the pharmaceutical composition of claim 9 for use according to claim 11, wherein the use comprises inducing a sequence encoding a suicide protein, and optionally the method comprises administering an anti-EGFR antibody and / or a caspase-inducing drug (CID) to the subject.

15. A process for producing the pharmaceutical composition of claim 9, comprising combining a therapeutically effective amount of the MAIT cells of any one of claims 1 to 8 with a pharma- ceutical acceptable excipient.

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