POLYPEPTIDES

Abstract

It provides, among other things, a polypeptide comprising an IL-23-binding immunoglobulin chain variable domain, wherein the immunoglobulin chain variable domain comprises three complementarity determination regions (CDR1-CDR3) and four framework regions (FR1-FR4), wherein CDR1 comprises a sequence that shares 60% or more sequence identity with SEQ ID NO:1, CDR2 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO:2, and CDR3 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO:3.

Description

POLYPEPTIDES FIELD OF THE INVENTION The present invention relates to polypeptides comprising an immunoglobulin chain variable domain (or ICVD) that binds interleukin-23 (IL-23), as well as to constructs and pharmaceutical compositions comprising these polypeptides. The present invention also relates to nucleic acids encoding said polypeptides, to methods for preparing said polypeptides, to cDNAs and vectors comprising nucleic acids encoding said polypeptides, to host cells that express or are capable of expressing such polypeptides and to uses of such polypeptides, pharmaceutical compositions or constructs. BACKGROUND OF THE INVENTION IL-23 is a pleiotropic cytokine that has roles in regulating both physiology and pathology. IL-23 has functions associated with inflammation and immunoregulation and is considered important for the spread of chronic inflammation and associated pathologies in autoimmune diseases, including inflammatory bowel disease (IBD, e.g. Crohn's disease (CD) and ulcerative colitis (UC) (Croxford et al, 2012; Teng et al, 2015: Furfaro et al, 2017)). In patients with Eli, IL-23 production increases at sites of intestinal inflammation. IL-23 orchestrates inflammation through direct effects on pathogenic T cells; IL-23 enhances the activation of intraepithelial lymphocytes of ELI and NK cells and stimulates the production of proinflammatory cytokines by innate lymphoid cells (Eken et al, 2014). IL-23 is a heterodimeric cytokine within the IL-12 family of cytokines. IL-23 and IL-12 share a common p40 subunit, which dimerizes with a ligand-specific IL-23p19 subunit (also known as p19, IL-23A, and interleukin-23 alpha subunit) to form IL-23 or with IL12p35 to form IL-12. The results of preclinical studies in different models of inflammatory bowel disease clearly demonstrate that IL-23 promotes inflammation and intestinal pathology. Although structurally related to IL-12, studies with IL-23-specific neutralizing antibodies in these models have revealed that IL-23 and IL-12 have divergent functions in mucosal and systemic immune responses and that selective depletion of IL-23 can nullify intestinal inflammation while sparing systemic immune responses. Anti-TNF monoclonal antibodies have transformed the treatment of Crohn's disease and ulcerative colitis. By neutralizing TNF activity, antibodies such as infliximab and adalimumab promote mucosal healing and induce long-term remissions in many patients. However, approximately one-third of patients prescribed an anti-TNF agent are primary non-responders. Among primary responders, subsequent loss of response can vary between 10 and 50% per year (secondary nonresponse) (Colombel et al. 2007; Hanauer et al. 2002, 2006; Sandborn et al. 2007; Schreiber et al. 2007). Patients with primary non-response are unlikely to benefit from switching to a second anti-TNF agent; Consequently, therapeutic strategies targeting other inflammatory pathways are needed. The above suggests that IL-23 could be a therapeutic target for the treatment of ILD and also provides a rationale for local rather than systemic administration (McGovern and Powrie, 2007). Furthermore, such an agent could provide an effective treatment for ILD in circumstances where anti-TNF antibodies have failed. Documents WO2007005955 and WO2007027714 describe anti-IL23p19 antibodies. Recently, the efficacy and safety of brazikumab (AMG-139), a fully human IgG2 monoclonal antibody that selectively binds to the p19 subunit of IL-23, was investigated in patients with active CD who did not respond to or did not tolerate anti-inflammatory therapy. -TNFa (Sandborn et al 2018, Sands et al 2017). The superiority of many polypeptides of the invention over brazikumab is demonstrated in examples 2 and 5 below. Another state-of-the-art anti-IL-23 agent is 37D5, which is an anti-IL-23p19 (VHH) domain antibody (Desmyter et al 2017). The superiority of many polypeptides of the invention over 37D5 is demonstrated in Example 5 below. The polypeptides of the present invention may, at least in some embodiments, have one or more of the following advantages compared to prior art anti-IL-23 substances: (i) higher affinity for IL-23; (ii) higher specificity for IL-23; (iii) greater neutralization capacity against IL-23; (iv) greater specificity for IL-23 over IL-12; (v) increased cross-reactivity with IL-23 from different species such as humans and cynomolgus monkeys; (vi) reduced immunogenicity, for example when administered to a mouse, cynomolgus monkey or human; (vii) increased stability in the presence of proteases, for example (a) in the presence of proteases found in the small and / or large intestine and / or inflammatory proteases of Eli, for example, trypsin, chymotrypsin, MMP3, MMP10, MMP12 , other MMPs and cathepsin and / or (b) in the presence of proteases from intestinal commensal microflora and / or pathogenic bacteria, n / crzn / zznz / q / υιλι secreted and / or actively released by lysis of microbial cells found in the small intestine and / or thick; (viii) greater stability to protease degradation during production (e.g. resistance to yeast proteases) (ix) greater suitability for oral administration; (x) greater suitability for local administration in the intestinal tract and lamina propria after oral administration; (xi) greater suitability for expression, in a heterologous host such as bacteria such as Escherichia coli, or a yeast belonging to the genera Aspergillus, Saccharomyces, Kluyveromyces, Hansenula or Pichia, such as Saccharomyces cerevisiae or Pichia pastoris, (xii ) suitability and improved properties for use in a pharmaceutical product; (xiii) suitability and improved properties for use in a functional food; (xiv) improved tissue penetration such as penetration of the epithelium of the inflamed colonic mucosa and submucosal tissues to access the submucosal lamina propria; (xv) decreased immunogenicity in humans, for example, due to increased sequence similarity to human immunoglobulins; (xvi) greater suitability for formatting in a multispecific format; (xvii) binding to new epitopes. The advantages (i) to (xvii) above can potentially be realized by the polypeptides of the present invention in a monovalent format or in a multivalent format such as a bihead format (for example, homobihead or heterobihead formats). BRIEF DESCRIPTION OF THE INVENTION The present inventors have produced surprisingly suitable polypeptides comprising immunoglobulin chain variable domains that bind IL-23. These polypeptides are the immunoglobulin chain variable domains ID-L253T, 10E2, 10G10 and polypeptides related to each of these immunoglobulin chain variable domains. These polypeptides have been found to have unexpected advantages over the prior art anti-IL-23 agents brazikumab and 37D5 (see, in particular, the background section above and examples 2 and 5 below). These particular polypeptides benefit from surprisingly high potency. They are also able to cross-react with cynomolgus monkey IL-23 and remain stable upon exposure to small and large intestinal proteases. In one embodiment, these polypeptides have undergone further improvement by engineering. These improved polypeptides benefit from the above advantages, retain their IL-23 neutralizing activity during passage through the intestinal tract and further resist degradation and / or inactivation by intestinal tract proteases, for example. for example, digestive, inflammatory and microbial proteases from, for example, mammalian species. These polypeptides may be expected to have particular utility in the prevention or treatment of autoimmune and / or inflammatory diseases such as inflammatory bowel disease (for example, Crohn's disease or ulcerative colitis), or in the prevention or treatment of mucositis, particularly when administered orally. Many polypeptides of the invention have been found to have superior properties compared to brazikumab, a fully human IgG2 monoclonal antibody that selectively binds to the p19 subunit of IL-23 that has been investigated in patients with active CD who have not responded or were intolerant to anti-TNFa therapy. The superiority of many polypeptides of the invention over brazikumab is demonstrated in examples 2 and 5 below. Many polypeptides of the invention have also been found to have superior properties compared to 37D5, which is an anti-IL23p19 (VHH) domain antibody (Desmyter et al 2017). The superiority of many polypeptides of the invention over 37D5 is demonstrated in Example 5 below. In particular embodiments, the present inventors have provided the above polypeptides in a bihead format together with an anti-TNF-alpha polypeptide. The data provided herein illustrate that a therapeutic approach combining gastrointestinal tract-restricted antagonism of IL-23 and TNF-alpha can achieve a higher degree of efficacy, for a longer duration, in a greater proportion of patients with inflammatory bowel disease. , than monotherapy against any target alone. In one aspect, the present invention provides a polypeptide comprising an immunoglobulin chain variable domain that binds IL-23, wherein the immunoglobulin chain variable domain comprises three complementarity determining regions (CDR1-CDR3) and four framework regions (FR1-FR4), wherein CDR1 comprises a sequence that shares 60% or more sequence identity with SEQ ID NO: 1, CDR2 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO: 2 and CDR3 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO: 3. In another aspect, the present invention provides a polypeptide comprising an immunoglobulin chain variable domain that binds IL-23, wherein the immunoglobulin chain variable domain comprises three complementarity determining regions (CDR1-CDR3) and four framework regions (FR1-FR4), wherein CDR1 comprises a sequence that shares 60% or more sequence identity with SEQ n / crzn / zznz / q / υιλι ID NO: 14 CDR2 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO: 15 and CDR3 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO: 16. In another aspect, the present invention provides a polypeptide comprising an immunoglobulin chain variable domain that binds IL-23, wherein the immunoglobulin chain variable domain comprises three complementarity determining regions (CDR1-CDR3) and four framework regions (FR1-FR4), wherein CDR1 comprises a sequence that shares 60% or more sequence identity with SEQ ID NO: 22 CDR2 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO: 23 and CDR3 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO: 24. In another aspect, the invention provides a construct comprising two or more identical polypeptides according to the invention. In another aspect, the invention provides a construct comprising at least one polypeptide according to the invention and at least one different polypeptide, wherein the different polypeptide binds TNF-alpha. In another aspect, the invention provides a construct comprising at least one polypeptide according to the invention and at least one different polypeptide, wherein the different polypeptide binds to a target other than TNF-alpha. Other aspects of the invention are described elsewhere in this document. DESCRIPTION OF THE FIGURES Figure 1 – Average phospho-intensity values ​​for ex vivo UC-inflamed colon mucosa tissue treated with ID-L210T. Figure 2 – Average phospho-intensity values ​​for ex vivo UC-inflamed colon mucosa tissue treated with ID-L210T (continued). Figure 3 - Neutralizing potency of FA1K (pre- and post-trypsin cleavage) against TNF-alpha. Figure 4 - Neutralizing potency of FA1K (pre- and post-trypsin cleavage) against IL-23. Figure 5 - Stability of the original FA1K monomers ID-38F and ID-L253T after incubation for 4 hours in human fecal supernatant. Figure 6 – Average phospho-intensity values ​​for ex vivo UC-inflamed colon mucosa tissue treated with ID-L210T and ID-38F. Figure 7 – Average phosphorus intensity values ​​for ex vivo UC-inflamed colon mucosa tissue treated with ID-L210T and ID-38F (continued). DESCRIPTION OF THE SEQUENCES SEQ ID NO: 1 - ID-L253T CDR1 polypeptide sequence SEQ ID NO: 2 - ID-L253T CDR2 polypeptide sequence SEQ ID NO: 3 - ID-L253T CDR3 polypeptide sequence SEQ ID NO: 4 - ID-L253T FR1 polypeptide sequence SEQ ID NO: 5 - ID-L253T FR2 polypeptide sequence SEQ ID NO: 6 - ID-L253T FR3 polypeptide sequence SEQ ID NO: 7 - ID-L253T FR4 polypeptide sequence SEQ ID NO: 8 - Polypeptide sequence of ID-L253T SEQ ID NO: 9 - Polynucleotide sequence that encodes ID-L253T (with stop codons) SEQ ID NO: 10 - Polynucleotide sequence that encodes ID-L253T (without stop codons) SEQ ID NO: 11 - 12G1 polypeptide sequence SEQ ID NO: 12 - 1E2 polypeptide sequence SEQ ID NO: 13 - 10E2 polypeptide sequence SEQ ID NO: 14 - 10E2 CDR1 polypeptide sequence SEQ ID NO: 15 - 10E2 CDR2 polypeptide sequence SEQ ID NO: 16 - 10E2 CDR3 polypeptide sequence SEQ ID NO: 17 - Polypeptide sequence of 10E2 FR1 SEQ ID NO: 18 - 10E2 FR2 polypeptide sequence SEQ ID NO: 19 - Polypeptide sequence of 10E2 FR3 SEQ ID NO: 20 - Polypeptide sequence of 10E2 FR4 SEQ ID NO: 21 - 10G10 polypeptide sequence SEQ ID NO: 22 - 10G10 CDR1 polypeptide sequence SEQ ID NO: 23 - 10G10 CDR2 polypeptide sequence SEQ ID NO: 24 - 10G10 CDR3 polypeptide sequence SEQ ID NO: 25 - Polypeptide sequence of 10G10 FR1 SEQ ID NO: 26 - Polypeptide sequence of 10G10 FR2 SEQ ID NO: 27 - Polypeptide sequence of 10G10 FR3 SEQ ID NO: 28 - Polypeptide sequence of 10G10 FR4 SEQ ID NO: 29 - ID-L210T polypeptide sequence SEQ ID NO: 30 - Polypeptide sequence of ID-L237T SEQ ID NO: 31 - Polypeptide sequence of ID-L238T SEQ ID NO: 32 - Polypeptide sequence of ID-L239T SEQ ID NO: 33 - ID-L240T polypeptide sequence SEQ ID NO: SEQ ID NO: SEQ ID NO: SEQ ID NO: 34 - Polypeptide sequence of ID-L241T 35 - Polypeptide sequence of ID-L242T 36 - Polypeptide sequence of ID-L243T 37 - Polypeptide sequence of ID -L244T 5 SEQ ID NO: 38 - Polypeptide sequence of ID-L245T SEQ ID NO: 39 - Polypeptide sequence of ID-L246T SEQ ID NO: 40 - Polypeptide sequence of ID-L247T SEQ ID NO: 41 - Sequence of polypeptides of ID-L248T SEQ ID NO: 42 - Polypeptide sequence of ID-L249T 10 SEQ ID NO: 43 - Polypeptide sequence of ID-L250T SEQ ID NO: 44 - Polypeptide sequence of ID-L251T SEQ ID NO: 45 - Polypeptide sequence of ID-L252T SEQ ID NO: 46 - Polypeptide sequence of FA1K SEQ ID NO: 47 - Arm polypeptide sequence of ID-38F in FA1K 15 SEQ ID NO: 48 - Arm polypeptide sequence of ID -L253T in FA1K SEQ ID NO: 49 - Labile linker polypeptide sequence in FA1K SEQ ID NO: 50 - Polynucleotide sequence encoding ID-L210T SEQ ID NO: 51 - Polynucleotide sequence encoding ID-L237T SEQ ID NO: 52 - Polynucleotide sequence encoding ID-L238T 20 SEQ ID NO: 53 - Polynucleotide sequence encoding ID-L239T SEQ ID NO: 54 - Polynucleotide sequence encoding ID-L240T SEQ ID NO: 55 - Polynucleotide sequence encoding ID-L241T SEQ ID NO: 56 - Polynucleotide sequence encoding ID-L242T SEQ ID NO: 57 - Polynucleotide sequence encoding ID-L243T 25 SEQ ID NO: 58 - Polynucleotide sequence encoding encodes ID-L244T SEQ ID NO: 59 - Polynucleotide sequence encoding ID-L245T SEQ ID NO: 60 - Polynucleotide sequence encoding ID-L246T SEQ ID NO: 61 - Polynucleotide sequence encoding ID-L247T SEQ ID NO: 62 - Polynucleotide sequence encoding ID-L248T SEQ ID NO: 63 - Polynucleotide sequence encoding ID-L249T SEQ ID NO: 64 - Polynucleotide sequence encoding ID-L250T SEQ ID NO: 65 - Polynucleotide sequence encoding ID-L251T SEQ ID NO: 66 - Polynucleotide sequence encoding ID-L252T SEQ ID NO: 67 - Polypeptide sequence of ID-38F 35 SEQ ID NO: 68 - Polynucleotide sequence of 3' primer containing Spe site SEQ ID NO: 69 - Polypeptide sequence of 37D5 SEQ ID NO: 70 - Brazikumab heavy chain SEQ ID NO: 71 - Brazikumab light chain SEQ ID NO: 72 - IL-23p19 polypeptide sequence SEQ ID NO: 73 - IL-23p40 polypeptide sequence SEQ ID NO: 74 - Polypeptide sequence of a protease-labile linker formula SEQ ID NO: 75 - Polypeptide sequence of a protease-labile linker SEQ ID NO: 76 - Polypeptide sequence of a non-protease labile linker formula SEQ ID NO: 77 - Polypeptide sequence of a non-protease-labile linker DETAILED DESCRIPTION OF THE INVENTION Polypeptides including antibodies and antibody fragments including VH and VHH A conventional antibody or immunoglobulin (Ig) is a protein that comprises four polypeptide chains: two heavy chains (H) and two light chains (L). Each string is divided into a constant region and a variable domain. Heavy chain variable domains are abbreviated here as VHC, and light chain (L) variable domains are abbreviated here as VLC. These domains, domains related thereto and domains derived therefrom, are referred to herein as immunoglobulin chain variable domains. The HCV and VLC domains can be subdivided into regions of hypervariability, called complementarity determining regions (CDRs), interspersed with regions that are more conserved, called framework regions (FRs). The framework and complementarity determination regions have been precisely defined (Kabat et al 1991). In a conventional antibody, each VHC and VLC is composed of three CDRs and four FRs, arranged from the amino terminus to the carboxy terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. The conventional antibody tetramer of two heavy immunoglobulin chains and two light immunoglobulin chains is formed with the interconnected heavy and light immunoglobulin chains, for example, disulfide bonds and the similarity of the connected heavy chains. The heavy chain constant region includes three domains, CH1, CH2, and CH3. The constant region of the light chain is composed of one domain, CL. The heavy chain variable domain and the light chain variable domain are binding domains that interact with an antigen. Constant regions of antibodies typically mediate binding of the antibody to host tissues or factors, including various cells of the immune system (e.g., effector cells) and the first component (C1q) of the classical complement system. The term antibody includes immunoglobulins of the IgA, IgG, IgE, IgD, IgM type (as well as subtypes thereof), in which the light chains of the immunoglobulin may be of the kappa or lambda type. The general structure of immunoglobulin gamma (IgG) antibodies assembled from two identical heavy chain (H) and two identical light chain (L) polypeptides is well established and highly conserved in mammals (Padlan 1994). An exception to the conventional antibody structure is found in Camelidae sera. In addition to conventional antibodies, these sera have special IgG antibodies. These IgG antibodies, known as heavy chain antibodies (HCAb), lack the L chain polypeptide and lack the first constant domain (CH1). In its N-terminal region, the H chain of the homodimeric protein contains a dedicated immunoglobulin chain variable domain, termed VHH, which serves to associate with its cognate antigen (Muyldermans 2013, Hamers-Casterman et al 1993, Muyldermans et al 1994 ). An antigen-binding fragment (or antibody fragment or immunoglobulin fragment) as used herein refers to a portion of an antibody that specifically binds to IL-23 (for example, a molecule where one or more immunoglobulin chains are not full length), but it specifically binds to IL-23). Examples of binding fragments included in the term antigen-binding fragment include: (i) a Fab fragment (a monovalent fragment consisting of the VLC, VHC, CLyCHI domains); (i) an F(ab')2 fragment (a bivalent fragment comprising two Fab fragments linked by a disulfide bridge in the hinge region); (iii) an Fd fragment (consisting of the HCV and CH1 domains); (iv) an Fv fragment (consisting of the VLC and HCV domains of a single arm of an antibody); (v) an scFv fragment (consisting of VLC and HCV domains linked, by recombinant methods, by a synthetic linker that allows them to form a single protein chain where the VLC and HCV regions pair to form monovalent molecules); (vi) a VH (an immunoglobulin chain variable domain consisting of a VHC domain (Ward et al 1989); (vii) a VL (an immunoglobulin chain variable domain consisting of a VLC domain); (viii) a V-NAR (an immunoglobulin chain variable domain consisting of a HCV domain of chondrichthyan IgNAR (Roux et al 1998 and Griffiths et al 2013) (ix) a VHH. The total number of amino acid residues in a VHH or VH may be in the region of 110-130, is suitably 115-125 and is more suitably 121. The immunoglobulin chain variable domains of the invention can be obtained, for example, by preparing a nucleic acid encoding an immunoglobulin chain variable domain using techniques for nucleic acid synthesis, followed by expression of the immunoglobulin chain variable domain. nucleic acid thus obtained. According to a specific embodiment, a variable domain of the immunoglobulin chain of the invention does not have an amino acid sequence that is exactly the same (i.e., shares 100% sequence identity with) the amino acid sequence of a polypeptide of natural origin such as a VH or VHH domain of a naturally occurring antibody. The examples provided herein refer to immunoglobulin chain variable domains per se that bind IL-23. However, the principles of the invention described here are equally applicable to any polypeptide comprising an immunoglobulin chain variable domain that binds IL-23, such as antibodies and antibody fragments. For example, the anti-IL-23 immunoglobulin chain variable domains described herein can be incorporated into a polypeptide such as a full-length antibody. McCoy et al 2014 demonstrate such an approach, providing an anti-HIV VHH engineered as a fusion with a human Fe region (including the hinge, CH2, and CH3 domains), expressed as a dimer construct. The replacement of at least one amino acid residue in the flanking region of a non-human immunoglobulin variable domain with the corresponding residue of a human variable domain is humanization. Humanization of a variable domain may reduce immunogenicity in humans. Suitably, the polypeptide of the present invention comprises an immunoglobulin chain variable domain. More suitably, the polypeptide of the present invention consists of an immunoglobulin chain variable domain, such as an immunoglobulin heavy chain variable domain. Suitably, the polypeptide of the present invention is an antibody or an antibody fragment. More suitably, the polypeptide of the present invention is an antibody fragment. Suitably, the antibody fragment is an immunoglobulin chain variable domain such as a VHH, a VH or a VL. Suitably, the antibody fragment is a VHH, a VH, a VL, a V-NAR, a scFv, a Fab fragment or an F(ab')2 fragment. Suitably, the antibody fragment is an immunoglobulin heavy chain variable domain. More suitably, the antibody fragment is a VHH or VH, and more suitably a VHH. Specificity, affinity, avidity and cross-reactivity Specificity refers to the number of different types of antigens or antigenic determinants to which a particular antigen-binding polypeptide can bind. The specificity of an antigen-binding polypeptide is the ability of the antigen-binding polypeptide to recognize a particular antigen as a unique molecular entity and distinguish it from another. Affinity, represented by the equilibrium constant for the dissociation of an antigen with an antigen-binding polypeptide (Kd), is a measure of the binding strength between an antigenic determinant and an antigen-binding site on the binding polypeptide. to antigen: the lower the Kd value, the stronger the binding strength between an antigenic determinant and the antigen-binding polypeptide (such as alternatively, affinity can also be expressed as the affinity constant (Ka), which is 1 / Kd). Affinity can be determined by known methods, depending on the specific antigen of interest. Suitably, affinity is determined using a dynamically switchable biosurface (e.g. switchSENSE®, see Knezevic et al 2012) or by surface plasmon resonance. Avidity is the measure of the binding strength between an antigen-binding polypeptide and the relevant antigen. Avidity is related to both the affinity between an antigenic determinant and its antigen-binding site on the antigen-binding polypeptide and the number of relevant binding sites present on the antigen-binding polypeptide. Suitably, the polypeptide of the invention will bind to IL-23 with a dissociation constant (Kd) of 10.6M or less, more suitably 10.7M or less, more suitably 10-8M or less, more suitably 10- 9M or less, more suitably 10'10M or less, more suitably 10-11M or less, more suitably 10-12M or less, more suitably 10-13M or less. Any Kd value less than 10'6M is considered to indicate union. The specific binding of an antigen-binding polypeptide to an antigen or antigenic determinant can be determined in any suitable known manner, including, for example, Scatchard assays and / or competitive binding assays, such as radioimmunoassays (RIAs), enzyme immunoassays ( EIA) and sandwich competition tests, and the different variants thereof known in the art. Suitably, the affinity of the polypeptide is determined by surface plasmon resonance. In one embodiment, the affinity of the polypeptide is established at 25°C by amine coupling of an α-p40 capture antibody to a 10 mM sodium n / crzn / zznz / q / υιλι acetate buffer, pH 5. , to a sensor chip. IL-23 is then immobilized on the chip by flowing 2 pg / mL or 0.5 pg / mL at 10 pL / min for 60 seconds. This leaves the P19 subunit free to bind to the polypeptide. The test polypeptides are then added for 300 seconds and 300 seconds at 30 pl / min in five different concentrations between 0.0195 and 5 nM (L253T) or 0.8 to 500 nM (Brazikumab Fab preparation) at pH 7.4, 0.01 M HEPES, 0.15 NaCl M, 0.05% polysorbate 20 and 3 mM EDTA pH regulator. Bound anti-P40 is regenerated between cycles with 10 mM glycine, pH 2 at 10 μl / min for 60 seconds. This methodology was used in example 5.2 below. An anti-IL-23 polypeptide, an IL-23-interacting polypeptide, or an anti-IL-23 polypeptide are all polypeptides that effectively bind IL-23. A polypeptide of the invention may bind to a linear or conformational epitope on IL-23. Suitably, the polypeptide of the invention binds to human IL-23. More suitably, the polypeptide of the invention will bind both human IL-23 and at least one additional primate IL-23 selected from the group consisting of baboon IL-23, marmoset IL-23, cynomolgus and rhesus IL-23. More suitably, the polypeptide of the invention binds to both human and cynomolgus IL-23. Suitably, the polypeptide of the invention neutralizes human IL-23. More suitably, the polypeptide of the invention will neutralize IL-23 from both human and at least one additional primate selected from the group consisting of baboon IL-23, marmoset IL-23, cynomolgus IL-23 and rhesus. More suitably, the polypeptide of the invention neutralizes both human and cynomolgus IL-23. Suitably, IL-23 is a polypeptide comprising SEQ ID NO: 72 (p19 subunit) and 73 (p40 subunit), more suitably IL-23 is a polypeptide consisting of SEQ ID NO: 72 and 73. Suitably , IL-23p19 is a polypeptide comprising SEQ ID NO: 72. More suitably, IL-23p19 is a polypeptide consisting of SEQ ID NO: 72. The p19 and p40 subunits used in the following examples also incorporated a single C-tag terminal 6xHis each. Polypeptides capable of reacting with human IL-23 and IL-23 from another species (cross-reacting), such as with cynomolgus monkey IL-23, are advantageous because they allow preclinical studies to be performed more easily in animal models. Suitably, the polypeptide of the invention is directed against the epitopes of IL-23 that are found in and / or form part of the binding sites of the IL-23 receptor, so that said polypeptide of the invention, By binding to IL-23, it is capable of inhibiting or reducing the cross-linking of the IL-23 receptor that is mediated by said IL-23 and / or the signal transduction that is mediated by said cross-linking of the receptor. The polypeptides of the present invention bind to one or more epitopes on IL-23. In n / crzn / zznz / q / υιλι one aspect of the invention, a polypeptide is provided that binds to the same epitope on IL23 as ID-L253T, 12G1, 1E2, 10E2 or 10G10; more appropriately ID-L253T. The mention of “IL-23” throughout the description may also be replaced with “p19” as appropriate, since the polypeptide of the invention is expected to be specific for the p19 subunit of IL-23. Suitably, the polypeptide of the invention is isolated. An isolated polypeptide is one that is removed from its original environment. For example, a naturally occurring polypeptide of the invention is isolated if it is separated from some or all of the coexisting materials in the natural system. Potency, inhibition and neutralization Potency is a measure of the activity of a therapeutic agent expressed in terms of the amount required to produce an effect of a given intensity. A very potent agent elicits a greater response at low concentrations compared to a less potent agent that elicits a lesser response at low concentrations. Potency is a function of affinity and effectiveness. Efficacy refers to the ability of the therapeutic agent to produce a biological response upon binding to a target ligand and the quantitative magnitude of this response. The term half-maximal effective concentration (EC50) refers to the concentration of a therapeutic agent that elicits a response halfway between baseline and maximum after a specified exposure time. The therapeutic agent may cause inhibition or stimulation. It is commonly used, and is used here, just as a measure of power. A neutralizing polypeptide for the purposes of the invention is a polypeptide that binds IL-23, inhibiting the binding of IL-23 to its cognate receptor (IL-23R) as measured by ELISA, such as the ELISA described in Examples, Method evaluation A. Suitably, the polypeptide of the invention neutralizes human IL-23 in the IL-23-IL-23R neutralization ELISA (see Examples, Evaluation Method A) with an EC50 of 5 nM or less, such as 4 nM or less, such as 3 nM or less, such as 2 nM or less, such as 1.7 nM or less, such as 1.5 nM or less, such as 1.4 nM or less, such as 1.3 nM or less, such as 1.2 nM or less, such as 1.1 nM or less, such as 1.0 nM or less, such as 0.9 nM or less, such as 0.8 nM or less, such as 0.75 nM or less, such as 0.70 nM or less, such as 0.65 nM or less, such as 0.60 nM or less, such as 0.55 nM or less, such as 0.50 nM or less, such as 0.45 nM or less, such as 0.40 nM or less. Polypeptide and polynucleotide sequences In order to compare two closely related polypeptide sequences, % sequence identity between a first polypeptide sequence and a second polypeptide sequence can be calculated using NCBI BLAST v2.0, using the standard settings for polypeptide sequences (BLASTP). . In order to compare two closely related polynucleotide sequences, % sequence identity between a first nucleotide sequence and a second nucleotide sequence can be calculated using NCBI BLAST v2.0, using standard settings for nucleotide sequences (BLASTN). . The BLAST algorithm parameters W, T, and X determine the sensitivity and speed of the alignment. The BLASTN program (for nucleotide sequences) uses by default a word length (W) of 11, an expectation (E) or 10, M=5, N=-4 and a comparison of both strings. For amino acid sequences, the BLASTP program uses by default a word length of 3, an expectation (E) of 10, and the BLOSUM62 scoring matrix (see Henikoff & Henikoff, Proc. Nati. Acad. Sci. USA 89:10915 (1989)) alignments (B) of 50, expectation (E) of 10, M-5, N-4 and a comparison of both strands. The BLAST algorithm also performs a statistical analysis of the similarity between two sequences (see, for example, Karlin & Altschul, Proc. Nati. Acad. Sci. USA 90:5873-5787 (1993)). A measure of similarity provided by the BLAST algorithm is the smallest sum probability (P(N)), which provides an indication of the probability by which a match between two nucleotide or amino acid sequences would occur by chance. For example, a nucleic acid is considered similar to a reference sequence if the probability of the smallest sum in a comparison of the test nucleic acid with the reference nucleic acid is less than about 0.2, more suitably less than about 0.01, and more suitably less than about 0.001. Polypeptide or polynucleotide sequences are said to be the same or identical to other polypeptide or polynucleotide sequences if they share 100% sequence identity along their entire length. Residues in the sequences are numbered from left to right, that is, from N- to C-terminal for polypeptides; from 5' to 3' terminal for polynucleotides. A difference between sequences refers to an insertion, deletion or substitution of a single amino acid residue at a position in the second sequence, compared to the first sequence. Two polypeptide sequences may contain one, two or more such amino acid differences. Insertions, deletions, or substitutions in a second sequence that is otherwise identical (100% sequence identity) to a first sequence result in a reduced % sequence identity. For example, if identical sequences are 9 amino acid residues long, a substitution in the second sequence results in a sequence identity of 88.9%. If identical sequences are 17 amino acid residues long, two substitutions in the second sequence result in 88.2% sequence identity. If the identical sequences are 7 amino acid residues long, three substitutions in the second sequence result in a sequence identity of 57.1%. If the first and second polypeptide sequences are 9 amino acid residues long and share 6 identical residues, the first and second polypeptide sequences share greater than 66% identity (the first and second polypeptide sequences share 66.7% identity ). If the first and second polypeptide sequences are 17 amino acid residues long and share 16 identical residues, the first and second polypeptide sequences share greater than 94% identity (the first and second polypeptide sequences share 94.1% identity ). If the first and second polypeptide sequences are 7 amino acid residues long and share 3 identical residues, the first and second polypeptide sequences share greater than 42% identity (the first and second polypeptide sequences share 42.9% identity ). Alternatively, in order to compare a first reference polypeptide sequence with a second comparison polypeptide sequence, the number of additions, substitutions and / or deletions made to the first sequence to produce the second sequence can be determined. An addition is the addition of an amino acid residue in the sequence of the first polypeptide (including the addition at either end of the first polypeptide). A substitution is the replacement of an amino acid residue in the sequence of the first polypeptide with a different amino acid residue. A deletion is the deletion of an amino acid residue from the sequence of the first polypeptide (including a deletion at either end of the first polypeptide). In order to compare a first reference polynucleotide sequence with a second comparison polynucleotide sequence, the number of additions, substitutions and / or deletions made to the first sequence to produce the second sequence can be determined. An addition is the addition of a nucleotide residue in the sequence of the first polynucleotide (including the addition at either end of the first polynucleotide). A substitution is the replacement of a nucleotide residue in the sequence of the first polynucleotide with a different nucleotide residue. A deletion is the deletion of a nucleotide residue from the sequence of the first polynucleotide (including a deletion at either end of the first polynucleotide). A conservative amino acid substitution is an amino acid substitution where one amino acid residue is replaced with another amino acid residue of similar chemical structure and which is expected to have little influence on the function, activity or other biological properties of the polypeptide. Such conservative substitutions are n / crzn / zznz / q / υιλι appropriately substitutions in which an amino acid within the following groups is replaced by another amino acid residue within the same group: Group Amino acid residue Aliphatic non-polar Glycine Alanine Valine Leucine Isoleucine Aromatic Phenylalanine Tyrosine Tryptophan Polar discharged Serine Threonine Asparagine Glutamine Negatively charged Aspartate Glutamate Positively charged Lysine Arginine Suitably, a hydrophobic amino acid residue is a non-polar amino acid. More suitably, a hydrophobic amino acid residue is selected from V, I, L, M, F, Wo C. As used herein, polypeptide sequence numbering and CDR and FR definitions are defined according to the Kabat system (Kabat et al 1991). A corresponding amino acid residue between a first and a second polypeptide sequence is an amino acid residue in a first sequence that shares the same position according to the Kabat system with an amino acid residue in a second sequence, while the amino acid residue in the second sequence it may differ in identity from the first. Properly corresponding residues will share the same number (and letter) if the frame and CDRs have the same length according to Kabat's definition. Alignment can be achieved manually or using, for example, a known computer algorithm for sequence alignment such as NCBI BLAST v2.0 (BLASTP or BLASTN) using standard settings. Suitably, the polynucleotides used in the present invention are isolated. An isolated polynucleotide is one that is removed from its original environment. For example, a naturally occurring polynucleotide is isolated if it is separated from some or all of the coexisting materials in the natural system. A polynucleotide is considered isolated if, for example, it is cloned in a vector that is not part of its natural environment or if it is included in cDNA. In one aspect of the invention, a polynucleotide encoding the polypeptide of the invention is provided. Suitably, the polynucleotide comprises or consists of a sequence that is shared by 70% or more, such as 80% or more, such as 90% or more, such as 95% or more, such as 99% or more. further, sequence identity with SEQ ID NOs: 9, 10 or 50 to 66. More suitably, the polynucleotide comprises or consists of any of SEQ ID NOs: 9, 10 or 50 to 66. In another aspect, a cDNA is provided comprising said polynucleotide. In one aspect of the invention, there is provided a polynucleotide comprising or consisting of a sequence that is shared by 70% or more, such as 80% or more, such as 90% or more, such as 95% or more, such as 99% or more sequence identity with any of the portions of SEQ ID NOs: 9, 10 or 50 to 66 encoding CDR1, CDR2 or CDR3 of the encoded immunoglobulin chain variable domain. Suitably, the polypeptide sequence of the present invention contains at least one alteration with respect to a native sequence. Suitably, the polynucleotide sequences of the present invention contain at least one alteration with respect to a native sequence. Suitably, alteration of the polypeptide sequence or polynucleotide sequence is carried out to increase the stability of the encoded polypeptide or polypeptide against proteases present in the intestinal tract (for example, trypsin and chymotrypsin). Embodiments related to the particular polypeptide sequences of the invention are described below. ID-L253T and related polypeptides The polypeptide sequence of ID-L253T in Kabat format The polypeptide sequence of ID-L253T, a particularly advantageous polypeptide of the invention, is set forth below in Kabat format. CDR1 (SEQ ID NO: 1) is labeled 'CDR-HT, CDR2 (SEQ ID NO: 2) is labeled 'CDR-H2' and CDR3 (SEQ ID NO: 3) is labeled 'CDR-H3'. The top row provides the Kabat numbering of each polypeptide residue (prefixed with Ή'), the middle row provides the polypeptide residues, and the bottom row provides the sequential numbering of each polypeptide residue. H1 H2 H3 H4 H5 H6 H7 H8 H9 H10 Hll H12 H13 H14 H15 H16 H17 H18 H19 H20 D V Q L V E S G G G Q V Q P G G S L S L 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 CDR-H1 H21 H22 H23 H24 H25 H26 H27 H28 H29 H30 H31 H32 H33 H34 H35 H36 H37 H38 H39 H40 S C E 5 5 V 5 I W 5 F K V M G W F R Q V 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 CDR-H2 H41 H42 H43 H44 H45 H46 H47 H48 H49 H50 H51 H52 H53 H54 H55 H56 H57 H58 H59 H60 P G K Q R E L V A T I T T G G S P D Y S 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 CDR-H2 H61 H62 H63 H64 H65 H66 H67 H68 H69 H70 H71 H72 H73 H74 H75 H76 H77 H78 H79 H80 D S V K G R F T I S R D Y D K R T L Y L 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 CDR-H3 H81 H82 H82A H82B H82C H83 H84 H85 H86 H87 H88 H89 H90 H91 H92 H93 H94 H95 H96 H97 Q M N S L K P E D T A V Y Y C A G R L W 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 CDR-H3 H98 H99 H100 H100A H100B H100C H100D H100E H101 H102 H103 H104 H105 H106 H107 A H I T S 5 G H D V W G Q G T 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 H108 H109 H110 Hlll H112 H113 Q. V T V 5 5 116 117 118 119 120 121 CDRs of ID-L253T and related polypeptides Suitably, CDR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence that shares 80% or more sequence identity with SEQ ID NO: 1. Alternatively, CDR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 2, more suitably no more than 1 addition(s) compared to SEQ ID NO: 1. Suitably, CDR1 of the The polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 2, more suitably no more than 1 substitution(s) compared to SEQ ID NO: 1. Suitably, the CDR1 of the polypeptide of the present invention The invention comprises or more suitably consists of a sequence having no more than 2, more suitably no more than 1 deletion(s) compared to SEQ ID NO: 1. Suitably, any CDR1 residues that differ from their corresponding residues in SEQ ID NO: 1 are conservative substitutions with respect to their corresponding residues. Suitably, CDR1 comprises or more suitably consists of SEQ ID NO: 1. Suitably, the CDR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence that shares 55% or more, more suitably 60% or more, more suitably 70% or more, more suitably 75% or more, more suitably 80% or more, more suitably 85% or more, more suitably 90% or more sequence identity, with SEQ ID NO: 2. Alternatively, the CDR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 8, more suitably no more than 7, more suitably no more than 6, more suitably no more than 5, more suitably no more than 4, more suitably no more than 3, more suitably no more than 2, more suitably no more than 1 addition(s) compared to SEQ ID NO: 2. Suitably, the CDR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 8, most suitably no more than 7, most suitably no more than 6, most suitably no more than 5, most suitably no more than 4, most suitably no more than 3, more suitably no more than 2, more suitably no more than 1 substitution(s) compared to SEQ ID NO: 2. Suitably, the CDR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 8, most suitably no more than 7, most suitably no more than 6, most suitably no more than 5, most suitably no more than 4, most suitably no more than 3, most suitably no more than 2, most suitably no more than 1 deletion(s) compared to SEQ ID NO: 2. Suitably, any CDR2 residues that differ from their corresponding residues in SEQ ID NO: 2 are conservative substitutions with respect to their corresponding residues. Suitably, the CDR2 residue corresponding to residue number 9 of SEQ ID NO: 2 is D or H. Suitably, the CDR2 residue corresponding to residue number 10 of SEQ ID NO: 2 is Y or D. Suitable, the CDR2 residue corresponding to residue number 11 of SEQ ID NO: 2 is S, G, R or A (more suitably S, R or A, more suitably S or A). Suitably, the CDR2 residue corresponding to residue number 14 of SEQ ID NO: 2 is V or A. Suitably, the CDR2 residue corresponding to residue number 9 of SEQ ID NO: 2 is D or H; the CDR2 residue corresponding to residue number 10 of SEQ ID NO: 2 is Y or D; the CDR2 residue corresponding to residue number 11 of SEQ ID NO: 2 is S, G, R or A (more suitably S, R or A, more suitably S or A) and the CDR2 residue corresponding to residue number 14 of SEQ ID NO: 2 is V or A. Suitably, CDR2 comprises or more suitably consists of SEQ ID NO: 2. Suitably, the CDR3 of the polypeptide of the present invention comprises or more suitably consists of a sequence that shares 60% or more, more suitably 65% ​​or more, more suitably 75% or more, more suitably 80% or more, more suitably 90% or more sequence identity with SEQ ID NO: 3. Alternatively, the CDR3 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 3, more suitably no more than 2, more suitably no more than 1 addition(s) as compared to SEQ ID NO: 3. Suitably, CDR3 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 3, more suitably no more than 2, more suitably no more than 1 substitution(s) as compared to SEQ ID NO: 3. Suitably, CDR3 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 3, more suitably no more than 2, more suitably no more than 1 deletion compared to SEQ ID NO : 3. Suitably, any substitutions are conservative, with respect to their corresponding residues in SEQ ID NO: 3. Suitably, any CDR3 residues that differ from their corresponding residues in SEQ ID NO: 3 are conservative substitutions with respect to their corresponding residues. Suitably, the CDR3 residue corresponding to residue number 6 of SEQ ID NO: 3 is I or L. Suitably (a) the CDR2 residue corresponding to residue number 9 of SEQ ID NO: 2 is D or H; the CDR2 residue corresponding to residue number 10 of SEQ ID NO: 2 is Y or D; the CDR2 residue corresponding to residue number 11 of SEQ ID NO: 2 is S, G, R or A (more suitably S, R or A, more suitably S or A) and the CDR2 residue corresponding to residue number 14 of SEQ ID NO: 2 is V or A and (b) the CDR3 residue corresponding to residue number 6 of SEQ ID NO: 3 is I or L. FRs of ID-L253T and related polypeptides Suitably, the FR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence sharing 5%, 12%, 18%, 26%, 32%, 38%, 46%, 52%, 58%, 62 %, 66%, 68%, 72%, 75%, 78%, 82%, 85%, 90%, 95% or greater sequence identity, with SEQ ID NO: 4. Alternatively, the FR1 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 28, more suitably no more than 26, more suitably no more than 24, more suitably no more than 22, more suitably no more than 20, more conveniently not more than 18, more conveniently not more than 16, more conveniently not more than 14, more conveniently not more than 13, more conveniently not more than 12, more conveniently not more than 11, more conveniently not more of 10, most conveniently not more than 9, most conveniently not more than 8, most conveniently not more than 7, most conveniently not more than 6, most conveniently not more than 5, most conveniently not more than 4, most conveniently not more than 3, more suitably no more than 2, more suitably no more than 1 addition(s) compared to SEQ ID NO: 4. Suitably, the FR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 28, more suitably no more than 26, more suitably no more than 24, more suitably no more than 22, more suitably no more than 20, more suitably no more than 18, more suitably no more than 16, more suitably no more than 14, more suitably no more than 13, more suitably no more than 12, more suitably no more than 11, more suitably no more than 10, more suitably no more than 9, more suitably no more than 8, more suitably no more of 7, more suitably no more than 6, more suitably no more than 5, more suitably no more than 4, more suitably no more than 3, more suitably no more than 2, more suitably no more than 1 substitution(s) in comparison with SEQ ID NO: 4. Suitably, the FR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 28, more suitably no more than 26, more suitably no more than 24, most suitably no more than 22, more suitably no more than 20, more suitably no more than 18, more suitably no more than 16, more suitably no more than 14, more suitably no more than 13, more suitably no more than 12, more suitably no more than 11, most conveniently no more than 10, most conveniently no more than 9, most conveniently no more than 8, most conveniently no more than 7, most conveniently no more than 6, most conveniently no more than 5, most conveniently no more of 4, most suitably no more than 3, most suitably no more than 2, most suitably no more than 1 deletion(s) compared to SEQ ID NO: 4. Suitably, any FR1 residues that differ from their corresponding residues in SEQ ID NO: 4 are conservative substitutions with respect to their corresponding residues. Suitably, the FR1 residue corresponding to residue number 1 of SEQ ID NO: 4 is D or E. Suitably, the FR1 residue corresponding to residue number 11 of SEQ ID NO: 4 is Q or L. Suitably, the residue of FR1 corresponding to residue number 19 of SEQ ID NO: 4 is S or R. Suitably, the residue of FR1 corresponding to residue number 23 of SEQ ID NO: 4 is E or A. Suitably , the residue of FR1 corresponding to residue number 24 of SEQ ID NO: 4 is S or A. Suitably, the residue of FR1 corresponding to residue number 1 of SEQ ID NO: 4 is D or E; the residue of FR1 corresponding to residue number 11 of SEQ ID NO: 4 is Q or L; the residue of FR1 corresponding to residue number 19 of SEQ ID NO: 4 is S or R; the residue of FR1 corresponding to residue number 23 of SEQ ID NO: 4 is E or A and the residue of FR1 corresponding to residue number 24 of SEQ ID NO: 4 is S or A. Suitably, FR1 comprises or more suitably consists of SEQ ID NO: 4. Suitably, FR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence sharing 10%, 15%, 25%, 30%, 40%, 45%, 55%, 60%, 70%, 75% , 85%, 90% or more sequence identity, with SEQ ID NO: 5. Alternatively, FR2 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 13, more suitably no more than 12, more suitably no more than 11, more suitably no more than 10, more suitably no more of 9, most conveniently not more than 8, most conveniently not more than 7, most conveniently not more than 6, most conveniently not more than 5, most conveniently not more than 4, most conveniently not more than 3, most conveniently not more than 2, more suitably no more than 1 addition compared to SEQ ID NO: 5. Suitably, the FR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 13, more suitably no more than 12, most conveniently no more than 11, most conveniently no more than 10, most conveniently no more than 9, most conveniently no more than 8, most conveniently no more than 7, most conveniently no more than 6, most conveniently no more than 5 , more suitably no more than 4, more suitably no more than 3, more suitably no more than 2, more suitably no more than 1 substitution(s) compared to SEQ ID NO: 5. Suitably, the FR2 of the polypeptide of The present invention comprises or more suitably consists of a sequence having no more than 13, more suitably no more than 12, more suitably no more than 11, more suitably no more than 10, more suitably no more than 9, most suitably no more of 8, most suitably no more than 7, most suitably no more than 6, most suitably no more than 5, most suitably no more than 4, most suitably no more than 3, most suitably no more than 2, most suitably no more than 1 deletion(s) compared to SEQ ID NO: 5. Suitably, any FR2 residues that differ from their corresponding residues in SEQ ID NO: 5 are conservative substitutions with respect to their corresponding residues. Suitably, the FR2 residue corresponding to residue number 2 of SEQ ID NO: 5 is F or Y. Suitably, the FR2 residue corresponding to residue number 5 of SEQ ID NO: 5 is V or A. Suitably, the residue of FR2 corresponding to residue number 8 of SEQ ID NO: 5 is K or H. Suitably, the residue of FR2 corresponding to residue number 9 of SEQ ID NO: 5 is Q or E. Suitably , the residue of FR2 corresponding to residue number 10 of SEQ ID NO: 5 is R or L. Suitably, the residue of FR2 corresponding to residue number 12 of SEQ ID NO: 5 is L or F. Suitably, the residue of FR2 corresponding to residue number 2 of SEQ ID NO: 5 is F or Y; the residue of FR2 corresponding to residue number 5 of SEQ ID NO: 5 is V or A; the FR2 residue corresponding to residue number 8 of SEQ ID NO: 5 is K or H; the residue of FR2 corresponding to residue number 9 of SEQ ID NO: 5 is Q or E; the FR2 residue corresponding to residue number 10 of SEQ ID NO: 5 is R or L and the FR2 residue corresponding to residue number 12 of SEQ ID NO: 5 is L or F. Suitably, the FR3 of the polypeptide of the present invention comprises or more suitably consists of a sequence sharing 8%, 15%, 20%, 26%, 32%, 40%, 45%, 52%, 58%, 65 %, 70%, 76%, 80%, 82%, 85%, 90%, 92%, 95% or greater sequence identity, with SEQ ID NO: 6. Alternatively, the FR3 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 29, more suitably no more than 27, more suitably no more than 25, more suitably no more than 23, more suitably no more than 21, more conveniently not more than 19, more conveniently not more than 17, more conveniently not more than 15, more conveniently not more than 13, more conveniently not more than 11, more conveniently not more than 9, more conveniently not more of 7, most conveniently not more than 6, most conveniently not more than 5, most conveniently not more than 4, most conveniently not more than 3, most conveniently not more than 2, most conveniently not more than 1 addition(s) in comparison with SEQ ID NO: 6. Suitably, the FR3 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 29, more suitably no more than 27, more suitably no more than 25, more suitably no more than 23, more suitably no more than 21, more suitably no more than 19, more suitably no more than 17, more suitably no more than 15, more suitably no more than 13, more suitably no more than 11, more suitably no more than 9, more suitably no more than 7, more suitably no more than 6, more suitably no more than 5, more suitably no more than 4, more suitably no more than 3, more suitably no more than 2, more suitably no more of 1 substitution(s) compared to SEQ ID NO: 6. Suitably, the FR3 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 29, more suitably no more than 27, more suitably no more than 25, more suitably no more than 23, more suitably no more than 21, more suitably no more than 19, more suitably no more than 17, more suitably no more than 15, more suitably no more than 13, more conveniently no more than 11, most conveniently no more than 9, most conveniently no more than 7, most conveniently no more than 6, most conveniently no more than 5, most conveniently no more than 4, most conveniently no more than 3, most conveniently no more than 2, more conveniently no more than 1 deletion(s) compared to SEQ ID NO: 6. Suitably, the FR3 residue corresponding to residue number 4 of SEQ ID NO: 6 is I, L or M (more suitably I or M). Suitably, the FR3 residue corresponding to residue number 13 of SEQ ID NO: 6 is L or V. Suitably, the FR3 residue corresponding to residue number 14 of SEQ ID NO: 6 is Y or F. Suitably, the residue of FR3 corresponding to residue number 16 of SEQ ID NO: 6 is Q or E. Suitably, the residue of FR3 corresponding to residue number 18 of SEQ ID NO: 6 is N or D. Suitably , the FR3 residue corresponding to residue number 20 of SEQ ID NO: 6 is L or V. Suitably, the FR3 residue corresponding to residue number 22 of SEQ ID NO: 6 is P or S. Suitably, the residue of FR3 corresponding to residue number 25 of SEQ ID NO: 6 is T or A. Suitably, the residue of FR3 corresponding to residue number 27 of SEQ ID NO: 6 is V or R. Suitably, the residue of FR3 corresponding to residue number 31 of SEQ ID NO: 6 is A or N. Suitably, the FR3 residue corresponding to residue number 4 of SEQ ID NO: 6 is I, L or M (more suitably I or M); the FR3 residue corresponding to residue number 13 of SEQ ID NO: 6 is L or V; the FR3 residue corresponding to residue number 14 of SEQ ID NO: 6 is Y or F; the FR3 residue corresponding to residue number 16 of SEQ ID NO: 6esQoE; the residue of FR3 corresponding to residue number 18 of SEQ ID NO: 6 is N or D; the FR3 residue corresponding to residue number 20 of SEQ ID NO: 6 is L or V; the FR3 residue corresponding to residue number 22 of SEQ ID NO: 6 is P or S; the FR3 residue corresponding to residue number 25 of SEQ ID NO: 6 is T or A; the FR3 residue corresponding to residue number 27 of SEQ ID NO: 6 is V or R and the FR3 residue corresponding to residue number 31 of SEQ ID NO: 6 is A or N. Suitably, any FR3 residues that differ from their corresponding residues in SEQ ID NO: 6 are conservative substitutions with respect to their corresponding residues. Suitably, FR3 comprises or more suitably consists of SEQ ID NO: 6. Suitably, the FR4 of the polypeptide of the present invention comprises or more suitably consists of a sequence sharing 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90 % or greater sequence identity, with SEQ ID NO: 7. Alternatively, the FR4 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 10, more suitably no more than 9, more suitably no more than 8, more suitably no more than 7, more suitably no more than 6, more conveniently not more than 5, more conveniently not more than 4, more conveniently not more than 3, more conveniently not more than 2, more conveniently not more than 1 addition(s) compared to SEQ ID NO: 7 Suitably, the FR4 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 10, more suitably no more than 9, more suitably no more than 8, more suitably no more than 7, more suitably suitably not more than 6, most suitably not more than 5, most suitably not more than 4, most suitably not more than 3, most suitably not more than 2, most suitably not more than 1 substitution(s) compared to SEQ ID NO : 7. Suitably, the FR4 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 10, more suitably no more than 9, more suitably no more than 8, more suitably no more than 7 , most suitably no more than 6, most suitably no more than 5, most suitably no more than 4, most suitably no more than 3, most suitably no more than 2, most suitably no more than 1 deletion(s) compared to SEQ ID NO: 7. Suitably, any FR4 residues that differ from their corresponding residues in SEQ ID NO: 7 are conservative substitutions with respect to their corresponding residues. Suitably, FR4 comprises or more suitably consists of SEQ ID NO: 7. Suitably, the FR4 residue corresponding to residue number 6 of SEQ ID NO: 7 is Q or R. Full-length sequences of ID-L253T and related polypeptides Suitably, the polypeptide of the present invention more suitably comprises or consists of a sequence that shares 50% or more, more suitably 55% or more, more suitably 60% or more, more suitably 65% ​​or more, more suitably 70% or more, more suitably 75% or more, more suitably 80% or more, more suitably 85% or more, more suitably 90% or more, more suitably 95% or more, more suitably 96% or more, more suitably 97% or more, more suitably 98% or more, more suitably 99% or more sequence identity, with SEQ ID NO: 8. Alternatively, the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 20, more suitably no more than 15, more suitably no more than 10, more suitably no more than 9, more suitably no more than 8, most conveniently not more than 7, most conveniently not more than 6, most conveniently not more than 5, most conveniently not more than 4, most conveniently not more than 3, most conveniently not more than 2, most conveniently not more than 1 addition(s) compared to SEQ ID NO: 8. Suitably, the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 20, more suitably no more than 15, more suitably no more than 10, most suitably no more than 9, most suitably no more than 8, most suitably no more than 7, most suitably no more than 6, most suitably no more than 5, most suitably no more than 4, most suitably no more than 3 , more suitably no more than 2, more suitably no more than 1 substitution(s) compared to SEQ ID NO: 8. Suitably, the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 20, most suitably no more than 15, most suitably no more than 10, most suitably no more than 9, most suitably no more than 8, most suitably no more than 7, most suitably no more than 6, most suitably no more than 5 , most conveniently not more than 4, most conveniently not more than 3, most conveniently not more than 2, most conveniently not more than 1 deletion(s) compared to SEQ ID NO: 8. Suitably, the N terminus of the polypeptide is D. Suitably, the polypeptide comprises or more suitably consists of SEQ ID NO: 8. 10E2 and related polypeptides CDRs of 10E2 and related polypeptides Suitably, the CDR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence that shares 80% or more sequence identity with SEQ ID NO: 14. Alternatively, the CDR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 2, more suitably no more than 1 addition(s) compared to SEQ ID NO: 14. Suitably, the CDR1 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 2, more suitably no more than 1 substitution(s) compared to SEQ ID NO: 14. Suitably, the CDR1 of the polypeptide of the present invention The present invention comprises or more suitably consists of a sequence having no more than 2, more suitably no more than 1 deletion(s) compared to SEQ ID NO: 14. Suitably, any CDR1 residues that differ from their corresponding residues in SEQ ID NO: 14 are conservative substitutions with respect to their corresponding residues. Suitably, CDR1 comprises or more suitably consists of SEQ ID NO: 14. Suitably, the CDR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence that shares 55% or more, more suitably 60% or more, more suitably 70% or more, more suitably 75% or more, more suitably 80% or more, more suitably 85% or more, more suitably 90% or more sequence identity, with SEQ ID NO: 15. Alternatively, the CDR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 8, more suitably no more than 7, more suitably no more than 6, more suitably no more than 5, more suitably no more than 4, more suitably no more than 3, more suitably no more than 2, more suitably no more than 1 addition(s) compared to SEQ ID NO: 15. Suitably, the CDR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 8, most suitably no more than 7, most suitably no more than 6, most suitably no more than 5, most suitably no more than 4, most suitably no more than 3, more suitably no more than 2, more suitably no more than 1 substitution(s) compared to SEQ ID NO: 15. Suitably, the CDR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 8, most suitably not more than 7, most suitably not more than 6, most suitably not more than 5, most suitably not more than 4, most suitably not more than 3, most suitably not more than 2, most suitably not more than 1 deletion(s) compared to SEQ ID NO: 15. Suitably, any CDR2 residues that differ from their corresponding residues in SEQ ID NO: 15 are conservative substitutions with respect to their corresponding residues. Suitably, CDR2 comprises or more suitably consists of SEQ ID NO: 15. Suitably, the CDR3 of the polypeptide of the present invention comprises or more suitably consists of a sequence that shares 60% or more, more suitably 65% ​​or more, more suitably 75% or more, more suitably 80% or more, more suitably 90% or more sequence identity with SEQ ID NO: 16. Alternatively, the CDR3 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 3, more suitably no more than 2, more suitably no more than 1 addition(s) as compared to SEQ ID NO: 16. Suitably, the CDR3 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 3, more suitably no more than 2, more suitably no more than 1 substitution(s) as compared to SEQ ID NO: 16. Suitably, the CDR3 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 3, more suitably no more than 2, more suitably no more than 1 deletion compared to SEQ ID NO: 16. Suitably, any substitutions are conservative, with respect to their corresponding residues in SEQ ID NO: 16. Suitably, any CDR3 residues that differ from their corresponding residues in SEQ ID NO: 16 are conservative substitutions with respect to their corresponding residues. FRs of 10E2 and related polypeptides Suitably, the FR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence sharing 5%, 12%, 18%, 26%, 32%, 38%, 46%, 52%, 58%, 62 %, 66%, 68%, 72%, 75%, 78%, 82%, 85%, 90%, 95% or greater sequence identity, with SEQ ID NO: 17. Alternatively, the FR1 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 28, more suitably no more than 26, more suitably no more than 24, more suitably no more than 22, more suitably no more than 20, more conveniently not more than 18, more conveniently not more than 16, more conveniently not more than 14, more conveniently not more than 13, more conveniently not more than 12, more conveniently not more than 11, more conveniently not more of 10, most conveniently not more than 9, most conveniently not more than 8, most conveniently not more than 7, most conveniently not more than 6, most conveniently not more than 5, most conveniently not more than 4, most conveniently not more than 3, more conveniently no more than 2, more conveniently no more than 1 addition(s) compared to SEQ ID NO: 17. Suitably, the FR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 28, more suitably no more than 26, more suitably no more than 24, more suitably no more than 22, more suitably no more than 20, more suitably no more than 18, more suitably no more than 16, more suitably no more than 14, more suitably no more than 13, more suitably no more than 12, more suitably no more than 11, more suitably no more than 10, more suitably no more than 9, more suitably no more than 8, more suitably no more of 7, more suitably no more than 6, more suitably no more than 5, more suitably no more than 4, more suitably no more than 3, more suitably no more than 2, more suitably no more than 1 substitution(s) in comparison with SEQ ID NO: 17. Suitably, the FR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 28, more suitably no more than 26, more suitably no more than 24, most suitably not more than 22, more conveniently not conveniently not conveniently not more than 20, more more than 16, more more than 13, more conveniently not conveniently not conveniently no more than 18, more more than 14, more more than 12, more conveniently no more than 11, more appropriately not more than 10, more appropriately not more than 9, more appropriately not more than 8, more appropriately not more than 7, more appropriately not more than 6, more appropriately not more than 5, more appropriately not more of 4, most suitably no more than 3, most suitably no more than 2, most suitably no more than 1 deletion(s) compared to SEQ ID NO: 17. Suitably, any FR1 residues that differ from their corresponding residues in SEQ ID NO: 17 are conservative substitutions with respect to their corresponding residues. Suitably, FR1 comprises or more suitably consists of SEQ ID NO: 17. Suitably, the FR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence that shares 10%, 15%, 25%, 30%, 40%, 45%, 55%, 60%, 70%, 75 %, 85%, 90% or more sequence identity, with SEQ ID NO: 18. Alternatively, the FR2 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 13, more suitably no more than 12, more suitably no more than 11, more suitably no more than 10, more suitably no more than 9, most conveniently no more than 8, most conveniently no more than 7, most conveniently no more than 6, most conveniently no more than 5, most conveniently no more than 4, most conveniently no more than 3, most conveniently no more of 2, more suitably no more than 1 addition(s) compared to SEQ ID NO: 18. Suitably, the FR2 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 13, more suitably no more than 12, more suitably no more than 11, more suitably no more than 10, more suitably no more than 9, most suitably no more than 8, most suitably no more than 7, most suitably no more than 6, most suitably no more than 5, more suitably no more than 4, more suitably no more than 3, more suitably no more than 2, more suitably no more than 1 substitution(s) compared to SEQ ID NO: 18. Suitably, the FR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 13, more suitably no more than 12, more suitably no more than 11, more suitably no more than 10, most suitably no more than 9, most conveniently no more than 8, most conveniently no more than 7, most conveniently no more than 6, most conveniently no more than 5, most conveniently no more than 4, most conveniently no more than 3, most conveniently no more than 2, more suitably no more than 1 deletion(s) compared to SEQ ID NO: 18. Suitably, any FR2 residues that differ from their corresponding residues in SEQ ID NO: 18 are conservative substitutions with respect to their corresponding residues. Suitably, the FR3 of the polypeptide of the present invention comprises or more suitably consists of a sequence sharing 8%, 15%, 20%, 26%, 32%, 40%, 45%, 52%, 58%, 65 %, 70%, 76%, 80%, 82%, 85%, 90%, 92%, 95% or greater sequence identity, with SEQ ID NO: 19. Alternatively, the FR3 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 29, more suitably no more than 27, more suitably no more than 25, more suitably no more than 23, more suitably no more than 21, more conveniently not more than 19, more conveniently not more than 17, more conveniently not more than 15, more conveniently not more than 13, more conveniently not more than 11, more conveniently not more than 9, more conveniently not more of 7, most conveniently not more than 6, most conveniently not more than 5, most conveniently not more than 4, most conveniently not more than 3, most conveniently not more than 2, most conveniently not more than 1 addition(s) in comparison with SEQ ID NO: 19. Suitably, the FR3 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 29, more suitably no more than 27, more suitably no more than 25, more suitably no more than 23, more suitably no more than 21, more suitably no more than 19, more suitably no more than 17, more suitably no more than 15, more suitably no more than 13, more suitably no more than 11, more suitably no more than 9, more suitably no more than 7, more suitably no more than 6, more suitably no more than 5, more suitably no more than 4, more suitably no more than 3, more suitably no more than 2, more suitably no more of 1 substitution(s) compared to SEQ ID NO: 19. Suitably, the FR3 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 29, more suitably no more than 27, more suitably no more than 25, more suitably no more than 23, more suitably no more than 21, more suitably no more than 19, more suitably no more than 17, more suitably no more than 15, more suitably no more than 13, more conveniently no more than 11, most conveniently no more than 9, most conveniently no more than 7, most conveniently no more than 6, most conveniently no more than 5, most conveniently no more than 4, most conveniently no more than 3, most conveniently no more than 2, more suitably no more than 1 deletion(s) compared to SEQ ID NO: 19. Suitably, any FR3 residues that differ from their corresponding residues in SEQ ID NO: 19 are conservative substitutions with respect to their corresponding residues. Suitably, FR3 comprises or more suitably consists of SEQ ID NO: 19. Suitably, the FR4 of the polypeptide of the present invention comprises or more suitably consists of a sequence sharing 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90 % or greater sequence identity, with SEQ ID NO: 20. Alternatively, the FR4 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 10, more suitably no more than 9, more suitably no more than 8, more suitably no more than 7, more suitably no more than 6, more conveniently not more than 5, more conveniently not more than 4, more conveniently not more than 3, more conveniently not more than 2, more conveniently not more than 1 addition(s) compared to SEQ ID NO: 20 Suitably, the FR4 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 10, more suitably no more than 9, more suitably no more than 8, more suitably no more than 7, more suitably suitably no more than 6, more suitably no more than 5, more suitably no more than 4, more suitably no more than 3, more suitably no more than 2, more suitably no more than 1 substitution(s) compared to SEQ ID NO : 20. Suitably, the FR4 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 10, more suitably no more than 9, more suitably no more than 8, more suitably no more than 7 , most suitably no more than 6, most suitably no more than 5, most suitably no more than 4, most suitably no more than 3, most suitably no more than 2, most suitably no more than 1 deletion(s) compared to SEQ ID NO: 20. Suitably, any FR4 residues that differ from their corresponding residues in SEQ ID NO: 20 are conservative substitutions with respect to their corresponding residues. Suitably, FR4 comprises or more suitably consists of SEQ ID NO: 20. Full-length sequences of 10E2 and related polypeptides Suitably, the polypeptide of the present invention more suitably comprises or consists of a sequence that shares 50% or more, more suitably 55% or more, more suitably 60% or more, more suitably 65% ​​or more, more suitably 70% or more, more suitably 75% or more, more suitably 80% or more, more suitably 85% or more, more suitably 90% or more, more suitably 95% or more, more suitably 96% or more, more suitably 97% or more, more suitably 98% or more, more suitably 99% or more sequence identity, with SEQ ID NO: 13. Alternatively, the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 20, more suitably no more than 15, more suitably no more than 10, more suitably no more than 9, more suitably no more than 8, most conveniently not more than 7, most conveniently not more than 6, most conveniently not more than 5, most conveniently not more than 4, most conveniently not more than 3, most conveniently not more than 2, most conveniently not more than 1 addition(s) compared to SEQ ID NO: 13. Suitably, the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 20, more suitably no more than 15, more suitably no more than 10, most suitably no more than 9, most suitably no more than 8, most suitably no more than 7, most suitably no more than 6, most suitably no more than 5, most suitably no more than 4, most suitably no more than 3 , more suitably no more than 2, more suitably no more than 1 substitution(s) compared to SEQ ID NO: 13. Suitably, the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 20, most suitably no more than 15, most suitably no more than 10, most suitably no more than 9, most suitably no more than 8, most suitably no more than 7, most suitably no more than 6, most suitably no more than 5 , most suitably no more than 4, most suitably no more than 3, most suitably no more than 2, most suitably no more than 1 deletion(s) compared to SEQ ID NO: 13. Suitably, the N terminus of the polypeptide is D. Suitably, the polypeptide comprises or more suitably consists of SEQ ID NO: 13. 10G10 and related polypeptides CDRs of 10G10 and related polypeptides Suitably, the CDR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence that shares 80% or more sequence identity with SEQ ID NO: 22. Alternatively, the CDR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 2, more suitably no more than 1 addition(s) compared to SEQ ID NO: 22. Suitably, the CDR1 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 2, more suitably no more than 1 substitution(s) compared to SEQ ID NO: 22. Suitably, the CDR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 2, more suitably no more than 1 deletion(s) compared to SEQ ID NO: 22. Suitably, any CDR1 residues that differ from their corresponding residues in SEQ ID NO: 22 are conservative substitutions with respect to their corresponding residues. Suitably, CDR1 comprises or more suitably consists of SEQ ID NO: 22. Suitably, the CDR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence that shares 55% or more, more suitably 60% or more, more suitably 70% or more, more suitably 75% or more, more suitably 80% or more, more suitably 85% or more, more suitably 90% or more sequence identity, with SEQ ID NO: 23. Alternatively, the CDR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 8, more suitably no more than 7, more suitably no more than 6, more suitably no more than 5, more suitably no more than 4, more suitably no more than 3, more suitably no more than 2, more suitably no more than 1 addition(s) compared to SEQ ID NO: 23. Suitably, the CDR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 8, more suitably no more than 7, more suitably no more than 6, more suitably no more than 5, most suitably no more than 4, most suitably no more than 3, more suitably no more than 2, more suitably no more than 1 substitution(s) compared to SEQ ID NO: 23. Suitably, the CDR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 8, most suitably not more than 7, most suitably not more than 6, most suitably not more than 5, most suitably not more than 4, most suitably not more than 3, most suitably not more than 2, most suitably not more than 1 deletion(s) compared to SEQ ID NO: 23. Suitably, any CDR2 residues that differ from their corresponding residues in SEQ ID NO: 23 are conservative substitutions with respect to their corresponding residues. Suitably, CDR2 comprises or more suitably consists of SEQ ID NO: 23. Suitably, the CDR3 of the polypeptide of the present invention comprises or more suitably consists of a sequence that shares 60% or more, more suitably 65% ​​or more, more suitably 75% or more, more suitably 80% or more, more suitably 90% or more sequence identity with SEQ ID NO: 24. Alternatively, the CDR3 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 3, more suitably no more than 2, more suitably no more than 1 addition(s) as compared to SEQ ID NO: 24. Suitably, the CDR3 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 3, more suitably no more than 2, more suitably no more than 1 substitution(s) as compared to SEQ ID NO: 24. Suitably, the CDR3 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 3, more suitably no more than 2, more suitably no more than 1 deletion as compared to SEQ ID NO: 24. Suitably, any substitutions are conservative, with respect to their corresponding residues in SEQ ID NO: 24. Suitably, any CDR3 residues that differ from their corresponding residues in SEQ ID NO: 24 are conservative substitutions with respect to their corresponding residues. FRs of 1QG10 and related polypeptides Suitably, the FR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence sharing 5%, 12%, 18%, 26%, 32%, 38%, 46%, 52%, 58%, 62 %, 66%, 68%, 72%, 75%, 78%, 82%, 85%, 90%, 95% or greater sequence identity, with SEQ ID NO: 25. Alternatively, the FR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 28, more suitably no more than 26, more suitably no more than 24, more suitably no more than 22, more suitably no more than 20, more conveniently not more than 18, more conveniently not more than 16, more conveniently not more than 14, more conveniently not more than 13, more conveniently not more than 12, more conveniently not more than 11, more conveniently not more of 10, most conveniently not more than 9, most conveniently not more than 8, most conveniently not more than 7, most conveniently not more than 6, most conveniently not more than 5, most conveniently not more than 4, most conveniently not more than 3, more suitably no more than 2, more suitably no more than 1 addition(s) compared to SEQ ID NO: 25. Suitably, the FR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 28, more suitably no more than 26, more suitably no more than 24, more suitably no more than 22, more suitably no more than 20, more suitably no more than 18, more suitably no more than 16, more suitably no more than 14, more suitably no more than 13, more suitably no more than 12, more suitably no more than 11, more suitably no more than 10, more suitably no more than 9, more suitably no more than 8, more suitably no more of 7, more suitably no more than 6, more suitably no more than 5, more suitably no more than 4, more suitably no more than 3, more suitably no more than 2, more suitably no more than 1 substitution(s) in comparison with SEQ ID NO: 25. Suitably, the FR1 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 28, more suitably no more than 26, more suitably no more than 24, more suitably no more than 22, most suitably no more than 20, most suitably not more than 18, more conveniently not more than 16, more conveniently not more than 14, more conveniently not more than 13, more conveniently not more than 12, more conveniently not more than 11, more conveniently not more than 10, more conveniently not more than 9, most conveniently not more than 8, most conveniently not more than 7, most conveniently not more than 6, most conveniently not more than 5, most conveniently not more than 4, most conveniently not more than 3, most suitably no more than 2, more suitably no more than 1 deletion(s) compared to SEQ ID NO: 25. Suitably, any FR1 residues that differ from their corresponding residues in SEQ ID NO: 25 are conservative substitutions with respect to their corresponding residues. Suitably, FR1 comprises or more suitably consists of SEQ ID NO: 25. Suitably, the FR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence that shares 10%, 15%, 25%, 30%, 40%, 45%, 55%, 60%, 70%, 75 %, 85%, 90% or more sequence identity, with SEQ ID NO: 26. Alternatively, the FR2 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 13, more suitably no more than 12, more suitably no more than 11, more suitably no more than 10, more suitably no more than 9, most conveniently no more than 8, most conveniently no more than 7, most conveniently no more than 6, most conveniently no more than 5, most conveniently no more than 4, most conveniently no more than 3, most conveniently no more of 2, more suitably no more than 1 addition compared to SEQ ID NO: 26. Suitably, the FR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 13, more suitably no more of 12, most conveniently no more than 11, most conveniently no more than 10, most conveniently no more than 9, most conveniently no more than 8, most conveniently no more than 7, most conveniently no more than 6, most conveniently no more than 5, more suitably no more than 4, more suitably no more than 3, more suitably no more than 2, more suitably no more than 1 substitution(s) compared to SEQ ID NO: 26. Suitably, the FR2 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 13, more suitably no more than 12, more suitably no more than 11, more suitably no more than 10, more suitably no more than 9, most suitably no more than 8, more suitably no more than 7, more suitably no more than 6, more suitably no more than 5, more suitably no more than 4, more suitably no more than 3, more suitably no more than 2, more suitably no more of 1 deletion(s) compared to SEQ ID NO: 26. Suitably, any FR2 residues that differ from their corresponding residues in SEQ ID NO: 26 are conservative substitutions with respect to their corresponding residues. Suitably, the FR3 of the polypeptide of the present invention comprises or more suitably consists of a sequence sharing 8%, 15%, 20%, 26%, 32%, 40%, 45%, 52%, 58%, 65 %, 70%, 76%, 80%, 82%, 85%, 90%, 92%, 95% or greater sequence identity, with SEQ ID NO: 27. Alternatively, the FR3 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 29, more suitably no more than 27, more suitably no more than 25, more suitably no more than 23, more suitably no more than 21, most conveniently not more than 19, most conveniently not more than 17, most conveniently not more than 15, most conveniently not more than 13, n 7 00701177071^ / ΥΙΛΙ most conveniently not more than 11, most conveniently not more than 9, most conveniently not more than 7, most conveniently not more than 6, most conveniently not more than 5, most conveniently not more than 4, most conveniently not more than 3, most conveniently not more than 2, most conveniently not more than 1 addition(s) compared to SEQ ID NO: 27. Suitably, the FR3 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 29, more suitably no more than 27, more suitably no more than 25, more suitably no more than 23, more suitably no more than 21, more suitably no more than 19, more suitably no more than 17, more suitably no more than 15, more suitably no more than 13, more suitably no more than 11, more suitably no more than 9, more suitably no more than 7, more suitably no more than 6, more suitably no more than 5, more suitably no more than 4, more suitably no more than 3, more suitably no more of 2, more conveniently no more than 1 substitution(s) compared to SEQ ID NO: 27. Suitably, the FR3 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 29, more suitably no more than 27, more suitably no more than 25, more suitably no more than 23, more suitably no more than 21, more suitably no more than 19, more suitably no more than 17, more suitably no more than 15, more suitably no more than 13, most conveniently no more than 11, most conveniently no more than 9, most conveniently no more than 7, most conveniently no more than 6, most conveniently no more than 5, most conveniently no more than 4, most conveniently no more than 3, more conveniently no more than 2, more conveniently no more than 1 elimination compared to SEQ ID NO: 27. Suitably, any FR3 residues that differ from their corresponding residues in SEQ ID NO: 27 are conservative substitutions with respect to their corresponding residues. Suitably, FR3 comprises or more suitably consists of SEQ ID NO: 27. Suitably, the FR4 of the polypeptide of the present invention comprises or more suitably consists of a sequence sharing 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90 % or greater sequence identity, with SEQ ID NO: 28. Alternatively, the FR4 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 10, more suitably no more than 9, more suitably no more than 8, more suitably no more than 7, more suitably no more than 6, more conveniently not more than 5, more conveniently not more than 4, more conveniently not more than 3, more conveniently not more than 2, more conveniently not more than 1 addition(s) compared to SEQ ID NO: 28 Suitably, the FR4 of the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 10, more suitably no more than 9, more suitably no more than 8, more suitably no more than 7, more suitably suitably not more than 6, most suitably not more than 5, most suitably not more than 4, most suitably not more than 3, most suitably not more than 2, most suitably not more than 1 substitution(s) compared to SEQ ID NO : 28. Suitably, the FR4 of the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 10, more suitably no more than 9, more suitably no more than 8, more suitably no more than 7 , most suitably no more than 6, most suitably no more than 5, most suitably no more than 4, most suitably no more than 3, most suitably no more than 2, most suitably no more than 1 deletion(s) compared to SEQ ID NO: 28. Suitably, any FR4 residues that differ from their corresponding residues in SEQ ID NO: 28 are conservative substitutions with respect to their corresponding residues. Suitably, FR4 comprises or more suitably consists of SEQ ID NO: 28. Full-length sequences of 10G10 and related polypeptides Suitably, the polypeptide of the present invention more suitably comprises or consists of a sequence that shares 50% or more, more suitably 55% or more, more suitably 60% or more, more suitably 65% ​​or more, more suitably 70% or more, more suitably 75% or more, more suitably 80% or more, more suitably 85% or more, more suitably 90% or more, more suitably 95% or more, more suitably 96% or more, more suitably 97% or more, more suitably 98% or more, more suitably 99% or more sequence identity, with SEQ ID NO: 21. Alternatively, the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 20, more suitably no more than 15, more suitably no more than 10, more suitably no more than 9, more suitably no more than 8, most conveniently not more than 7, most conveniently not more than 6, most conveniently not more than 5, most conveniently not more than 4, most conveniently not more than 3, most conveniently not more than 2, most conveniently not more than 1 addition(s) compared to SEQ ID NO: 21. Suitably, the polypeptide of the present invention comprises or more suitably consists of a sequence having no more than 20, more suitably no more than 15, more suitably no more than 10, most suitably no more than 9, most suitably no more than 8, most suitably no more than 7, most suitably no more than 6, most suitably no more than 5, most suitably no more than 4, most suitably no more than 3 , more suitably no more than 2, more suitably no more than 1 substitution(s) compared to SEQ ID NO: 21. Suitably, the polypeptide of the present invention more suitably comprises or consists of a sequence having no more than 20, most suitably no more than 15, most suitably no more than 10, most suitably no more than 9, most suitably no more than 8, most suitably no more than 7, most suitably no more than 6, most suitably no more than 5 , most conveniently not more than 4, most conveniently not more than 3, most conveniently not more than 2, most conveniently not more than 1 deletion(s) compared to SEQ ID NO: 21. Suitably, the N terminus of the polypeptide is D. Suitably, the polypeptide comprises or more suitably consists of SEQ ID NO: 21. Other embodiments related to ID-L253T, 10E2, 10G10 and related polypeptides In one embodiment, a polypeptide comprising an immunoglobulin chain variable domain that binds IL-23 is provided, wherein the immunoglobulin chain variable domain comprises three complementarity determining regions (CDR1CDR3) and four framework regions (FR1 -FR4), wherein the complementarity determination regions (and more suitably the framework regions) are selected from the complementarity determination regions (and framework regions) described herein. In one embodiment, a polypeptide comprising an immunoglobulin chain variable domain that binds IL-23 is provided, wherein the immunoglobulin chain variable domain comprises three complementarity determining regions (CDR1CDR3) and four framework regions (FR1 -FR4), where: CDR1 comprises a sequence selected from SEQ ID NO: 1, SEQ ID NO: 14 or SEQ ID NO: 22; CDR2 comprises a sequence selected from SEQ ID NO: 2, SEQ ID NO: 15 or SEQ ID NO: 23; CDR3 comprises a sequence selected from SEQ ID NO: 3, SEQ ID NO: 16 or SEQ ID NO: 24. Suitably, the polypeptide described herein more suitably comprises or consists of a sequence that shares 70% or more, more suitably 80% or more, more suitably 90% or more, more suitably 95% or more , more suitably 98% or more, more suitably 99% or more, more suitably 99.5% or more sequence identity with any of SEQ ID NOs: 8, 11, 12, 13, 21 0 29-45. In one embodiment, a polypeptide is provided that more suitably comprises or consists of a sequence that shares 70% or more, more suitably 80% or more, more suitably 90% or more, more suitably 95% or more, more suitably 95% or more. suitably 98% or more, more suitably 99% or more, more suitably 99.5% or more of sequence identity with any of SEQ ID NOs: 8, 11, 12, 13, 21 or 29-45. Linkers and multimers A construct according to the invention comprises several polypeptides and may therefore suitably be multivalent. Such a construct may comprise at least two identical polypeptides according to the invention. A construct consisting of two identical polypeptides according to the invention is a homobihead. In one aspect of the invention, a construct is provided comprising two or more identical polypeptides of the invention. Alternatively, a construct may comprise at least two polypeptides that are different, but both remain polypeptides according to the invention (a heterobihead). Alternatively, said construct may comprise (a) at least one polypeptide according to the invention and (b) at least one polypeptide such as an antibody or antigen-binding fragment thereof, which is not a polypeptide of the invention (also a heterobihead"). The at least one polypeptide from (b) may bind to IL-23 (e.g., through a different epitope than (a)) or, alternatively, may bind to a target other than IL-23. Suitably, the different polypeptide (b) binds, for example, to an interleukin (such as IL-1, IL-1ra, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11, IL-12, IL-13, IL15, IL-17 and IL-18), an interleukin receptor (such as IL-6R and IL-7R), a factor of transcription (such as NF-kB), a cytokine (such as TNF-alpha, IFN-gamma, TGF-beta and TSLP), a transmembrane protein (such as gp130 and CD3), a surface glycoprotein (such as CD4, CD20 , CD40), a soluble protein (such as CD40L), an integrin (such as α4b7 and AlphaEbeta7), an adhesion molecule (such as MAdCAM), a chemokine (such as IP10 and CCL20), a chemokine receptor (such as CCR2 and CCR9), an inhibitory protein (such as SMAD7), a kinase (such as JAK3), a G protein-coupled receptor (such as the sphingosine-1-Ρ receptor), other inflammatory mediators or immunologically relevant ligands involved in human pathological processes. Thus, the different polypeptide (b) binds, for example, to IL-6R, IL-6, IL-12, IL-1-beta, IL-17A, TNF-alpha or CD3; or other inflammatory mediators or immunologically relevant ligands involved in human pathological processes. More suitably, the different polypeptide (b) binds TNF-alpha, more suitably the different polypeptide (b) is ID-38F. Constructions can be multivalent and / or multispecific. A multivalent construct (such as a bivalent construct) comprises two or more binding polypeptides, thereby having two or more sites at which binding to one or more antigens can occur. An example of a multivalent construction could be a homobihead or a heterobihead. A multispecific construct (such as a bispecific construct) comprises two or more different binding polypeptides having two or more sites at which (a) binding to two or more different antigens can occur or (b) binding to two can occur. or more different epitopes on the same antigen. An example of a multispecies construct could be a heterobihead. A multispecies construct is multivalent. Suitably, the polypeptides comprised within the construct are antibody fragments. More suitably, the polypeptides comprised within the construct are selected from the list consisting of: VHH, VH, VL, V-NAR, scFv, Fab fragment or F(ab')2 fragment. More suitably, the polypeptides comprised within the construct are VH or VHH, more suitably VHH. The polypeptides of the invention can be linked together directly (i.e., without using a linker) or through a linker. Suitably, the linker is a protease-labile linker (a labile linker) or a non-protease-labile linker. The linker is suitably a polypeptide and will be selected to allow binding of the polypeptides to their epitopes. If used for therapeutic purposes, the linker is suitably non-immunogenic in the subject to whom the polypeptides are administered. Suitably, the protease-labile linker has the format: [-(GaS)x-B-(GbS)y-]z where a is 1 to 10; b is from 1 to 10; x is 1 to 10; and it is from 1 to 10; z is 1 to 10 and B is K or R (SEQ ID NO: 74). and more appropriately: [-(G4S)x-B-(G4S)y-]zen where x is 1 to 10; y is 1 to 10 z is 1 to 10 y n / crzn / zznz / q / υιλι B is K or R. More appropriately, a is 2 to 5, b is 2 to 5, x is 1 to 3, y is 1 to 3, z is 1, and Bes K. More suitably, the protease-labile linker has the format -(G4S)2-K-(G4S)2(SEQ ID NO: 75). Suitably, all polypeptides are connected by non-protease labile linkers. Suitable non-protease labile linkers are of the format (G4S)xen where x is 1 to 10 (SEQ ID NO: 76). More suitably, x is 6 (SEQ ID NO: 77). Accordingly, a construct is provided comprising at least one polypeptide according to the invention and at least one different polypeptide, wherein the different polypeptide binds TNF-alpha. Suitably, the TNF-alpha binding polypeptide is ID-38F or a variant thereof, such as a polypeptide that shares at least 70% sequence identity, such as at least 80% sequence identity. , such as at least 90% sequence identity, such as at least 95% sequence identity, such as at least 99% sequence identity with ID-38F (SEQ ID NO: 67). More suitably, the polypeptide that binds TNF-alpha is ID-38F. In one embodiment, this construct comprises a non-protease-labile linker, such as (G4S)e. Alternatively, this construct comprises a protease-labile linker, such as -(G4S)2-K-(G4S)2-. Suitably, this construct shares at least 80%, such as at least 90%, such as at least 95% sequence identity with FA1K (SEQ ID NO: 46). In embodiments where the construct comprises a non-protease-labile linker, then suitably the construct as a whole (i.e., the binding polypeptides (which may be variable domains of the immunoglobulin chain) and the non-protease-labile linker ) is substantially resistant to proteases such as trypsin and chymotrypsin. In embodiments where the construct comprises a protease-labile linker, then suitably the polypeptides (i.e., binding polypeptides, which may be variable domains of the immunoglobulin chain) are substantially resistant to proteases such as trypsin and chymotrypsin, but the protease-labile linker is labile to proteases such as trypsin or chymotrypsin. Vectors and hosts The term vector, as used herein, refers to a nucleic acid molecule capable of carrying another nucleic acid to which it has been linked. One type of vector is a plasmid, which refers to a circular loop of double-stranded DNA into which additional DNA segments can be ligated. Another type of vector is a viral vector, where additional DNA segments can be ligated into the viral genome. Certain vectors are capable of autonomous replication in a host cell into which they are introduced (for example, bacterial vectors that have a bacterial origin of replication and episomal vectors from mammals and yeast). Other vectors (e.g., non-episomic mammalian vectors) can integrate into the genome of a host cell after introduction into the host cell and therefore replicate along with the host genome. Furthermore, certain vectors are capable of directing the expression of genes to which they are operatively linked. Such vectors are referred to herein as recombinant expression vectors (or simply, expression vectors). In general, expression vectors useful in recombinant DNA techniques are usually in the form of plasmids. In the present specification, plasmid and vector can be used interchangeably since the plasmid is the most commonly used form of vector. However, the invention is intended to include other forms of expression vectors, such as viral vectors (for example, replication-defective retroviruses, adenoviruses and adeno-associated viruses), which perform equivalent functions, and also bacteriophage and phagemid systems. The invention also relates to nucleotide sequences that code for polypeptide sequences or multivalent and / or multispecific constructions. The term recombinant host cell (or simply host cell), as used herein, refers to a cell into which a recombinant expression vector has been introduced. These terms are intended to refer not only to the particular cell but also to the progeny of said cell. In one aspect of the invention, there is provided a vector comprising the polynucleotide encoding the polypeptide or construct of the invention or the cDNA comprising said polynucleotide. In another aspect of the invention, a host cell transformed with said vector is provided, which is capable of expressing the polypeptide or construct of the invention. Suitably, the host cell is a bacteria such as Escherchia coli, a yeast belonging to the genera Aspergillus, Saccharomyces, Kluyveromyces, Hansenula or Pichia, such as Saccharomyces cerevisiae or Pichia pastoris. Stability Suitably, the polypeptide or construct of the present invention substantially retains neutralization capacity and / or potency when administered orally and after exposure to the intestinal tract (for example, after exposure to small intestinal proteases and / or thick and / or inflammatory proteases of Eli). Such proteases include enteropeptidase, trypsin, chymotrypsin and inflammatory bowel disease proteases (such as MMP3, MMP12 and cathepsin). Proteases of or produced in the small and / or large intestine include proteases from intestinal commensal microflora and / or pathogenic bacteria, for example, wherein the proteases are cell membrane-bound proteases, excreted proteases, and proteases. released in cell lysis). More suitably, the proteases are trypsin and chymotrypsin. Suitably, the intestinal tract is the intestinal tract of a dog, pig, human, cynomolgus monkey or mouse. More suitably, the intestinal tract is the intestinal tract of a human being, a cynomolgus monkey or a mouse, more suitably a mouse or a human being, most suitably a human being. The small intestine properly consists of the duodenum, jejunum, and ileum. The large intestine properly consists of the cecum, colon, rectum, and anal canal. The intestinal tract, unlike the gastrointestinal tract, consists only of the small intestine and the large intestine. The polypeptide or construct of the present invention substantially retains neutralization capacity when suitably 10% or more, more suitably 20% or more, more suitably 30% or more, more suitably 40% or more, more suitably 50% or more, more suitably 60% or more, more suitably 70% or more, more suitably 80% or more, more suitably 90% or more, more suitably 95% or more, or more suitably 100% of the original neutralizing capacity of the polypeptide of the invention or construction is retained after exposure to proteases present in the small and / or large intestine and / or inflammatory proteases of Eli. Suitably, the polypeptide or construct of the invention substantially retains the neutralization capacity after exposure to proteases present in the small and / or large intestine and / or inflammatory proteases of Eli for, for example, up to at least 1, plus suitably up to at least 2, more suitably up to at least 3, more suitably up to at least 4, more suitably up to at least 7, more suitably up to at least 16 hours at 37°C. By "substantially retains neutralizing capacity" it is appropriately meant that the polypeptide or construct of the invention retains 10% or more, more suitably 20% or more, more suitably 30% or more, more suitably 40% or more, more suitably 40% or more. suitably 50% or more, more suitably 60% or more, more suitably 70% or more, more suitably 80% or more, more suitably 90% or more of the neutralization capacity of the polypeptide or construct of the invention. Suitably 10% or more, more suitably 20% or more, more suitably 30% or more, more suitably 40% or more, more suitably 50% or more, more suitably 60% or more, more suitably 70% or more The neutralizing capacity of the polypeptide or construct of the invention is retained after 4 hours of exposure to conditions of the intestinal tract, more suitably the small or large intestine, more suitably human fecal extract. Suitably 10% or more, more suitably 20% or more, more suitably 30% or more, more suitably 40% or more, more suitably 50% or more, more suitably 60% or more, more suitably 70% or more The neutralizing capacity of the polypeptide or construct of the invention is retained after 7 hours of exposure to conditions of the intestinal tract, more suitably the small or large intestine, more suitably human fecal extract. Suitably 10% or more, more suitably 20% or more, more suitably 30% or more, more suitably 40% or more, more suitably 50% or more, more suitably 60% or more, more suitably 70% or more The neutralizing capacity of the polypeptide or construct of the invention is retained after 16 hours of exposure to conditions of the intestinal tract, more suitably the small or large intestine, more suitably human fecal extract. Suitably 10% or more, more suitably 20% or more, more suitably 30% or more, more suitably 40% or more, more suitably 50% or more, more suitably 60% or more, more suitably 70% or more The neutralizing capacity of the polypeptide or construct of the invention is retained after 1 hour of exposure to the conditions of the intestinal tract, more suitably the small or large intestine, more suitably the supernatant of mouse small intestine. Suitably 10% or more, more suitably 20% or more, more suitably 30% or more, more suitably 40% or more, more suitably 50% or more, more suitably 60% or more, more suitably 70% or more The neutralizing capacity of the polypeptide or construct of the invention is retained after 4 hours of exposure to the conditions of the intestinal tract, more suitably the small or large intestine, more suitably the supernatant of mouse small intestine. Suitably 10% or more, more suitably 20% or more, more suitably 30% or more, more suitably 40% or more, more suitably 50% or more, more suitably 60% or more, more suitably 70% or more The administered dose of the polypeptides or constructs of the invention retain the neutralization capacity against IL-23 and remain in the feces of a mouse, cynomolgus monkey and / or human (feces adequately excreted or excreted from the intestinal tract) after 1, 2 , 3, 4, 5, 6 or 7 hours of exposure to intestinal tract conditions. A polypeptide of the invention or construct of the invention remains substantially intact when suitably 10% or more, more suitably 20% or more, more suitably 30% or more, more suitably 40% or more, more suitably 50% or more, more suitably 60% or more, more suitably 70% or more, more suitably 80% or more, more suitably 90% or more, more suitably 95% or more, more suitably 99% or more, more suitably 100% of the administered amount of polypeptide of the invention or construction remains intact n / crzn / zznz / q / υιλι after exposure to proteases present in the small and / or large intestine and / or inflammatory proteases of Eli. Therapeutic use and administration A therapeutically effective amount of a polypeptide, pharmaceutical composition or construct of the invention is an amount that is effective, upon single or multiple dose administration to a subject, to neutralize IL-23 to a significant degree in a subject. A therapeutically effective amount may vary according to factors such as the disease state, age, sex and weight of the individual, and the ability of the polypeptide, pharmaceutical composition or construct to elicit a desired response in the individual. A therapeutically effective amount is also one where any toxic or harmful effects of the polypeptide of the invention, the pharmaceutical composition or the construction are outweighed by the therapeutically beneficial effects. The polypeptide or construct of the invention may be incorporated into pharmaceutical compositions suitable for administration to a subject. The polypeptide or construct of the invention may be in the form of a pharmaceutically acceptable salt. A pharmaceutical composition of the invention may be suitably formulated for oral, intramuscular, subcutaneous or intravenous administration. The pharmaceutical compositions of the invention may be in a variety of forms. These include, for example, liquid, semisolid and solid dosage forms, such as liquid solutions (e.g., injectable and infusible solutions), dispersions or suspensions, tablets, pills, powders, liposomes and suppositories. Solid dosage forms are preferred. The polypeptide, pharmaceutical composition or construction of the invention may be incorporated with excipients and used in the form of ingestible tablets, buccal tablets, troches, capsules, elixirs, suspensions, syrups, wafers and the like. Typically, the pharmaceutical composition comprises a polypeptide or construct of the invention and a pharmaceutically acceptable diluent or carrier. Examples of pharmaceutically acceptable carriers include one or more of water, saline, phosphate buffered saline, dextrose, glycerol, ethanol and the like, as well as combinations thereof. Pharmaceutically acceptable carriers may further comprise minor amounts of auxiliary substances such as wetting or emulsifying agents, preservatives or pH regulators, which improve the shelf life or effectiveness of the polypeptide or construct of the invention. Pharmaceutical compositions may include release agents, binders, coatings, disintegrants, flavors, colorants, lubricants, adsorbents, preservatives, sweeteners, lyophilized excipients (including lyoprotectants) or compression aids. More suitably, the polypeptide, pharmaceutical composition or n / crzn / zznz / q / υιλι construct of the invention is administered orally. A key problem with oral administration is ensuring that enough polypeptide, pharmaceutical composition or construct reaches the area of ​​the intestinal tract where it is required. Factors that prevent a polypeptide, pharmaceutical composition or construct of the invention from reaching the area of ​​the intestinal tract where it is required include the presence of proteases in digestive secretions that can degrade a polypeptide, pharmaceutical composition or construct of the invention. . Suitably, the polypeptide, pharmaceutical composition or construct of the invention is substantially stable in the presence of one or more such proteases by virtue of the inherent properties of the polypeptide or construct itself. Suitably, the polypeptide or construct of the invention is lyophilized before being incorporated into a pharmaceutical composition. A polypeptide of the invention may also be provided with an enteric coating. An enteric coating is a polymer barrier applied to oral medication that helps protect the polypeptide from the low pH of the stomach. Materials used for enteric coatings include fatty acids, waxes, shellac, plastics, and plant fibers. Suitable enteric coating components include methyl acrylate and methacrylic acid copolymers, cellulose acetate succinate, hydroxypropylmethylcellulose phthalate, hydroxypropylmethylcellulose acetate succinate (hypromellose acetate succinate), polyvinylacetate phthalate (PVAP), methacrylate copolymers. methyl and methacrylic acid, sodium alginate and stearic acid. Suitable enteric coatings include pH-dependent release polymers. These are polymers that are insoluble at the highly acidic pH found in the stomach, but dissolve rapidly at a less acidic pH. Therefore, appropriately, the enteric coating will not dissolve in the acidic juices of the stomach (pH ~3), but will do so in the higher pH environment present in the small intestine (pH greater than 6) or colon ( pH greater than 7.0). The pH-dependent release polymer is selected so that the polypeptide or construct of the invention is released at approximately the time the dose reaches the small intestine. A polypeptide, construct or pharmaceutical composition of the invention can be formulated into preparations for injection by dissolving, suspending or emulsifying them in an aqueous or non-aqueous solvent, such as vegetable oils or other similar oils, glycerides of synthetic aliphatic acids, esters of higher aliphatic acids. acids or propylene glycol; and if desired, with conventional additives such as solubilizers, isotonic agents, suspending agents, emulsifying agents, stabilizers and preservatives. Acceptable carriers, excipients and / or stabilizers are not toxic to the receptors at the doses and concentrations used, and include pH regulators such as phosphate, n / crzn / zznz / q / υιλι citrate and other organic acids; antioxidants including ascorbic acid, glutathione, cysteine, methionine and citric acid; preservatives (such as ethanol, benzyl alcohol, phenol, m-cresol, p-chloro-m-cresol, methyl or propyl parabens, benzalkonium chloride or combinations thereof); amino acids such as arginine, glycine, ornithine, lysine, histidine, glutamic acid, aspartic acid, isoleucine, leucine, alanine, phenylalanine, tyrosine, tryptophan, methionine, serine, proline and combinations thereof; monosaccharides, disaccharides and other carbohydrates; low molecular weight polypeptides (less than about 10 residues); proteins, such as gelatin or serum albumin; chelating agents such as EDTA; sugars such as trehalose, sucrose, lactose, glucose, mannose, maltose, galactose, fructose, sorbose, raffinose, glucosamine, N-methylglucosamine, galactosamine and neuraminic acid; and / or nonionic surfactants such as polysorbates, POE ethers, poloxamers, Triton-X or polyethylene glycol. A pharmaceutical composition of the invention can be administered topically to the skin (for example, for use in the treatment of an autoimmune disease such as psoriasis or eczema). Said pharmaceutical composition may suitably be in the form of a cream, ointment, lotion, gel, foam, transdermal patch, powder, paste or tincture and may suitably include vitamin D3 analogues (for example, calcipotriol and maxacalcitol), steroids (for example, propionate of fluticasone, betamethasone valerate and clobetasol propionate), retinoids (for example, Tazarotene), coal tar and dithranol. Topical medications are often used in combination with each other (for example, a vitamin D3 and a spheroid) or with other agents such as salicylic acid. If the pharmaceutical composition of the invention is to be administered topically for the treatment of psoriasis or eczema, an additional substance that is considered effective in the treatment of psoriasis or eczema may suitably be included in the composition, such as steroids, especially Class 4 or Class 5 steroids such as hydrocortisone (e.g., hydrocortisone cream 1%); cyclosporine or similar macrolide agent or retinoids. For all modes of administration, the polypeptide, pharmaceutical composition or construct of the invention may be formulated in a pH regulator, to stabilize the pH of the composition, at a concentration between 5 and 50, or more suitably between 15 and 40. or more appropriately 25-30 g / liter. Examples of suitable pH regulating components include physiological salts such as sodium citrate and / or citric acid. Suitable pH regulators contain 100-200, more suitably 125-175 mM of physiological salts such as sodium chloride. Suitably, the pH regulator is selected to have a pKa close to the pH of the composition or the physiological pH of the patient. Exemplary concentrations of polypeptide or construct in a pharmaceutical composition may range from about 1 mg / mL to about 200 mg / mL n / crzn / zznz / q / υιλι or from about 50 mg / mL to about 200 mg / mL, or from approximately 150 mg / mL and approximately 200 mg / mL. An aqueous formulation of the polypeptide, construct or pharmaceutical composition of the invention can be prepared in a pH buffered solution, for example, at a pH ranging from about 4.0 to about 7.0, or from about 5.0 to about 6.0, or alternatively about 5.5. Examples of suitable pH regulators include phosphate, histidine, citrate, succinate, acetate and other organic acid pH regulators. The concentration of pH regulator may be from about 1 mM to about 100 mM, or from about 5 mM to about 50 mM, depending, for example, on the pH regulator and the desired tonicity of the formulation. The tonicity of the pharmaceutical composition can be altered by including a tonicity modifier. Said tonicity modifiers can be charged or uncharged chemical species. Typical uncharged tonicity modifiers include sugars or sugar alcohols or other polyols, preferably trehalose, sucrose, mannitol, glycerol, 1,2-propanediol, raffinose, sorbitol or lactitol (especially trehalose, mannitol, glycerol or 1,2-propanediol). Typical charged tonicity modifiers include salts such as a combination of sodium, potassium or calcium ions, with chloride, sulfate, carbonate, sulfite, nitrate, lactate, succinate, acetate or maleate ions (especially sodium chloride or sodium sulfate ); or amino acids such as arginine or histidine. Suitably, the aqueous formulation is isotonic, although hypertonic or hypotonic solutions may be suitable. The term isotonic denotes a solution that has the same tonicity as some other solution with which it is compared, such as a physiological saline solution or serum. The tonicity agents can be used in an amount of about 5 mM to about 350 mM, for example, in an amount of 1 mM to 500 nM. Suitably, at least one isotonic agent is included in the composition. A surfactant may also be added to the pharmaceutical composition to reduce aggregation of the formulated polypeptide or construct and / or minimize particulate formation in the formulation and / or reduce adsorption. Exemplary surfactants include polyoxyethylenesorbitan fatty acid esters (Tween), polyoxyethylenealkyl ethers (Brij), alkylphenylpolyoxyethylene ethers (Triton-X), polyoxyethylene-polyoxypropylene copolymer (Poloxamer, Pluronic) and sodium dodecyl sulfate (SDS). Examples of suitable polyoxyethylenesorbitan fatty acid esters are polysorbate 20 and polysorbate 80. Exemplary concentrations of surfactant can range from about 0.001% to about 10% w / v. A lyoprotectant may also be added to protect the polypeptide or construct of the invention from destabilizing conditions during the lyophilization process. For example, known lyoprotectants include sugars (including glucose, sucrose, mannose and trehalose); polyols (including mannitol, sorbitol and glycerol); and amino acids (including alanine, glycine and glutamic acid). Lyoprotectants can be included in an amount of about 10 mM to 500 mM. The dosage ranges for administration of the polypeptide of the invention, pharmaceutical composition or construct of the invention are those to produce the desired therapeutic effect. The required dosage range depends on the precise nature of the polypeptide of the invention, pharmaceutical composition or construction, the route of administration, the nature of the formulation, the age of the patient, the nature, extent or severity of the patient's condition, contraindications. , if applicable, and the judgment of the treating physician. Variations in these dosage levels can be adjusted using standard empirical routines for optimization. Suitable daily doses of the polypeptide of the invention, pharmaceutical composition or construction of the invention are in the range of 50 ng-50 mg per kg, such as 50 ug-40 mg per kg, such as 5-30 mg per kg of weight. bodily. The unit dose may vary from less than 100 mg, but will typically be in the region of 250-2000 mg per dose, which may be administered daily or more frequently, for example, 2, 3 or 4 times a day or less frequently, for example, every other day or once a week, once a fortnight or once a month. In one aspect of the invention, use of the polypeptide, pharmaceutical composition or construct of the invention in the manufacture of a medicament for the treatment of autoimmune diseases is provided. In another aspect of the invention, there is provided a method of treating autoimmune diseases comprising administering to a person in need thereof a therapeutically effective amount of the polypeptide, pharmaceutical composition or construct of the invention. The word treatment is intended to encompass both prophylaxis and therapeutic treatment. Treatment of diseases also encompasses the treatment of disease exacerbations and also encompasses the treatment of patients in remission of disease symptoms to prevent relapse of disease symptoms. Combination therapy A pharmaceutical composition of the invention may also comprise one or more active agents (for example, active agents suitable for treating the diseases mentioned herein). It is within the scope of the invention to use the pharmaceutical composition of the invention in therapeutic methods for the treatment of autoimmune diseases as an adjunct or in conjunction with other established therapies normally used in the treatment of autoimmune diseases. For the treatment of Eli (such as Crohn's disease or ulcerative colitis), possible combinations include combinations with, for example, one or more active agents selected from the list comprising: 5-aminosalicylic acid, or a prodrug of the same (such as sulfasalazine, olsalazine or bisalazide); corticosteroids (for example, prednisolone, methylprednisolone, or budesonide); immunosuppressants (for example, cyclosporine, tacrolimus, methotrexate, azathioprine, or 6-mercaptopurine); anti-TNF-alpha antibodies (for example, infliximab, adalimumab, certolizumab pegol or golimumab); anti-IL12 / IL23 antibodies (e.g., ustekinumab); anti-IL6R antibodies or small molecule IL12 / IL23 inhibitors (e.g., apilimod); anti-alpha-4-beta-7 antibodies (e.g., vedolizumab); MAdCAM-1 blockers (e.g., PF-00547659); antibodies against the cell adhesion molecule alpha-4-integrin (for example, natalizumab); antibodies against the alpha subunit of the IL2 receptor (for example, daclizumab or basiliximab); JAK3 inhibitors (for example, tofacitinib or R348); Syk inhibitors and prodrugs thereof (e.g., fostamatinib and R-406); phosphodiesterase-4 inhibitors (for example, tetomilast); HMPL-004; probiotics; dersalazine; semapimod / CPSI-2364; and protein kinase C inhibitors (e.g., AEB-071). The most suitable combination agents are infliximab, adalimumab, certolizumab pegol or golimumab. Therefore, another aspect of the invention provides a pharmaceutical composition of the invention in combination with one or more additional active agents, for example, one or more active agents described above. In another aspect of the invention, the polypeptide, pharmaceutical composition or construct is administered sequentially, simultaneously or separately with at least one active ingredient selected from the list above. Similarly, another aspect of the invention provides a combination product comprising: (A) a polypeptide, pharmaceutical composition or construct of the present invention; and (B) one or more other active agents, wherein each of components (A) and (B) is formulated in admixture with a pharmaceutically acceptable adjuvant, diluent or carrier. In this aspect of the invention, the combined product may be a single (combined) formulation or a set of parts. Therefore, this aspect of the invention encompasses a combination formulation that includes a polypeptide, pharmaceutical composition or construct of the present invention and another therapeutic agent, mixed with a pharmaceutically acceptable adjuvant, diluent or carrier. The invention also encompasses a kit of parts comprising components: (i) a polypeptide, pharmaceutical composition or construct of the present invention mixed with a pharmaceutically acceptable adjuvant, diluent or carrier; and (i) a formulation that includes one or more active agents, mixed with a pharmaceutically acceptable adjuvant, diluent or carrier, the components (i) and (i) of which are each provided in a form that is suitable for administration together with the other. Component (i) of the parts kit is therefore component (A) above mixed with a pharmaceutically acceptable adjuvant, diluent or carrier. Similarly, component (ii) is component (B) above mixed with a pharmaceutically acceptable adjuvant, diluent or carrier. The one or more of the other active agents (i.e., component (B) above) may be, for example, any of the agents mentioned above in relation to the treatment of autoimmune diseases such as Eli (for example, Crohn's disease and / or ulcerative colitis). If component (B) is more than one additional active agent, these additional active agents may be formulated together or formulated with component (A) or may be formulated separately. In one embodiment, component (B) is another therapeutic agent. In another embodiment, component (B) is two other therapeutic agents. The combination product (whether a combination preparation or a set of parts) of this aspect of the invention can be used in the treatment or prevention of an autoimmune disease (for example, the autoimmune diseases mentioned herein). Suitably, the polypeptide, pharmaceutical composition or construct of the invention is for use as a medicament and, more suitably, for use in the treatment of an autoimmune and / or inflammatory disease. Autoimmune diseases and / or inflammatory diseases Autoimmune diseases develop when the immune system responds adversely to the body's normal tissues. Autoimmune disorders can result in damage to the body's tissues, abnormal organ growth, and / or changes in organ function. The disorder may affect only one type of organ or tissue or may affect multiple organs and tissues. Organs and tissues commonly affected by autoimmune disorders include blood components such as red blood cells, blood vessels, connective tissues, endocrine glands such as the thyroid or pancreas, muscles, joints, and skin. An inflammatory disease is a disease characterized by inflammation. Many inflammatory diseases are autoimmune diseases and vice versa. Autoimmune diseases and / or inflammatory diseases of the GIT Chronic inflammatory bowel diseases (CLI), Crohn's disease and n / crzn / zznz / q / υιλι ulcerative colitis, which affect both children and adults, are examples of inflammatory and autoimmune diseases of the GIT (Hendrickson et al 2002) . Ulcerative colitis is defined as a condition where the inflammatory response and morphological changes remain confined to the colon. The rectum is affected in 95% of patients. Inflammation is largely limited to the mucosa and consists of continuous involvement of varying severity with ulceration, edema and hemorrhage throughout the colon (Hendrickson et al 2002). Ulcerative colitis is usually manifested by the presence of blood and mucus mixed with stool, along with lower abdominal cramps that are most severe during the passage of bowel movements. Clinically, the presence of diarrhea with blood and mucus differentiates ulcerative colitis from irritable bowel syndrome, where there is no blood. Unlike ulcerative colitis, the presentation of Crohn's disease is often subtle, leading to delayed diagnosis. Factors such as location, extent, and severity of involvement determine the extent of gastrointestinal symptoms. Patients with ileocolonic involvement typically have postprandial abdominal pain, with right lower quadrant tenderness and an occasional inflammatory mass. Symptoms associated with gastroduodenal Crohn's disease include early satiety, nausea, emesis, epigastric pain, or dysphagia. Perianal disease is common, along with anal papillomas, deep anal fissures and fistulas (Hendrickson et al 2002). Other diseases of the GIT include, for example, the inflammatory disease mucositis (adequately drug- and radiation-induced mucositis). In mucositis, lesions may occur from the mouth to the anus, and for lesions of the mouth and esophagus, a mouthwash or cream containing the variable domain may be used. For anal and rectal lesions, suppositories, creams or foams containing the variable domain would be suitable for topical application. The variable domains of the immunoglobulin chain will be removed from the lamina propria or other inflammatory sites by absorption into the bloodstream at sites of inflammation or by lymphatic clearance and subsequent entry into the bloodstream. Therefore, the domains will reach the liver through the bloodstream and be eliminated by glomerular filtration in the kidney. Therefore, there is good reason that the domains will work therapeutically in diseases such as autoimmune hepatitis, type II diabetes, and glomerular nephritis. Suitably, the polypeptide, pharmaceutical composition or construct of the invention is used in the treatment of an autoimmune and / or inflammatory disease of the Gl (gastrointestinal) tract wherein IL-23 contributes to the pathology of such disease. Suitably, the polypeptide, pharmaceutical composition or construct of the invention is for use in the treatment of an autoimmune and / or inflammatory disease of the Gl tract selected from the list consisting of Crohn's disease, ulcerative colitis, irritable bowel disease, type II diabetes, glomerulonephritis, autoimmune hepatitis, Sjógren's syndrome, celiac disease and drug- or radiation-induced mucositis (more suitably Crohn's disease or ulcerative colitis, more suitably ulcerative colitis). Oral administration of the immunoglobulin chain variable domain will ideally treat inflammatory diseases where IL-23 contributes to at least a proportion of the pathology and the immunoglobulin chain variable domain can access tissue where IL-23 is biologically active. Autoimmune diseases and / or inflammatory skin diseases Psoriasis is a debilitating autoimmune dermatological disease. Plaque psoriasis, the most common form of the disease, is characterized by red skin covered with silvery scales. Histologically, the picture is one of disordered differentiation and hyperproliferation of keratinocytes within the psoriatic plaque with infiltrates of inflammatory cells (Ortonne, 1999). Psoriatic skin lesions are red, well-defined, inflammatory plaques of various shapes, with a characteristic shiny silvery scale. The term psoriasis includes psoriasis and the symptoms of psoriasis including erythema, thickening / raising of the skin, and peeling. Biological agents used in the treatment of psoriasis include anti-TNF-alpha therapies (such as monoclonal antibodies against TNF, for example, adalimumab and infliximab, or TNF-alpha receptor fusion proteins such as etanercept), humanized antibodies against CD11a (efalizumab) or agents that bind to CD2 such as alefacept (thus blocking the CD2 LFA3 interaction). It should be noted that not all biologic agents listed here have been approved for use in the treatment of psoriasis. The polypeptide of the invention can be incorporated into a cream / ointment or other topical carrier for administration to inflammatory skin lesions where IL-23 contributes to the pathology of such lesions. Suitably, the polypeptide, pharmaceutical composition or construct of the invention is for use in the treatment of an autoimmune and / or inflammatory skin disease selected from the list consisting of pemphigus, psoriasis, eczema and scleroderma. Suitably, the polypeptide, pharmaceutical composition or construct is used in the treatment of other autoimmune / inflammatory diseases in which IL-23 is responsible for a proportion of the pathology observed. Preparation methods Polypeptides of the invention can be obtained and manipulated using the techniques described, for example, in Green and Sambrook 2012 Molecular Cloning: A Laboratory Manual 4th edition Coid Spring Harbor Laboratory Press. n J 0070117.7071^ / ΥΙΛΙ Monoclonal antibodies can be produced using hybridoma technology, by fusing a specific antibody-producing B cell with a myeloma (B-cell cancer) cell that is selected for its ability to grow in tissue culture and for the absence of antibody chain synthesis (Kóhler and Milstein 1975 and Nelson et al 2000). A monoclonal antibody directed against a given antigen can be obtained, for example, by: a) immortalize lymphocytes obtained from the peripheral blood of an animal previously immunized with a specific antigen, with an immortal cell and preferably with myeloma cells, to form a hybridoma, b) cultivate the immortalized cells (hybridoma) formed and recover the cells that produce the antibodies that have the desired specificity. Alternatively, the use of a hybridoma cell is not required. Consequently, monoclonal antibodies can be obtained through a process that includes the steps of: a) cloning in vectors, especially in phages and more particularly in filamentous bacteriophages, DNA or cDNA sequences obtained from lymphocytes, especially peripheral blood lymphocytes of an animal (suitably previously immunized with certain antigens), b) transform prokaryotic cells with the previous vectors under conditions that allow the production of the antibodies, c) select the antibodies by subjecting them to selection by affinity to the antigen, d) recover the antibodies that have the desired specificity. Methods for immunizing camelids, cloning of the VHH repertoire of B cells circulating in the blood (Chomezynnski and Sacchi 1987) and isolation of antigen-specific VHHs from immune (Arbabi-Ghahroudi et al 1997) and non-immune libraries (Tanha et al 2002 ) using phage, yeast or ribosome display (WO92 / 01047, Nguyen et al 2001 and Harmsen et al 2007). Antigen-binding antibody fragments, such as scFv and Fv fragments, can be isolated and expressed in E. coli (Miethe et al 2013, Skerra et al 1988, and Ward et al 1989). Mutations can be made in DNA or cDNA encoding polypeptides that do not know the amino acid sequence of the polypeptide, but that provide preferred codons for translation in a particular host. Preferred codons for translation of a nucleic acid are known in, for example, E. coli and S. cerevisiae. Mutation of polypeptides can be achieved, for example, by substitutions, additions or deletions of a nucleic acid encoding the polypeptide. Substitutions, additions or deletions of a nucleic acid encoding the polypeptide can be introduced by many methods, including, for example, error-prone PCR, random shuffling, oligonucleotide-directed mutagenesis, assembly PCR, PCR mutagenesis, mutagenesis in live, cassette mutagenesis, recursive ensemble mutagenesis, exponential ensemble mutagenesis, site-specific mutagenesis (Ling et al 1997), gene reassembly, gene site saturation mutagenesis (GSSM), synthetic ligation reassembly (SLR) or a combination of these methods. Modifications, additions or deletions of a nucleic acid may also be introduced by a method comprising recombination, recursive sequence recombination, phosphothioate modified DNA mutagenesis, uracil-containing template mutagenesis, gapped duplex mutagenesis, point mismatch repair mutagenesis , repair deficient host strain mutagenesis, chemical mutagenesis, radiogenic mutagenesis, deletion mutagenesis, restriction-selection mutagenesis, restriction-purification mutagenesis, ensemble mutagenesis, creation of multimers of chimeric nucleic acids, or a combination thereof. In particular, artificial gene synthesis can be used (Nambiar et al 1984, Sakamar and Khorana 1988, Wells et al 1985 and Grundstrom et al 1985). A gene encoding a polypeptide of the invention can be produced synthetically, for example, by solid phase DNA synthesis. Complete genes can be synthesized de novo, without the need for precursor template DNA. To obtain the desired oligonucleotide, the building blocks are sequentially coupled to the growing oligonucleotide chain in the order required by the product sequence. Once chain assembly is complete, the product is released from the solid phase into solution, deprotected, and collected. The products can be isolated by high-performance liquid chromatography (HPLC) to obtain the desired oligonucleotides of high purity (Verma and Eckstein 1998). Expression of immunoglobulin chain variable domains, such as VH and VHH, can be achieved using a suitable expression vector, such as a prokaryotic cell, such as a bacteria, for example, E. coli (for example, according to with the protocols described in WO94 / 04678, which is incorporated herein by reference and detailed below). The expression of immunoglobulin chain variable domains such as VH and VHH can also be achieved using eukaryotic cells, for example, insect cells, CHO cells, Vero cells or suitably yeast cells such as yeasts belonging to the genera Aspergillus, Saccharomyces, Kluyveromyces, Hansenula or Pichia. Suitably, S. cerevisiae is used (for example, according to the protocols described in WO94 / 025591, which is incorporated herein by reference and detailed below). Specifically, VHHs can be prepared according to the methods described in WO94 / 04678 using E. coli cells by a process comprising the steps of: a) cloning into a Bluescript vector (Agilent Technologies) a DNA or cDNA sequence that encodes for HHV (for example, obtained from camelid lymphocytes or produced synthetically) optionally including a His tag, b) recover the cloned fragment after amplification using a 5' primer specific for VHH containing an Xhol site and a 3' primer containing the Spel site having the sequence TC TTA ACT AGT GAG GAG ACG GTG ACC TG (SEQ ID NO: 68), c) cloning the fragment recovered in phase in the Immuno PBS vector (Huse et al 1989) after digestion of the vector with the restriction enzymes Xhol and Spel, d) transform host cells, especially E. coli by transfection with the recombinant immunoimmuno PBS vector from step c, e) recovering the expression product of the VHH coding sequence, for example by affinity purification such as by column chromatography using Protein A, cation exchange or a nickel affinity resin if the VHH includes a His tag. Alternatively, immunoglobulin chain variable domains such as VH and VHH can be obtained by a process comprising the steps of: a) obtain a DNA or cDNA sequence that codes for a VHH, which has a specific antigen binding site, b) amplify the DNA or cDNA obtained, using a 5' primer that contains a start codon and a Hindlll site, and a 3' primer that contains a termination codon that has an Xhol site, c) recombine the amplified DNA or cDNA at the Hindlll (position 2650) and Xhol (position 4067) sites of a plasmid pMM984 (Merchlinsky et al 1983), d) transfect permissive cells, especially NB-E cells (Faisst et al 1995) with the recombinant plasmid, e) recover the products obtained. Additionally, immunoglobulin chain variable domains such as VHH or VH can be produced using E. coli or S. cerevisiae according to the methods described in Frenken et al 2000 and WO99 / 23221 (incorporated herein by reference in its entirety). as follows: After taking a blood sample from an immunized llama and enriching the lymphocyte population via Ficoll (a high-mass, highly branched, neutral hydrophilic polysaccharide that dissolves easily in aqueous solutions - Pharmacia) discontinuous gradient centrifugation, isolating total RNA by extraction with acidic guanidium thiocyanate (Chomezynnski and Sacchi 1987), and synthesis of the first strand of cDNA (e.g., using a cDNA kit such as RPN 1266 (Amersham)), the DNA fragments encoding for the VHH and VH fragments and part of the short or long hinge region are amplified by PCR using the specific primer method detailed on pages 22 and 23 of document WO99 / 23221. After digestion of the PCR fragments with Pstl and Hindlll or BstEII, DNA fragments with a length between approximately 300 and 450 bp are purified by agarose gel electrophoresis and ligated into the E. coli phagemid vector pUR4536 or in the S. cerevisiae episomal expression vector pUR4548, respectively. pUR4536 is derived from pHEN (Hoogenboom et al 1991) and contains the laclq gene and unique restriction sites to allow cloning of the VHH and llama VH genes. pUR4548 is derived from pSY1 (Harmsen et al 1993). From this plasmid, the BstEII site in the Ieu2 gene is removed by PCR and the cloning sites between the SUC2 signal sequence and the terminator are replaced to facilitate cloning of the HAV / HH gene fragments. VH / VHHs have the c-myc tag at the C terminus for detection. Individual colonies of E. coli JM109 are transferred to 96-well microtiter plates containing 150 mL of supplemental 2TY medium with 1% glucose and 100 mg L-1 of ampicillin. After overnight growth (37 degrees C), plates are duplicated in 2TY medium containing 100 mg L'1 of ampicillin and 0.1 mM IPTG. After another overnight incubation and optionally freezing and thawing, the cells are centrifuged and pelleted and the supernatant can be used in an ELISA. Individual colonies of S. cerevisiae are transferred to test tubes containing selective minimal medium (comprising 0.7% yeast nitrogen base, 2% glucose, supplemented with essential amino acids and bases) and grown for 48 hours at 30 degrees C. Subsequently, the cultures are diluted tenfold in YPGal medium (comprising 1% yeast extract, 2% bactopeptone and 5% galactose). After 24 and 48 h of growth, the cells are pelleted and the culture supernatant can be analyzed in an ELISA. The absorbance at 600 nm (OD600) is optionally measured. Additionally, immunoglobulin chain variable domains, such as VHA / HH, can be produced using S. cerevisiae by the following procedure: Isolate a naturally occurring DNA sequence encoding VH / VHH or obtain a synthetically produced DNA sequence encoding VH / VHH, including a 5'-UTR signal sequence, stop codons, and flanked with Sacl and n j crzn sites / zznz / q / υιλι Hindlll (such a synthetic sequence can be produced as described above or, for example, can be ordered from a commercial supplier such as Geneart (Life Technologies)). Use the restriction sites for transfer of the VH / VHH gene to the multicopy integration (MCI) vector pUR8569 or pUR8542, as indicated below. Cut the DNA sequence encoding VHH optionally contained within a promiscuous vector, cassette or other synthetic genetic construct and the MCI vector with Sacl and Hindlll using: 25 ul VHH DNA (Geneart plasmid or MCI vector), 1 ul of Sacl, 1 ul of Hindlll, 3 ul of a buffer suitable for double digestion, such as NEB 1 buffer (New England Biolabs) overnight at 37 degrees C. Run 25 ul of digested DNA encoding for VHH and 25 ul of the MCI vector digested on a 1.5% agarose gel with 1xTAE pH buffer and then carry out gel extraction, for example, using the QIAquick gel extraction kit (Qiagen). Set up a ligation of the digested MCI vector and the digested DNA encoding VH / VHH as follows: 100 ng vector, 30 ng VHH gene, 1.5 ul 10x ligase buffer, 1 ul T4 DNA ligase and ddH2O. He will then carry out the ligation overnight at 16 degrees C. Next, transform the E. coli cells. For chemically competent XL-1 blue cells, thaw 200 ul of heat competent XL-1 blue cells and add 5 ul of ligation mix on ice for approximately 30 minutes, followed by heat shock for 90 seconds at 42 degrees C. Then Add 800 ul of LuriaBertani low-salt medium supplemented with 2% glucose and recover cells for 2 hours at 37 degrees C. Plate cells on Luria-Bertani agar plates and ampicillin (100 ug / mL) and keep overnight. at 37 degrees C. For electrocompetent E. coli TG1 cells, use an electroporation cuvette. In the electroporation cuvette: thaw 50 ul of electrocompetent TG1 cells and 1 ul of ligation mix on ice for about 15 minutes. Place the cuvette on the support and press. Add 500 ul of 2TY medium and recover the cells for 30 minutes at 37 degrees C. Plate 100 ul of cells on Luria-Bertani agar, containing ampicillin (100 ug / mL) and 2% glucose plates. Keep the plates at 37 degrees C overnight. Following cloning of the VH / VHH gene into E. coli as detailed above, S. cerevisiae can be transformed with the linearized MCI vector. Before carrying out the transformation, some steps are carried out: (i) the DNA must be changed from circular to linear by digestion or else the DNA cannot be integrated into the yeast genome and (i) The digested DNA must be cleaned of impurities with ethanol precipitation. Additionally, during the transformation process, yeast cells become semipermeable so that DNA can pass through the membrane. Preparation for yeast transformation: Carry out a Hpal digestion of the n j crzn / zznz / q / υιλι midi-prep prepared from the selected E. coli colony expressing the VH / VHH gene as follows. Prepare a 100 ul solution containing 20 ng of midi-prep, 5 ul of Hpal, 10 ul of suitable pH buffer, such as NEB4 pH buffer (BioLabs), and ddH2O. Cut the DNA with Hpal at room temperature overnight. Next, perform an ethanol precipitation (and set aside a 5 ul sample of the Hpal digestion). Add 300 ul of 100% ethanol to 95 ul of Hpal-digested midiprep, vortex and centrifuge at maximum speed for 5 minutes. Decant carefully when there is a sediment, add 100 ul of 70% ethanol and centrifuge again for 5 minutes at maximum speed. Decant the sample again and keep at 50-60 degrees C until the sediment is dry. Resuspend the pellet in 50 ul ddH2O. Run 5 ul on a gel next to the sample digested with 5 ul of Hpal. Yeast transformation: prepare YNBglu plates. Use 10 g of agar + 425 mL of water (sterilized), 25 mL of 20x filtered YNB (3.35 g of YNB (yeast nitrogen base) in 25 mL of sterilized H2O) and 50 mL of sterile 20% glucose and pour into Petri dishes. Choose a yeast colony from the master plate and grow it in 3 mL of YPD (yeast extract peptone dextrose) overnight at 30 degrees C. The next day, prepare about 600 mL of YPD and use it to fill 3 flasks with 275 mL, 225 mL and 100 mL of YPD. Add 27.5 ul of YPD yeast culture to the first flask and mix gently. Take 75 mL from the first flask and put it in the second flask, mix gently. Take 100 mL from the second flask and put in the third, mix gently. Grow until reaching an OD660 of between 1 and 2. Divide the flask until this OD is reached into 4 Falcon tubes, ± 45ml each. Centrifuge for 2 minutes at 4200 rpm. Discard the supernatant. Dissolve the granules in two Falcon tubes with 45 mL of H2O (reducing the number of tubes from 4 to 2). Spin for 2 minutes at 4200 rpm. Dissolve the granules in 45 mL of H2O (2 tubes to 1). Spin for 2 minutes at 4200 rpm. Gently dissolve the pellets in 5 mL of lithium acetate (LiAc) (100 mM) and centrifuge for a few seconds. Carefully discard some of the LiAc, but keep more than half of the LiAc in the tube. Vortex the cells, boil the carrier DNA for 5 minutes, and cool rapidly in ice water. Add to a 15 mL tube containing: 240 ul of PEG, 50 ul of cells, 36 ul of LiAc (1 M), 25 ul of carrier DNA, 45 ul of ethanol-precipitated VH / VHH. Mix gently after each step (treat blank sample the same, just without ethanol-precipitated VH / VHH). Incubate for 30 minutes at 30 degrees C, gently invert the tube 3 or 4 times, then apply heat for 20 to 25 minutes at 42 degrees C. Centrifuge up to 6000 rpm for a short period of time. Gently remove the supernatant and add 250 ul of ddH2O and mix. Spread everything on a YNBglu plate until the plates are dry and grow for 4-5 days at 30 degrees C. Finally, prepare the YNBglu plates by dividing them into 6 equal parts, number the parts from 1 to 6, inoculate the largest colony and dry off number 1. Repeat for other large to small colonies 1 to 6. Culture at 30 degrees C for 3-4 days until large colonies are produced. VH / VHH clones are grown using glucose as a carbon source, and induction of VH / VHH expression is carried out by activating the galactose-7 promoter by adding 0.5% galactose. Perform a small scale culture of 3 mL to test the colonies and choose which shows the best VH or VHH expression. This colony is then used in purification. Purification: VH / VHH is purified by cation exchange chromatography with a strong anion resin (such as Capto S). On day 1, inoculate the selected yeast colony expressing VH / VHH into 5 mL of YPD medium (YP medium + 2% glucose) and grow the cells in sterile sealed 25 mL tubes at 30 °C overnight ( stirring at 180 rpm). On day 2, dilute 5 mL overnight culture in 50 mL freshly prepared YP medium + 2% glucose + 0.5% galactose, grow cells in 250 mL aerated baffled flasks at 30 degrees C for two nights (stirring at 180 rpm). On day 4, spin the cells in a centrifuge at 4200 rpm for 20 min. Cation exchange purification step using a strong anion resin: adjust the pH of the supernatant containing the ligand to 3.5. Wash 0.75 mL of resin (+ / -0.5 mL of suspension) per 50 mL of supernatant with 50 mL of ddH2O followed by three washes with binding buffer. Add the washed resin to the supernatant and incubate the suspension at 4 degrees C on a shaker for 1.5 hours. Sediment the VH / VHH bound to the resin by centrifugation at 500 g for 2 minutes and wash it with washing pH regulator. Decant the supernatant and resuspend the resin with 10 mL of binding buffer. Place a filter on a PD-10 column, pour the resin into the column and let the resin settle for a while, then add a filter on top of the resin. Wait until the entire link buffer has been used up. Elute the VH / VHH with 6 x 0.5 mL of elution pH regulator. Collect elution fractions in eppendorf tubes. Measure the protein concentration of the 6 eluted fractions with a Nanodrop. Pool the VHH-containing fractions and transfer the solution to a 3500 Da cutoff dialysis membrane. Dialyze the purified protein solution against 3 L of PBS overnight at 4 degrees C. On day 5, dialyze the purified protein solution against 2 L of fresh PBS for an additional 2 hours at 4 degrees C. Finally, calculate the final concentration by BCA. Although discussed in the context of VH / VHH, the techniques described above could also be used for scFv, Fab, Fv and other antibody fragments if necessary. Various antigen-binding fragments (suitably VH / VHH) can be fused n / crzn / zznz / q / υιλι by chemical cross-linking by reacting amino acid residues with an organic derivatizing agent such as that described by Blattler et al 1985. Alternatively, The antigen-binding fragments can be genetically fused at the DNA level, that is, a polynucleotide construct is formed that encodes the complete polypeptide construct comprising one or more antigen-binding fragments. One way to link multiple antigen-binding fragments through the genetic pathway is by linking the coding sequences of the antigen-binding fragment directly or via a peptide linker. For example, the carboxy-terminal end of the first antigen-binding fragment may be linked to the amino-terminal end of the next antigen-binding fragment. This binding mode can be extended to bind antigen-binding fragments for the construction of tri-, tetra-, etc. constructs. functional. A method for producing multivalent (such as bivalent) VHH polypeptide constructs is described in WO 96 / 34103 (incorporated herein in its entirety by reference). Suitably, the polypeptide of the invention (in particular, a VHH of the invention) can be produced in a fungus such as a yeast (for example, S. cerevisiae) comprising growth of the fungus in a medium comprising a source carbon where 50-100% by weight of said carbon source is ethanol, according to the methods described in document WO02 / 48382. Large-scale production of VHH fragments in S. cerevisiae is described in Thomassen et al 2002. In one aspect of the invention, a process is provided for the preparation of the polypeptide or construct of the invention comprising the following steps: i) cloning in a vector, such as a plasmid, the polynucleotide of the invention, i) transforming a cell, such as a bacterial cell or a yeast cell capable of producing the polypeptide or construct of the invention, with said vector in conditions that allow the production of the polypeptide or construction, iii) recover the polypeptide or the construction, for example by affinity chromatography. The clauses that establish other modalities of the invention are the following: 1. A polypeptide comprising an immunoglobulin chain variable domain that binds IL-23, wherein the immunoglobulin chain variable domain comprises three complementarity determining regions (CDR1-CDR3) and four framework regions (FR1-FR4 ), where CDR1 comprises a sequence that shares 60% or more sequence identity with SEQ ID NO: 1, CDR2 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO: 2 and CDR3 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO: 3. 2. The polypeptide according to clause 1, wherein CDR3 comprises a sequence that shares 80% or more sequence identity with SEQ ID NO: 3. 3. The polypeptide according to clause 2, wherein the CDR3 consists of a sequence that shares 80% or more sequence identity with SEQ ID NO: 3. 4. The polypeptide according to clause 2 or 3, wherein any CDR3 residues that differ from their corresponding residues in SEQ ID NO: 3 are conservative substitutions with respect to their corresponding residues. 5. The polypeptide according to clause 2 or 3, wherein the CDR3 residue corresponding to residue number 6 of SEQ ID NO: 3 is I. 6. The polypeptide according to clause 2 or 3, wherein the CDR3 residue corresponding to residue number 6 of SEQ ID NO: 3 is L. 7. The polypeptide according to clause 4, wherein the CDR3 residue corresponding to residue number 6 of SEQ ID NO: 3 is I or L and any other CDR3 residue that differs from its corresponding residues in SEQ ID NO: 3 They are conservative substitutions with respect to their corresponding residues. 8. The polypeptide according to clause 2, wherein CDR3 comprises SEQ ID NO: 3. 9. The polypeptide according to clause 3, wherein the CDR3 consists of SEQ ID NO: 3. 10. The polypeptide according to any of clauses 1 to 9, wherein CDR1 comprises a sequence that shares 80% or more sequence identity with SEQ ID NO: 1. 11. The polypeptide according to clause 10, wherein CDR1 consists of a sequence that shares 80% or more sequence identity with SEQ ID NO: 1. 12. The polypeptide according to any of clauses 1 to 9, wherein any residues of CDR1 that differ from their corresponding residues in SEQ ID NO: 1 are conservative substitutions with respect to their corresponding residues. 13. The polypeptide according to clause 11, wherein CDR1 comprises SEQ ID NO: 1. 14. The polypeptide according to clause 13, wherein CDR1 consists of SEQ ID NO: 1. 15. The polypeptide according to any of clauses 1 to 14, wherein CDR2 comprises a sequence that shares 55% or more sequence identity, such as shares 60% or more sequence identity, such as shares 70% or more sequence identity, such as sharing 75% or more sequence identity, such as sharing 80% or more sequence identity, such as sharing 85% or more sequence identity, such as sharing 90 % or more sequence identity, with SEQ ID NO: 2. 16. The polypeptide according to clause 15, wherein the CDR2 consists of a sequence that shares 55% or more sequence identity, such as shares 60% or more sequence identity, such as shares 70% or more sequence identity, such as sharing 75% or more sequence identity, such as sharing 80% or more sequence identity, such as sharing 85% or more sequence identity, such as sharing 90 % or more sequence identity, with SEQ ID NO: 2. 17. The polypeptide according to any of clauses 1 to 16, wherein the CDR2 residue corresponding to residue number 9 of SEQ ID NO: 2 is D or H and / or the CDR2 residue corresponding to residue number 10 of SEQ ID NO: 2 is Y or D and / or the CDR2 residue corresponding to residue number 11 of SEQ ID NO: 2 is S, G, R or A (such as S, R or A, such as S or A) and / or the CDR2 residue corresponding to residue number 14 of SEQ ID NO: 2 is V or A. 18. The polypeptide according to any of clauses 1 to 17, wherein any CDR2 residues that differ from their corresponding residues in SEQ ID NO: 2 are conservative substitutions with respect to their corresponding residues. 19. The polypeptide according to clause 15, wherein CDR2 comprises SEQ ID NO: 2. 20. The polypeptide according to clause 19, wherein CDR2 consists of SEQ ID NO: 2. 21. The polypeptide according to any of clauses 1 to 20, wherein the FR1 comprises a sequence that shares a sequence identity of 5% or more, such as shares a sequence identity of 12% or more, such as shares a sequence identity of 18% or more, such as sharing 26% or more sequence identity, such as sharing 32% or more sequence identity, such as sharing 38% or more sequence identity, such as sharing 46 % or more sequence identity, such as sharing 52% or more sequence identity, such as sharing 58% or more sequence identity, such as sharing 62% or more sequence identity, such as sharing 66% or more more sequence identity, such as sharing 68% or more sequence identity, such as sharing 72% or more sequence identity, such as sharing 75% or more sequence identity, such as sharing 78% or more sequence identity sequence identity, such as sharing 82% or more sequence identity, such as sharing 85% or more sequence identity, such as sharing 90% or more sequence identity, such as sharing 95% or more sequence identity sequence, with SEQ ID NO: 4. 22. The polypeptide according to clause 21, wherein the FR1 consists of a sequence that shares 5% or more sequence identity, such as shares 12% or more sequence identity, such as shares 18% or more sequence identity, such as sharing 26% or more sequence identity, such as sharing 32% or more sequence identity, such as sharing 38% or more sequence identity, such as sharing 46% or more sequence identity, such as sharing 52% or more sequence identity, such as sharing 58% or more sequence identity, such as sharing 62% or more sequence identity, such as sharing 66% or more sequence identity, such as sharing 68% or more sequence identity, such as sharing 72% or more sequence identity, such as sharing 75% or more sequence identity, such as sharing 78% or more sequence identity sequence, such as sharing 82% or more sequence identity, such as sharing 85% or more sequence identity, such as sharing 90% or more sequence identity, such as sharing 95% or more sequence identity, with SEQ ID NO: 4. 23. The polypeptide according to any of clauses 1 to 22, wherein the residue of FR1 corresponding to residue number 1 of SEQ ID NO: 4 is D or E. 24. The polypeptide according to clause 23, wherein the residue of FR1 corresponding to residue number 1 of SEQ ID NO: 4 is D. 25. The polypeptide according to clause 24, wherein the residues of FR1 corresponding to residue numbers 1 to 5 of SEQ ID NO: 4 are DVQLV. 26. The polypeptide according to any of clauses 1 to 25, wherein any residues of FR1 that differ from their corresponding residues in SEQ ID NO: 4 are conservative substitutions with respect to their corresponding residues. 27. The polypeptide according to clause 21, wherein FR1 comprises SEQ ID NO: 4. 28. The polypeptide according to clause 27, wherein the FR1 consists of SEQ ID NO: 4. 29. The polypeptide according to any of clauses 1 to 28, wherein the FR2 comprises a sequence that shares 10% or more sequence identity, such as shares 15% or more sequence identity, such as shares 25% or more sequence identity, such as sharing 30% or more sequence identity, such as sharing 40% or more sequence identity, such as sharing 45% or more sequence identity, such as sharing 55 % or more sequence identity, such as sharing 60% or more sequence identity, such as sharing 70% or more sequence identity, such as sharing 75% or more sequence identity, such as sharing 85% or more more sequence identity, such as sharing 90% or more sequence identity, with SEQ ID NO: 5. 30. The polypeptide according to clause 29, wherein the FR2 consists of a sequence that shares 10% or more sequence identity, such as shares 15% or more sequence identity, such as shares 25% or more sequence identity, such as sharing 30% or more sequence identity, such as sharing 40% or more sequence identity, such as sharing 45% or more sequence identity, such as sharing 55% or more sequence identity more sequence identity, such as sharing 60% or more sequence identity, such as sharing 70% or more sequence identity, such as sharing 75% or more sequence identity, such as sharing 85% or more of sequence identity, such as sharing 90% or more sequence identity, with SEQ ID NO: 5. 31. The polypeptide according to any of clauses 1 to 30, wherein any residues of FR2 that differ from their corresponding residues in SEQ ID NO: 5 are conservative substitutions with respect to their corresponding residues. 32. The polypeptide according to clause 29, wherein FR2 comprises SEQ ID NO: 5. 33. The polypeptide according to clause 32, wherein the FR2 consists of SEQ ID NO: 5. 34. The polypeptide according to any of clauses 1 to 33, wherein the FR3 comprises a sequence that shares 8% or more sequence identity, such as shares 15% or more sequence identity, such as shares 20% or more sequence identity, such as sharing 26% or more sequence identity, such as sharing 32% or more sequence identity, such as sharing 40% or more sequence identity, such as sharing 45 % or more sequence identity, such as sharing 52% or more sequence identity, such as sharing 58% or more sequence identity, such as sharing 65% or more sequence identity, such as sharing 70% or more more of sequence identity, such as sharing 76% or more of sequence identity, such as sharing 80% or more of sequence identity, such as sharing 82% or more of sequence identity, such as sharing 85% or more of sequence identity, such as sharing 90% or more sequence identity, such as sharing 92% or more sequence identity, such as sharing 95% or more sequence identity, with SEQ ID NO: 6. 35. The polypeptide according to clause 34, wherein the FR3 consists of a sequence that shares 8% or more sequence identity, such as shares 15% or more sequence identity, such as shares 20% or more sequence identity, such as sharing 26% or more sequence identity, such as sharing 32% or more sequence identity, such as sharing 40% or more sequence identity, such as sharing 45% or more more sequence identity, such as sharing 52% or more sequence identity, such as sharing 58% or more sequence identity, such as sharing 65% or more sequence identity, such as sharing 70% or more sequence identity of sequence, such as sharing 76% or more sequence identity, such as sharing 80% or more sequence identity, such as sharing 82% or more sequence identity, such as sharing 85% or more sequence identity sequence, such as sharing 90% or more sequence identity, such as sharing 92% or more sequence identity, such as sharing 95% or more sequence identity, with SEQ ID NO: 6. 36. The polypeptide according to any of clauses 1 to 35, wherein any residues of FR3 that differ from their corresponding residues in SEQ ID NO: 6 are conservative substitutions with respect to their corresponding residues. 37. The polypeptide according to clause 34, wherein FR3 comprises SEQ ID NO: 6. 38. The polypeptide according to clause 37, wherein the FR3 consists of SEQ ID NO: 6. 39. The polypeptide according to any of clauses 1 to 38, wherein FR4 comprises a sequence that shares 5% or more sequence identity, such as shares 10% or more sequence identity, such as shares 20% or more sequence identity, such as sharing 30% or more sequence identity, such as sharing 40% or more sequence identity, such as sharing 50% or more sequence identity, such as sharing 60 % or more sequence identity, such as sharing 70% or more sequence identity, such as sharing 80% or more sequence identity, such as sharing 90% or more sequence identity, with SEQ ID NO: 7 . 40. The polypeptide according to clause 39, wherein the FR4 consists of a sequence that shares 5% or more sequence identity, such as shares 10% or more sequence identity, such as shares 20% or more sequence identity, such as sharing 30% or more sequence identity, such as sharing 40% or more sequence identity, such as sharing 50% or more sequence identity, such as sharing 60% or more sequence identity more sequence identity, such as sharing 70% or more sequence identity, such as sharing 80% or more sequence identity, such as sharing 90% or more sequence identity, with SEQ ID NO: 7. 41. The polypeptide according to any of clauses 1 to 40, wherein any residues of FR4 that differ from their corresponding residues in SEQ ID NO: 7 are conservative substitutions with respect to their corresponding residues. 42. The polypeptide according to clause 39, wherein FR4 comprises SEQ ID NO: 7. 43. The polypeptide according to clause 42 wherein the FR4 consists of SEQ ID NO: 7. 44. The polypeptide according to any of clauses 1 to 43 comprising a sequence that shares 50% or more sequence identity, such as shares 55% or more sequence identity, such as shares 60% or more more sequence identity, such as sharing 65% or more sequence identity, such as sharing 70% or more sequence identity, such as sharing 75% or more sequence identity, such as sharing 80% or more sequence identity, such as sharing 85% or more sequence identity, such as sharing 90% or more sequence identity, such as sharing 95% or more sequence identity, such as sharing 96 % or more sequence identity, such as sharing 97% or more sequence identity, such as sharing 98% or more sequence identity, such as sharing 99% or more sequence identity, with SEQ ID NO: 8. 45. The polypeptide according to clause 44 consisting of a sequence that shares 50% or more sequence identity, such as shares 55% or more sequence identity, such as shares 60% or more sequence identity of sequence, such as sharing 65% or more sequence identity, such as sharing 70% or more sequence identity, such as sharing 75% or more sequence identity, such as sharing 80% or more of sequence identity, such as sharing 85% or more sequence identity, such as sharing 90% or more sequence identity, such as sharing 95% or more sequence identity, such as sharing a sequence identity sequence of 96% or more, such as sharing a sequence identity of 97% or more, such as sharing a sequence identity of 98% or more, such as sharing a sequence identity of 99% or more, with SEQ ID NO :8. 46. ​​The polypeptide according to any of clauses 1 to 45, wherein the N terminus of the polypeptide is D. 47. The polypeptide according to clause 44 comprising SEQ ID NO: 8. 48. The polypeptide according to clause 47 consisting of SEQ ID NO: 8. 49. A polypeptide comprising an immunoglobulin chain variable domain that binds IL-23, wherein the immunoglobulin chain variable domain comprises three complementarity determining regions (CDR1-CDR3) and four framework regions (FR1-FR4 ), where: (a) CDR1 consists of a sequence that shares 60% or more sequence identity with SEQ ID NO: 1, CDR2 consists of a sequence that shares 70% or more sequence identity with SEQ ID NO: 2 and CDR3 consists of a sequence that shares 70% or more sequence identity with SEQ ID NO: 2 greater sequence identity with SEQ ID NO: 3; (b) FR1 consists of a sequence that shares 70% or more sequence identity with SEQ ID NO: 4, FR2 consists of a sequence that shares 70% or more sequence identity with SEQ ID NO: 5 , FR3 consists of a sequence that shares 70% or more sequence identity with SEQ ID NO: 5 greater sequence identity with SEQ ID NO: 6 and FR4 consists of a sequence that shares 70% or more sequence identity with SEQ ID NO: 7; and (c) the polypeptide consists of a sequence that shares a sequence identity of 70% or more with SEQ ID NO: 8. 50. A polypeptide comprising an immunoglobulin chain variable domain that binds IL-23, wherein the immunoglobulin chain variable domain comprises three complementarity determining regions (CDR1-CDR3) and four framework regions (FR1-FR4 ), where CDR1 comprises a sequence that shares 60% or more sequence identity with SEQ ID NO: 14 CDR2 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO: 15 and CDR3 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO: 16. 51. The polypeptide according to clause 50, wherein CDR3 comprises a sequence that shares 60% or more sequence identity, such as 80% or more sequence identity, with SEQ ID NO: 16. 52. The polypeptide according to clause 51, wherein the CDR3 consists of a sequence that shares 60% or more sequence identity, such as 80% or more sequence identity, with SEQ ID NO: 16. 53. The polypeptide according to any of clauses 50 to 52, wherein any CDR3 residues that differ from their corresponding residues in SEQ ID NO: 16 are conservative substitutions with respect to their corresponding residues. 54. The polypeptide according to clause 51, wherein CDR3 comprises SEQ ID NO: 16. 55. The polypeptide according to clause 54, wherein the CDR3 consists of SEQ ID NO: 16. 56. The polypeptide according to any of clauses 50 to 55, wherein CDR1 comprises a sequence that shares 80% or more sequence identity with SEQ ID NO: 14. 57. The polypeptide according to clause 56, wherein CDR1 consists of a sequence that shares 80% or more sequence identity with SEQ ID NO: 14. 58. The polypeptide according to any of clauses 50 to 57, wherein any residues of CDR1 that differ from their corresponding residues in SEQ ID NO: 14 are conservative substitutions with respect to their corresponding residues. 59. The polypeptide according to clause 56, wherein CDR1 comprises SEQ ID NO: 14. 60. The polypeptide according to clause 59, wherein CDR1 consists of SEQ ID NO: 14. 61. The polypeptide according to any of clauses 50 to 60, wherein CDR2 comprises a sequence that shares 55% or more sequence identity, such as shares 60% or more sequence identity, such as shares 70% or more sequence identity, such as sharing 75% or more sequence identity, such as sharing 80% or more sequence identity, such as sharing 85% or more sequence identity, such as sharing 90 % or more sequence identity, with SEQ ID NO: 15. 62. The polypeptide according to clause 61, wherein the CDR2 consists of a sequence that shares 60% or more sequence identity, such as shares 70% or more sequence identity, such as shares 75% or more of sequence identity, such as sharing 80% or more of sequence identity, such as sharing 85% or more of sequence identity, such as sharing 90% or more of sequence identity, with SEQ ID NO: fifteen. 63. The polypeptide according to any of clauses 50 to 62, wherein any CDR2 residues that differ from their corresponding residues in SEQ ID NO: 15 are conservative substitutions with respect to their corresponding residues. 64. The polypeptide according to clause 61, wherein CDR2 comprises SEQ ID NO: 15. 65. The polypeptide according to clause 64, wherein CDR2 consists of SEQ ID NO: 15. 66. The polypeptide according to any of clauses 50 to 65, wherein: (a) FR1 comprises a sequence that shares 5% or more sequence identity, such as shares 12% or more sequence identity, such as shares 18% or more sequence identity, such as shares a 26% or more sequence identity, such as sharing 32% or more sequence identity, such as sharing 38% or more sequence identity, such as sharing 46% or more sequence identity, such as sharing 52% or more sequence identity, such as sharing 58% or more sequence identity, such as sharing 62% or more sequence identity, such as sharing 66% or more sequence identity, such as shares 68% or more sequence identity, such as shares 72% or more sequence identity, such as shares 75% or more sequence identity, such as shares 78% or more sequence identity, such as sharing 82% or more sequence identity, such as sharing 85% or more sequence identity, such as sharing 90% or more sequence identity, such as sharing 95% or more sequence identity, with SEQ ID NO: 17; (b) FR2 comprises a sequence that shares 10% or more sequence identity, such as shares 15% or more sequence identity, such as shares 25% or more sequence identity, such as shares a 30% or more sequence identity, such as sharing 40% or more sequence identity, such as sharing 45% or more sequence identity, such as sharing 55% or more sequence identity, such as sharing 60% or more sequence identity, such as sharing 70% or more sequence identity, such as sharing 75% or greater sequence identity, such as sharing 85% or greater sequence identity, such as sharing 90 % or greater sequence identity, with SEQ ID NO: 18; (c) FR3 comprises a sequence that shares 8% or more sequence identity, such as shares 15% or more sequence identity, such as shares 20% or more sequence identity, such as shares a 26% or more sequence identity, such as sharing 32% or more sequence identity, such as sharing 40% or more sequence identity, such as sharing 45% or more sequence identity, such as sharing 52% or more sequence identity, such as sharing 58% or more sequence identity, such as sharing 65% or more sequence identity, such as sharing 70% or more sequence identity, such as shares 76% or more sequence identity, such as shares 80% or more sequence identity, such as shares 82% or more sequence identity, such as shares 85% or more sequence identity, such as sharing 90% or greater sequence identity, such as sharing 92% or greater sequence identity, such as sharing 95% or greater sequence identity, with SEQ ID NO: 19; and / or (d) the FR4 comprises a sequence that shares 5% or more sequence identity, such as shares 10% or more sequence identity, such as shares 20% or more sequence identity, such as such as sharing 30% or more sequence identity, such as sharing 40% or more sequence identity, such as sharing 50% or more sequence identity, such as sharing 60% or more sequence identity, such as sharing 70% or more sequence identity, such as sharing 80% or more sequence identity, such as sharing 90% or greater sequence identity, with SEQ ID NO: 20. 67. The polypeptide according to clause 66, wherein FR1 comprises SEQ ID NO: 17 and / or FR2 comprises SEQ ID NO: 18 and / or FR3 comprises SEQ ID NO: 19 and / or FR4 comprises SEQ ID NO: 20. 68. The polypeptide according to any of clauses 50 to 67 comprising a sequence that shares 50% or more sequence identity, such as sharing n / crzn / zznz / q / υιλι 55% or more sequence identity, such as sharing 60% or more sequence identity, such as sharing 65% or more sequence identity, such as sharing 70% or more sequence identity, such as sharing 75% or more sequence identity, such as sharing 80% or more sequence identity, such as sharing 85% or more sequence identity, such as sharing 90% or more sequence identity, such as shares 95% or more sequence identity, such as shares 96% or more sequence identity, such as shares 97% or more sequence identity, such as shares 98% or more sequence identity, such as it shares 99% or greater sequence identity, with SEQ ID NO: 13. 69. The polypeptide according to clause 68 comprising or consisting of SEQ ID NO: 13. 70. A polypeptide comprising an immunoglobulin chain variable domain that binds IL-23, wherein the immunoglobulin chain variable domain comprises three complementarity determining regions (CDR1-CDR3) and four framework regions (FR1-FR4 ), where CDR1 comprises a sequence that shares 60% or more sequence identity with SEQ ID NO: 22, CDR2 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO: 23 and CDR3 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO: 24. 71. The polypeptide according to clause 70, wherein CDR3 comprises a sequence that shares 60% or more sequence identity, such as 80% or more sequence identity, with SEQ ID NO: 24. 72. The polypeptide according to clause 71, wherein the CDR3 consists of a sequence that shares 60% or more sequence identity, such as 80% or more sequence identity, with SEQ ID NO: 24. 73. The polypeptide according to any of clauses 70 to 72, wherein any CDR3 residues that differ from their corresponding residues in SEQ ID NO: 24 are conservative substitutions with respect to their corresponding residues. 74. The polypeptide according to clause 71, wherein CDR3 comprises SEQ ID NO: 24. 75. The polypeptide according to clause 74, wherein the CDR3 consists of SEQ ID NO: 24. 76. The polypeptide according to any of clauses 70 to 75, wherein CDR1 comprises a sequence that shares 80% or more sequence identity with SEQ ID NO: 22. 77. The polypeptide according to clause 76, wherein CDR1 consists of a sequence that shares 80% or more sequence identity with SEQ ID NO: 22. 78. The polypeptide according to any of clauses 70 to 77, wherein any residues of CDR1 that differ from their corresponding residues in SEQ ID NO: 22 are conservative substitutions with respect to their corresponding residues. 79. The polypeptide according to clause 76, wherein CDR1 comprises SEQ ID NO: 22. 80. The polypeptide according to clause 79, wherein CDR1 consists of SEQ ID NO: 22. 81. The polypeptide according to any of clauses 70 to 80, wherein CDR2 comprises a sequence that shares a sequence identity of 55% or more, such as shares a sequence identity of 60% or more, such as shares a sequence identity of 70% or more, such as sharing 75% or more sequence identity, such as sharing 80% or more sequence identity, such as sharing 85% or more sequence identity, such as sharing 90 % or more sequence identity, with SEQ ID NO: 23. 82. The polypeptide according to clause 81, wherein the CDR2 consists of a sequence that shares 60% or more sequence identity, such as shares 70% or more sequence identity, such as shares 75% or more of sequence identity, such as sharing 80% or more of sequence identity, such as sharing 85% or more of sequence identity, such as sharing 90% or more of sequence identity, with SEQ ID NO: 2. 3. 83. The polypeptide according to any of clauses 70 to 82, wherein any CDR2 residues that differ from their corresponding residues in SEQ ID NO: 23 are conservative substitutions with respect to their corresponding residues. 84. The polypeptide according to clause 81, wherein CDR2 comprises SEQ ID NO: 23. 85. The polypeptide according to clause 84, wherein CDR2 consists of SEQ ID NO: 23. 86. The polypeptide according to any of clauses 70 to 85, wherein: (a) FR1 comprises a sequence that shares 5% or more sequence identity, such as shares 12% or more sequence identity, such as shares 18% or more sequence identity, such as shares a 26% or more sequence identity, such as sharing 32% or more sequence identity, such as sharing 38% or more sequence identity, such as sharing 46% or more sequence identity, such as sharing 52% or more sequence identity, such as sharing 58% or more sequence identity, such as sharing 62% or more sequence identity, such as sharing 66% or more sequence identity, such as share a 68% or more sequence identity, such as sharing 72% or more sequence identity, such as sharing 75% or more sequence identity, such as sharing 78% or more sequence identity, such as sharing 82% or more sequence identity, such as sharing 85% or more sequence identity, such as sharing 90% or more sequence identity, such as sharing 95% or more sequence identity, with SEQ ID NO: 25; (b) FR2 comprises a sequence that shares 10% or more sequence identity, such as shares 15% or more sequence identity, such as shares 25% or more sequence identity, such as shares a 30% or more sequence identity, such as sharing 40% or more sequence identity, such as sharing 45% or more sequence identity, such as sharing 55% or more sequence identity, such as sharing 60% or more sequence identity, such as sharing 70% or more sequence identity, such as sharing 75% or greater sequence identity, such as sharing 85% or greater sequence identity, such as sharing 90 % or greater sequence identity, with SEQ ID NO: 26; (c) FR3 comprises a sequence that shares 8% or more sequence identity, such as shares 15% or more sequence identity, such as shares 20% or more sequence identity, such as shares a 26% or more sequence identity, such as sharing 32% or more sequence identity, such as sharing 40% or more sequence identity, such as sharing 45% or more sequence identity, such as sharing 52% or more sequence identity, such as sharing 58% or more sequence identity, such as sharing 65% or more sequence identity, such as sharing 70% or more sequence identity, such as shares 76% or more sequence identity, such as shares 80% or more sequence identity, such as shares 82% or more sequence identity, such as shares 85% or greater sequence identity, such as sharing 90% or greater sequence identity, such as sharing 92% or greater sequence identity, such as sharing 95% or greater sequence identity, with SEQ ID NO: 27; and / or (d) the FR4 comprises a sequence that shares 5% or more sequence identity, such as shares 10% or more sequence identity, such as shares 20% or more sequence identity, such as such as sharing 30% or more sequence identity, such as sharing 40% or more sequence identity, such as sharing 50% or more sequence identity, such as sharing 60% or more sequence identity, such as sharing 70% or more sequence identity, such as sharing 80% or more sequence identity, such as sharing 90% or greater sequence identity, with SEQ ID NO: 28. n / crzn / zznz / q / υιλι 87. The polypeptide according to clause 86, wherein FR1 comprises SEQ ID NO: 25 and / or FR2 comprises SEQ ID NO: 26 and / or FR3 comprises SEQ ID NO: 27 and / or FR4 comprises SEQ ID NO: 28. 88. The polypeptide according to any of clauses 70 to 87 comprising a sequence that shares 50% or more sequence identity, such as shares 55% or more sequence identity, such as shares 60% or more more sequence identity, such as sharing 65% or more sequence identity, such as sharing 70% or more sequence identity, such as sharing 75% or more sequence identity, such as sharing 80% or more sequence identity, such as sharing 85% or more sequence identity, such as sharing 90% or more sequence identity, such as sharing 95% or more sequence identity, such as sharing 96 % or more sequence identity, such as sharing 97% or more sequence identity, such as sharing 98% or more sequence identity, such as sharing 99% or more sequence identity, with SEQ ID NO: twenty-one. 89. The polypeptide according to clause 88 comprising or consisting of SEQ ID NO: 21. The polypeptide according to any of clauses 1 to 89, wherein the polypeptide is an antibody. 91. The polypeptide according to clause 90, wherein the polypeptide is an antibody fragment. 92. The polypeptide according to clause 91, which is selected from the list consisting of: a VHH, a VH, a VL, a V-NAR, a Fab fragment and an F(ab')2 fragment. 93. The polypeptide according to clause 92, wherein the polypeptide is a VHH. 94. The polypeptide according to clause 92, wherein the polypeptide is a VH. 95. A construct comprising two or more identical polypeptides according to any of clauses 1 to 94. 96. A construct comprising at least one polypeptide according to any of clauses 1 to 94 and at least one different polypeptide, wherein the different polypeptide binds TNF-alpha. 97. A construct comprising at least one polypeptide according to any one of clauses 1 to 94 and at least one different polypeptide, wherein the different polypeptide binds to a target other than TNF-alpha. 98. The construction according to any of clauses 95 to 97, wherein the polypeptides are connected by at least one protease-labile linker. 99. The construction according to clause 98, wherein the protease-labile linker has the form: [-(GaS)x-B-(GbS)y-]zen where a is 1 to 10; b is from 1 to 10; x is 1 to 10; and it is from 1 to 10; z is 1 to 10 and Bes Ko R. 100. The construction according to clause 99 where a is 2 to 5, b is 2 to 5, x is 1 to 3, y is 1 to 3, z is 1 and B is K. 101. The construction according to clause 100, where the construction more appropriately comprises or consists of SEQ ID NO: 46. 102. The construction according to any one of clauses 95 to 97, wherein all polypeptides are connected by non-protease labile linkers. 103. The construction according to clause 102, wherein the non-protease-labile linkers have the form (G4S)Xen where x is 1 to 10. 104. The construction according to clause 103 where x is 6. 105. The polypeptide or construct according to any of clauses 1 to 104, which neutralizes human IL-23 in the IL-23-IL-23R neutralization ELISA (Evaluation Method A) with an EC50 of 5 nM or less, such as 4 nM or less, such as 3 nM or less, such as 2 nM or less, such as 1.7 nM or less, such as 1.5 nM or less, such as 1.4 nM or less, such as 1.3 nM or less , such as 1.2 nM or less, such as 1.1 nM or less, such as 1.0 nM or less, such as 0.9 nM or less, such as 0.8 nM or less, such as 0.75 nM or less, such as 0.70 nM or less, such as 0.65 nM or less, such as 0.60 nM or less, such as 0.55 nM or less, such as 0.50 nM or less, such as 0.45 nM or less, such as 0.40 nM or less, such as 0.35 nM or less, such as such as 0.30 nM or less, such as 0.25 nM or less, such as 0.20 nM or less. 106. The polypeptide or construct according to any of clauses 1 to 105, which is substantially resistant to one or more proteases. 107. The polypeptide or construct according to clause 106, wherein the one or more proteases are present in the stomach or in the small or large intestine. 108. The polypeptide or construct according to clause 107, wherein the one or more proteases are present in the small intestine. 109. The polypeptide or construct according to clause 106, wherein the one or more proteases are selected from the group consisting of enteropeptidase, trypsin, chymotrypsin and inflammatory bowel disease proteases. 110. The polypeptide or construct according to clause 109, wherein the one or more proteases are selected from the group consisting of trypsin, chymotrypsin and inflammatory bowel disease inflammatory proteases. 111. The polypeptide or construct according to any of clauses 109 or 110, wherein the inflammatory bowel disease inflammatory proteases are one or more proteases selected from the group consisting of MMP3, MMP12 and cathepsin. 112. The polypeptide or construct according to clause 110, wherein the proteases are trypsin and chymotrypsin. 113. A pharmaceutical composition comprising the polypeptide or construct according to any of clauses 1 to 112 and one or more pharmaceutically acceptable diluents or carriers. 114. The pharmaceutical composition according to clause 113, wherein the composition is in the form of an enteric coating. 115. The pharmaceutical composition according to any of clauses 113 or 114 comprising at least one additional active agent. 116. The pharmaceutical composition according to clause 115 wherein the at least one additional active agent is selected from the list consisting of: 5-aminosalicylic acid, or a prodrug thereof (such as sulfasalazine, olsalazine or bisalazide); corticosteroids (for example, prednisolone, methylprednisolone, or budesonide); immunosuppressants (for example, cyclosporine, tacrolimus, methotrexate, azathioprine or 6mercaptopurine); anti-TNF-alpha antibodies (for example, infliximab, adalimumab, certolizumab pegol or golimumab); anti-IL12 / IL23 antibodies (e.g., ustekinumab); anti-IL6R antibodies or small molecule IL12 / IL23 inhibitors (e.g., apilimod); anti-alpha-4-beta-7 antibodies (e.g., vedolizumab); MAdCAM-1 blockers (e.g., PF00547659); antibodies against the cell adhesion molecule alpha-4-integrin (for example, natalizumab); antibodies against the alpha subunit of the IL2 receptor (for example, daclizumab or basiliximab); JAK3 inhibitors (for example, tofacitinib or R348); Syk inhibitors and prodrugs thereof (e.g., fostamatinib and R-406); phosphodiesterase-4 inhibitors (for example, tetomilast); HMPL-004; probiotics; dersalazine; semapimod / CPSI-2364; and protein kinase C inhibitors (e.g., AEB-071). 117. The pharmaceutical composition according to clause 116, wherein at least one additional active agent is 5-aminosalicylic acid. 118. The polypeptide, pharmaceutical composition or construction according to any of clauses 1 to 117 for use as a medicine. 119. The polypeptide, pharmaceutical composition or construction according to clause 118 for use in the treatment of an autoimmune and / or inflammatory disease. 120. The polypeptide, pharmaceutical composition or construction according to clause 119, wherein the autoimmune and / or inflammatory disease is selected from the list consisting of Crohn's disease, ulcerative colitis, irritable bowel disease, type II diabetes, glomerulonephritis , autoimmune hepatitis, Sjógren's syndrome, celiac disease, drug- or radiation-induced mucositis, pemphigus, psoriasis, eczema and scleroderma. 121. The polypeptide, pharmaceutical composition or construct for use according to clause 120, wherein the autoimmune and / or inflammatory disease is Crohn's disease. 122. The polypeptide, pharmaceutical composition or construct for use according to any of clauses 118 to 121, which is administered orally. 123. The polypeptide, pharmaceutical composition or construct for use according to any of clauses 118 to 119, which is administered topically to the skin. 124. Use of the polypeptide, pharmaceutical composition or construction according to any of clauses 1 to 117 in the manufacture of a medicament for the treatment of autoimmune and / or inflammatory diseases. 125. Use of the polypeptide, pharmaceutical composition or construction according to clause 124, wherein the autoimmune and / or inflammatory disease is selected from the list consisting of Crohn's disease, ulcerative colitis, irritable bowel disease, type II diabetes, glomerulonephritis, autoimmune hepatitis, Sjógren's disease syndrome, celiac disease, drug- or radiation-induced mucositis, pemphigus, psoriasis, eczema and scleroderma. 126. Use according to clause 125 wherein the autoimmune and / or inflammatory disease is Crohn's disease. 127. Use in accordance with any of clauses 124 to 126 where the medicine is administered orally. 128. Use according to clause 124 where the medicine is administered topically to the skin. 129. A method of treating autoimmune and / or inflammatory diseases comprising administering to a person in need thereof a therapeutically effective amount of the polypeptide, pharmaceutical composition or construct according to any of clauses 1 to 117. 130. The method of treatment of autoimmune and / or inflammatory diseases of i! 7 0070117.7071^ / ΥΙΛΙ according to clause 129, wherein the autoimmune and / or inflammatory disease is selected from the list consisting of Crohn's disease, ulcerative colitis, irritable bowel syndrome, type II diabetes, glomerulonephritis, autoimmune hepatitis, syndrome Sjógren's disease, celiac disease, drug- or radiation-induced mucositis, pemphigus, psoriasis, eczema and scleroderma. 131. The method of treating autoimmune diseases according to clause 130, wherein the autoimmune disease is Crohn's disease. 132. The method of treating autoimmune diseases according to any of clauses 129 to 131, wherein the polypeptide, pharmaceutical composition or construct is administered orally. 133. The method of treating autoimmune diseases according to clause 129, wherein the polypeptide, pharmaceutical composition or construct is administered topically to the skin. 134. The polypeptide, pharmaceutical composition, construction, use or method according to any of clauses 118 to 133 wherein the polypeptide, pharmaceutical composition or construction is administered sequentially, simultaneously or separately with at least one active agent selected from the list that consists of 5-aminosalicylic acid, or a prodrug thereof (such as sulfasalazine, olsalazine or bisalazide); corticosteroids (for example, prednisolone, methylprednisolone, or budesonide); immunosuppressants (for example, cyclosporine, tacrolimus, methotrexate, azathioprine, or 6-mercaptopurine); anti-TNFalpha antibodies (for example, infliximab, adalimumab, certolizumab pegol or golimumab); anti-IL12 / IL23 antibodies (e.g., ustekinumab); anti-IL6R antibodies or small molecule IL12 / IL23 inhibitors (e.g., apilimod); anti-alpha-4-beta-7 antibodies (e.g., vedolizumab); MAdCAM-1 blockers (e.g., PF-00547659); antibodies against the cell adhesion molecule alpha-4-integrin (for example, natalizumab); antibodies against the alpha subunit of the IL2 receptor (for example, daclizumab or basiliximab); JAK3 inhibitors (for example, tofacitinib or R348); Syk inhibitors and prodrugs thereof (e.g., fostamatinib and R-406); phosphodiesterase-4 inhibitors (for example, tetomilast); HMPL-004; probiotics; dersalazine; semapimod / CPSI-2364; and protein kinase C inhibitors (e.g., AEB-071). 135. The polypeptide, pharmaceutical composition, construct or method according to clause 134, wherein the polypeptide, pharmaceutical composition or construct is administered sequentially, simultaneously or separately with infliximab, adalimumab, certolizumab pegol or golimumab. 136. A polynucleotide comprising or consisting of a sequence that is shared by 70% or more, such as 80% or more, such as 90% or more, such as 95% or more, such as n / crzn / zznz / q / υιλι 99% or more, sequence identity with any of the portions of SEQ ID NO: 10 that encode CDR1, CDR2 or CDR3 of the encoded immunoglobulin chain variable domain. 137. A polynucleotide encoding the polypeptide or construct according to any of clauses 1 to 135. 138. The polynucleotide according to clause 137, wherein the polynucleotide comprises or consists of a sequence that shares 70% or more, such as 80% or more, such as 90% or more, such as 95% or more, such as 99% or more sequence identity with SEQ ID NO: 10. 139. The polynucleotide according to clause 138, wherein the polynucleotide comprises or consists of SEQ ID NO: 10. 140. A cDNA comprising the polynucleotide according to any of clauses 136 to 139. 141. A vector comprising the polynucleotide or cDNA according to any of clauses 136 to 140. 142. A host cell transformed with a vector according to clause 141 and which is capable of expressing the polypeptide or construct according to any of clauses 1 to 112. 143. The host cell transformed with a vector according to clause 142, wherein the host cell is a yeast cell such as S. cerevisiae or P. pastorís. 144. The host cell transformed with a vector according to clause 142, wherein the host cell is a bacterial cell such as E. coli. 145. A process for the preparation of the polypeptide or construct according to any of clauses 1 to 112, comprising the following steps: i) cloning into a vector, such as a plasmid, the polynucleotide according to any of clauses 136 to 139; i) transforming a cell, such as a bacterial cell or a yeast cell capable of producing the polypeptide or construct according to with any of clauses 1 to 112, with said vector under conditions that allow the production of the polypeptide or construct, iii) recover the polypeptide or the construct, for example by affinity chromatography. The additional clauses that establish other modalities of the invention are the following: 1. A polypeptide comprising an immunoglobulin chain variable domain that binds IL-23, wherein the immunoglobulin chain variable domain comprises three complementarity determining regions (CDR1-CDR3) and four framework regions (FR1-FR4 ), where CDR1 comprises a sequence that shares 60% or more sequence identity with SEQ ID NO: 1, CDR2 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO: 2 and CDR3 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO: 3. 2. The polypeptide according to clause 1, wherein CDR1 comprises a sequence that shares 80% or more sequence identity with SEQ ID NO: 1, CDR2 comprises a sequence that shares 80% or more identity sequence with SEQ ID NO: 2 and the CDR3 comprises a sequence sharing 80% or more sequence identity with SEQ ID NO: 3. 3. The polypeptide according to clause 3, wherein CDR1 consists of SEQ ID NO: 1, CDR2 consists of SEQ ID NO: 2 and CDR3 consists of SEQ ID NO: 3. 4. The polypeptide according to any of clauses 1 to 3, wherein the FR1 comprises a sequence that shares a sequence identity of 80% or more with SEQ ID NO: 4, the FR2 comprises a sequence that shares a sequence identity of sequence of 80% or more with SEQ ID NO: 5, FR3 comprises a sequence that shares 80% or more sequence identity with SEQ ID NO: 6 and FR4 comprises a sequence that shares 80% or more identity sequence with SEQ ID NO: 7. 5. The polypeptide according to any of clauses 1 to 4 comprising a sequence that shares 70% or more sequence identity with SEQ ID NO: 8. 6. The polypeptide according to any of clauses 1 to 5, wherein the polypeptide is an antibody or fragment thereof. 7. The polypeptide according to clause 6, wherein the polypeptide is a VH or a VHH. 8. A construct comprising at least one polypeptide according to any of clauses 1 to 7 and at least one different polypeptide, wherein the different polypeptide binds TNF-alpha. 9. The construction according to clause 8, wherein the polypeptides are connected by at least one protease-labile linker. 10. The polypeptide or construct according to any of clauses 1 to 9, wherein the polypeptide or construct neutralizes human IL-23 in the IL-23-IL-23R neutralization ELISA (Evaluation Method A) with a EC50 of 2 nM or less. 11. The polypeptide or construct according to any of clauses 1 to 10, wherein the polypeptide or construct is substantially resistant to one or more proteases present in the small intestine. 12. The polypeptide or construct according to clause 11, wherein the proteases are trypsin and chymotrypsin. 13. The polypeptide, pharmaceutical composition or construction according to any of clauses 1 to 12 for use in the treatment of an autoimmune and / or inflammatory disease. 14. The polypeptide, pharmaceutical composition or construction for use according to clause 13, wherein the polypeptide, pharmaceutical composition or construction for use is administered orally. 15. A polynucleotide encoding the polypeptide or construct according to any of clauses 1 to 14. The present invention will now be described in more detail by means of the following non-limiting examples. EXAMPLES Evaluation methods used in the examples Evaluation Method A: IL-23-IL-23R Neutralization ELISA Maxisorp 96-well plates were coated overnight with 50 μΙ / well, 0.3 pg / mL IL-23R-Fc and then blocked with 4% milk, 1% BSA. ICVDs were serially diluted in 4% milk, 1% BSA and mixed 1:1 with 40 ng / mL recombinant human IL-23. ICVDs mixed with IL-23 were then added to the IL-23R coated plates. Bound IL-23 was detected with biotinylated anti-p40 pAb BAF219 (R&D Systems) followed by Extravidin-HRP. This allowed the calculation of the neutralizing activity of IL-23 in the sample. Evaluation Method B: IL-23-IL-23R Neutralization ELISA Using a High Salt pH Regulator A high-salt IL-23-IL-23R ELISA was used to measure ICVD anti-IL-23 concentrations in fecal extracts. This ELISA was the same as the previous ELISA (Evaluation Method A), except that the buffer used for dilution of fecal supernatant and preparation of IL-23 was 1% BSA, 4% milk in PBS containing 0.6 M NaCl, 0.05% Tween20 and protease inhibitors. Evaluation method C: mouse splenocyte assay Splenocytes were isolated from mouse spleen and plated in 96-well round-bottom microplates at 4x105 cells / 50 μΙ / well in culture medium containing 20 ng / mL mouse IL-2 (2x the assay concentration). Peak concentrations of ICVD were prepared at 300 nM (2x) in culture medium containing 10 ng / mL THP-1-derived nhlL-23 (2x the assay concentration), and subsequent 2.6-fold dilutions were made directly in culture medium containing nhlL-23 (2x). Next, 50 μl of each ICVD mixture (2x) was transferred to the cells (50 μΙ) to obtain a n / crzn / zznz / q / υιλι final assay concentration of 1x of ICVD, hlL-23 and mlL-2 . 'mlL-2 alone' and 'mlL-2 + hlL-23' were used as negative and positive controls, respectively, for the stimulation and secretion of mouse IL-17 in culture supernatants. After 3 days of incubation at 37°C, 5% CO2, the plates were centrifuged for 2 minutes at 2000 rpm and 50 pL of culture supernatant was recovered from each well. Levels of mlL-17 in culture supernatants were measured using an IL-17 binding ELISA, and neutralization of hlL-23 was determined. Example 1: Immunizations, phage library selections, master plate selection and ICVD production in E. coli Example 1.1: Immunization and construction of phage libraries Llamas were immunized with soluble human recombinant IL-23 and good serum antibody titers were obtained in both animals. RNA was isolated from white blood cells collected from each llama after several booster immunizations with IL-23. Peripheral blood mononuclear cells (PBMCs) collected from each llama at the end of each immunization phase were used to generate seven separate phage display libraries. Construction of the ICVD phage display libraries and primary selection of ICVD-expressing phages with IL-23 binding activity were performed using standard protocols and reagents. In general, total RNA was extracted from peripheral blood lymphocytes that were isolated from each of the immunized llamas. The RNA was then used to generate cDNA and PCR was performed to specifically amplify the variable regions of the ICVD heavy chain-only antibodies. The cDNA fragments encoding the ICVD repertoire were cloned into a phagemid vector and the library was introduced into E. coli. Phage libraries were produced by culturing E. coli with helper phages and pelleting the resulting ICVD-displaying phages. The numbers in each library were determined by titration and infection of the E. coli strain TG1 in log phase with the different dilutions. Each of the libraries was estimated to contain between 6x107 and 5x108 ICVD sequences. Example 1.2: Library Screens for Phages with Human IL-23 Binding Activity: Propagation and Generation of Periplasmic Extracts Phage library selection strategies were established to enrich ICVDs that specifically bind to the IL-23p19 subunit. Phages were selected by screening on hlL-23 or biotinylated hlL-23 in the presence of soluble hlL-12. The bound ICVDs were washed using different methods and removed from the plates using specific elution with IL-23R or total elution with TEA. Selection and elution conditions were established to isolate ICVDs that bind with high affinity to p19 epitopes that are present in the soluble active form of IL-23 and that interfere with the binding of IL-23 to the IL-23 receptor. (IL-23). 23R). Phages present in the eluates of the selections were used to infect E. coli TG1 cells. Colonies were randomly selected from twelve 96-well master plates and propagated to generate clonal cultures. The outer membranes of the bacterial cells were lysed by freezing and thawing to release the ICVD-containing periplasmic fraction (also referred to herein as peri). Cell debris was removed by centrifugation and supernatants were transferred to new 96-well plates to evaluate ICVD properties. Example 1.3: Detection of periplasmic extracts In order to identify specific ICVDs to inhibit IL-23 signaling, the ability of periplasmic extracts to disrupt three interactions was analyzed: 1) binding of IL-23 to IL-23R, 2) binding of IL-23 to IL -12Rp1 and 3) Binding of IL-12 to IL-12Rp1. Each of these interactions was tested by ELISA. Three ELISA plate formats were developed whereby periplasmic extracts containing the ICVD were mixed with the appropriate cytokine before the mixture was applied to a Maxisorp plate coated with the appropriate cytokine receptor. In the absence of interference with cytokine receptor binding by ICVD, this allowed capture of the cytokine, which in all cases could be detected by a biotinylated anti-p40 antibody and subsequently Extravidin-HRP. The neutralizing activity of each ICVD was measured as the ability to reduce the binding of the cytokine to its receptor relative to an irrelevant VHH control. Promising ICVD clones were selected for production in E. coli and further evaluation. Example 1.4: Production of selected clones in E. coli The DNA sequences of the selected ICVDs were recloned into the pMEK222 vector (thereby introducing C-terminal FLAG and 6xHis tags) for production in E. coli and the ICVDs were affinity purified on Talon resin via the 6xHis tag. for more detailed evaluation studies. ICVDs that were not well expressed from E. coli were excluded from further analysis. Example 2: Potency of purified primary clones The IL-23-IL-23R neutralizing activities of the purified ICVDs were evaluated in an IL-23-IL-23R neutralization ELISA (Assessment Method A) to evaluate potency against human IL-23. The ICVDs that were found to have greater potency than the comparative example monoclonal antibody brazikumab (heavy chain SEQ ID NO: 70, light chain SEQ ID NO: 71) are set forth in the following table. Clone# IL-23 Family: IL-23R ELISA EC50 (nM) 12G1 L 0.387 1E2 L 0.546 10E2 - 1.454 10G10 - 1.466 Brazikumab (comparative example) - 2.23 The ELISA results showed that the Family L clones (12G1 and 1E2) are remarkably potent, not only showing greater potency in the IL-23-IL-23R ELISA than the comparative example anti-IL-23 antibody brazikumab, but even showing a subnanomolar power. Clones 10E2 and 10G10 also demonstrated greater potency in this trial than the comparative brazikumab example. 10E2, 12G1 and 1E2 were also tested in a cynomolgus monkey IL-23-IL-23R neutralization ELISA and all showed high neutralization potencies in this assay (data not shown), similar to those demonstrated in the IL-23 standard. -IL-23R ELISA. It was also established that these clones were not capable of neutralizing the interaction of IL-23 with IL-12R or IL-12 with IL-12R. Without wishing to be bound by theory, the inventors believe that these clones are specific for the p19 subunit of IL-23. Example 3: Intrinsic protease stability of purified primary clones Orally administered ICVDs are likely to be susceptible to proteolytic digestion during passage through the small and large intestines. To further investigate resistance to intestinal proteases, the (retention of) potency of purified ICVDs was tested after incubation in the presence of mouse small intestine supernatant and a supernatant prepared from pooled human fecal samples. Mouse small intestine supernatant: The contents of the small intestines of seven male C57BL / 6 mice were removed with 0.9% saline, combined, homogenized, and centrifuged. The resulting supernatant was removed, aliquoted, and frozen. Human fecal supernatant: Fecal samples from five humans were converted to suspensions with the addition of 1x PBS. The suspensions were then pooled, centrifuged, and the supernatants were separated, aliquoted, and stored at −80°C. This process removes the fecal matrix, including any cellular material. After incubation of ICVDs for different periods at 37 °C, the anti-IL-23 activities of the digested ICVD samples were analyzed using the IL-23-IL-23R neutralization ELISA (Evaluation Method B) and the percentage of activity was maintained from the “undigested” ICVD to the calculated “digested” ICVD. The results are provided in the following table. Protease Stability Clone# Family 1 hour digestion in mouse small intestine material 4 hours digestion in human fecal matter 12G1 L 51.2% 5.6% 1E2 L 41.3% 6.1% 10E2 - 19.3% 14.3% ICVDs demonstrated substantial intrinsic stability to proteases present in mouse small intestine material and human fecal matter. Family L ICVD 12G1 was chosen for further optimization based on its potency and intrinsic protease resistance. Example 4: Production and characterization of optimized 12G1 variants Family 4 ICVD 12G1 underwent sequence modification to produce multiple ICVD variants. These ICVD variants were tested in the protease stability and potency assays detailed above. The ICVD variants, their mutations relative to ID-L253T, and their performance in these assays are detailed in the table below (where EC50 values ​​are given in nM, 'mouse splenocytes' refers to data obtained using the Method of evaluation C above and residues are numbered using N- to C-terminal numbering, as opposed to Kabat numbering). It was observed that high potency and stability of the protease were generally maintained among ICVD variants. Therefore, ID-L253T variants can be expected to substantially maintain high protease potency and stability. Of these variant ICVDs, ID-L253T was finally chosen to continue its characterization. 12G1 varies from ID-L253T by the following mutations: E1D, L11Q, R19S, A23E, A24S, Y37F, A60S, M69I, V78L, F79Y, E81Q, D83N, V85L, A90T, N96A, L103I and R116Q (using N- to C-terminal, unlike Kabat numbering). Spy on us mouse | 5.63±2.1 | 1 ςε-9 I 1 5.54 | $ | not tested | in rn q O q a 1 ™ 1 1 3.99 013.67 I | opeqojd ot | in 1 4.47 | O Π} o o c 1 ws 1 1 o” 1 | 13.5114.32 1 Protease stability Human fecal material 16h | 23.4% ±5.1 | g PM 26.0% | 24.0% | not tested | 28.0% | | 20.0% 1 23.0% | 1 28% ± 2 1 | opeqcjdou 28% ± 7 1 27.0% 1 a? ιΛ not tested 13.5% | | I F %9Z 1 *6? X r* | 37% 113 | g s | 34.7% I | 35.5% | 1 1 | 33.9% | | not tested | | 46.3% | | 48.0% | 1 53% ± 7 1 | untested | 55% 114 1 61%±13 1 | %ess | o fD o o c 31.9% 42% 1 5 | Mouse ID Material | a o 3 I 4h I 53.4% ​​±23 | • • • • 1 56.7% I • • | %E'V9 51% 116 | Group A | I Mt 57.4% 115 * q fiO * q 95.0% 5.0% 89.0% 80.0% 69.0% 84.0% 38.7% not tested 51.8% 39.3% 55.7% not tested 23.8% 38.8% • Power (EC50) 0.32 10.17' 0.2 Λ Or not tested m or d d [ 0.2510.1 1 1 2.15 s d d 1 0.74 6.95 661 9ΖΌ | 0.23 ±0.04 Mutations in relation to ID-L253T | OS > ai on a Llj Q D1E, V92H D1E, S19R, V40A, V92R 01E, S19R, R45L, V92R QC > < > 8 V) cT σ» £ I 00 m Q I heard I heard VI Q D1E, S19R, D58H, V92R D1E, S19R, S60R, V92R D1E, S19R, P87S,V92R | D1E, S19R Q D1E, V40A, 169 L, L78V in s f llT Q D1E, K43H, R45L 1 D1E, S19R, Q44E, L47F, D58H D1E, V40A, Q44E, R45L, 1691, L78V | clone* | ΙΟ CS ώ | ID-L237T | | ID-L238T | 1 16EZ1-BI 1 | ID-L240T | | ID-L241T | | ID-L242T | | ID-L243T | | ID-L244T | I ID-L245T I | ID-L246T | | I0-L247T | 1 ID-L248T I | ID-L249T | | ID-L250T | | ID-L251T | | ID-L2WT | 3 η / crzn / zznz / q / υιλι * average of 5 independent experiments excluding 1 experiment in which an outlier of 1.1 nM was obtained * * average of 8 independent experiments, excluding 1 experiment in which an outlier of 1.03 was obtained nM Example 5: ID-L253T Potency, Binding Affinity and Protease Stability Compared to Comparative Examples Brazikumab and 37D5 Brazikumab is a state-of-the-art fully human IgG2 monoclonal antibody that selectively binds to the p19 subunit of IL-23. 37D5 is a state-of-the-art (VHH) domain antibody that selectively binds to the p19 subunit of IL23 (Desmyteret al 2017, SEQ ID NO: 69). The potency, binding affinity, and protease stability of ID-L253T were evaluated relative to these prior art anti-IL-23 agents. Example 5.1: Potency of ID-L253T compared to brazikumab ID-L253T and the clinical comparator brazikumab were tested, side by side, for potency in the IL-23-IL-23R inhibition ELISA (Assessment Method A). The results are summarized in the following table. Anti-IL-23 agent IL-23-IL-23R ELISA (EC5o, nM) ID-L253T 0.202 Brazikumab (comparative example) 0.441 As expected based on the potency of the ICVD 12G1 parent and the ID-L253T variants described above, ID-L253T demonstrated greater potency than brazikumab in the IL-23-IL-23R ELISA. Example 5.2: Affinity of ID-L253T compared to brazikumab Fab The binding kinetics of ID-L253T were compared to a brazikumab Fab (prepared with a commercially available Fab preparation kit) and evaluated in a Biacore study. An anti-p40 mAb was attached to the Biacore sensor plate and loaded with recombinant human IL-23. This binding of IL-23 by its p40 subunit allows the p19 subunit (for which both brazikumab and ID-L253T are specific) to interact with the anti-IL-23 ICVD ID253T and the brazikumab Fab fragment, which were subsequently made to flow on the chip to detect the junction. ID-L253T had an average Kd of 32 pM, while the brazikumab Fab preparation had a much higher average Kd of 1200 pM, demonstrating that a brazikumab Fab has a much lower binding affinity than ID-L253T. These data are summarized in the following table. Anti-IL-23 agent Kd(pM) ID-L253T 32 Brazikumab Fab (comparative example) 1200 While not wishing to be bound by theory, based on the data provided above, the inventors expect that ID-L253T binds to the p19 subunit of IL-23. Example 5.3: Protease stability of ID-L253T compared to 37D5 The stability of ID-L253T was tested in mouse small intestine material and compared to that of Comparative Example 37D5. The anti-IL-23 activities of the digested ICVD samples were analyzed using the IL-23-IL-23R neutralization ELISA (Assessment Method B) and the percentage of activity maintained from the undigested ICVD to the ICVD was calculated. digested. These data are summarized in the following table. 2 hour digestion in mouse small intestine material 4 hour digestion in mouse small intestine material ID-L253T Not tested 51% 37D5 0% Not tested It is clear from these data that no ELISA signal could be established with respect to 37D5 after 2 hours of digestion in mouse small intestine material, whereas after an incubation period twice as long, ID-L253T achieved a survival of 51%. Therefore, ID-L253T is noticeably more stable in this digestive matrix than comparative example 37D5. It should be noted that the data provided here in ID-L253T corresponds to the same test as detailed above in Example 4 and the data provided here in 37D5 was produced in a separate test on a different occasion. Example 6: Specificity of ID-L253T for human IL-23 Example 6.1: Cross-reactivity with IL-23 of toxicological species A cynomolgus monkey IL-23-IL-23R neutralization ELISA was performed. To this end, Maxisorp 96-well plates were coated overnight with 50 μl / well, 0.5 pg / mL cynomolgus monkey IL-23R-Fc and then blocked with 4% milk, 1% BSA. ICVDs were serially diluted in 4% milk, 1% BSA and mixed 1:1 with 40 ng / mL recombinant cynomolgus monkey IL-23 (clL-23), then incubated for 30 minutes to allow binding before adding to clL-23R coated plates. Bound clL-23 was detected with BAF219 anti-p40 pAb and then Extravidin-HRP, and the level of ICVD neutralization of clL-23 binding to clL-23R was determined. ID-L253T was active in the cynomolgus monkey IL-23-IL-23R neutralization assay (data not shown), making the cynomolgus monkey a suitable toxicological species for any preclinical development studies. Example 6.2: Specificity against non-target cytokines The selectivity of ID-L253T against IL-23-related and non-IL-23-related cytokines was tested in binding or inhibition ELISA. IL-12 shares the p40 subunit with IL-23 and is therefore the most closely related cytokine in humans. In this trial, human and rhesus monkey IL-12 were tested along with another member of the IL12 cytokine family, IL-27. Additional important, but unrelated, inflammatory cytokines TNFα, IL-6, and IFNy were also tested. ID-L253T showed no interaction with the cytokines tested. This indicates that binding of ID-L253T to off-target molecules would be very unlikely in humans and non-human primates. Example 7: Further investigations of protease stability in ID-L253T gastrointestinal matrix metalloproteinase resistance and mouse gastrointestinal transit Example 7.1: Resistance to gastrointestinal matrix metalloproteinases Levels of activated matrix metalloproteinases (MMPs) are increased in the inflamed mucosa of patients with inflammatory bowel disease. These MMPs can digest native human IgG and therapeutic agents containing a human IgG scaffold (Biancheri et al, 2015). In the case of anti-TNFa therapy etanercept, this digestion causes a significant reduction in the neutralizing potency of TNFα. To confirm that ID-L253T is resistant to MMPs, ID-L253T was incubated for approximately 20 hours in the presence of activated recombinant human MMP3 and MMP12. ID-L253T demonstrated complete survival over the course of approximately 20 hours, while etanercept was degraded by the same enzyme preparations. ID-L253T is completely resistant to digestion by MMP3 and MMP12 within approximately 20 hours at 37°C. This indicates that ID-L253T should retain high stability in the inflamed environment of the Eli intestine, where MMP levels are high. This finding, together with previous findings regarding general protease resistance, suggests that the polypeptides of the invention have great potential as oral therapy for ILD. Example 7.2: Gastrointestinal transit and mouse survival The results of the in vitro studies described above showed that ID-L253T was resistant to inactivation by proteases present in a supernatant extract prepared from the contents of the mouse small intestine. In the author's experience, mouse small intestine supernatant is much more proteolytically active than small intestine supernatant obtained from humans or pigs. A study was carried out to investigate the stability of ID-L253T during passage through the mouse gastrointestinal system. ID-L253T was formulated with anti-TNF-alpha ICVD ID-38F (see WO2016156465, SEQ ID NO: 8 and Example 8 thereof) in a mixture of milk and bicarbonate. It has previously been established that ID-38F is stable during mouse gastrointestinal transit and therefore acts as a positive control here. After coadministration of ICVDs to four mice by oral gavage, concentrations of ICVDs were measured in fecal pellets collected between 0 and 3 hours and between 3 and 6 hours. ID-L253T was detected at both 0-3 h and 3-6 h post-dosing at levels comparable to ID-38F in the same mice. The results showed that ID-L253T survives equally or better than ID-38F in mice, reaching higher recovery concentrations of more than 15 μΜ in fecal pellet supernatants collected 3-6 hours after dosing. Example 8: Evaluation of the neutralizing activity of ID-L210T in human IBD tissue The IL-23 neutralizing activity of ID-L210T, a variant of ID-L253T lacking only the E1D, R19S and R92V mutations, was investigated in ex vivo cultures of inflamed colonic mucosa tissue using the assay system described by Vossenkámper et al (2014) and Crowe et al. (2018). The use of this model tested the inhibitory effects of ID-L210T on the elevated levels of signaling phosphoproteins that exist in Eli disease tissue under pathophysiological conditions. The study was carried out using biopsy tissue samples from four patients with active UC. After 24 hours of incubation with ID-L210T (at a concentration of 150 nM) or an isotype control ICVD that does not bind IL-23 (ID-2A, an irrelevant ICVD against C. difficile toxin, a a concentration of 225 nM), biopsy explants were analyzed for phosphoprotein levels using the proteome profiler human phosphokinase array technology. The average phosphorus intensity values ​​for all patients with respect to the various proteins analyzed are shown in Figures 1-2. Phosphorylation levels of most matrix proteins were reduced after IDL210T treatment. The effect of treatment on the total protein phosphorylation signal (Ση=39 phosphoproteins) detected for each biopsy was also evaluated. After treatment with ID-L210T, total phosphorylation levels measured in biopsies from all UC patients were inhibited by (20-52%; average 32% n=4). ID-L253T differs from ID-L210T by only three amino acids, shows similar IL-23-IL-23R inhibition potencies, resistance to in vitro digestion, and trafficking through the mouse. Therefore, these findings regarding ID-L210T are expected to be substantially applicable to ID-L253T. Example 9: Yeast productivity in fermentation culture A production strain of S. cerevisiae expressing ID-L253T was inoculated into a 5-liter fermentation. Production levels were assessed by SDS-PAGE with Coomassie staining, and biological activity was assessed by IL-23-IL-23R neutralization ELISA. The results showed a clean band in the supernatant at the end of fermentation (EoF) with the correct molecular weight, with very few contaminants. The yield of ID-L253T was measured as 0.188 g / L ID-L253T was also tested for production in P. pastoris using standard yeast fermentation technology. Production levels were assessed by SDSPAGE with Coomassie staining and the results showed a clean band in the EoF supernatant with the correct molecular weight. The yield of ID-L253T from this fermentation was measured as 1.3 g / L. Complete neutralization activity was demonstrated by IL-23-IL-23R neutralization ELISA. Example 10: Production and characterization of the heterobihead anti-IL23 / anti-TNF-alpha FA1K construct Example 10.1: Production of FA1K A heterobihead construct was produced comprising the anti-IL-23 ICVD ID-L253T and the anti-TNF-alpha ICVD ID-38F (WO2016156465, SEQ ID NO: 8 therein and SEQ ID NO: 67 in this description) (herein referred to as 'FA1K'). The ICVDs in this construct were cleaved using a flexible non-immunogenic linker (648)4 with a central lysine residue (SEQ ID NO: 49) to create a trypsin-cleavable site (ID-38F-(G4S)2-K-( G4S)2-ID-L253T), of the type described in document WO2016156466. The polypeptide sequence of the ID-38F arm used in FA1K was identical to that of ID-38F used previously (SEQ ID NO: 47) and the polypeptide sequence of the ID-L253T arm used in FA1K was identical to that used for ID-38F. Previous L253T but for a D1E substitution (SEQ ID NO: 48). FA1K was cloned into a Sacl / Hindlll fragment in the pUR9013 vector to facilitate stable multicopy integration into the chromosome of the S. cerevisiae expression strain vwkgall. Using this integration and expression system, FA1K was under the control of a galactose-inducible promoter in S. cerevisiae and biheader secretion was achieved through a yeast mating factor alpha signal sequence. Furthermore, FA1K with the same signal sequence was cloned into the P. pastoris chromosome under the control of the methanol-inducible pAOX1 promoter. S. cerevisiae FA1K expression was evaluated in 50 mL induction cultures. The supernatant from these shake flasks was purified. This purified preparation of FA1K was subsequently used for the experiments described below, unless otherwise indicated. FA1K was also cloned in P. pastoris and demonstrated excellent expression at a 50 mL scale. Example 10.2: In vitro characterization of FA1K Incubation of FA1K with trypsin at 37 °C resulted in rapid separation of the ID-L253T and ID-38F monomer arms. Therefore, FA1K is well formatted for rapid release of both monomer arms upon trypsin exposure in the human small intestine. The neutralizing potency of FA1K (pre- and post-trypsin cleavage) against TNF-alpha was investigated (see Figure 3, where 'FA1K' refers to pretreatment with trypsin FA1K and 'trypsin FA1K' refers to treatment later with trypsin FA1K). A biotinylated humira (adalimumab) competition ELISA was performed that measures competition for an epitope on TNF-alpha. When competition occurs, the epitope is occupied by an unlabeled polypeptide and the less biotinylated humira binds to TNFα, resulting in a lower assay signal. ELISA plates were coated with 100 ng / mL human TNFα in 250 pg / mL bovine serum albumin (BSA) in phosphate-regulated saline (1x PBS) and blocked with 1% BSA in 1x PBS. 1% BSA plus 0.1 mM PMSF was used as assay diluent for all experiments on polypeptides that had trypsin pretreatment. Otherwise, 1% BSA was used as assay diluent. Biotinylated adalimumab (LGC) was mixed 1:1 with all standards and samples to give a final concentration of 2 nM biotinylated adalimumab before adding the mixtures to the plates. Bound biotinylated adalimumab was detected using ExtrAvidin-horseradish peroxidase (Sigma E2886) and visualized using TMB Microwell Substrate (KPL 50-76-00) before stopping with 0.5 M H2SO4 and reading at 450 nm FA1K (before and after trypsin treatment) was found to be substantially as potent as ID-38F in this competition ELISA. The neutralizing potency of FA1K (pre- and post-trypsin cleavage) against IL-23 was investigated (see Figure 4, where FA1K refers to pre-treatment with trypsin FA1K, trypsin FA1K refers to post-treatment with trypsin FA1K ). FA1K (trypsin pre- and post-treatment) was at least as potent against IL-23 as ID94 L253T. The inclusion of ID-L253T in the C-terminal position of FA1K, so that the IDL253T arm has an N-terminal extension compared to the free ID-L253T monomer, may also appear to provide a benefit for IL-neutralization. 2. 3. FA1K produced and purified from expression in P. pastoris was also confirmed by ELISA to be fully potent against TNF-alpha and IL-23 (data not shown). Both monomeric arms of FA1K were shown to retain the favorable stability characteristics of the parent ID-38F and ID-L253T monomers after incubation for 4 hours in human fecal supernatant (see Figure 5, where, from left to right, the % survival of (a) ID-38F, (b) ID-38F in the form of FA1K monomer arm, (c) ID-L253T and (d) ID-L253T in the form of FA1K monomer arm. Taken together, the above findings demonstrate that FA1K is a suitable format for delivering high concentrations of each of these monomers as dual therapy. FA1K retains the favorable potency and protease stability characteristics of the original monomers. Due to the labile binding format, exposure of FA1K to trypsin results in rapid release of both monomer arms, allowing independent binding to their respective targets without interference from the other arm. Example 11: Ex vivo characterization of the combined administration of anti-IL-23 (ID-L210T) and anti-TNF-alpha (ID-38F) to human Eli tissue It has been shown previously and in other publications that ICVDs with TNF-alpha neutralizing activities (ID-38F) and IL-23 neutralizing activities (IDL210T) can suppress the phosphorylation of tyrosine kinase receptors and signaling proteins that increase in inflamed intestine tissue samples taken from patients with a diagnosis of Eli (see example 8 above and example 9 of WO2016156465). A new study was conducted to investigate the effects of combining ID-38F with L210T on phosphoprotein biomarker levels in ex vivo cultures of inflamed colonic mucosa tissue obtained from UC patients. ID-L210T differs from ID-L253T by only three amino acids and shows similar IL-23-IL-23R inhibition potencies and resistance to in vitro digestion. The effects of the individual ICVDs were compared with a mixture of the two ICVDs and with an isotype control ICVD (ID-2A, an irrelevant anti-C. difficile toxin ICVD) to evaluate what effects could be achieved by combining the different anti-cytokine mechanisms. The biopsies from each of the four patients with UC were incubated for 24 hours with the different antibodies (control ID-2A, ID-38F, ID-L210T or ID-38F+ID-L210T) and, after treatment, the lysates of tissue were analyzed on phosphoprotein antibody arrays. The average signal intensity data per patient for the 45 phosphoproteins detected on the individual arrays (4 arrays per treatment) are presented in Figures 6-7 (where L210T refers to ID-L210T). The inhibitory effects of the different antibody treatments are demonstrated by a shift from predominantly high levels of phosphorylation for biopsies treated with the ICVD ID2A control, to relatively low phosphointensity values ​​for biopsies treated with anti-TNF-alpha or anti-IL. -23 ICVD or a combination of the two. The data provided herein illustrate that a therapeutic approach combining Gl-restricted antagonism of TNF-alpha and IL-23 can achieve a higher degree of efficacy, for a longer duration, in a greater proportion of patients with inflammatory bowel disease, than monotherapy against any target alone. Diverse All references referenced in this application, including patents and patent applications, are incorporated herein by reference to the greatest extent possible. Throughout the specification, unless the context otherwise requires, the word 'comprise' and variations such as 'comprises' and 'comprising' will be understood to imply the inclusion of an integer, step, group of numbers. integers or group of steps, but without exclusion of any other integer, step, group of integers or group of steps. The application of which this description and claims form a part may be used as a basis for priority with respect to any subsequent application. The claims of said subsequent application may be directed to any feature or combination of features described herein. They may take the form of product, composition, process or use claims and may include, by way of example and without limitation, the following claims. 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Claims

1. A polypeptide characterized in that it comprises an immunoglobulin chain variable domain that binds to IL-23, wherein the immunoglobulin chain variable domain comprises three complementarity determination regions (CDR1-CDR3) and four frame regions (FR1-FR4), wherein CDR1 comprises a sequence that shares 60% or more sequence identity with SEQ ID NO: 1, CDR2 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO: 2, and CDR3 comprises a sequence that shares 50% or more sequence identity with SEQ ID NO:

3.

2. The polypeptide according to claim 1, characterized in that CDR1 comprises or consists of a sequence that shares 80% or more sequence identity with SEQ ID NO:

1.

3. The polypeptide according to claim 1 or 2, characterized in that CDR2 comprises or consists of a sequence that shares 80% or more sequence identity with SEQ ID NO:

2.

4. The polypeptide according to any of claims 1 to 3, characterized in that CDR3 comprises or consists of a sequence that shares 80% or more sequence identity with SEQ ID NO:

3.

5. The polypeptide according to claim 1, characterized in that CDR1 comprises or consists of SEQ ID NO: 1, CDR2 comprises or consists of SEQ ID NO: 2 and CDR3 comprises or consists of SEQ ID NO:

3.

6. The polypeptide according to any one of claims 1 to 5, characterized in that it comprises or consists of a sequence that shares 50% or more sequence identity, such as shares 55% or more sequence identity, such as shares 60% or more sequence identity, such as shares 65% or more sequence identity, such as shares 70% or more sequence identity, such as shares 75% or more sequence identity, such as shares 80% or more sequence identity, such as shares 85% or more sequence identity, such as shares 90% or more sequence identity, such as shares 95% or more sequence identity, such as shares 96% or more sequence identity, such as shares 97% or more sequence identity, such as shares 98% or more sequence identity, such as shares 99% or more sequence identity, with SEQ ID NO:

8.

7. The polypeptide according to claim 6, characterized in that it comprises SEQ ID NO:

8.

8. The polypeptide according to claim 7, characterized in that it consists of SEQ ID NO:

8.

9. The polypeptide according to any of claims 1 to 8, characterized in that the polypeptide is an antibody or an antibody fragment.

10. The polypeptide according to any one of claims 1 to 9, characterized in that the polypeptide consists of an immunoglobulin chain variable domain.

11. The polypeptide according to any one of claims 1 to 10, characterized in that the variable domain of the immunoglobulin chain is a VHH, VH or VL.

12. The polypeptide according to claim 11, characterized in that the variable domain of the immunoglobulin chain is a VHH or VH.

13. The polypeptide according to claim 12, characterized in that the variable domain of the immunoglobulin chain is a VHH.

14. A construction characterized in that it comprises at least one polypeptide according to any of claims 1 to 13 and at least one different polypeptide, wherein the different polypeptide binds to TNF-alpha.

15. The construction according to claim 14, characterized in that the different polypeptide comprises a sequence that shares at least 80% sequence identity with SEQ ID NO:

67.

16. The construction according to any of claims 14 or 15, characterized in that the polypeptides are connected by at least one protease-labile linker comprising or consisting of SEQ ID NO:

74.

17. The construction according to claim 16, characterized in that the construction comprises or consists of SEQ ID NO:

46.

18. The polypeptide or construct according to any one of claims 1 to 17, characterized in that it neutralizes human IL-23 in Assessment Method A with an EC50 of 5 nM or less, such as 4 nM or less, such as 3 nM or less, such as 2 nM or less, such as 1.7 nM or less, such as 1.5 nM or less, such as 1.4 nM or less, such as 1.3 nM or less, such as 1.2 nM or less, such as 1.1 nM or less, such as 1.0 nM or less, such as 0.9 nM or less, such as 0.8 nM or less, such as 0.75 nM or less, such as 0.70 nM or less, such as 0.65 nM or less, such as 0.60 nM or less, such such as 0.55 nM or less, such as 0.50 nM or less, such as 0.45 nM or less, such as 0.40 nM or less, such as 0.35 nM or less, such as 0.30 nM or less, such as 0.25 nM or less, such as 0.20 nM or less.

19. The polypeptide or construct according to any of claims 1 to 18, characterized in that the polypeptide or construct binds to IL-23 with a Kd of 10'6 M or less, such as 10-7 M or less, such as 10-8 M or less, such as 10-9 M or less, such as 10'10 M or less, such as 10'11 M or less, such as 10'12 M or less, such as 10'13 M or less.

20. The polypeptide or construct according to any of claims 1 to 19, characterized in that the polypeptide or polypeptides are substantially resistant to trypsin and chymotrypsin.

21. A pharmaceutical composition characterized in that it comprises the polypeptide or construct according to any of claims 1 to 20 and one or more pharmaceutically acceptable diluents or carriers.

22. The pharmaceutical composition according to claim 21, characterized in that it comprises at least one other active ingredient.

23. The polypeptide, pharmaceutical composition or construction according to any of claims 1 to 22 for use as a medicament.

24. The polypeptide, pharmaceutical composition or construct according to claim 23 for use in the treatment of an autoimmune and / or inflammatory disease.

25. A method for treating autoimmune and / or inflammatory diseases characterized in that it comprises administering to a person in need a therapeutically effective amount of the polypeptide, pharmaceutical composition or construct according to any of claims 1 to 22.

26. Use of the polypeptide, pharmaceutical composition or construction according to any of claims 1 to 22 in the manufacture of a medicament for the treatment of autoimmune and / or inflammatory diseases.

27. The polypeptide, pharmaceutical composition or construct for use, the method or use according to any one of claims 23 to 26, wherein the polypeptide, pharmaceutical composition or construct is administered orally.

28. The polypeptide, pharmaceutical composition or construct to be used, the method or use according to any of claims 24 to 27, wherein the autoimmune and / or inflammatory disease is Crohn's disease or ulcerative colitis.

29. A polynucleotide characterized in that it codes for the polypeptide or construct according to any of claims 1 to 20.

30. The polynucleotide according to claim 29, characterized in that the polynucleotide comprises or consists of a sequence that shares 70% or more, such as n / crzn / zznz / q / uili 101, 80% or more, such as 90% or more, such as 95% or more, such as 99% or more of sequence identity with SEQ ID NO:

10.

31. The polynucleotide according to claim 30, characterized in that the polynucleotide comprises or consists of SEQ ID NO: 10.