Antibodies that bind to VISTA at acidic pH

Abstract

This application relates to antibodies that specifically bind to T-cell activation inhibitory factor (VISTA) containing V-domain immunoglobulins at acidic pH, and their use in cancer treatment. In some embodiments, the antibody specifically binds to human VISTA at acidic pH, but does not significantly bind to human VISTA at neutral or physiological pH.

Description

Invention Field

[0001] This application relates to antibodies that specifically bind to T-cell activation inhibitory factor (VISTA) containing V-domain immunoglobulins at acidic pH and their use in cancer treatment. Background Technology

[0002] VISTA, a T-cell activation inhibitor containing the V-domain Ig, is a co-inhibitory member of the B7 family of immune receptors expressed by granulocytes, monocytes, and other leukocytes. However, the mechanism by which VISTA suppresses immune responses is poorly understood.

[0003] The inventors have discovered that, unlike other known immune receptors, VISTA binds to its antireceptor and functions selectively at acidic pH, exhibiting less activity at physiological pH (e.g., 7.3–7.4). VISTA can thus suppress immune responses in acidic microenvironments (e.g., tumor beds or sites of inflammation) without disrupting blood cell circulation or residing in non-inflammatory, non-acidic tissues. Furthermore, the inventors have discovered that anti-VISTA antibodies can be engineered to selectively bind to VISTA at acidic pH, exhibiting less or no binding at physiological pH, thus reflecting VISTA's inherent acidic pH selectivity. These acidic pH-selective antibodies, compared to antibodies that bind VISTA at physiological pH, can provide desired properties for treating diseases such as cancer. Summary of the Invention

[0004] This disclosure relates to antibodies that specifically bind to the extracellular domain (ECD) of VISTA (e.g., human VISTA (“hVISTA” or “huVISTA”)) at acidic pH (e.g., under acidic conditions). This disclosure also relates to antibodies that specifically bind to the extracellular domain (ECD) of VISTA (e.g., hVISTA) at acidic pH and exhibit less binding or no binding at neutral or physiological pH. The inventors note herein that the hVISTA-ECD amino acid sequence contains numerous conserved and non-conserved histidine residues, and that the frequency of histidine residues in the VISTA ECD is significantly higher than that of other B7 family members and other immunoglobulin superfamily members. (See also...) Figure 1A and 1B In solution, the amino acid histidine has a pK value of approximately 6.5. aThis means that histidine residues within proteins are typically protonated and thus positively charged at or below pH 6.5, while becoming increasingly unprotonated and neutrally charged above pH 6.5. Tumor microenvironments and inflamed tissues are typically acidic, and VISTA proteins found in these microenvironments can be at least partially protonated at their histidine residues. As discussed herein, the inventors have hypothesized that histidine protonation can affect the conformation, surface structure, and / or charge density of VISTA, which in turn can generate pH-specific or pH-selective epitopes for receptor-ligand interactions and antibody binding. Targeting VISTA with antibodies that bind at acidic pH but not at neutral or physiological pH prevents target-mediated in vivo drug disposition via circulating and lymphoid organ-resident granulocytes / monocytes, thereby improving antibody PK, receptor occupancy, and tumor microenvironment activity. In the context of therapeutic modalities such as antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent phagocytosis (ADCP), complement-dependent cytotoxicity (CDC), and payload (antibody-drug conjugate) delivery, acidic pH-selective antibodies can also improve the specificity of VISTA antibodies for intratumoral (rather than circulating) target cells. Attached Figure Description

[0005] The U.S. provisional application that claims priority to this application contains at least one color drawing. Assuming the provisional application will subsequently become publicly available, a color-drawn copy may be obtained from the United States Patent and Trademark Office upon request and payment of the necessary fees.

[0006] Figure 1A-1C The results show that the extracellular domain of VISTA contains an exceptionally high frequency of histidine residues, many of which are conserved, and at least some of which are involved in receptor-ligand binding. Figure 1A A graph showing proteins containing immunoglobulin domains, with the number of amino acid residues in the extracellular domain of each protein plotted on the x-axis and the frequency of histidine residues in the extracellular domain of each protein plotted on the y-axis. The size of each data point corresponds to the total number of histidine residues in the extracellular domain of each protein. Figure 1B The aligned amino acid sequences of the extracellular domains of human VISTA, cynomolgus monkey VISTA, and mouse VISTA are shown. The positions of the signal peptide (Sig) and transmembrane domain (TMD) are marked. Conserved histidine residues in all three species are shown in bold and underlined; conserved histidine residues in humans and cynomolgus monkeys are shown in bold only. Figure 1CA model showing the three-dimensional structure of the human VISTA immunoglobulin domain. Histidine residues are plotted as sphere and stick traces.

[0007] Figure 2A-2B This model demonstrates that histidine residues in the extracellular domain of VISTA confer reverse receptor selectivity against acidic pH rather than physiological pH. Figure 2A This shows the balance between the absence and presence of protonation of the pyrrolidone (NH) group in histidine residues. The pKa of histidine in solution is 6.5, indicating that histidine residues are more likely to be protonated at pH 6.5 and lower than at higher pH, and thus carry a positive charge. Figure 2B The model demonstrates that VISTA selectively binds to P-selectin glycoprotein ligand 1 (PSGL-1) or other antireceptors and ligands (“VISTA-R”) at acidic pH. Therefore, antibodies that bind to the extracellular domain of VISTA at acidic pH, rather than at physiological pH, may be crucial for inhibiting or modulating VISTA activity.

[0008] Figure 3 This image shows the surface expression level of VISTA on tumor-infiltrating macrophages, dendritic cells, neutrophils, CD4+ effector T cells, CD4+ regulatory T cells, CD8+ T cells, natural killer (NK) cells, and B cells (mean fluorescence intensity (MFI) of anti-VISTA antibody staining). VISTA is expressed on many tumor-infiltrating leukocytes, especially myeloid cells. The tumor microenvironment is typically acidic, which allows VISTA to bind to its antireceptor and ligand.

[0009] Figure 4A-4G The results showed that VISTA selectively binds to leukocytes and PSGL-1 at acidic pH and has little or no binding at neutral pH, and this binding can be blocked by anti-VISTA antibodies. Figure 4A On the left, representative histograms of fluorescently conjugated recombinant VISTA multimers bound to activated human CD4+ T cells are shown. Filled histograms, from darker gray to lighter gray, depict binding at pH 7.0, 6.5, 6.4, 6.3, 6.1, and 6.0. Some histograms are labeled with their corresponding pH values. Binding of the non-VISTA control multimer at pH 6.0 is shown as an unfilled histogram. On the right, the mean MFI of VISTA (circles) and control (triangles) multimers bound to activated human CD4+ T cells from two donors at different pH values ​​is plotted. Figure 4BRepresentative histograms of recombinant VISTA multimers bound to peripheral blood mononuclear cells (PBMCs) at pH 6.0 and pH 7.4. Histograms filled from darker gray to lighter gray represent binding to CD19+ B cells, CD4+ T cells, CD8+ T cells, CD56+ NK cells, and CD14+ monocytes at pH 6.0. Histograms without filled solid and dashed borders represent binding to total PBMC lymphocytes and monocytes, respectively, at pH 7.4. Figure 4C The diagram shows representative recombinant VISTA multimers that bind to activated human CD4+ T cells in the presence of anti-VISTA blocking antibody (squares) or non-VISTA-specific isotype-matched control antibody (circles). Antibody concentrations are plotted on a logarithmic scale. Non-linear regression is also shown. Triangles represent background signal from activated human CD4+ T cells not stained with recombinant VISTA multimers. Figure 4D A representative two-dimensional flow cytometry plot showing recombinant VISTA multimers bound at pH 6.0 to heparan sulfate-deficient Chinese hamster ovary (CHO) cells (cell line pGSD-677, American Type Culture Collection) transfected to express human PSGL-1. (Presence and absence of...) Figure 4C Cells showing anti-VISTA blocking antibody binding were subjected to multimer binding. Cells not stained with recombinant VISTA multimers are shown as controls. PSGL-1 antibody staining is plotted on the y-axis, and VISTA multimer staining is plotted on the x-axis. Figure 4E Representative histograms showing the binding of recombinant mouse VISTA-Fc fusion protein to mouse spleen cells at pH 6.0 and pH 7.4. Histograms filled from darker gray to lighter gray represent binding to CD8+ T cells, CD11b+ myeloid cells, and CD4+ T cells at pH 6.0. Unfilled histograms represent binding to total spleen cells at pH 7.4. Figure 4F and 4G The results showed that VISTA multimers bound to monocytes and neutrophils, respectively, and the binding was stronger at pH 6.0 than at pH 7.4.

[0010] Figures 5A-5D The results showed that VISTA preferentially mediates T cell suppression and cell-to-cell adhesion at acidic pH, and both effects can be reversed by anti-VISTA blocking antibodies. Figure 5A Representative cells at pH 6.0 and 7.0 are shown between 293T cells expressing hVISTA or vector controls (plotted on the y-axis) and CHO cells endogenously expressing heparan sulfate on the cell surface (on the x-axis): cell conjugate formation. Figure 5BThis is a graph showing the frequency of cell conjugates formed between identical cells at pH 6.0 in the presence of anti-VISTA blocking antibody, anti-VISTA non-blocking antibody, or isotype-matched non-VISTA-specific control antibody. Figure 5C A representative plot showing the luciferase activity generated by Jurkat (human T cell line) cells expressing the NFkB luciferase reporter gene after co-culturing with 293T cells expressing hVISTA and a single-chain variable fragment of the anti-human T cell receptor agonist antibody OKT3 (“artificial antigen-presenting cells”) at various pH levels. Anti-VISTA blocking antibody (squares) or isotype-matched non-VISTA-specific control antibody (circles) was added to the co-cultured cells. Figure 5D In the middle, Figure 5A The data shown are plotted as the fold increase in luciferase signal relative to control when treated with anti-VISTA antibody ("effect size").

[0011] Figure 6A-6G The results showed that VISTA can be found in intracellular endosomes, especially in Rab11+ recirculating endosomes, and can be transported and recirculated into and out of the cell surface via endosomes. Figure 6A This demonstrates the co-localization of VISTA, Rab5 (early endosomal marker), Rab7 (late endosomal marker), and Rab11 (recirculating endosomal marker) in 293T cells expressing human VISTA. Figure 6B This demonstrates the co-localization of VISTA and Rab11 in human monocytes. Intracellular VISTA co-localizes with Rab11+ circulating endosomes. The non-VISTA-binding control antibody (“cAb”), which is the same type as the VISTA antibody, does not bind detectably to monocytes. Figure 6C The images show the binding of three anti-VISTA antibodies to recombinant VISTA at pH 7.4 (black), 6.7 (darker gray), and 6 (lighter gray). Figure 6D The susceptibility of the same anti-VISTA antibody 1 (inverted triangle), 2 (circle), 3 (square), or a non-VISTA-specific control antibody (triangle) with a cathepsin B-sensitive linker and cytotoxic payload to killing VISTA-expressing acute myeloid leukemia (AML) cell lines is shown. Cell viability (CellTiter-Glo LU) is plotted on the y-axis and antibody concentration on the x-axis. Figure 6E The binding of anti-VISTA antibody 3 to hVISTA, an engineered variant (“VISTA mAb3c”) that does not exhibit impaired binding at acidic pH, was compared. Figure 6F An antibody-drug conjugate assay showing the efficacy of anti-VISTA antibodies 3 (square) and 3c (rhombus). Figure 6GThis diagram illustrates endosome transport, where VISTA recirculates into and out of the cell surface via early endosomes and recirculating endosomes.

[0012] Figures 7A-7F This demonstrates the method for designing and screening a library of anti-VISTA antibody variants to obtain acidic pH-selective antibodies. Figure 7A Amino acid substitutions were performed in VH CDR 3 of the anti-human VISTA antibody clone P1-061029 (abbreviated as '029) to generate a '029 library for screening. To potentially improve binding to histidine-rich regions of VISTA at acidic pH, the library allows substitution of negatively charged amino acids aspartate and glutamate, as well as pH-responsive histidines. X = H, D, or E. Bracketed sequences were removed during synthesis to avoid introducing susceptibility. A total of 647 unique sequences were synthesized from P1-061029HCDR3 with 1-2 mutations. Figure 7B This displays the procedure for iterative screening and selection of acidic pH-selective antibody variants from the '029 library. R indicates the selection round number. Figure 7C This displays representative two-dimensional flow cytometry plots of the variant pool after nine rounds of selection. VISTA binding is plotted on the y-axis, and variant antibody expression is plotted on the x-axis. Binding data are shown at various antibody concentrations and pH levels. Figure 7D The graph shows the binding of P1-061029 and its progeny clones to human VISTA at pH 6.0 and 7.4. Figure 7E The graph shows the dissociation rates of P1-061029 and its progeny clones with human VISTA at pH 6.0. Figure 7F The data show the SPR binding of antibodies P1-068761, P1-068767, and P1-061029 to human VISTA at pH 6.0 and pH 7.4.

[0013] Figures 8A-8F The acid pH-selective cell binding, blocking, and effector activities of VISTA antibodies P1-068761 and P1-068767 were demonstrated. Figure 8A and Figure 8B The acidic pH-selective antibody P1-068761 binds to Raji cells ectopically expressing human VISTA. Figure 8A ) and P1-068767 ( Figure 8B The average fluorescence intensity of the cells was measured. Cells were incubated at approximately pH 6.0 (circular). Figure 8AThe highest curve in the middle), 6.1 (square; third highest curve), 6.2 (triangle; second highest curve), 6.4 (inverted triangle; fourth highest curve and close to pH 6.1 curve), 6.6 (diamond; fourth curve from the bottom), 7.0 (circle; third curve from the bottom), 7.2 (square; second curve from the bottom) and 8.1 (unfilled triangle; Figure 8A Staining was performed under the bottom curve (in the diagram). Binding was detected using fluorescently conjugated anti-human IgG secondary antibody. Figure 8C The image shows the binding of P1-068767 (round) and the isotype-matched nonspecific control antibody (triangle) to Raji cells ectopically expressing 3125 ng / mL human VISTA at various pH values. "pH" 50 (The pH of the P1-068767 binding with 50% loss is approximately 6.6.) Figure 8D The images show isotype-matched nonspecific control antibody (pH 7.0 and 6.0, filled and unfilled circles, respectively) binding to human monocytes, and anti-VISTA mAb 2 (“Control”, see below). Figure 6C The mean fluorescence intensity (MFI) of P1-068761 (pH 7.0 and 6.0 for filled squares and unfilled squares, respectively), P1-068767 (pH 7.0 and 6.0 for filled triangles and unfilled triangles, respectively), and P1-068767 (pH 7.0 and 6.0 for filled inverted triangles and unfilled inverted triangles, respectively) was measured by detecting binding of fluorescently conjugated anti-human IgG secondary antibodies. Figure 8E The results showed that P1-061029 (square), P1-068761 (triangle), and P1-068767 (inverted triangle) significantly blocked the binding of recombinant VISTA multimers to activated human CD4+ T cells at pH 6.0, while the non-VISTA-specific control antibody (round) did not block VISTA binding. Figure 8F The efficacy of P1-068761 (triangle) and P1-068767 (inverted triangle) in reducing antibody-dependent cytotoxicity (ADCC) mediated by physiological pH is shown. P1-061029 (square), non-VISTA-specific positive control antibody (circle), and non-VISTA-specific negative control antibody (diamond) are also shown. NK cell-specific lysis of target cells (as a percentage of total target cells) is plotted on the y-axis and antibody concentration on the x-axis. Nonlinear regression is also shown.

[0014] Figure 9 The figure shows the enhanced pharmacokinetics (PK) of the acidic pH-selective anti-VISTA antibody in cynomolgus monkeys. The figure shows the enhanced pharmacokinetics (PK) of the anti-VISTA antibody 2 (“Control”, circle, see figure 2). Figure 6C VISTA antibody 3 (“acid pH sensitive”, square, see also) Figure 6CSerum antibody concentrations over time in cynomolgus monkeys treated with P1-068767 (triangle) or P1-068767 (triangle).

[0015] Figure 10A and 10B This demonstrates the binding effect of mutations in acidic pH-selective anti-VISTA antibodies '761 and '767. Figure 10A This shows the kinetic binding data of the P1-068761 reversion mutant at pH 7.4, pH 6.7, and pH 6.0, and the position of the reversion mutant relative to P1-068761. Figure 10B This shows the kinetic binding data of the P1-068767 reversion mutant at pH 7.4, pH 6.7, and pH 6.0, and the position of the reversion mutant relative to P1-068767.

[0016] Figure 11A-11C Displaying and mapping the epitope binning of various anti-VISTA antibodies. Figure 11A The results show that P1-068761 and P1-068767 compete for the VISTA epitope with P1-061029 and the VISTA antibody control. Figure 11B and Figure 11C The antibody showed blocking hVISTA ( Figure 11B ) and non-blocking hVISTA antibody (mAb1; Figure 11C Epitopes of all residues compared to (as listed in Table 14). Amino acid residues 66(H) and 162(A) are used to indicate molecular orientation. Histidine residues are gray, and epitope residues are black.

[0017] Figures 12A-12C Display the following imaging capillary isoelectric focusing (icIEF) data: Figure 12A P1-061029 Figure 12B P1-068761, and Figure 12C P1-068767. Indicates the isoelectric point of the main substance (pI main) and the pI marker.

[0018] Figure 13A and 13B Shows the alignment of the variable regions of the '029 and '015 offspring clones. Figure 13A This shows the amino acid sequence alignment of the variable region of '029 and its progeny clones. Figure 13B This shows the amino acid sequence alignment of the variable region of '015 and its progeny clones.

[0019] Figure 14The image shows the alignment of the VH sequence of P1-068761 with and without K16R and T84A substitutions. Double-underlined residues indicate positions 16 and 84 in the frame region, and shaded areas indicate CDRs.

[0020] Figure 15A-15O MC38 tumors were implanted into wild-type C57BL6 mice, and the mice were treated with a non-binding isotype-matched control antibody (black square), mouse VISTA blocking antibody VISTA.10 (upward triangle), mouse PD-1 blocking antibody (square), or a combination of VISTA and PD-1 blocking antibodies (downward triangle). All antibodies were mouse IgG1-D265A (Fc-inert) isotypes. (See also...) Figures 15A-15D These data represent three independent experiments. Figures 15A-15D The tumor volume is displayed over time. n = 10 / group. "TF" indicates mice that reject the tumor. Figure 15E and 15F The frequency of CD8+ T cells and CD4+ T cells in the tumor was shown 7 days after the start of treatment. n = 5 / group. Single-factor ANOVA and Dunnett's multiple comparison were used, with P = 0.0001. Figure 15G and 15H Show Figures 15A-15D The results for the individual mice shown are as follows. Figure 15I VISTA knockout mice and wild-type littermates were implanted with MC38 tumors and treated with either a non-binding, allotype-matched control antibody (the two upper curves, 0 / 7TF and 0 / 5TF, marked with circles and downward-pointing triangles) or a mouse PD-1 blocking antibody (the two lower curves, 0 / 5TF and 5 / 8TF, marked with squares and downward-pointing triangles). Adjacent curves show median tumor growth and the number of tumor-free (TF) mice at the end of the study compared to the total number of mice (e.g., 0 / 7TF). These data represent two independent experiments. Error bars plot the interquartile range. Figure 15J-15M This indicates implantation into MC38 tumors using a non-binding isotype-matched control antibody. Figure 15J ), mouse PD-1 blocking antibody ( Figure 15K A combination of mouse PD-1 blocking antibody and non-pH-selective human VISTA blocking antibody P1-061029 ( Figure 15L ) or a combination of mouse PD-1 blocking antibody and acidic pH-selective human VISTA blocking antibody P1-068767 ( Figure 15M Tumor volume in human VISTA knock-in (KI) mice treated with the drug. All antibodies were mouse IgG1-D265A isotypes. Tumor volume changes over time are shown. n = 5–8 per group. These data represent an independent experiment. Figure 15N The data show serum antibody concentrations in human VISTA KI and wild-type littermate (WT) mice following intravenous injection of 5 mg / kg P1-061029 (WT, down-facing triangle; KI, square) or P1-068767 (WT, up-facing triangle; KI, rhombus). The calculated mean serum retention time (MRT) for P1-061029 and P1-068767 in KI mice was estimated to be 4.1 h and 71 h, respectively. For each antibody, n = 4 KI mice and 1–2 WT mice. These data represent a single experiment. Figure 15O The table shows serum antibody concentrations in cynomolgus macaques following intravenous injection of 5 mg / kg VISTA.4 (round) or P1-068767 (square). The calculated mean serum retention time (MRT) for VISTA.4 and P1-061029 was estimated to be 7.6 h and 717 h, respectively. n = 1 macaque / antibody. These data represent a single experiment. Error bars show the standard error of the mean unless otherwise indicated.

[0021] Figures 16A-16C The results showed that PD-1 was detected 7 days after the start of treatment. Figure 16A ), LAG-3 ( Figure 16B ) and TIM-3 ( Figure 16C A representative histogram of CD8+ T cell expression within the tumor. Error bars represent the standard error of the mean.

[0022] Figures 17A-17C The results showed that VISTA binds to PSGL-1 at acidic pH and this interaction is blocked by VISTA antibodies P1-061029, P1-068761, P1-068767 and VISTA.4. Figure 17A BLI binding smears showing P-selectin-Fc and VISTA-Fc binding to PSGL1 at pH 6.0 and pH 7.4. Figure 17B This is a histogram showing the inhibition of PSGL-1 binding to hVISTA by antibodies P1-061029, P1-068761, P1-068767, and VISTA.4. Figure 17C The data show antibody blocking of VISTA.4 (upward-pointing triangle) and anti-PSGL-1 antibody KPL-1 (circle) on the binding of VISTA-Fc to CHO-PSGL-1 cells. These data represent two independent experiments. Error bars plot the standard error of the mean.

[0023] Figures 18A-18E Display P1-068767Fab and hVISTA, or (in...) Figure 18EA representative diagram of the co-crystal structure of the non-blocking antibodies VISTA.5 and hVISTA. The VISTA IgV domain is characterized by an aberration in its central β-sheet and an enriched histidine extension. The VISTA IgV domain is co-crystallized with the P1-068767 antigen-binding fragment (Fab). The crystal structure of the VISTA+P1-068767 complex was determined at high resolution. Figure 18A This shows the VISTA IgV domain: P1-068767Fab eutectic structure. Figure 18A The overall structure of the complex of the VISTA IgV domain and P1-068767Fab is shown (heavy chain, dark gray; light chain, light gray). Figure 18B The superposition of the VISTA and PD-L1 IgV domains is shown. The histidine residues of VISTA are represented by a stick diagram. Figure 18B The results show that the VISTA IgV domain has an abnormally enriched histidine β-sheet extension. Figure 18C The molecular surface (light gray electrostatic surface) of the P1-068767 epitope is shown as revealed by the crystal structure of VISTA+P1-068767. Figure 18C The results showed that the blocking antibody bound to the enriched histidine β-sheet extension of VISTA. Figure 18D A magnified view showing the interface between VISTA (gray ribbon cartoon, with epitope residues H121, H122 and H123 drawn in stick diagram form) and P1-068767 (drawn as an electrostatic surface, with its residues E100 and D102 in stick diagram form). Figure 18D The results show that the acidic pH-selective P1-068767 uses acidic residues to bind VISTA histidine. Figure 18E The results showed that the non-blocking antibody VISTA.5 binds to the hVISTA region, which is different from that of P1-068767.

[0024] Figure 19 The epitopes of VISTA.4 are shown as determined by MS-HDX (MS traces).

[0025] Figure 20 Display based on Figure 19 The position of the VISTA.4 epitope in the hVISTA amino acid sequence of the data. Figure 19 Residues 57-68, 86-97, and 148-165 are also highlighted in Figure 20 It is illustrated in light gray text and underlines.

[0026] Figure 21A and 21BThe VISTA multimers bound to activated human CD4+ T cells at pH 6.0 in the presence of antibodies VISTA.4 (triangle), VISTA.5 (square), and non-VISTA-binding antibody (control, circle). Figure 21B The blocking efficiency of each antibody relative to non-blocking T cells is shown. Single-factor ANOVA and Dunnett multiple comparisons were performed, ***, P < 0.001. These data represent more than four independent experiments. Error bars plot the standard error of the mean.

[0027] Figure 22 shows that antibodies that block VISTA binding at acidic pH are functional. Blocking antibody VISTA.4 (square), non-blocking antibody VISTA.5 (triangle), and non-VISTA-binding (control, circle) antibody pairs are used to promote the proliferation of human CD4+ T cells co-cultured with 293T cells engineered to express VISTA and TCR agonists (293T-OKT3-VISTA). Figure 22A ) and interferon-γ production ( Figure 22B The effect of ) was observed. Single-factor ANOVA and Dunnett multiple comparisons were performed, *, P<0.05. These data represent more than four independent experiments.

[0028] Figure 23 The effect of VISTA.4 on JurkatT cell activation was shown to be blocked at different pH levels after co-culturing with 293T-OKT3-VISTA cells (by measuring NF-κB inhibition). These data represent a combination of three independent experiments.

[0029] Figure 24 The effect of pH on VISTA inhibition of human CD4+ T cells is shown. Cells were stimulated at indicated pH using plates coated with OKT3 and VISTA-Fc in the presence of VISTA.4 (upward triangle), VISTA.5 (downward triangle), or a non-VISTA-binding antibody (antibody control, square). Cells stimulated using plates coated with OKT3 and control IgG (VISTA control, black circle) or without OKT3 (no OKT3, gray diamond) are also shown. These data represent a single independent experiment.

[0030] Figures 25A-25E The binding specificity of VISTA:PSGL-1 was determined by histidine and sulfotyrosine residues. Figure 25A The results show the production of human PSGL-1 19-mer-Fc recombinant protein in cells with and without sialyl Lewis X modification (SLX+ and SLX-, respectively). The binding strength of indicated VISTA-Fc and P-selectin-Fc to BLI is shown at pH 6.0 (white) and 7.4 (black). Data represent single independent experiments. Figure 25B The results show that human PSGL-1 19-mer-Fc glycopeptide generated using sialyl Lewis X modification was isolated into fractions with greater than 90% tyrosine sulfate (sY-enrichment) and less than 1% tyrosine sulfate (sY-deficient). The BLI binding strengths of indicated VISTA-Fc and P-selectin-Fc are shown at pH 6.0 (white) and 7.4 (black). These data represent single, independent experiments. Figure 25C-25D The provided information produces a human VISTA-Fc recombinant protein in which histidine residues at positions 153-155 remain intact (WT VISTA) or are replaced by alanine (H2A mutant), aspartic acid (H2D mutant), or arginine (H2R mutant). Figure 25C The data show the BLI binding strength to wild-type and mutant VISTA-Fc proteins that capture PSGL-1 at pH 6.0 and 7.4. These data represent a single experiment. Figure 25D The images show the binding of WT VISTA (circles), H2A mutant (squares), H2D mutant (downward-pointing triangles), and H2R mutant (gray upward-pointing triangles), as well as the control (diamonds), to VISTA-Fc in CHO-PSGL-1 cells at pH 6.0. These data represent two independent experiments. Figure 25E A computational model of the complex of the PSGL-1 19-meric glycopeptide (top) with the histidine-rich ligand interface of VISTA (gray ribbon, bottom) is shown. VISTA residues H98, H100, H153, and H154 are labeled. PSGL-1 residues Y46, Y48, E56, T57, and Y58 are also labeled. Detailed Implementation

[0031] definition

[0032] In this application, unless otherwise stated, the word "or" means "and / or". In the context of multiple dependent claims, the use of "or" merely refers to one or more of the preceding independent or dependent claims in an alternative form. The terms "comprising", "including", and "having" are used interchangeably herein. According to the invention, a "separated" molecule is a molecule that has been removed from its natural environment. Therefore, the term "separated" does not necessarily reflect the degree of purification of the molecule.

[0033] The term "peptide" refers to a polymer of amino acid residues and is not limited to a minimum length. "Protein" may include one or more peptides. Such polymers of amino acid residues may contain native or non-native amino acid residues and include (but are not limited to) peptides, oligopeptides, dimers, trimers, and polymers of amino acid residues. Full-length proteins and fragments thereof are covered by this definition. The term also includes post-expression modifications of peptides, such as glycosylation, sialylation, acetylation, phosphorylation, and the like. Additionally, for the purposes of this invention, "peptide" or "protein" respectively refers to a peptide or protein that includes modifications (e.g., deletions, additions, and substitutions, which are generally conserved) of its native sequence, provided that the protein maintains the desired activity. These modifications may be intentional (e.g., via site-directed mutagenesis) or accidental (e.g., via host mutation, which may result in protein or error amplification by PCR). A protein may comprise two or more peptides.

[0034] “VISTA” is an abbreviation for T-cell activation inhibitory protein containing the V-domain immunoglobulin, a member of the B7 family of immune checkpoint regulators. VISTA is also known as PD-1 homologue (PD1H), B7-H5, C10orf54, ESC-1 differentiated form (Dies-1), platelet receptor Gi24 precursor, and death domain 1α (DD1α). The term “hVISTA” or “huVISTA” refers to the human VISTA protein. The amino acid sequence of hVISTA (including its signal peptide) is provided in SEQ ID NO:1, while the sequence without the signal peptide is provided in SEQ ID NO:2. (See sequence listing below.) The extracellular domain of VISTA, or “ECD” or “VISTA-ECD”, refers to the extracellular portion of the VISTA protein, which, in the case of hVISTA, contains amino acids 1-162 of SEQ ID NO:2. (See also...) Figure 1B The "IgV domain" portion of hVISTA contains residues 5-135 of SEQ ID NO:2.

[0035] The term "lead peptide" or "lead sequence" refers to the amino acid residue sequence located at the N-terminus of a polypeptide that facilitates the polypeptide's secretion from mammalian cells. The leader sequence cleaves the polypeptide after it has been exported from mammalian cells, forming the mature protein. Leader sequences can be natural or synthetic, and can be heterologous or homologous to the protein to which they are attached.

[0036] The term “antibody” or “Ab” is used in the broadest sense herein and encompasses a wide variety of antibody structures, including (but not limited to) monoclonal antibodies, polyclonal antibodies, multispecific antibodies (e.g., bispecific antibodies), and antibody fragments, provided they exhibit the desired antigen-binding activity. As used herein, the term refers to a molecule comprising at least a complementarity-determining region (CDR)1, CDR2, and CDR3 of a heavy chain and at least a CDR1, CDR2, and CDR3 of a light chain, wherein said molecule is capable of binding to an antigen. The term antibody includes (but is not limited to) fragments capable of binding antigens (e.g., Fv, single-chain Fv (scFv), Fab, Fab', and (Fab')2). The term antibody also includes (but is not limited to) chimeric antibodies, humanized antibodies, human antibodies, and antibodies from various species (e.g., mice, cynomolgus monkeys, etc.).

[0037] The term "heavy chain" or "HC" refers to a polypeptide that contains at least a heavy chain variable region and may or may not contain a leader sequence. In some embodiments, the heavy chain contains at least a portion of the heavy chain constant region. The term "full-length heavy chain" refers to a polypeptide that contains both a heavy chain variable region and a heavy chain constant region, and may or may not contain a leader sequence and may or may not contain a C-terminal lysine (K).

[0038] The term "heavy chain variable region" or "VH" refers to the region comprising the heavy chain complementarity-determining region (CDR) 1, framework region (FR) 2, CDR 2, FR 3, and CDR 3 of the heavy chain. In some embodiments, the heavy chain variable region also comprises at least a portion of FR 1 and / or at least a portion of FR 4. As specified below, in some embodiments, heavy chain CDR 1 comprises residues 26-35 of the VH SEQ ID NO herein; heavy chain CDR 2 comprises residues 50-66 of the VH SEQ ID NO herein; and heavy chain CDR 3 comprises residues 99-110 of the VH SEQ ID NO herein. In other embodiments, if specified, heavy chain CDR 1 corresponds to Kabat residues 31-35; heavy chain CDR 2 corresponds to Kabat residues 50-65; and heavy chain CDR 3 corresponds to Kabat residues 95-102. See, for example, Kabat Sequences of Proteins of Immunological Interest (1987 and 1991, NIH, Bethesda, Md.). In some implementations, the heavy chain CDR is as specified herein, for example, in the sequence listing below or Table 2.

[0039] The term "light chain" or "LC" refers to a polypeptide that contains at least a light chain variable region and may or may not contain a leader sequence. In some embodiments, the light chain contains at least a portion of the light chain constant region. The term "full-length light chain" refers to a polypeptide that contains both a light chain variable region and a light chain constant region and may or may not contain a leader sequence.

[0040] The term "light chain variable region" or "VL" refers to the region comprising light chain CDR1, FR2, HVR2, FR3, and HVR3. In some embodiments, the light chain variable region also comprises FR1 and / or FR4. As specified below, in some embodiments, light chain CDR1 comprises residues 24-35 of the VL SEQ ID NO herein; light chain CDR2 comprises residues 51-57 of the VL SEQ ID NO herein; and light chain CDR3 comprises residues 90-98 of the VL SEQ ID NO herein. In other embodiments, if specified, light chain CDR1 corresponds to Kabat residues 24 to 34; light chain CDR2 corresponds to Kabat residues 50 to 56; and light chain CDR3 corresponds to Kabat residues 89 to 97. See, for example, Kabat Sequences of Proteins of Immunological Interest (1987 and 1991, NIH, Bethesda, Md.). In some embodiments, the light chain CDRs are as specified herein in, for example, the sequence listing.

[0041] A "chimeric antibody" is an antibody in which a portion of the heavy chain and / or light chain originates from a specific source or species, while the remainder of the heavy chain and / or light chain originates from a different source or species. In some embodiments, a chimeric antibody is an antibody comprising at least one variable region from a first species (e.g., mouse, rat, cynomolgus monkey, etc.) and at least one constant region from a second species (e.g., human, cynomolgus monkey, etc.). In some embodiments, a chimeric antibody comprises at least one mouse variable region and at least one human constant region. In some embodiments, a chimeric antibody comprises at least one cynomolgus monkey variable region and at least one human constant region. In some embodiments, all variable regions of a chimeric antibody are from the first species and all constant regions of a chimeric antibody are from the second species.

[0042] A "humanized antibody" is an antibody in which at least one amino acid in the framework region of a non-human variable region is replaced by a corresponding amino acid from a human variable region. In some embodiments, the humanized antibody contains at least one human constant region or a fragment thereof. In some embodiments, the humanized antibody is Fab, scFv, (Fab')2, etc.

[0043] The term "human antibody" as used in this article refers to antibodies produced in humans and antibodies containing human immunoglobulin genes produced in non-human animals (e.g., antibodies produced in humans). ) and antibodies selected using in vitro methods (e.g., phage display), where the antibody profile is based on human immunoglobulin sequences.

[0044] As used herein, "VISTA antibody" or "anti-VISTA antibody" refers to an antibody that specifically binds to VISTA under at least some conditions (e.g., acidic pH). In some embodiments, the antibody may be a "huVISTA antibody" or "anti-huVISTA antibody," indicating that it specifically binds to human VISTA protein under at least some conditions (e.g., acidic pH). For example, a VISTA antibody that specifically binds to the extracellular domain (ECD) of VISTA may be referred to as a "VISTA-ECD antibody."

[0045] In some embodiments, the antibodies described herein may contain one or more “conserved substitutions” compared to a specific, designated sequence. “Conserved amino acid substitution” as used herein refers to the substitution of an amino acid residue with an amino acid residue having a similar side chain. Families of amino acid residues with similar side chains include amino acids with basic side chains (e.g., lysine, arginine, histidine), amino acids with acidic side chains (e.g., aspartic acid, glutamic acid), amino acids with nonpolar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine, tryptophan), amino acids with nonpolar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine), amino acids with β-branched side chains (e.g., threonine, valine, isoleucine), and amino acids with aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine). In some implementations, the predicted non-essential amino acid residues in the antibodies described herein are replaced by another amino acid residue from the same side chain family (e.g., basic, acidic, β-branched, aromatic, non-polar). Methods for identifying nucleotides and conserved substitutions of amino acids that do not eliminate antigen binding have been described (e.g., Brummell et al., Biochem. 32:1180-1187 (1993); Kobayashi et al., Protein Eng. 12(10):879-884 (1999); and Burks et al., Proc. Natl. Acad. Sci. USA 94:412-417 (1997)).

[0046] In some embodiments, the antibody can bind to VISTA with higher affinity at acidic pH rather than neutral and / or physiological pH. In some embodiments, the antibody can bind to VISTA with higher affinity at acidic pH and can bind negligibly or nonspecifically at neutral and / or physiological pH.

[0047] "K" of antibody-binding proteins (such as VISTA-ECD protein) D The "dissociation constant" or "dissociation constant" is a measure of the affinity or specificity of an antibody for a protein (such as VISTA-ECD protein). Lower K... DIndicator relative to higher K D It has improved binding or affinity. K D This refers to the "dissociation rate" or kJ / kJ of antibodies and peptides. 解离 or k d And "association rate" or k 缔合 or k a The ratio between them. Dissociation rate and association rate are the rates at which two bound pairs associate and dissociate in a system. Therefore, a slower dissociation rate (where the association rate remains approximately constant) produces a higher overall affinity and thus a lower Kg. D As used in this article, k is a specific value "or less". 解离 Instructions, k 解离 Or, “dissociation rate” is as specified or slower than the specified rate.

[0048] The term "specific binding" or similar terms refers to the binding of two peptides (e.g., an antibody and its peptide target) to each other. D It is smaller than the case where two random polypeptides exist under the same conditions. In other words, K D The difference is smaller than that caused by the non-specific aggregation of polypeptides in the system.

[0049] In some implementations, the antibody specifically binds to the VISTA-ECD protein at a specific pH or pH range. “Acidic” pH as used herein generally refers to a pH less than 7.0, “alkaline” pH generally refers to a pH greater than 7.0, and “neutral” pH generally refers to a pH of approximately 7.0. “Physiological pH” as used herein refers to pH under normal (i.e., non-cancerous) physiological conditions, such as 7.35 to 7.45 or 7.3 to 7.4, for example, approximately 7.4. Phrases such as “binding in acidic conditions” or “binding in physiological conditions” and similar expressions (used in the context of the binding of two molecules such as VISTA and VISTA binding to a partner or VISTA and T cells) refer to binding at acidic pH and binding at physiological pH, respectively.

[0050] When referring to antibodies that "block the binding of a ligand (or receptor) or competitive antibody to a receptor (or ligand) alone or on cells" or "inhibit said binding," binding is blocked if there is a statistically significant overall reduction compared to a control (e.g., an overall reduction of 50% or greater, such as 75%, 80%, 85%, 90%, 95%, or greater). For example, an "anti-VISTA blocking antibody" is one that can block VISTA binding to PSGL-1 or another VISTA ligand or receptor or heparan sulfate proteoglycan under at least some conditions (e.g., in an acidic pH).

[0051] The term "tumor model" as used in this article refers to in vivo preclinical assays that can be used to study the bioactivity of the VISTA-ECD antibody, and includes xenograft or natural mouse tumor assay systems. In some cases, tumor models allow for tracking tumor size or growth and / or the presence of immune cells (e.g., specific types of T cells or NK cells) within the tumor during antibody therapy to determine whether the antibody has triggered or enhanced an immune response.

[0052] As used herein, the term "immunostimulant" refers to a molecule that stimulates the immune system by acting as an agonist of an immunostimulatory molecule (including co-stimulatory molecules) or as an antagonist of an immunosuppressive molecule (including co-inhibitory molecules). Immunostimulatory or immunosuppressive molecules may be immune checkpoint regulators, such as VISTA or another member of the B7 family, or another molecule described separately below. Immunostimulants may be biological agents (e.g., antibodies or antibody fragments, other proteins, or vaccines) or may be small molecule drugs. "Immunostimulatory molecules" include receptors or ligands that enhance, stimulate, induce, or otherwise "turn on" an immune response. As defined herein, immunostimulatory molecules include co-stimulatory molecules. "Immunosuppressive molecules" include receptors or ligands that reduce, inhibit, suppress, or otherwise "turn off" an immune response. As defined herein, immunosuppressive molecules include co-inhibitory molecules. Such immunostimulatory and immunosuppressive molecules may be, for example, receptors or ligands found on immune cells (e.g., T cells) or on cells involved in innate immunity (e.g., NK cells).

[0053] For peptide, polypeptide, or antibody sequences, "percentage of amino acid sequence identity (%)" and "homology" are defined as the percentage of amino acid residues in a candidate sequence that are identical to amino acid residues in a specific peptide or polypeptide sequence after sequence alignment and the introduction of vacancies (if necessary) to achieve the maximum percentage of sequence identity, and without considering any conserved substitutions as part of sequence identity. For the purpose of determining the percentage of amino acid sequence identity, alignment can be performed in various ways well known to those skilled in the art, such as using publicly available computer software, such as BLAST, BLAST-2, ALIGN, or MEGALIGN™ (DNASTAR) software. Those skilled in the art can determine appropriate parameters for measuring alignment, including any algorithm required to achieve maximum alignment across the full length of the compared sequences.

[0054] The terms “trigger” or “enhancement” refer to the initiation or enhancement of any event (e.g., protein ligand binding), or the initiation or enhancement of any biological activity (e.g., an immune response) or phenotypic property, or the occurrence, extent, or likelihood of initiating or enhancing activity or property. “Trigger” or “enhancement” is the initiation or enhancement of activity, function, and / or quantity compared to a reference. Triggering or enhancement is not necessarily complete. For example, in some embodiments, “enhancement” means the ability to cause an overall increase of 20% or greater. In another embodiment, “enhancement” means the ability to cause an overall increase of 50% or greater. In yet another embodiment, “enhancement” means the ability to cause an overall increase of 75%, 85%, 90%, 95%, or greater.

[0055] The term "inhibition" or "inhibit" more generally refers to the reduction or cessation of any event (e.g., protein ligand binding) or the reduction or cessation of any phenotypic property or the reduction or cessation of the occurrence, extent, or likelihood of a property. "Reduction" or "inhibition" means a reduction, decrease, or prevention of activity, function, and / or quantity compared to a reference. Inhibition or reduction is not necessarily complete. For example, in some embodiments, "reduction" or "inhibition" means an overall reduction of 20% or greater. In another embodiment, "reduction" or "inhibition" means an overall reduction of 50% or greater. In yet another embodiment, "reduction" or "inhibition" means an overall reduction of 75%, 85%, 90%, 95%, or greater.

[0056] As used herein, “treatment” encompasses the administration or application of any therapeutic agent for a human disease, and includes suppressing the progression of a disease or a disease or one or more symptoms thereof, inhibiting or slowing the progression of a disease or a disease or one or more symptoms thereof, preventing its development, partially or completely alleviating a disease or one or more symptoms thereof, or preventing the recurrence of one or more symptoms thereof.

[0057] The terms “subject” and “patient” are used interchangeably in this article and refer to a person.

[0058] The term "effective amount" or "therapeutic effective amount" refers to the amount of medicine that effectively treats a subject's disease or condition (e.g., to partially or completely alleviate one or more symptoms). In some implementations, "effective amount" refers to the amount that effectively achieves the desired therapeutic or preventative outcome within the required dose and time period.

[0059] The term "cancer" is used herein to refer to a population of cells exhibiting an abnormally high degree of proliferation and growth. Cancer can be benign (also known as a benign tumor), pre-malignant, or malignant. Cancer cells can be solid cancer cells or leukemia cancer cells. The term "tumor growth" is used herein to refer to the proliferation or growth of one or more cancerous cells that results in a corresponding increase in the size or extent of the cancer.

[0060] Examples of cancers suitable for the treatment methods described in this article include (but are not limited to) carcinomas, lymphomas, blastomas, sarcomas, and leukemias. More specific, non-limiting examples of such cancers include squamous cell carcinoma, small cell lung cancer, pituitary cancer, esophageal cancer, astrocytoma, soft tissue sarcoma, non-small cell lung cancer (including squamous non-small cell lung cancer), lung adenocarcinoma, squamous cell lung cancer, peritoneal cancer, hepatocellular carcinoma, gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatocellular carcinoma, breast cancer, colon cancer, colorectal cancer, endometrial or uterine cancer, salivary gland cancer, kidney cancer, renal cell carcinoma, liver cancer, prostate cancer, vulvar cancer, thyroid cancer, liver cancer, brain cancer, endometrial cancer, testicular cancer, bile duct cancer, gallbladder cancer, gastric cancer, melanoma, and various types of head and neck cancers (including head and neck squamous cell carcinoma).

[0061] Administering in combination with one or more other therapeutic agents includes administering them simultaneously (in parallel) and sequentially (in order) in any sequence.

[0062] "Pharmaceutically acceptable carriers" refer to non-toxic solid, semi-solid, or liquid fillers, diluents, encapsulating materials, formulation adjuvants, or carriers that are commonly used in conjunction with therapeutic agents to form pharmaceutical compositions for administration to subjects. Pharmaceutically acceptable carriers are non-toxic to the recipient at the dosage and concentration used and are compatible with other components of the formulation. Pharmaceutically acceptable carriers are suitable for the formulation used. For example, if the therapeutic agent is intended for oral administration, the carrier may be a gel capsule. If the therapeutic agent is intended for subcutaneous administration, the carrier ideally should be non-irritating to the skin and should not cause a reaction at the injection site.

[0063] "Chemotherapy agents" are chemical compounds that can be used to treat cancer. Examples of chemotherapy agents that can be applied in the methods described herein include (but are not limited to) alkylating agents, such as thiotepa and... Cyclophosphamide; alkyl sulfonates, such as busulfan, improsulfan, and piposulfan; aziridines, such as benzodopa, carboquone, meturedopa, and uredopa; ethylenimine and methylmelamine, including altretamine, triethylmelamine, triethylphosphamide, triethylthiophosphamide, and tris(hydroxymethyl)melamine; acetogenin (especially bullatacin and bullatacinone); camptothecin (including synthetic compounds). Analogs include topotecan; bryostatin; callystatin; CC-1065 (including its synthetic analogs adozelesin, carzelesin, and bizelesin); cryptophycin (especially cryptophycin 1 and cryptophycin 8); dolastatin; duocarmycin (including synthetic analogs KW-2189 and CBI-TMI); eleutherobin; pancratistatin; sarcodictyin; spongistatin; and nitrogen mustard. Mustard, such as chlorambucil, chlornaphazine, cholophosphamide, estramustine, ifosfamide, mechlorethamine, mechlorethamine oxide hydrochloride, melphalan, novombhichin, phenesterine, prednimustine, trofosfamide, and uracil mustard;Nitroureas, such as carmustine, chlorozotocin, fotemustine, lomustine, nimustine, and ranimnustine; antibiotics, such as enediyne antibiotics (e.g., calicheamicin, especially calicheamicin γ1I and calicheamicin ωI1 (e.g., see Agnew, ChemIntl. Ed. Engl., 33:183-186 (1994)); dynemicins, including dynemicin A; bisphosphonates, such as clodronate; esperamicin; and neocarzinostatin chromophores. Chromophores and related chromophores, including alkenyne antibiotic chromophores, aclacinomycin, actinomycin, autramycin, azaserine, bleomycin, cactinomycin C, carabicin, carminomycin, carzinophilin, chromomycin, dactinomycin D, daunorubicin, detorubicin, and 6-diazo-5-oxo-L-leucine. Doxorubicin (including morpholino-doxorubicin, cyanomorpholino-doxorubicin, 2-pyrrolino-doxorubicin, and deoxydoxorubicin), epirubicin, esorubicin, idarubicin, marcellomycin, mitomycin (e.g., mitomycin C), and mycophenolic acid Drugs containing citric acid, nogalamycin, olivomycin, peplomycin, potfiromycin, puromycin, quelamycin, rodorubicin, streptonigrin, streptozocin, tubercidin, ubenimex, zinostatin, and zorubicin; antimetabolites, such as methotrexate and 5-fluorouracil (5-FU); and folic acid analogues, such as desodium folate. Terin), methotrexate, pteropterin, trimetrexate; purine analogs, such as fludarabine, 6-mercaptopurine, thiamiprine, thioguanine; pyrimidine analogs, such as ancitabine, azacitidine, 6-azauridine, carmofur, cytarabine, dideoxyuridine, doxifluridine, enocitabine, fluxuridine; and androgens, such as calusterone, dromostanolone. Propionate, epitiostanol, mepitiostane, testolactone; anti-adrenergics, such as aminoglutethimide, mitotane, trilostane; folic acid supplements, such as folinic acid; aceglatone.Aldophosphamide glycoside; aminolevulinic acid; eniluracil; amsacrine; bestrabucil; bisantrene; edatrexate; defosfamine; demecolcine; diaziquone; eflornithine; elliptinium acetate); epothilone; etoglucid; gallium nitrate; hydroxyurea; lentinan; lonidainine; maytansinoids, such as maytansine and ansamitocin; mitoguazone; mitoxantrone; mopidamol; nitracrine; pentostatin; phenamet; pirarubicin; losoxantrone; podophyllic acid; 2-ethylhydrazine; procarbazine; Polysaccharide complex (JHS Natural Products, Eugene, OR); razoxane; rhizoxin; sizofiran; spirogermanium; tenuazonic acid; triaziquone; 2,2',2”-trichlorotriethylamine; trichothecenes (especially T-2 toxin, verrucarin A, roridin A) A) and anguidine; urethan; vindesine; dacarbazine; mannomustine; mitobronitol; mitolactalol; pipebroman; gacytosine; arabinoside (“Ara-C”); cyclophosphamide; thiotepa; taxoids, such as Pacific paclitaxel (Bristol-Myers Squibb Oncology, Princeton, NJ) Pacific paclitaxel without cremaphore, albumin-engineered nanoparticle formulation (American Pharmaceutical Partners, Schaumberg, Illinois) and Docetaxel (docetaxel) Rorer, Antony, France); Chlorobutyrate; Gemcitabine; 6-thioguanine; mercaptopurine; methotrexate; platinum analogs, such as cisplatin, oxaliplatin, and carboplatin; vinblastine; platinum; etoposide (VP-16); ifosfamide; mitoxantrone; vincristine; Vinorelbine; Novantrone; Teniposide; Edatraxate; Daunomycin; Aminopterin; Xeloda; Ibandronate; Irinotecan (Camptosar, CPT-11) (including irinotecan with 5-FU and leucovorin) Treatment regimens include: (leucovorin); topoisomerase inhibitor RFS2000; difluoromethylornithine (DMFO); retinoids, such as retinoic acid; capecitabine; compressatin; leucovorin (LV); oxaliplatin, including oxaliplatin-based regimens (FOLFOX); and inhibitors of PKC-α, Raf, H-Ras, and EGFR (e.g., erlotinib). ) and VEGF-A that reduces cell proliferation; and pharmaceutically acceptable salts, acids or derivatives of any of the above substances.

[0064] Other non-limiting exemplary chemotherapeutic agents that may be applied in the methods described herein include anti-hormonal agents used to modulate or inhibit the hormonal effects on cancer, such as anti-estrogenic agents and selective estrogen receptor modulators (SERMs), including (e.g.) tamoxifen. Tamoxifen, raloxifene, droloxifene, 4-hydroxytamoxifen, trioxifene, keoxifene, LY117018, onapristone, and Toremifene is an aromatase inhibitor that inhibits the enzyme aromatase, which regulates estrogen production in the adrenal glands, such as 4(5)-imidazole, aminoglutethimide, etc. megestrol acetate Exemestane, Formestanie, Fadrozole vorozole Letrozole and Anastrozole; and antiandrogen agents (e.g., flutamide, nilutamide, bicalutamide, leuprolide, and goserelin); and troxacitabine (a 1,3-dioxane nucleoside cytosine analog); antisense oligonucleotides, particularly those that inhibit gene expression in signaling pathways involved in adherent cell proliferation, such as PKC-α, Ralf, and H-Ras; ribozymes, such as VEGF expression inhibitors (e.g., ribozymes and HER2 expression inhibitors; vaccines, such as gene therapy vaccines, for example vaccine, Vaccines and vaccine; rIL-2; Topoisomerase 1 inhibitors; rmRH; and pharmaceutically acceptable salts, acids, or derivatives of any of the above substances.

[0065] "Anti-angiogenic agents" or "angiogenic inhibitors" refer to small molecular weight substances, polynucleotides (e.g., including repressive RNA (RNAi or siRNA)), peptides, isolated proteins, recombinant proteins, antibodies, or conjugates or fusion proteins thereof that directly or indirectly inhibit angiogenesis, vascularization, or undesirable vascular permeability. It should be understood that anti-angiogenic agents include those that bind to angiogenic factors or their receptors and block their angiogenic activity. For example, anti-angiogenic agents that may be administered in the methods described herein may include antibodies or other antagonists of angiogenic agents, such as VEGF-A antibodies (e.g., bevacizumab). Antibodies against VEGF-A receptors (e.g., KDR receptors or Flt-1 receptors), anti-PDGFR inhibitors (e.g.) (Imatinib Mesylate), small molecules that block VEGF receptor signaling (e.g., PTK787 / ZK2284, SU6668) (sunitinibmalate), AMG706, or as described in, for example, international patent application WO 2004 / 113304). Anti-angiogenic agents also include natural angiogenesis inhibitors, such as angiostatin and endostatin. See, for example, Klagsbrun and D'Amore (1991) Annu. Rev. Physiol. 53:217-39; Streit and Detmar (2003) Oncogene 22:3172-3179 (e.g., Table 3 listing anti-angiogenic therapies in malignant melanoma); Ferrara & Alitalo (1999) Nature Medicine 5(12):1359-1364; Tonini et al. (2003) Oncogene 22:6549-6556 (e.g., Table 2 listing known anti-angiogenic factors); and Sato (2003) Int. J. Clin. Oncol. 8:200-206 (e.g., Table 1 listing anti-angiogenic agents used in clinical trials).

[0066] As used herein, “growth inhibitor” refers to a compound or composition that inhibits the growth of cells (e.g., cells expressing VEGF) in vitro or in vivo. Therefore, a growth inhibitor that can be applied in the methods described herein may be one that significantly reduces the percentage of cells in S phase (e.g., cells expressing VEGF). Examples of growth inhibitors include (but are not limited to) agents that block cell cycle progression (beyond S phase), such as agents that induce G1 arrest and M phase arrest. Classical M phase blockers include vinca extract (vincristine and vinblastine), taxane, and topoisomerase II inhibitors (e.g., doxorubicin, epirubicin, daunorubicin, etoposide, and bleomycin). Those that block G1 also further arrest S phase, such as DNA alkylating agents, such as tamoxifen, prednisone, dacarbazine, dichloroethylmethylamine, cisplatin, methotrexate, 5-fluorouracil, and ara-C. Further information can be found in Mendelsohn and Israel, eds., *The Molecular Basis of Cancer*, Chapter 1, entitled "Cell cycle regulation, oncogenes, and antineoplastic drugs," Murakami et al. (WBSaunders, Philadelphia, 1995), e.g., p. 13. Taxanes (paclitaxel and docetaxel) are anticancer drugs both derived from the yew tree. Docetaxel, derived from the European yew (… Rhone-Poulenc Rorer is a paclitaxel (Pacific paclitaxel) Semi-synthetic analogues of Bristol-Myers Squibb. Pacific paclitaxel and docetaxel promote the assembly of microtubules from tubulin dimers and stabilize microtubules by preventing depolymerization, which inhibits cell mitosis.

[0067] The term "anti-hypertrophic composition" refers to a composition comprising at least one active therapeutic agent that can be used to treat cancer. Examples of therapeutic agents include, but are not limited to, chemotherapeutic agents, growth inhibitors, cytotoxic agents, agents used in radiotherapy, anti-angiogenic agents, cancer immunotherapy agents, apoptosis agents, anti-microtubule agents, and other agents used to treat cancer (e.g., anti-HER-2 antibodies, anti-CD20 antibodies, epidermal growth factor receptor (EGFR) antagonists (e.g., tyrosine kinase inhibitors), HER1 / EGFR inhibitors (e.g., erlotinib)). Platelet-derived growth factor inhibitors (e.g.) (imatinib mesylate), COX-2 inhibitors (e.g., celecoxib), interferon, CTLA4 inhibitors (e.g., the anti-CTLA antibody ipilimumab). ), PD-1 or PD-L1 inhibitors (e.g. This includes, but is not limited to, TIM3 inhibitors (e.g., anti-TIM3 antibodies), cytokines, antagonists (e.g., neutralizing antibodies) that bind to one or more of the following targets: ErbB2, ErbB3, ErbB4, PDGFR-β, BlyS, APRIL, BCMA, CTLA4, TIM3, or VEGF receptors, TRAIL / Apo2, and other biologically active and organic chemical agents. Combinations thereof are also included in this disclosure.

[0068] Antibodies that specifically bind to VISTA-ECD at acidic pH

[0069] Because VISTA has a large number of histidine residues in its extracellular domain (ECD), its folding and overall structure, as well as its surface that can be used to bind ligands (e.g., antibodies), are suitable for use at acidic and neutral pH levels, especially near pH 6.5 (where histidine pK is the highest). a This is different. Because the tumor microenvironment is usually acidic, in order to bind to VISTA in those microenvironments, antibodies may need to bind specifically to VISTA at an acidic pH, where at least some surface histidine residues are more likely to be protonated.

[0070] The sequence listing below provides the amino acid sequences of human VISTA (hVISTA) (SEQ ID NO:1 and SEQ ID NO:2 (mature hVISTA)) with or without the signal peptide. The signal peptide constitutes amino acid residues 1-32 of SEQ ID NO:1. The extracellular domain (ECD) consists of amino acid residues 1-162 of SEQ ID NO:2. The IgV domain constitutes amino acid residues 37-167 of SEQ ID NO:1 and amino acid residues 5-135 of SEQ ID NO:2. The stalk region is located at amino acid residues 172-194 of SEQ ID NO:1 and amino acid residues 136-162 of SEQ ID NO:2; the transmembrane domain is located at amino acid residues 195-216 of SEQ ID NO:1 and amino acid residues 163-184 of SEQ ID NO:2. Amino acid residue 187 of SEQ ID NO:1 and 155 of SEQ ID NO:2 (bold and underlined) can be D or E, representing polymorphism in hVISTA. The residues are shown in bold and underlined. Therefore, SEQ ID NO:1 and SEQ ID NO:2 cover the two human polymorphisms at these residues. Histidine residues in the ECD of VISTA are shaded in gray.

[0071] The anti-VISTA antibody (Ab) can specifically bind to VISTA-ECD or fragments thereof at acidic pH (e.g., regions containing the IgV domain of VISTA or hVISTA containing, for example, amino acids 20-95, 20-70, 35-70, 35-95, 35-127, or 37-125 of SEQ ID NO:2). In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH values ​​below 7.0. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH values ​​below 6.8. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH values ​​below 6.5. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH values ​​below 6.3. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH values ​​below 6.0. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH values ​​below 5.8. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH values ​​below 5.5. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH values ​​below 5.3. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH values ​​below 5.0.

[0072] Certain abs specifically bind to the VISTA-ECD protein within a pH range of 5.0-7.0. Certain abs specifically bind to the VISTA-ECD protein within a pH range of 5.0-6.5. Certain abs specifically bind to the VISTA-ECD protein within a pH range of 5.0-6.0. Certain abs specifically bind to the VISTA-ECD protein within a pH range of 5.5-7.0. Certain abs specifically bind to the VISTA-ECD protein within a pH range of 5.5-6.5. Certain abs specifically bind to the VISTA-ECD protein within a pH range of 6.0-6.5.

[0073] This article also provides information on using 10 at pH 6.5 or lower. -6 M or smaller K D An Ab binds to the VISTA-ECD protein (e.g., hVISTA-ECD or a fragment of hVISTA containing the IgV domain of VISTA or a region of hVISTA containing, for example, amino acids 20-95, 20-70, 35-70, 35-95, 35-127, or 37-125 of SEQ ID NO:2). In some embodiments, the Ab is in 10...- 7 M or smaller K D To combine. In some implementations, Ab is in 10 -8 M or smaller K D To combine. In some implementations, Ab is in 10 -9 M's K D To combine. In some implementations, Ab is in 10 -10 M or smaller K D Binding occurs. For example, Ab can bind at pH 6.5 or lower at a rate of 10. -8 M or smaller K D It binds to the VISTA-ECD protein.

[0074] This article also provides information on using 10 in the pH range of 6.0-6.5. -6 M or smaller K D Ab binds to the VISTA-ECD protein. In some embodiments, the Ab is in the form of 10... -7 M or smaller K D To combine. In some implementations, Ab is in 10 -8 M or smaller K D To combine. In some implementations, Ab is in 10 -9 M's K D To combine. In some implementations, Ab is in 10 -10 M or smaller K D Binding occurs. For example, Ab can bind at pH 6.5 or lower (e.g., in the pH range of 6.0–6.5) at a concentration of 10. -7 M or smaller K D It binds to the VISTA-ECD protein. Additionally, the Ab can bind at pH 6.5 or lower (e.g., in the pH range of 6.0–6.5) at a concentration of 10. -8 M or smaller K D Binds to the VISTA-ECD protein. Ab can bind at pH 6.5 or lower (e.g., in the pH range of 6.0–6.5) at a rate of 10. -9 M or smaller K D Combined with hVISTA-ECD.

[0075] This article also provides, for example, at pH 6.5 or lower, at 10 -5 s -1 or smaller k 解离An Ab that specifically binds to the VISTA-ECD protein (e.g., hVISTA-ECD or a fragment of hVISTA containing the IgV domain of VISTA or a region of amino acids 20-95, 20-70, 35-70, 35-95, 35-127, or 37-125 of SEQ ID NO:2) at 25°C or 37°C. In some embodiments, the Ab has a concentration of 10 at 25°C or 37°C. -4 s -1 or smaller k 解离 In some implementations, Ab has a strength of 210 at 25°C or 37°C. -4 s -1 or smaller k 解离 In some implementations, Ab exhibits a strength of 5-10 at 25°C or 37°C. -4 s -1 or smaller k 解离 In some implementations, Ab exhibits a strength of 7-10 at 25°C or 37°C. -4 s -1 or smaller k 解离 In some implementations, Ab has a strength of 10 at 25°C or 37°C. -3 s -1 or smaller k 解离 In some implementations, Ab has a strength of 210 at 25°C or 37°C. -3 s -1 or smaller k 解离 In some implementations, Ab exhibits a strength of 5-10 at 25°C or 37°C. -3 s -1 or smaller k 解离 In some embodiments, Ab has a temperature of 7-10°C at 25°C or 37°C. -3 s -1 or smaller k 解离 In some implementations, Ab has a strength of 10 at 25°C or 37°C. -2 s -1 k 解离 In some implementations, Ab has a strength of 10 at 25°C or 37°C. -1 s -1 or smaller k 解 For example, Ab can be released at pH 6.5 or lower at a concentration of 10. -3 s -1 or smaller k 解离 It specifically binds to the VISTA-ECD protein at 25°C or 37°C. Ab can be released at pH 6.5 or lower at a concentration of 10... -3 s-1 or smaller k 解离 It specifically binds to hVISTA-ECD at 25°C or 37°C. Additionally, the Ab can bind at pH 6.5 or lower at a concentration of 10... -2 s -1 or smaller k 解离 It specifically binds to the VISTA-ECD protein at 25°C or 37°C.

[0076] This article provides, for example, at pH 6.5 or lower, at (i) 10 -6 M or smaller, 10 -7 M or smaller, 10 -8 M or smaller, 10 -9 M or smaller or 10 -10 M or smaller K D and (ii)10 -5 s -1 or smaller, 10 -4 (or 2, 5, or 7, 10) -4 )s -1 or smaller, 10 -3 (or 2, 5, or 7, 10) -4 )s -1 or smaller, 10 -2 s -1 or smaller or 10 -1 s -1 or smaller k 解离 The Ab binds to the VISTA-ECD protein (e.g., at a rate (e.g., measured at 25°C or 37°C) at a rate (e.g., measured at 25°C or 37°C) containing the IgV domain of hVISTA or a fragment of hVISTA containing, for example, amino acids 20-95, 20-70, 35-70, 35-95, 35-95, 35-127, or 37-125 of SEQ ID NO:2). For example, the Ab can bind at a rate of 10 at pH 6.5 or lower. -7 M or smaller K D and 10 -3 s -1 or smaller k 解离 The rate (e.g., measured at 25°C or 37°C) binds to the VISTA-ECD protein. Ab can bind at pH 6.5 or lower at a rate of 10... -8 M or smaller K D and 10 -3 s -1 or smaller k 解离 The rate (e.g., measured at 25°C or 37°C) binds to the VISTA-ECD protein. Ab can bind at pH 6.5 or lower at a rate of 10... -8 M or smaller KD and 10 -2 s -1 or smaller k 解离 The rate (e.g., measured at 25°C or 37°C) binds to the VISTA-ECD protein. For example, Ab can bind at a rate of 10 at pH 6.5 or lower. -7 M or smaller K D and 10 -3 s -1 or smaller k 解离 The rate (e.g., measured at 25°C or 37°C) binds to hVISTA-ECD. Ab can bind at pH 6.5 or lower at a rate of 10... -9 M or smaller K D and 10 -3 s -1 or smaller k 解离 The rate (e.g., measured at 25°C or 37°C) binds to hVISTA-ECD. Ab can bind at pH 6.5 or lower at a rate of 10... -9 M or smaller K D and 10 -2 s -1 or smaller k 解离 The rate (e.g., measured at 25°C or 37°C) binds to hVISTA-ECD. Ab can bind at pH 6.5 or lower at a rate of 10... -8 M or smaller K D and 10 -4 (or 2, 5, or 7, 10) -4 )s -1 or smaller k 解离 The rate (e.g., measured at 25°C or 37°C) binds to hVISTA-ECD. Ab can bind at pH 6.5 or lower at a rate of 10... -8 M or smaller K D and 10 -5 (or 2, 5, or 7, 10) -5 )s -1 or smaller k 解离 The rate (e.g., measured at 25°C or 37°C) binds to hVISTA-ECD. Ab can bind at pH 6.5 or lower at a rate of 10... -9 M or smaller K D and 10 -4 (or 2, 5, or 7, 10) -4 )s -1 k 解离 The rate of binding to hVISTA-ECD is lower (e.g., measured at 25°C or 37°C). Ab can bind at pH 6.5 or lower at a rate of 10. -9 M or smaller KD and 10 -5 (or 2, 5, or 7, 10) -5 )s -1 Or a smaller k dissociation rate (such as that measured at, for example, 25°C or 37°C) is incorporated into hVISTA-ECD.

[0077] This article provides, for example, at pH 6.5 or lower, at 10 4 M -1 s -1 or higher k 缔合 The Ab specifically binds to the VISTA-ECD protein at 25°C or 37°C. In some such embodiments, the Ab can be 10 5 M -1 s -1 or higher k 缔合 To combine. In some such implementations, Ab can be 10 6 M -1 s -1 or higher k 缔合 To combine. In some such implementations, Ab can be 10 7 M -1 s -1 or higher k 缔合 Binding occurs. For example, Ab can bind at pH 6.5 or lower at a rate of 10. 6 M -1 s -1 or higher k 缔合 (As measured, for example, at 25°C or 37°C) binds to the VISTA-ECD protein. For instance, Ab can bind at pH 6.5 or lower at a concentration of 10... 6 M -1 s -1 or higher k 缔合 (As measured, for example, at 25°C or 37°C) is incorporated into hVISTA's ECD.

[0078] This article provides, for example, at pH 6.5 or lower, at (i) 10 -6 M or smaller, 10 -7 M or smaller, 10 -8 M or smaller, 10 -9 M or smaller or 10 -10 M or smaller K D and (ii)10 4 M -1 s -1 or higher, 10 5 M -1 s -1 or higher, 10 6 M-1 s -1 or higher, 10 7 M -1 s -1 or higher k 缔合 Abs (as measured, for example, at 25°C or 37°C) bind to the VISTA-ECD protein. For instance, the Abs can bind at pH 6.5 or lower at a concentration of 10... -7 M or smaller K D and 10 6 M -1 s -1 or higher k 缔合 The rate (e.g., measured at 25°C or 37°C) binds to the VISTA-ECD protein. For example, Ab can bind at a rate of 10 at pH 6.5 or lower. -8 M or smaller K D and 10 6 M -1 s -1 or higher k 缔合 The rate (e.g., measured at 25°C or 37°C) binds to the VISTA-ECD protein. For example, Ab can bind at a rate of 10 at pH 6.5 or lower. -7 M or smaller K D and 10 6 M -1 s -1 k 缔合 The rate (e.g., measured at 25°C or 37°C) binds to hVISTA-ECD. For example, the Ab can bind at a rate of 10 at pH 6.5 or lower. -8 M or smaller K D and 10 6 M -1 s -1 or higher k 缔合 The rate (e.g., measured at 25°C or 37°C) is incorporated into hVISTA-ECD.

[0079] In some implementations, the Ab can be used at a pH of 6.5 or lower at a concentration of 10. -7 M or smaller K D and 10 -5 s -1 Or smaller, 2 10 -5 s -1 Or smaller, 5 10 -5 s -1 Or smaller, 7 10 -5 s -1 or smaller, 10 -4 s -1 Or smaller, 2 10-4 s -1 Or smaller, 510 -4 s -1 Or smaller, 7 10 -4 s -1 or smaller, 10 -3 s -1 Or smaller, 2 10 -3 s -1 Or smaller, 5 10 -3 s -1 Or smaller, 7 10 -3 s -1 or smaller, 10 -2 s -1 or smaller or 10 -1 s -1 or smaller k 解离 (As measured, for example, at 25°C or 37°C) binds to the VISTA-ECD protein. In some embodiments, the Ab can be used at pH 6.5 or lower at a concentration of 10... -9 M or smaller K D and 10 -5 s -1 or smaller, 10 -4 s -1 or smaller, 10 -3 s -1 or smaller, 10 -2 s -1 or smaller or 10 -1 s -1 or smaller k 解离 (As measured, for example, at 25°C or 37°C) binds to the VISTA-ECD protein. In some such embodiments, the Ab can be used at pH 6.5 or lower at a concentration of 10... -10 M or smaller K D and 10 -5 s -1 or smaller, 10 -4 s -1 or smaller, 10 -3 s -1 or smaller, 10 -2 s -1 or smaller or 10 -1 s -1 or smaller k 解离 (As measured, for example, at 25°C or 37°C) binds to the VISTA-ECD protein.

[0080] In some implementations, the Ab can be used at a pH of 6.5 or lower at a concentration of 10. -7 M or smaller K D and 10 4 M-1 s -1 or higher, 10 5 M -1 s -1 or higher, 10 6 M -1 s -1 or higher, 10 7 M -1 s -1 or higher k 缔合 (As measured, for example, at 25°C or 37°C) binds to the VISTA-ECD protein. In some embodiments, the Ab can be used at pH 6.5 or lower at a concentration of 10... -8 M or smaller K D and 10 4 M -1 s -1 or higher, 10 5 M -1 s -1 or higher, 10 6 M -1 s -1 or higher, 10 7 M -1 s -1 or higher k 缔合 (As measured, for example, at 25°C or 37°C) binds to the VISTA-ECD protein. In some embodiments, the Ab can be used at pH 6.5 or lower at a concentration of 10... -9 M or smaller K D and 10 4 M -1 s -1 or higher, 10 5 M -1 s -1 or higher, 10 6 M -1 s -1 or higher, 10 7 M -1 s -1 or higher k 缔合 (As measured, for example, at 25°C or 37°C) binds to the VISTA-ECD protein. In some such embodiments, the Ab can be used at pH 6.5 or lower at a concentration of 10... -10 M or smaller K D and 10 4 M -1 s -1 or higher, 10 5 M -1 s -1 or higher, 10 6 M -1 s-1 or higher, 10 7 M -1 s -1 or higher k 缔合 (As measured, for example, at 25°C or 37°C) binds to the VISTA-ECD protein.

[0081] In some implementations, the Ab can be used at a pH of 6.5 or lower at a concentration of 10. -7 M or smaller K D and 10 -5 s -1 or smaller, 10 -4 s -1 or smaller, 10 -3 s -1 or smaller, 10 -2 s -1 or smaller or 10 -1 s -1 or smaller k 解离 (e.g., measured at 25°C or 37°C) and 10 4 M -1 s -1 or higher, 10 5 M -1 s -1 or higher, 10 6 M -1 s -1 or higher, 10 7 M -1 s -1 or higher k 缔合 (As measured, for example, at 25°C or 37°C) binds to the VISTA-ECD protein. In some embodiments, the Ab can be used at pH 6.5 or lower at a concentration of 10... -8 M or smaller K D and 10 -5 s -1 or smaller, 10 -4 s -1 or smaller, 10 -3 s -1 or smaller, 10 -2 s -1 or smaller or 10 -1 s -1 or smaller k 解离 (e.g., measured at 25°C or 37°C) and 10 4 M -1 s -1 or higher, 10 5 M -1 s -1 or higher, 10 6 M-1 s -1 or higher, 10 7 M -1 s -1 or higher k 缔合 (As measured, for example, at 25°C or 37°C) binds to the VISTA-ECD protein. In some embodiments, the Ab can be used at pH 6.5 or lower at a concentration of 10... -9 M or smaller K D and 10 -5 s -1 or smaller, 10 -4 s -1 or smaller, 10 -3 s -1 or smaller, 10 -2 s -1 or smaller or 10 -1 s -1 or smaller k 解离 (e.g., measured at 25°C or 37°C) and 10 4 M -1 s -1 or higher, 10 5 M -1 s -1 or higher, 10 6 M -1 s -1 or higher, 10 7 M -1 s -1 or higher k 缔合 (As measured, for example, at 25°C or 37°C) binds to the VISTA-ECD protein. In some such embodiments, the Ab can be used at pH 6.5 or lower at a concentration of 10... -10 M or smaller K D and 10 -5 s -1 or smaller, 10 -4 s -1 or smaller, 10 -3 s -1 or smaller, 10 -2 s -1 or smaller or 10 -1 s -1 or smaller k 解离 (e.g., measured at 25°C or 37°C) and 10 4 M -1 s -1 or higher, 10 5 M -1 s -1 or higher, 10 6 M -1s -1 or higher, 10 7 M -1 s -1 or higher k 缔合 (As measured, for example, at 25°C or 37°C) binds to the VISTA-ECD protein.

[0082] As described above, in some of the above embodiments, the VISTA-ECD protein is hVISTA-ECD or a portion of hVISTA-ECD (e.g., the IgV domain). In some of the above embodiments, the Ab can specifically bind to an epitope containing amino acids 20-95 of SEQ ID NO:2. In some of the above embodiments, the Ab can specifically bind to an epitope containing amino acids 20-70 of SEQ ID NO:2. In some of the above embodiments, the Ab can specifically bind to an epitope containing amino acids 35-95 of SEQ ID NO:2. In some of the above embodiments, the Ab can specifically bind to an epitope containing amino acids 35-70 of SEQ ID NO:2. In some of the above embodiments, the epitope is a three-dimensional epitope that not only contains one of the above-described portions of residues 20-95, 20-70, 35-95, or 35-70 of SEQ ID NO:2, but also contains another portion of SEQ ID NO:2 (e.g., residues 95-105 of SEQ ID NO:2). In some embodiments, the Ab binds to the hVISTA epitope bound by the Ab described in WO2015 / 097536. For example, the Ab may compete or cross-compete with the Ab disclosed in WO2015 / 097536 for binding to hVISTA. In some embodiments, the Ab binds to a conformational epitope of human VISTA. In some embodiments, the Ab binds to a conformational epitope comprising residues 103-111 and 136-146 of SEQ ID NO:2 of human VISTA, or present within said residues. In some embodiments, the Ab binds to residues 24-36, 54-65, and 100-102 of SEQ ID NO:2 of human VISTA, or present within said residues. In some embodiments, the Ab binds to a conformational epitope comprising amino acid residues in the FG ring of human VISTA. In some embodiments, the Ab binds to a polypeptide comprising amino acid residues 35 to 127 and / or 37-125 of SEQ ID NO:2.In some embodiments, the antibody binds to the VISTA ECD polypeptide or a portion thereof containing amino acid residues 350-127 of SEQ ID NO:2, but the antibody does not bind or binds with reduced affinity to the VISTA ECD polypeptide or a portion thereof containing amino acid substitutions, wherein the substitution (1) is a substitution of one of the following amino acid residues: T35, Y37, K38, T39, Y41, R54, T61, F62, Q63, L65, H66, L67, H68, H69, F97, L115, V117, I119, H121, H122, S124, E125, R127 and SEQ ID NO:2 or (2) a substitution of one of the following amino acid residues: Y37, T39, R54, F62, Q63, H66, L115, V117, I119, S124 or E125. In some embodiments, the anti-VISTA antibody has the same binding properties (or significantly the same binding properties) as the antibodies described herein (e.g., as stated in the examples and / or claims).

[0083] Some of the aforementioned antibodies exhibit differential binding affinity to the VISTA-ECD protein based on pH. Certain antibodies specifically bind to the VISTA-ECD protein under acidic conditions (e.g., pH 6.5 or lower) and also bind with similar affinity to the VISTA-ECD protein at neutral and / or alkaline pH levels (i.e., they are "pan binders"). For example, some of these antibodies can bind to VISTA-ECD proteins at pH 10. -7 M or smaller K D It binds to the VISTA-ECD protein at pH 6.5 and pH 7.0 (at constant temperatures, such as 25°C or 37°C), thereby enabling K at pH 6.5. D K at pH 7.0 D Within 1.5 times. Some of these Abs can be 10. -8 M or smaller K D It binds to the VISTA-ECD protein at pH 6.5 and pH 7.0 (at constant temperatures, such as 25°C or 37°C), thereby enabling K at pH 6.5. D K at pH 7.0 D Within 1.5 times. Some of these Abs can be 10. -8 M or smaller K D It binds to hVISTA-ECD at pH 6.5 and pH 7.0 (at constant temperatures, e.g., 25°C or 37°C), thus K at pH 6.5. D K at pH 7.0 D Within 1.5 times.

[0084] Certain Abs specifically bind to the VISTA-ECD protein under acidic conditions (e.g., at pH 6.5 or lower) and may bind to the VISTA-ECD protein with low affinity under neutral, physiological, and / or alkaline conditions (“pH-sensitive binders” or “pH-sensitive Abs”). Some Abs specifically bind to the VISTA-ECD protein under acidic conditions (e.g., at pH 6.5 or lower) and may have non-significant (e.g., almost undetectable) binding to the VISTA-ECD protein under neutral, physiological, and / or alkaline conditions. For example, in some embodiments, the Ab may bind to the VISTA-ECD protein with a 10% affinity at pH 6.5. -8 M or smaller K D and at pH 7.0 and / or pH 7.4 with a concentration greater than 10 -8 M's K D Binds to the VISTA-ECD protein. In some such embodiments, Ab can be used at pH 6.5 at a concentration of 10... -8 M or smaller K D And at pH 7.0 and / or pH 7.4, the K content is 1.5 times higher than at pH 6.5. D Binds to the VISTA-ECD protein. In some embodiments, a pH-sensitive Ab is provided, which, at pH 6.5, has a K+ concentration at least 1.5, 2, 5, 10, 20, 50, 100, 300, 500, 1000, or 5000 times higher than that at pH 7.0. D (At constant temperature, such as 25°C or 37°C) specifically binds to the VISTA-ECD protein. For example, in some cases, Ab binds at pH 6.0 with at least 1.5, 2, 5, 10, 20, 50, 100, 300, 500, 1000, or 5000 times the K at pH less than pH 7.0 and / or pH 7.4 or higher. D (At a constant temperature, such as 25°C or 37°C) it binds to the VISTA-ECD protein.

[0085] In some implementations, Ab is administered at a lower kJ value under acidic conditions than under neutral, physiological, or alkaline conditions. 解离 Specifically binds to the VISTA-ECD protein. In some embodiments, kJ is provided under acidic conditions at pH 6.5 at a concentration lower than pH 7.0 and / or pH 7.4. 解离 At least 1.5 times, 2 times, 5 times, 10 times, 20 times, 50 times, 100 times, or 1000 times the value of k. 解离Abs (as measured, for example, at 25°C or 37°C) bind to the VISTA-ECD protein. In other words, the dissociation rate is slower at acidic pH than at neutral pH. For example, in some embodiments, the Abs at pH 6.0 have a kJ / kJ / kE ratio at least 1.5, 2, 5, 10, 20, 50, 100, or 1000 times lower than that at pH 7.0 and / or pH 7.4. 解离 The rate (e.g., measured at 25°C or 37°C) specifically binds to the VISTA-ECD protein. In some embodiments, a rate at pH 6.5 below pH 7.4 is provided. 解离 At least 1.5 times, 2 times, 5 times, 10 times, 20 times, 50 times, 100 times, or 1000 times the value of k. 解离 Abs (as measured, for example, at 25°C or 37°C) bind to the VISTA-ECD protein. In some embodiments, the Abs are at pH 6.0 with a kJ at least 1.5, 2, 5, 10, 20, 50, 100, or 1000 times lower than pH 7.4. 解离 The rate (e.g., measured at 25°C or 37°C) specifically binds to the VISTA-ECD protein. In some embodiments, kJ is provided at pH 6.0-6.5 at a rate lower than pH 7.0-7.4. 解离 At least 1.5 times, 2 times, 5 times, 10 times, 20 times, 50 times, 100 times, or 1000 times the value of k. 解离 (e.g., measured at 25°C or 37°C) Abs that bind to the VISTA-ECD protein.

[0086] In some implementations, Ab is at a higher kJ value under acidic conditions than under neutral, physiological, or alkaline conditions. 缔合 Specifically binds to the VISTA-ECD protein. In some embodiments, it is provided to bind at acidic conditions at pH 6.5 with a concentration higher than pH 7.0 and / or pH 7.4. 缔合 At least 2 times, 5 times, 10 times, 20 times, 50 times, 100 times, or 1000 times the value of k. 缔合 Abs (as measured, for example, at 25°C or 37°C) bind to the VISTA-ECD protein. For instance, in some embodiments, the Abs are at pH 6.0 with a kJ at a concentration at least 2, 5, 10, 20, 50, 100, or 1000 times higher than pH 7.0 and / or pH 7.4. 缔合 (As measured, for example, at 25°C or 37°C) specifically binds to the VISTA-ECD protein.

[0087] In some embodiments, the Ab specifically binds to the VISTA-ECD protein at a pH where at least one histidine residue (e.g., His98 in SEQ ID NO:1) is protonated. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at a pH where most histidine residues in the ECD are protonated (which is expected to be pH 6.5 or lower, e.g., between pH 6.0 and pH 6.5).

[0088] This article also covers Abs that specifically bind to the VISTA-ECD protein at neutral, physiological, or alkaline pH with an affinity higher than that at acidic pH, provided that the binding affinity remains high at acidic pH. For example, Abs can bind at pH 6.5 and pH 7.0 with an affinity of 10... -8 M or smaller K D Binds to VISTA-ECD protein, but Ab at pH 7.0 with at least 1.5, 2, 5, 10, 20, 50, 100, 300, 500, and 1000 times the K at pH 6.5. D To combine.

[0089] This article also covers Abs that share one or more of the above properties. The above properties (e.g., specific K) D k 解离 k 缔合 (Specific epitopes) are not treated in isolation. Therefore, Ab can bind to epitopes containing one of the aforementioned regions of SEQ ID NO:2, and can also have pan-binding, pH-sensitive, or pH-selective binding properties as described above, such as through its K D k 解离 or k 缔合 The behavior exhibited at different pH levels is one or more.

[0090] In any of the above embodiments, the Ab may be, for example, a full-length antibody (i.e., containing a full-length heavy chain (with or without a C-terminal lysine) and a full-length light chain) or an antigen-binding fragment (e.g., Fab fragment, Fab' fragment, (Fab')2 fragment, scFv fragment, Fv fragment), or the Ab may be a chimeric, humanized, or human antibody, or the Ab may be a bispecific or multispecific antibody.

[0091] Several different methods can be used to determine how well Ab binds to the VISTA-ECD protein at a given pH. For example, by surface plasmon resonance (SPR), such as through... Determination. Example SPR assays include those using a fixed capture reagent (e.g., using...) Anti-human Fc Capture Kit, GE Healthcare, Catalog No. BR-1008-39; or The Anti-Mouse Capture Kit (GE Healthcare, Catalog No. BR-1008-39) captures one or more antibodies onto a CM4 sensor chip and flows VISTA antigen (an analyte in a series of concentrations) to determine binding kinetics and affinity in electrophoresis buffer at the desired pH. In one embodiment, VISTA is injected at two to five concentrations (e.g., 0.1 nM, 1 nM, 10 nM, 100 nM, 500 nM) in the range of 0.1 nM to 500 nM at a flow rate of 30 μL / min, with a maximum association time of 4 min and a maximum dissociation time of 10 min. Between binding cycles, the capture surface is regenerated according to the manufacturer's instructions for each capture kit. All data are referenced using both a reference flow cell and a blank injection. The T200 evaluation software fits data with simple 1:1 kinetics into a Langmuir binding model with mass transfer. The SPR method described in the examples can also be used.

[0092] The affinity of an Ab for the VISTA ECD peptide can be determined using cells expressing the VISTA ECD peptide, PSGL-1, or heparan sulfate on its surface. The method includes flow cytometry, wherein the binding of the Ab to the VISTA-ECD bound to the cells is measured at a given pH (e.g., pH 6.5 or lower). An example flow cytometry assay includes the following steps: 293T cells or other cells ectopically expressing hVISTA ECD are resuspended in a buffer consisting of HBSS + 1% BSA adjusted to a desired pH (e.g., pH 6.0 using MES or pH 7.4 using HEPES). An Ab targeting hVISTA (e.g., human IgG) is serially diluted from approximately 20 μg / mL and incubated with the resuspended cells at 4°C for 30 min. The cells are then washed twice with the same buffer, maintaining the desired pH (e.g., pH 6.0 or 7.4), and incubated with a secondary antibody conjugated to a fluorophore recognizing the primary antibody (e.g., human IgG), which is more stable at reduced pH levels. The cells were then washed as previously described and immediately transferred to a BD Fortessa or other flow cytometer without fixation. The affinity of the Ab for the VISTAECD peptide can be determined as illustrated in the examples.

[0093] In some embodiments, the Ab binding to hVISTA ECD blocks the binding of hVISTA to its binding partner (e.g., the VISTA receptor) on cells. Inhibition or blockage may be 100% or at least 99%, 95%, 90%, 85%, 80%, 75%, or 50%. In some embodiments, the Ab binds to the VISTA-ECD protein at an acidic pH (e.g., pH 6.5 or lower) and inhibits the binding of VISTA to its binding partner by at least 50% (e.g., at least 75%, 80%, 85%, 90%, 95%, or 100%). In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH less than 7.0 and inhibits the binding of VISTA to its binding partner by at least 50%. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH less than 6.8 and inhibits the binding of VISTA to its binding partner by at least 50%. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH values ​​below 6.5 and inhibits the binding of VISTA to its binding partner by at least 50%. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH values ​​below 6.3 and inhibits the binding of VISTA to its binding partner by at least 50%. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH values ​​below 6.0 and inhibits the binding of VISTA to its binding partner by at least 50%. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH values ​​below 5.8 and inhibits the binding of VISTA to its binding partner by at least 50%. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH values ​​below 5.5 and inhibits the binding of VISTA to its binding partner by at least 50%. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH values ​​below 5.3 and inhibits the binding of VISTA to its binding partner by at least 50%. In some embodiments, the Ab specifically binds to the VISTA-ECD protein at pH less than 5.0 and inhibits the binding of VISTA to its binding partner by at least 50%.

[0094] Certain abs specifically bind to the VISTA-ECD protein at a pH range of 5.0–7.0, inhibiting the binding of VISTA to its binding partner by at least 50%. Certain abs specifically bind to the VISTA-ECD protein at a pH range of 5.0–6.5, inhibiting the binding of VISTA to its binding partner by at least 50%. Certain abs specifically bind to the VISTA-ECD protein at a pH range of 5.0–6.0, inhibiting the binding of VISTA to its binding partner by at least 50%. Certain abs specifically bind to the VISTA-ECD protein at a pH range of 5.5–6.5, inhibiting the binding of VISTA to its binding partner by at least 50%. Certain Abs specifically bind to the VISTA-ECD protein at a pH range of 6.0–6.5 and inhibit the binding of VISTA to its binding partner by at least 50%. The inhibition can be measured as described in the examples.

[0095] The VISTA binding partner may be PSGL-1 (e.g., human PSGL-1). Sequences of human PSGL-1 isotypes are provided herein as SEQ ID NO: 3-10. VISTA binds to PSGL-1 with or without a sialyl Lewis X. The binding partner may also be, for example, a heparan sulfate proteoglycan present on certain cells.

[0096] Inhibition of binding to the VISTA binding couple can be determined by measuring the inhibition of binding of VISTA (or VISTA ECD or VISTA IgV domain or VISTA-positive cells) to VISTA-binding cells (e.g., T cells (e.g., CD4+ T cells, CD8+ T cells, activated or inactive), NK cells or other VISTA-binding cells) in the presence or absence of antibodies. An exemplary assay that can be used to determine whether an antibody inhibits the binding of VISTA to its binding couple or T cells expressing the binding couple is a flow cytometry assay, for example, including the following steps: resuspending human peripheral blood mononuclear cells from donor blood, erythrocyte sedimentation rate (ESR), or apheresis-concentrated leukocytes in a buffer consisting of HBSS + 1% BSA adjusted to the desired pH (e.g., pH 6.0 using MES or pH 7.4 using HEPES). Cells were then incubated at 4°C for 30 minutes with 20 μg / mL of a recombinant chimeric protein consisting of hVISTA ECD (VISTA-Fc) fused to human IgG1 Fc, along with varying concentrations of candidate VISTA blocking antibodies or control antibodies. Cells were then washed twice in the same buffer, maintaining the desired pH (e.g., pH 6.0 or 7.4), and incubated again at 4°C for 30 minutes with a secondary antibody conjugated to a VISTA-Fc fluorophore (but without candidate blocking antibodies or control antibodies), showing greater stability at the reduced pH. Cells were then washed as previously described and immediately transferred to a BD Fortessa or other flow cytometer without fixation. Binding inhibition can be measured, for example, as illustrated in the examples.

[0097] In specific embodiments, the Abs described herein can trigger or enhance immune responses (e.g., antigen-specific immune responses). In some embodiments, the Abs stimulate T cell activity, particularly at acidic pH (e.g., as found in the tumor microenvironment). T cell activity stimulation can be measured, for example, in a mixed lymphocyte reaction (MLR) or in an in vitro assay using antigen-presenting cells (natural or artificial) and T cells. T cell activity stimulation can also be measured using, for example, the Jurkat assay described in the examples. T cell activity stimulation can also be measured by measuring IFN-γ secretion from T cells, where enhanced IFN-γ secretion indicates T cell stimulation. The secretion of other cytokines that activate T cells can also be measured. In some embodiments, signal transduction of activated T cells (e.g., NF-κB levels) is measured. In specific embodiments, the Abs described herein inhibit cell adhesion, which can be measured as described in the examples.

[0098] It can also show anti-VISTA Ab activity in monocyte assays, ADCC assays and ADCP assays, especially at acidic pH (e.g., found in the tumor microenvironment).

[0099] In some implementations, anti-VISTA Ab inhibits tumor growth in tumor models (e.g., human VISTA knock-in tumor models).

[0100] As shown in the examples herein, the recycling of anti-VISTA Abs in the body to (e.g.) enhance the pharmacokinetic (PK) properties (i.e., half-life) of the antibody requires the anti-VISTA antibody to bind to VISTA under acidic conditions. Therefore, as further illustrated herein, anti-VISTA Abs that bind to VISTA at low pH (e.g., pH 6.5 or lower) are also expected to have a longer acceptable half-life relative to VISTA antibodies that do not bind to VISTA at acidic pH.

[0101] Instant hVISTA-ECD combined with Ab

[0102] This article provides Abs that preferentially bind to VISTA (ECD) at acidic pH (e.g., under acidic conditions) relative to physiological or neutral pH.

[0103] In some embodiments, the anti-hVISTA Ab comprises a heavy chain variable region (“VH”) containing VHCDR1, CDR2, and / or CDR3 of any anti-hVISTA Ab provided herein. In some embodiments, the anti-hVISTA Ab comprises a VH containing VH CDR1, CDR2, and CDR3 of any anti-hVISTA Ab provided herein. In some embodiments, the anti-hVISTA... Ab contains P1-061029 or P1-061015 or their offspring (e.g., P1-061029, P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068775, P1-069059, P1-069061, P1-069063, P1-069065, P1-069067, P1-069069, P1-069071). , P1-069073, P1-069075, P1-069077, P1-061015, P1-068736, P1-068738, P1-068740, P1-068742, P1-068744, P1-068766, P1-06 8748, P1-068750, P1-068752, P1-068754, P1-068761_E55A, P1-068761_H100G, P1-068761_E56N, P1-068761_E55A_E56N, P1-06 8761_E30D, P1-068761_E30D_E55A, P1-068761_E56N_H100G, P1-068761_E30D_H100G, P1-068761_E30D_E56N, P1-068761_E100 fF、P1-068761_E55A_E100fF、P1-068761_H100G_E100fF、P1-068761_E30D_E100fF、P1-068761_E56N_E100fF、P1-068761_E32Y , P1-068761_E32Y_E55A, P1-068761_E32Y_E56N, P1-068761_E30D_E32Y, P1-068761_E32Y_H100G, P1-068761_E32Y_E100fF, P1 -068767_D52N_D102V、P1-068767_D52N、P1-068767_D52N_E55A、P1-068767_E55A_D102V、P1-068767_D102V、P1-068767_E55A、P1-068767_E30D_D52N, P1-068767_E30D_D102V, P1-068767_E30D, P1-068767_E30 D_E55A, P1-068767_E100fF_D102V, P1-068767_E55A_E100fF, P1-068767_D52N_E10 The VH of VH CDR1, CDR2 and / or CDR3 of each of the following antibody substances: 0fF, P1-068767_E100fF, P1-068767_E30D_E100fF, P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E or P1-061029_Y32E_F100fE. The VH CDR1, CDR2 and CDR3 of each of these substances comprises amino acid positions 26-35 (VH CDR1), 50-66 (VH CDR2) and 99-110 (VH CDR3) of the VH sequence of each of these antibody substances as provided in the sequence listing below. The CDRs for each VH sequence of the antibody material provided in the sequence listing below are also underlined and in bold.

[0104] In some embodiments, the anti-hVISTA Ab comprises a VL containing any of the anti-hVISTA Abs provided herein, namely VLCDR1, CDR2, and CDR3. In some embodiments, the anti-hVISTA... Ab contains VLs with one of the following VLCDR1, CDR2, and CDR3: P1-061029, P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068775, P1-069059, P1-069061, P1-069063, P1-069065, P1-069067, P1-069069, P1-069071, P1-069073, P1- 069075, P1-069077, P1-061015, P1-068736, P1-068738, P1-068740, P1-068742, P1-068744, P1-068766, P1-068748, P1-068750, P1-068 752, P1-068754, P1-068761_E55A, P1-068761_H100G, P1-068761_E56N, P1-068761_E55A_E56N, P1-068761_E30D, P1-068761_E30D_E55 A. P1-068761_E56N_H100G, P1-068761_E30D_H100G, P1-068761_E30D_E56N, P1-068761_E100fF, P1-068761_E55A_E100fF, P1-068761_ H100G_E100fF、P1-068761_E30D_E100fF、P1-068761_E56N_E100fF、P1-068761_E32Y、P1-068761_E32Y_E55A、P1-068761_E32Y_E56N、P 1-068761_E30D_E32Y、P1-068761_E32Y_H100G、P1-068761_E32Y_E100fF、P1-068767_D52N_D102V、P1-068767_D52N、P1-068767_D52N_ E55A, P1-068767_E55A_D102V, P1-068767_D102V, P1-068767_E55A, P1-068767_E30D_D52N, P1-068767_E30D_D102V, P1-068767_E30D,P1-068767_E30D_E55A, P1-068767_E100fF_D102V, P1-068767_E55A_E100fF, P1-068767_D52N_E100fF, P1-068767_E100fF, P1-068767_E30D_E100fF, P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E or P1-061029_Y32E_F100fE. The VL CDR1, CDR2, and CDR3 of each of the aforementioned substances comprise amino acid positions 24-35 (VL CDR1), 51-57 (VL CDR2), and 90-98 (VL CDR3) of the VL sequence of each of the antibody substances provided in the sequence listing below. The CDRs in each of those sequences are also underlined and in bold.

[0105] In some embodiments, the anti-hVISTA Ab comprises a VH containing VHCDR1, CDR2, and / or CDR3 of any anti-hVISTA Ab provided herein and a VL containing CDR1, CDR2, and / or CDR3 of any anti-hVISTA Ab provided herein. In some embodiments, the anti-hVISTA Ab comprises a VH containing VH, CDR1, CDR2, and CDR3 of any anti-hVISTA Ab provided herein and a VL containing CDR1, CDR2, and CDR3 of any anti-hVISTA Ab provided herein. In some embodiments, the anti-hVISTA... Ab contains: VH, which contains P1-061029 or P1-061015 or their offspring (e.g., P1-061029, P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068775, P1-069059, P1-069061, P1-069063, P1-069065, P1-0 69067, P1-069069, P1-069071, P1-069073, P1-069075, P1-069077, P1-061015, P1-068736, P1-068738, P1-068740 , P1-068742, P1-068744, P1-068766, P1-068748, P1-068750, P1-068752, P1-068754, P1-068761_E55A, P1-068761_ H100G, P1-068761_E56N, P1-068761_E55A_E56N, P1-068761_E30D, P1-068761_E30D_E55A, P1-068761_E56N_H100 G. P1-068761_E30D_H100G, P1-068761_E30D_E56N, P1-068761_E100fF, P1-068761_E55A_E100fF, P1-068761_H100 G_E100fF, P1-068761_E30D_E100fF, P1-068761_E56N_E100fF, P1-068761_E32Y, P1-068761_E32Y_E55A, P1-06876 1_E32Y_E56N, P1-068761_E30D_E32Y, P1-068761_E32Y_H100G, P1-068761_E32Y_E100fF, P1-068767_D52N_D102V,P1-068767_D52N, P1-068767_D52N_E55A, P1-068767_E55A_D102V, P1-068767_D102V, P1-068767_E55A, P1-0 68767_E30D_D52N, P1-068767_E30D_D102V, P1-068767_E30D, P1-068767_E30D_E55A, P1-068767_E100fF_D1 02V, P1-068767_E55A_E100fF, P1-068767_D52N_E100fF, P1-068767_E100fF, P1-068767_E30D_E100fF, P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E or P1-061029_Y32E_F100fE) of VH CDR1, CDR2 and / or CDR3; and VL, which contains P1-061029 or P1-061015 or their descendants (e.g., P1-061029, P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068773, P1-068774, P1-068775 ... 68775, P1-069059, P1-069061, P1-069063, P1-069065, P1-069067, P1-069069, P1-069071, P 1-069073, P1-069075, P1-069077, P1-061015, P1-068736, P1-068738, P1-068740, P1-06874 2. P1-068744, P1-068766, P1-068748, P1-068750, P1-068752, P1-068754, P1-068761_E55A, P1-068761_H100G, P1-068761_E56N, P1-068761_E55A_E56N, P1-068761_E30D, P1-068761_E 30D_E55A, P1-068761_E56N_H100G, P1-068761_E30D_H100G, P1-068761_E30D_E56N, P1-068 761_E100fF、P1-068761_E55A_E100fF、P1-068761_H100G_E100fF、P1-068761_E30D_E100fF、P1-068761_E56N_E100fF, P1-068761_E32Y, P1-068761_E32Y_E55A, P1-068761_ E32Y_E56N, P1-068761_E30D_E32Y, P1-068761_E32Y_H100G, P1-068761_E32Y_E1 00fF, P1-068767_D52N_D102V, P1-068767_D52N, P1-068767_D52N_E55A, P1-068 767_E55A_D102V, P1-068767_D102V, P1-068767_E55A, P1-068767_E30D_D52N, P1 -068767_E30D_D102V, P1-068767_E30D, P1-068767_E30D_E55A, P1-068767_E10 0fF_D102V, P1-068767_E55A_E100fF, P1-068767_D52N_E100fF, P1-068767_E100 VLCDR1, CDR2, and CDR3 of fF, P1-068767_E30D_E100fF, P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E, or P1-061029_Y32E_F100fE.

[0106] In some implementations, anti-hVISTA Ab may include:

[0107] (a) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-061029 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-061029;

[0108] (b) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-061015 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of VL containing P1-061015;

[0109] (c) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068757 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of VL containing P1-068757;

[0110] (d) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068759 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068759;

[0111] (e) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761;

[0112] (f) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068763 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of VL containing P1-068763;

[0113] (g) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068765 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of VL containing P1-068765;

[0114] (h) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767;

[0115] (i) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068769 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of VL containing P1-068769;

[0116] (j) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068771 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068771;

[0117] (k) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068773 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068773;

[0118] (l) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068775 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of VL containing P1-068775;

[0119] (m) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-069059 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-069059;

[0120] (n) VH containing the amino acid sequences of VH CDR1, CDR2 and CDR3 of P1-069061 and VL containing the amino acid sequences of VL CDR1, CDR2 and CDR3 of P1-069061;

[0121] (o) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-069063 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-069063;

[0122] (p) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-069065 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-069065;

[0123] (q) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-069067 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-069067;

[0124] (r) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-069069 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-069069;

[0125] (s) VH containing the amino acid sequences of VH CDR1, CDR2 and CDR3 of P1-069071 and VL containing the amino acid sequences of VL CDR1, CDR2 and CDR3 of P1-069071;

[0126] (t) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-069073 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-069073;

[0127] (u) VH containing the amino acid sequences of VH CDR1, CDR2 and CDR3 of P1-069075 and VL containing the amino acid sequences of VL CDR1, CDR2 and CDR3 of P1-069075;

[0128] (v) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-069077 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-069077;

[0129] (w) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068736 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of VL containing P1-068736;

[0130] (x) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068738 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of VL containing P1-068738;

[0131] (y) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068740 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068740;

[0132] (z) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068742 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068742;

[0133] (aa) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068744 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068744;

[0134] (bb) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068746 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068746;

[0135] (cc) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068748 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068748;

[0136] (dd) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068750 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068750;

[0137] (ee) VH containing the amino acid sequence of VH CDR1, CDR2 and CDR3 of P1-068752 and VL containing the amino acid sequence of VL CDR1, CDR2 and CDR3 of P1-068752;

[0138] (ff) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068754 and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068754;

[0139] (gg) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E55A and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E55A;

[0140] (hh) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_H100G and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_H100G;

[0141] (ii) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068761_E56N and VL containing CDR1, CDR2 and CDR3 of VL containing P1-068761_E56N;

[0142] (jj) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E55A_E56N and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E55A_E56N;

[0143] (kk) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E30D and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E30D;

[0144] (ll) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068761_E30D_E55A and VL containing CDR1, CDR2 and CDR3 of VL containing P1-068761_E30D_E55A;

[0145] (mm) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068761_E56N_H100G and VL containing CDR1, CDR2 and CDR3 of VL containing P1-068761_E56N_H100G;

[0146] (nn) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068761_E30D_H100G and VL containing CDR1, CDR2 and CDR3 of VL containing P1-068761_E30D_H100G;

[0147] (oo) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068761_E30D_E56N and VL containing CDR1, CDR2 and CDR3 of VL containing P1-068761_E30D_E56N;

[0148] (pp) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068761_E100fF and VL containing CDR1, CDR2 and CDR3 of VL containing P1-068761_E100fF;

[0149] (qq) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E55A_E100fF and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E55A_E100fF;

[0150] (rr) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068761_H100G_E100fF and VL containing CDR1, CDR2 and CDR3 of VL containing P1-068761_H100G_E100fF;

[0151] (ss) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E30D_H100fF and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E30D_H100fF;

[0152] (tt)VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068761_E56N_H100fF and VL containing CDR1, CDR2 and CDR3 of VL containing P1-068761_E56N_H100fF;

[0153] (uu) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E32Y and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E32Y;

[0154] (vv) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E32Y_E55A and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E32Y_E55A;

[0155] (ww) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E32Y_E56N and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068761_E32Y_E56N;

[0156] (xx) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068761_E30D_E32Y and VL containing CDR1, CDR2 and CDR3 of VL containing P1-068761_E30D_E32Y;

[0157] (yy) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068761_E32Y_H100G and VL containing CDR1, CDR2 and CDR3 of VL containing P1-068761_E32Y_H100G;

[0158] (zz) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068761_E32Y_H100fF and VL containing CDR1, CDR2 and CDR3 of VL containing P1-068761_E32Y_H100fF;

[0159] (aaa) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_D52N_D102V and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_D52N_D102V;

[0160] (bbb)VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_D52N and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_D52N;

[0161] (ccc) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_D52N_E55A and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_D52N_E55A;

[0162] (ddd) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_E55A_D102V and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_E55A_D102V;

[0163] (eee) VH containing the amino acid sequence of CDR1, CDR2 and CDR3 of P1-068767_D102V and VL containing the amino acid sequence of CDR1, CDR2 and CDR3 of P1-068767_D102V;

[0164] (fff) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_E55A and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_E55A;

[0165] (ggg) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_E30D_D52N and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_E30D_D52N;

[0166] (hhh) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_E30D_D102V and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_E30D_D102V;

[0167] (iii) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068767_E30D and VL containing CDR1, CDR2 and CDR3 of VL containing P1-068767_E30D;

[0168] (jjj) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_E30D_E55A and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_E30D_E55A;

[0169] (kkk) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_E100fF_D102V and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_E100fF_D102V;

[0170] (lll) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068767_E55A_E100fF and VL containing CDR1, CDR2 and CDR3 of VL containing P1-068767_E55A_E100fF;

[0171] (mmm) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_D52N_E100fF and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_D52N_E100fF;

[0172] (nnn) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_E100fF and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-068767_E100fF;

[0173] (ooo)VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-068767_E30D_H100fF and VL containing CDR1, CDR2 and CDR3 of VL containing P1-068767_E30D_H100fF;

[0174] (ppp) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of VH containing P1-061029_F100fE_V102D and VL containing CDR1, CDR2 and CDR3 of VL containing P1-061029_F100fE_V102D;

[0175] (qqq) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-061029_F100fE and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-061029_F100fE;

[0176] (rrr) VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-061029_V102D and VL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-061029_V102D;

[0177] (sss) VH containing the amino acid sequences of CDR1, CDR2, and CDR3 of P1-061029_Y32E and VL containing the amino acid sequences of CDR1, CDR2, and CDR3 of P1-061029_Y32E; or

[0178] (ttt)VH containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-061029_Y32E_F100fE andVL containing the amino acid sequences of CDR1, CDR2 and CDR3 of P1-061029_Y32E_F100fE.

[0179] Similarly, the sequence listing below provides the heavy and light chain variable region sequences and full-length heavy and light chain sequences of the antibodies listed above that have the IgG1.3 heavy chain constant region (unless different HC constant regions are indicated in the table), and indicates the positions of VH CDR1, CDR2, and CDR3 and VL CDR1, CDR2, and CDR3 (by amino acid residues), with each VH and VL sequence's CDRs bolded and underlined. Thus, for example, the VH CDR1 of P1-061029 contains amino acids 26-35 of SEQ ID NO:67, while the VH CDR2 contains amino acids 50-66 of SEQ ID NO:67, and the VH CDR3 contains amino acids 99-110 of SEQ ID NO:67, and so on, as indicated by the bolded and underlined amino acids of SEQ ID NO:67 shown in the sequence listing.

[0180] In some embodiments, the anti-hVISTA Ab comprises a VH containing the amino acid sequence of the VH of any of the anti-hVISTA Abs provided herein. The individual VH sequences of the specific antibody substances provided herein are listed in the sequence listing. In some embodiments, the anti-hVISTA... Ab contains P1-061029 or P1-061015 or their offspring (e.g., P1-061029, P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068775, P1-069059, P1-069061, P1-069063, P1-069065, P1-069067, P1-069069, P1-069071, P1-069073, P1- 069075, P1-069077, P1-061015, P1-068736, P1-068738, P1-068740, P1-068742, P1-068744, P1-068766, P1-068748, P1-068750, P1-068 752, P1-068754, P1-068761_E55A, P1-068761_H100G, P1-068761_E56N, P1-068761_E55A_E56N, P1-068761_E30D, P1-068761_E30D_E55 A. P1-068761_E56N_H100G, P1-068761_E30D_H100G, P1-068761_E30D_E56N, P1-068761_E100fF, P1-068761_E55A_E100fF, P1-068761_ H100G_E100fF、P1-068761_E30D_E100fF、P1-068761_E56N_E100fF、P1-068761_E32Y、P1-068761_E32Y_E55A、P1-068761_E32Y_E56N、P 1-068761_E30D_E32Y、P1-068761_E32Y_H100G、P1-068761_E32Y_E100fF、P1-068767_D52N_D102V、P1-068767_D52N、P1-068767_D52N_ E55A, P1-068767_E55A_D102V, P1-068767_D102V, P1-068767_E55A, P1-068767_E30D_D52N, P1-068767_E30D_D102V, P1-068767_E30D,The amino acid sequences of VH in P1-068767_E30D_E55A, P1-068767_E100fF_D102V, P1-068767_E55A_E100fF, P1-068767_D52N_E100fF, P1-068767_E100fF, P1-068767_E30D_E100fF, P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E or P1-061029_Y32E_F100fE) are VH.

[0181] In some implementations, the anti-hVISTA Ab comprises VH of any of the following antibodies: P1-061029, P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068775, P1-069059, P1-069061, P1-069063, P1-069065, P1-069067, P1-069069, P1-069071, P1-069073, P1-069075, P1-069077, P1-061015, P1-068 736, P1-068738, P1-068740, P1-068742, P1-068744, P1-068766, P1-0687 48. P1-068750, P1-068752, P1-068754, P1-068761_E55A, P1-068761_H10 0G, P1-068761_E56N, P1-068761_E55A_E56N, P1-068761_E30D, P1-06876 1_E30D_E55A, P1-068761_E56N_H100G, P1-068761_E30D_H100G, P1-0687 61_E30D_E56N, P1-068761_E100fF, P1-068761_E55A_E100fF, P1-068761 _H100G_E100fF, P1-068761_E30D_E100fF, P1-068761_E56N_E100fF, P1- 068761_E32Y, P1-068761_E32Y_E55A, P1-068761_E32Y_E56N, P1-068761 _E30D_E32Y, P1-068761_E32Y_H100G, P1-068761_E32Y_E100fF, P1-0687 67_D52N_D102V, P1-068767_D52N, P1-068767_D52N_E55A, P1-068767_E5 5A_D102V, P1-068767_D102V, P1-068767_E55A, P1-068767_E30D_D52N, P 1-068767_E30D_D102V, P1-068767_E30D, P1-068767_E30D_E55A, P1-068 767_E100fF_D102V, P1-068767_E55A_E100fF, P1-068767_D52N_E100fF,P1-068767_E100fF, P1-068767_E30D_E100fF, P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E, or P1-061029_Y32E_F100fE, but with 1, 2, 3, 4, or 5 amino acid substitutions in the frame region of the VH sequence, for example, 1, 2, 3, 4, or 5 conserved substitutions. In some embodiments, anti-hVISTA... Ab contains the VH of antibody P1-061029 or any of its progeny such as: P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068775, P1-069059, P1-069061, P1-069063, P1-069065, P1-069067, P1-069069, P1-06 9071, P1-069073, P1-069075, P1-069077, P1-068766, P1-068761_E55A, P1-068761_H100G, P1-068761_E56N, P1-06876 1_E55A_E56N, P1-068761_E30D, P1-068761_E30D_E55A, P1-068761_E56N_H100G, P1-068761_E30D_H100G, P1-068761_E 30D_E56N, P1-068761_E100fF, P1-068761_E55A_E100fF, P1-068761_H100G_E100fF, P1-068761_E30D_E100fF, P1-068 761_E56N_E100fF, P1-068761_E32Y, P1-068761_E32Y_E55A, P1-068761_E32Y_E56N, P1-068761_E30D_E32Y, P1-06876 1_E32Y_H100G, P1-068761_E32Y_E100fF, P1-068767_D52N_D102V, P1-068767_D52N, P1-068767_D52N_E55A, P1-06876 7_E55A_D102V, P1-068767_D102V, P1-068767_E55A, P1-068767_E30D_D52N, P1-068767_E30D_D102V, P1-068767_E30D,P1-068767_E30D_E55A, P1-068767_E100fF_D102V, P1-068767_E55A_E100fF, P1- 068767_D52N_E100fF, P1-068767_E100fF, P1-068767_E30D_E100fF, P1-061029_F 100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E, or P1-061029_Y32E_F100fE, but with one or more germline reversion substitutions in the frame region of the VH sequence shown in the sequence listing, such as one or both of K16R and / or T84A substitutions. Exemplary VH sequences with such amino acid substitutions are provided in the sequence listing, where residues 16 and 84 are highlighted in bold and underlined. It should be noted that P1-061015 contains R at position 16 and A at position 84 in its VH frame region.

[0182] In some embodiments, the anti-hVISTA Ab comprises VH CDR1, CDR2, and CDR3 containing the amino acid sequence of the VH CDR of any anti-hVISTA Ab provided herein, and comprises a VH having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the VH of any anti-hVISTA Ab provided herein. In some embodiments, the anti-hVISTA Ab... Ab contains a VH containing an amino acid sequence that is at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the VH of the following substances: P1-061029, P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-0687 75. P1-069059, P1-069061, P1-069063, P1-069065, P1-069067, P1-069069, P1-069071, P1-069073, P1-069075, P1-0690 77. P1-061015, P1-068736, P1-068738, P1-068740, P1-068742, P1-068744, P1-068766, P1-068748, P1-068750, P1-0687 52. P1-068754, P1-068761_E55A, P1-068761_H100G, P1-068761_E56N, P1-068761_E55A_E56N, P1-068761_E30D, P1-068 761_E30D_E55A, P1-068761_E56N_H100G, P1-068761_E30D_H100G, P1-068761_E30D_E56N, P1-068761_E100fF, P1-0687 61_E55A_E100fF, P1-068761_H100G_E100fF, P1-068761_E30D_E100fF, P1-068761_E56N_E100fF, P1-068761_E32Y, P1- 068761_E32Y_E55A, P1-068761_E32Y_E56N, P1-068761_E30D_E32Y, P1-068761_E32Y_H100G, P1-068761_E32Y_E100fF,P1-068767_D52N_D102V, P1-068767_D52N, P1-068767_D52N_E55A, P1-068767_E55A_D102V, P1-068767_D102V, P1 -068767_E55A, P1-068767_E30D_D52N, P1-068767_E30D_D102V, P1-068767_E30D, P1-068767_E30D_E55A, P1-0687 67_E100fF_D102V, P1-068767_E55A_E100fF, P1-068767_D52N_E100fF, P1-068767_E100fF, P1-068767_E30D_E100fF, P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E or P1-061029_Y32E_F100fE. In some embodiments, the VH of the antibody differs from the VH sequence shown in the sequence listing due to one or both of the following substitutions in the VH sequence frame region: 1, 2, 3, 4, or 5 amino acids (e.g., 1, 2, 3, 4, or 5 conserved substitutions) or K16R and / or T84A substitutions in P1-061029 or its progeny.

[0183] In some embodiments, the anti-hVISTA Ab comprises a VH consisting of the amino acid sequence of the VH of any of the anti-hVISTA Abs provided herein. In some embodiments, the anti-hVISTA... Ab contains P1-061029 or P1-061015 or their descendants (e.g., P1-061029, P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068775, P1-069059, P1-069061, P1-069063, P1-069065, P1-069067, P1-069069, P1-069071, P1-069073, P1-069075). , P1-069077, P1-061015, P1-068736, P1-068738, P1-068740, P1-068742, P1-068744, P1-068766, P1-068748, P1-068750, P1-068752, P1-0 68754, P1-068761_E55A, P1-068761_H100G, P1-068761_E56N, P1-068 761_E55A_E56N, P1-068761_E30D, P1-068761_E30D_E55A, P1-068761 _E56N_H100G、P1-068761_E30D_H100G、P1-068761_E30D_E56N、P1-068761_E100fF、P1-068761_E55A_E100fF、P1-068761_H100G_E100fF、 P1-068761_E30D_E100fF, P1-068761_E56N_E100fF, P1-068761_E32Y, P1-068761_E32Y_E55A, P1-068761_E32Y_E56N, P1-068761_E30D_E 32Y, P1-068761_E32Y_H100G, P1-068761_E32Y_E100fF, P1-068767_D52N_D102V, P1-068767_D52N, P1-068767_D52N_E55A, P1-068767_E5 5A_D102V, P1-068767_D102V, P1-068767_E55A, P1-068767_E30D_D52 N. P1-068767_E30D_D102V, P1-068767_E30D, P1-068767_E30D_E55A,A VH is a VH composed of the amino acid sequence of the VH of the following species: P1-068767_E100fF_D102V, P1-068767_E55A_E100fF, P1-068767_D52N_E100fF, P1-068767_E100fF, P1-068767_E30D_E100fF, P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E, or P1-061029_Y32E_F100fE, wherein the VH optionally has one or both of K16R and / or T84A substitutions.

[0184] In some embodiments, the anti-hVISTA Ab comprises a VL containing the amino acid sequence of any of the anti-hVISTA Abs provided herein. In some embodiments, the anti-hVISTA... Ab contains P1-061029 or P1-061015 or their offspring (e.g., P1-061029, P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068775, P1-069059, P1-069061, P1-069063, P1-069065, P1-069067, P1-069069, P1-069071, P1-069073, P1-06907). 5. P1-069077, P1-061015, P1-068736, P1-068738, P1-068740, P1-068742, P1-068744, P1-068766, P1-068748, P1-068750, P1-068752, P1- 068754, P1-068761_E55A, P1-068761_H100G, P1-068761_E56N, P1-06 8761_E55A_E56N, P1-068761_E30D, P1-068761_E30D_E55A, P1-06876 1_E56N_H100G, P1-068761_E30D_H100G, P1-068761_E30D_E56N, P1-068761_E100fF, P1-068761_E55A_E100fF, P1-068761_H100G_E100fF , P1-068761_E30D_E100fF, P1-068761_E56N_E100fF, P1-068761_E32 Y, P1-068761_E32Y_E55A, P1-068761_E32Y_E56N, P1-068761_E30D_E 32Y, P1-068761_E32Y_H100G, P1-068761_E32Y_E100fF, P1-068767_D52N_D102V, P1-068767_D52N, P1-068767_D52N_E55A, P1-068767_E5 5A_D102V, P1-068767_D102V, P1-068767_E55A, P1-068767_E30D_D52 N. P1-068767_E30D_D102V, P1-068767_E30D, P1-068767_E30D_E55A,The amino acid sequence of VL of P1-068767_E100fF_D102V, P1-068767_E55A_E100fF, P1-068767_D52N_E100fF, P1-068767_E100fF, P1-068767_E30D_E100fF, P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E or P1-061029_Y32E_F100fE) is VL. In some embodiments, the anti-hVISTA Ab comprises VL CDR1, CDR2, and CDR3 containing the amino acid sequence of the VL CDR of any anti-hVISTA Ab provided herein, and comprises a VL having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the VL of any anti-hVISTA Ab provided herein. In some embodiments, the anti-hVISTA Ab... Ab contains VLs with amino acid sequences that are at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the amino acid sequences of the following substances: P1-061029, P1-068757, P1-068759, P1-068761, P1-068763, P1-06 8765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068775, P1-069059, P1-069061 , P1-069063, P1-069065, P1-069067, P1-069069, P1-069071, P1-069073, P1-069075, P1- 069077, P1-061015, P1-068736, P1-068738, P1-068740, P1-068742, P1-068744, P1-0687 66. P1-068748, P1-068750, P1-068752, P1-068754, P1-068761_E55A, P1-068761_H100G, P1-068761_E56N, P1-068761_E55A_E56N, P1-068761_E30D, P1-068761_E30D_E55A, P1-0 68761_E56N_H100G, P1-068761_E30D_H100G, P1-068761_E30D_E56N, P1-068761_E100fF,P1-068761_E55A_E100fF, P1-068761_H100G_E100fF, P1-068761_E30D_E100fF, P1-068 761_E56N_E100fF, P1-068761_E32Y, P1-068761_E32Y_E55A, P1-068761_E32Y_E56N, P1- 068761_E30D_E32Y, P1-068761_E32Y_H100G, P1-068761_E32Y_E100fF, P1-068767_D52N _D102V, P1-068767_D52N, P1-068767_D52N_E55A, P1-068767_E55A_D102V, P1-068767_D 102V, P1-068767_E55A, P1-068767_E30D_D52N, P1-068767_E30D_D102V, P1-068767_E3 0D, P1-068767_E30D_E55A, P1-068767_E100fF_D102V, P1-068767_E55A_E100fF, P1-068 767_D52N_E100fF, P1-068767_E100fF, P1-068767_E30D_E100fF, P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E, or P1-061029_Y32E_F100fE. In some embodiments, the VL of the antibody differs from the VL sequence shown in the sequence listing due to substitutions of 1, 2, 3, 4, or 5 amino acids (e.g., 1, 2, 3, 4, or 5 conserved substitutions) in the frame region of the VL sequence.

[0185] In some embodiments, the anti-hVISTA Ab comprises a VL consisting of the amino acid sequence of the VL of any of the anti-hVISTA Abs provided herein. In some embodiments, the anti-hVISTA Ab... Ab contains P1-061029 or P1-061015 or their descendants (e.g., P1-061029, P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068775, P1-069059, P1-069061, P1-069063, P1-069065, P1-069067, P1-069069, P1-069071, P1-069073, P1-069075). , P1-069077, P1-061015, P1-068736, P1-068738, P1-068740, P1-068742, P1-068744, P1-068766, P1-068748, P1-068750, P1-068752, P1-0 68754, P1-068761_E55A, P1-068761_H100G, P1-068761_E56N, P1-068 761_E55A_E56N, P1-068761_E30D, P1-068761_E30D_E55A, P1-068761 _E56N_H100G、P1-068761_E30D_H100G、P1-068761_E30D_E56N、P1-068761_E100fF、P1-068761_E55A_E100fF、P1-068761_H100G_E100fF、 P1-068761_E30D_E100fF, P1-068761_E56N_E100fF, P1-068761_E32Y, P1-068761_E32Y_E55A, P1-068761_E32Y_E56N, P1-068761_E30D_E 32Y, P1-068761_E32Y_H100G, P1-068761_E32Y_E100fF, P1-068767_D52N_D102V, P1-068767_D52N, P1-068767_D52N_E55A, P1-068767_E5 5A_D102V, P1-068767_D102V, P1-068767_E55A, P1-068767_E30D_D52 N. P1-068767_E30D_D102V, P1-068767_E30D, P1-068767_E30D_E55A,The VL is composed of the amino acid sequences of the following VLs: P1-068767_E100fF_D102V, P1-068767_E55A_E100fF, P1-068767_D52N_E100fF, P1-068767_E100fF, P1-068767_E30D_E100fF, P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E, or P1-061029_Y32E_F100fE.

[0186] In some embodiments, the anti-hVISTA Ab comprises a VH containing the amino acid sequence of the VH of any anti-hVISTA Ab provided herein, and a VL containing the amino acid sequence of the VL of any anti-hVISTA Ab provided herein. In some embodiments, the anti-hVISTA... Ab contains P1-061029 or P1-061015 or their offspring (e.g., P1-061029, P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068775, P1-069059, P1-069061, P1-069063, P1-069065, P1-069067, P1-069069, P1-069071, P1-069073). P1-069075, P1-069077, P1-061015, P1-068736, P1-068738, P1-068740, P1-068742, P1-068744, P1-068766, P1-068748, P1-068750, P 1-068752, P1-068754, P1-068761_E55A, P1-068761_H100G, P1-068761_E56N, P1-068761_E55A_E56N, P1-068761_E30D, P1-068761_E 30D_E55A, P1-068761_E56N_H100G, P1-068761_E30D_H100G, P1-068761_E30D_E56N, P1-068761_E100fF, P1-068761_E55A_E100fF, P 1-068761_H100G_E100fF、P1-068761_E30D_E100fF、P1-068761_E56N_E100fF、P1-068761_E32Y、P1-068761_E32Y_E55A、P1-068761_ E32Y_E56N, P1-068761_E30D_E32Y, P1-068761_E32Y_H100G, P1-068761_E32Y_E100fF, P1-068767_D52N_D102V, P1-068767_D52N, P1 -068767_D52N_E55A、P1-068767_E55A_D102V、P1-068767_D102V、P1-068767_E55A、P1-068767_E30D_D52N、P1-068767_E30D_D102V、P1-068767_E30D, P1-068767_E30D_E55A, P1-068767_E100fF_D102V, P1-068767_E5 5A_E100fF、P1-068767_D52N_E100fF、P1-068767_E100fF、P1-068767_E30D_E100fF、 VH is the amino acid sequence of VH containing P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E, or P1-061029_Y32E_F100fE; and VL is the amino acid sequence of VL containing P1-061029 or P1-061015.

[0187] However, in some implementations, the VH of the antibody is P1-061029, P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068775, P1-069059, P1-069061, P1-069063, P1-069065, P1-069067, P1-069069, P1-069071, P1-069073, P1-069075, P1-069077, P1-061015, P1-068736. P1-068738, P1-068740, P1-068742, P1-068744, P1-068766, P1-068748, P1 -068750, P1-068752, P1-068754, P1-068761_E55A, P1-068761_H100G, P1- 068761_E56N, P1-068761_E55A_E56N, P1-068761_E30D, P1-068761_E30D_ E55A, P1-068761_E56N_H100G, P1-068761_E30D_H100G, P1-068761_E30D_ E56N, P1-068761_E100fF, P1-068761_E55A_E100fF, P1-068761_H100G_E1 00fF, P1-068761_E30D_E100fF, P1-068761_E56N_E100fF, P1-068761_E32 Y, P1-068761_E32Y_E55A, P1-068761_E32Y_E56N, P1-068761_E30D_E32Y, P1-068761_E32Y_H100G, P1-068761_E32Y_E100fF, P1-068767_D52N_D102 V, P1-068767_D52N, P1-068767_D52N_E55A, P1-068767_E55A_D102V, P1-0 68767_D102V, P1-068767_E55A, P1-068767_E30D_D52N, P1-068767_E30D_ D102V, P1-068767_E30D, P1-068767_E30D_E55A, P1-068767_E100fF_D102 V、P1-068767_E55A_E100fF、P1-068767_D52N_E100fF、P1-068767_E100fF、The VH of P1-068767_E30D_E100fF, P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E or P1-061029_Y32E_F100fE, but with 1, 2, 3, 4 or 5 amino acid substitutions (e.g., 1, 2, 3, 4 or 5 conserved substitutions) in the frame region of the VH sequence, and the VL is the VL of P1-061029 or P1-061015. However, in some embodiments, the VH of the antibody is P1-061029 or its progeny (e.g., P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068775, P1-069059, P1-069061, P1-069063, P1-069065, P1-069067, P1-069069, P1-0 69071, P1-069073, P1-069075, P1-069077, P1-068766, P1-068761_E55A, P1-068761_H100G, P1-068761_E56N, P1-0687 61_E55A_E56N, P1-068761_E30D, P1-068761_E30D_E55A, P1-068761_E56N_H100G, P1-068761_E30D_H100G, P1-068761_ E30D_E56N, P1-068761_E100fF, P1-068761_E55A_E100fF, P1-068761_H100G_E100fF, P1-068761_E30D_E100fF, P1-06 8761_E56N_E100fF, P1-068761_E32Y, P1-068761_E32Y_E55A, P1-068761_E32Y_E56N, P1-068761_E30D_E32Y, P1-06876 1_E32Y_H100G, P1-068761_E32Y_E100fF, P1-068767_D52N_D102V, P1-068767_D52N, P1-068767_D52N_E55A, P1-06876 7_E55A_D102V, P1-068767_D102V, P1-068767_E55A, P1-068767_E30D_D52N, P1-068767_E30D_D102V, P1-068767_E30D,P1-068767_E30D_E55A, P1-068767_E100fF_D102V, P1-068767_E55A_E100fF, P1- 068767_D52N_E100fF、P1-068767_E100fF、P1-068767_E30D_E100fF、P1-061029_ The VH of (F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E or P1-061029_Y32E_F100fE) is a substituted VH, but has one or both of K16R or T84A, and the VL is the VL of P1-061029 or P1-061015.

[0188] In some implementations, the anti-hVISTA Ab contains P1-061029 or P1-061015 or its progeny (e.g., P1-061029, P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068775, P1-069059, P1-069061, P1-069063, P1-069065, P1-069067, P1-069069, P1-069071, P1-069073, P1-069075, P1-069077). P1-061015, P1-068736, P1-068738, P1-068740, P1-068742, P1-068744, P1-068766, P1-068748, P1-068750, P1-068752, P1-068754, P1-068761_E 55A, P1-068761_H100G, P1-068761_E56N, P1-068761_E55A_E56N, P1-06 8761_E30D, P1-068761_E30D_E55A, P1-068761_E56N_H100G, P1-068761_ E30D_H100G, P1-068761_E30D_E56N, P1-068761_E100fF, P1-068761_E5 5A_E100fF, P1-068761_H100G_E100fF, P1-068761_E30D_E100fF, P1-068 761_E56N_E100fF, P1-068761_E32Y, P1-068761_E32Y_E55A, P1-068761 _E32Y_E56N, P1-068761_E30D_E32Y, P1-068761_E32Y_H100G, P1-068761 _E32Y_E100fF, P1-068767_D52N_D102V, P1-068767_D52N, P1-068767_D 52N_E55A, P1-068767_E55A_D102V, P1-068767_D102V, P1-068767_E55A, P1-068767_E30D_D52N, P1-068767_E30D_D102V, P1-068767_E30D, P1-0 68767_E30D_E55A, P1-068767_E100fF_D102V, P1-068767_E55A_E100fF,The amino acid sequences of VH and VL of P1-068767_D52N_E100fF, P1-068767_E100fF, P1-068767_E30D_E100fF, P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E or P1-061029_Y32E_F100fE) are specified, and optionally, VH contains one or both of K16R and / or T84A substitutions.

[0189] In some embodiments, the anti-hVISTA Ab comprises VH CDR1, CDR2, and CDR3 containing the amino acid sequence of the VH CDR of any anti-hVISTA Ab provided herein, and VL CDR1, CDR2, and CDR3 containing the amino acid sequence of the VL CDR of any anti-hVISTA Ab provided herein, and further comprises VH and VL that are at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the corresponding VH and VL of any anti-hVISTA Ab provided herein. In some embodiments, the VH and VL of the antibody differ from the VH and VL sequences shown in the sequence listing due to one or both of the following substitutions: 1, 2, 3, 4, or 5 amino acids in the sequence frame region (e.g., 1, 2, 3, 4, or 5 conserved substitutions) or (e.g.) K16R and / or T84A substitutions in the VH sequence.

[0190] In some embodiments, the anti-hVISTA Ab comprises VH and VL consisting of the amino acid sequences of VH and VL of any of the anti-hVISTA Abs provided herein. In some embodiments, the anti-hVISTA... Ab contains each of the following free P1-061029 or P1-061015 or their offspring (e.g., P1-061029, P1-068757, P1-068759, P1-068761, P1-068763, P1-068765, P1-068767, P1-068769, P1-068771, P1-068773, P1-068775, P1-069059, P1-069061, P1-069063, P1-069065, P1-069067, P1-069069, P1-069071, P1-069073, P1-06907). 5. P1-069077, P1-061015, P1-068736, P1-068738, P1-068740, P1-068742, P1-068744, P1-068766, P1-068748, P1-068750, P1-068752, P1- 068754, P1-068761_E55A, P1-068761_H100G, P1-068761_E56N, P1-06 8761_E55A_E56N, P1-068761_E30D, P1-068761_E30D_E55A, P1-06876 1_E56N_H100G, P1-068761_E30D_H100G, P1-068761_E30D_E56N, P1-068761_E100fF, P1-068761_E55A_E100fF, P1-068761_H100G_E100fF , P1-068761_E30D_E100fF, P1-068761_E56N_E100fF, P1-068761_E32 Y, P1-068761_E32Y_E55A, P1-068761_E32Y_E56N, P1-068761_E30D_E 32Y, P1-068761_E32Y_H100G, P1-068761_E32Y_E100fF, P1-068767_D52N_D102V, P1-068767_D52N, P1-068767_D52N_E55A, P1-068767_E5 5A_D102V, P1-068767_D102V, P1-068767_E55A, P1-068767_E30D_D52 N. P1-068767_E30D_D102V, P1-068767_E30D, P1-068767_E30D_E55A,The VH and VL are composed of the amino acid sequences of P1-068767_E100fF_D102V, P1-068767_E55A_E100fF, P1-068767_D52N_E100fF, P1-068767_E100fF, P1-068767_E30D_E100fF, P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E or P1-061029_Y32E_F100fE, and optionally, wherein VH contains one or both of K16R and / or T84A substitutions.

[0191] Anti-hVISTA Ab may include:

[0192] (a) VH containing the amino acid sequence of VH in P1-061029 and VL containing the amino acid sequence of VL in P1-061029;

[0193] (b) VH containing the amino acid sequence of VH in P1-061015 and VL containing the amino acid sequence of VL in P1-061015;

[0194] (c) VH containing the amino acid sequence of VH in P1-068757 and VL containing the amino acid sequence of VL in P1-068757;

[0195] (d) VH containing the amino acid sequence of VH in P1-068759 and VL containing the amino acid sequence of VL in P1-068759;

[0196] (e) VH containing the amino acid sequence of VH in P1-068761 and VL containing the amino acid sequence of VL in P1-068761;

[0197] (f) VH containing the amino acid sequence of VH in P1-068763 and VL containing the amino acid sequence of VL in P1-068763;

[0198] (g) VH containing the amino acid sequence of VH in P1-068765 and VL containing the amino acid sequence of VL in P1-068765;

[0199] (h) VH containing the amino acid sequence of VH in P1-068767 and VL containing the amino acid sequence of VL in P1-068767;

[0200] (i) VH containing the amino acid sequence of VH in P1-068769 and VL containing the amino acid sequence of VL in P1-068769;

[0201] (j) VH containing the amino acid sequence of VH in P1-068771 and VL containing the amino acid sequence of VL in P1-068771;

[0202] (k) VH containing the amino acid sequence of VH in P1-068773 and VL containing the amino acid sequence of VL in -068773;

[0203] (l) VH containing the amino acid sequence of VH in P1-068775 and VL containing the amino acid sequence of VL in P1-068775;

[0204] (m) VH containing the amino acid sequence of VH in P1-069059 and VL containing the amino acid sequence of VL in P1-069059;

[0205] (n) VH containing the amino acid sequence of VH in P1-069061 and VL containing the amino acid sequence of VL in P1-069061;

[0206] (o) VH containing the amino acid sequence of VH in P1-069063 and VL containing the amino acid sequence of VL in P1-069063;

[0207] (p) VH containing the amino acid sequence of VH in P1-069065 and VL containing the amino acid sequence of VL in P1-069065;

[0208] (q) VH containing the amino acid sequence of VH in P1-069067 and VL containing the amino acid sequence of VL in P1-069067;

[0209] (r) VH containing the amino acid sequence of VH in P1-069069 and VL containing the amino acid sequence of VL in P1-069069;

[0210] (s) VH containing the amino acid sequence of VH in P1-069071 and VL containing the amino acid sequence of VL in P1-069071;

[0211] (t) VH containing the amino acid sequence of VH in P1-069073 and VL containing the amino acid sequence of VL in P1-069073;

[0212] (u) VH containing the amino acid sequence of VH in P1-069075 and VL containing the amino acid sequence of VL in P1-069075;

[0213] (v) VH containing the amino acid sequence of VH in P1-069077 and VL containing the amino acid sequence of VL in P1-069077;

[0214] (w) VH containing the amino acid sequence of VH in P1-068736 and VL containing the amino acid sequence of VL in P1-068736;

[0215] (x) VH containing the amino acid sequence of VH in P1-068738 and VL containing the amino acid sequence of VL in P1-068738;

[0216] (y) VH containing the amino acid sequence of VH in P1-068740 and VL containing the amino acid sequence of VL in P1-068740;

[0217] (z) VH containing the amino acid sequence of VH in P1-068742 and VL containing the amino acid sequence of VL in P1-068742;

[0218] (aa) VH containing the amino acid sequence of VH in P1-068744 and VL containing the amino acid sequence of VL in P1-068744;

[0219] (bb) VH containing the amino acid sequence of VH in P1-068746 and VL containing the amino acid sequence of VL in P1-068746;

[0220] (cc) VH containing the amino acid sequence of VH in P1-068748 and VL containing the amino acid sequence of VL in P1-068748;

[0221] (dd) VH containing the amino acid sequence of VH in P1-068750 and VL containing the amino acid sequence of VL in P1-068750;

[0222] (ee) contains the amino acid sequence of VH in P1-068752 and VL contains the amino acid sequence of VL in P1-068752;

[0223] (ff) VH containing the amino acid sequence of VH in P1-068754 and VL containing the amino acid sequence of VL in P1-068754;

[0224] (gg) VH containing the amino acid sequence of VH in P1-068761_E55A and VL containing the amino acid sequence of VL in P1-068761_E55A;

[0225] (hh) VH contains the amino acid sequence of VH in P1-068761_H100G and VL contains the amino acid sequence of VL in P1-068761_H100G;

[0226] (ii) VH containing the amino acid sequence of VH in P1-068761_E56N and VL containing the amino acid sequence of VL in P1-068761_E56N;

[0227] (jj) contains the amino acid sequence of VH in P1-068761_E55A_E56N and the amino acid sequence of VL in P1-068761_E55A_E56N;

[0228] (kk) contains the amino acid sequence of VH in P1-068761_E30D and VL contains the amino acid sequence of VL in P1-068761_E30D;

[0229] (ll) VH containing the amino acid sequence of VH in P1-068761_E30D_E55A and VL containing the amino acid sequence of VL in P1-068761_E30D_E55A;

[0230] (mm) VH containing the amino acid sequence of VH in P1-068761_E56N_H100G and VL containing the amino acid sequence of VL in P1-068761_E56N_H100G;

[0231] (nn) VH containing the amino acid sequence of VH in P1-068761_E30D_H100G and VL containing the amino acid sequence of VL in P1-068761_E30D_H100G;

[0232] (oo) VH containing the amino acid sequence of VH in P1-068761_E30D_E56N and VL containing the amino acid sequence of VL in P1-068761_E30D_E56N;

[0233] (pp) VH containing the amino acid sequence of VH in P1-068761_E100fF and VL containing the amino acid sequence of VL in P1-068761_E100fF;

[0234] (qq) contains the amino acid sequence of VH in P1-068761_E55A_E100fF and the amino acid sequence of VL in P1-068761_E55A_E100fF;

[0235] (rr) VH containing the amino acid sequence of VH in P1-068761_H100G_E100fF and VL containing the amino acid sequence of VL in P1-068761_H100G_E100fF;

[0236] (ss) contains the amino acid sequence of VH in P1-068761_E30D_H100fF and VL contains the amino acid sequence of VL in P1-068761_E30D_H100fF;

[0237] (tt) contains the amino acid sequence of VH in P1-068761_E56N_H100fF and VL contains the amino acid sequence of VL in P1-068761_E56N_H100fF;

[0238] (uu) contains the amino acid sequence of VH in P1-068761_E32Y and VL contains the amino acid sequence of VL in P1-068761_E32Y;

[0239] (vv) VH contains the amino acid sequence of VH in P1-068761_E32Y_E55A and VL contains the amino acid sequence of VL in P1-068761_E32Y_E55A;

[0240] (ww) VH contains the amino acid sequence of VH in P1-068761_E32Y_E56N and VL contains the amino acid sequence of VL in P1-068761_E32Y_E56N;

[0241] (xx) VH containing the amino acid sequence of VH in P1-068761_E30D_E32Y and VL containing the amino acid sequence of VL in P1-068761_E30D_E32Y;

[0242] (yy) contains the amino acid sequence of VH in P1-068761_E32Y_H100G and VL contains the amino acid sequence of VL in P1-068761_E32Y_H100G;

[0243] (zz) VH containing the amino acid sequence of VH in P1-068761_E32Y_H100fF and VL containing the amino acid sequence of VL in P1-068761_E32Y_H100fF;

[0244] (aaa) contains the amino acid sequence of VH in P1-068767_D52N_D102V and the amino acid sequence of VL in P1-068767_D52N_D102V;

[0245] (bbb)VH contains the amino acid sequence of VH in P1-068767_D52N and VL contains the amino acid sequence of VL in P1-068767_D52N;

[0246] (ccc) contains the amino acid sequence of VH in P1-068767_D52N_E55A and the amino acid sequence of VL in P1-068767_D52N_E55A;

[0247] (ddd) contains the amino acid sequence of VH in P1-068767_E55A_D102V and the amino acid sequence of VL in P1-068767_E55A_D102V;

[0248] (eee) contains the amino acid sequence of VH in P1-068767_D102V and the amino acid sequence of VL in P1-068767_D102V;

[0249] (fff) contains the amino acid sequence of VH in P1-068767_E55A and VL contains the amino acid sequence of VL in P1-068767_E55A;

[0250] (ggg) contains the amino acid sequence of VH in P1-068767_E30D_D52N and the amino acid sequence of VL in P1-068767_E30D_D52N;

[0251] (hhh) VH contains the amino acid sequence of VH in P1-068767_E30D_D102V and VL contains the amino acid sequence of VL in P1-068767_E30D_D102V;

[0252] (iii) VH containing the amino acid sequence of VH in P1-068767_E30D and VL containing the amino acid sequence of VL in P1-068767_E30D;

[0253] (jjj) contains the amino acid sequence of VH in P1-068767_E30D_E55A and the amino acid sequence of VL in P1-068767_E30D_E55A;

[0254] (kkk) contains the amino acid sequence of VH in P1-068767_E100fF_D102V and the amino acid sequence of VL in P1-068767_E100fF_D102V;

[0255] (lll) VH containing the amino acid sequence of VH in P1-068767_E55A_E100fF and VL containing the amino acid sequence of VL in P1-068767_E55A_E100fF;

[0256] (mmm) contains the amino acid sequence of VH in P1-068767_D52N_D100fF and VL contains the amino acid sequence of VL in P1-068767_D52N_D100fF;

[0257] (nnn) contains the amino acid sequence of VH in P1-068767_E100fF and the amino acid sequence of VL in P1-068767_E100fF;

[0258] (ooo) contains the amino acid sequence of VH in P1-068767_E30D_H100fF and VL contains the amino acid sequence of VL in P1-068767_E30D_H100fF;

[0259] (ppp) contains the amino acid sequence of VH in P1-061029_F100fE_V102D and the amino acid sequence of VL in P1-061029_F100fE_V102D;

[0260] (qqq) contains the amino acid sequence of VH in P1-061029_F100fE and the amino acid sequence of VL in P1-061029_F100fE;

[0261] (rrr) VH contains the amino acid sequence of VH in P1-061029_V102D and VL contains the amino acid sequence of VL in P1-061029_V102D;

[0262] (sss) contains the amino acid sequence of VH in P1-061029_Y32E and the amino acid sequence of VL in P1-061029_Y32E; or

[0263] (ttt) contains the amino acid sequence of VH in P1-061029_Y32E_F100fE and the amino acid sequence of VL in P1-061029_Y32E_F100fE.

[0264] Anti-hVISTA Ab may include:

[0265] (a) VH containing the amino acid sequence of VH of P1-061029 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-061029;

[0266] (b) VH containing the amino acid sequence of VH of P1-068757 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068757;

[0267] (c) A VH containing the amino acid sequence of a VH of P1-068759 modified by K16R and / or T84A substitution; and a VL containing the amino acid sequence of a VL of P1-068759;

[0268] (d) VH containing the amino acid sequence of VH of P1-068761 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068761;

[0269] (e) A VH containing the amino acid sequence of a VH modified by K16R and / or T84A substitution; and a VL containing the amino acid sequence of a VL containing a P1-068763;

[0270] (f) VH containing the amino acid sequence of VH of P1-068765 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068765;

[0271] (g) VH containing the amino acid sequence of VH of P1-068767 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068767;

[0272] (h) VH containing the amino acid sequence of VH of P1-068769 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068769;

[0273] (i) VH containing the amino acid sequence of VH of P1-068771 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068771;

[0274] (j) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing -068773;

[0275] (k) VH containing the amino acid sequence of VH of P1-068775 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068775;

[0276] (l) VH containing the amino acid sequence of VH of P1-069059 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-069059;

[0277] (m) VH containing the amino acid sequence of VH of P1-069061 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-069061;

[0278] (n) VH containing the amino acid sequence of VH of P1-069063 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-069063;

[0279] (o) A VH containing the amino acid sequence of a VH of P1-069065 modified by K16R and / or T84A substitution; and a VL containing the amino acid sequence of a VL of P1-069065;

[0280] (p) VH containing the amino acid sequence of VH of P1-069067 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-069067;

[0281] (q) VH containing the amino acid sequence of VH of P1-069069 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-069069;

[0282] (r) VH containing the amino acid sequence of VH of P1-069071 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-069071;

[0283] (s) VH containing the amino acid sequence of VH of P1-069073 modified by K16R and / or T84A substitution; VL containing the amino acid sequence of VL of P1-069073;

[0284] (t) VH containing the amino acid sequence of VH of P1-069075 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-069075;

[0285] (u) VH containing the amino acid sequence of VH of P1-069077 modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-069077;

[0286] (v) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing P1-068761_E55A;

[0287] (w) VH containing the amino acid sequence of VH of P1-068761_H100G modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068761_H100G;

[0288] (x) VH containing the amino acid sequence of VH of P1-068761_E56N modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068761_E56N;

[0289] (y) VH containing the amino acid sequence of VH of P1-068761_E55A_E56N modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068761_E55A_E56N;

[0290] (z) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing P1-068761_E30D;

[0291] (aa) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing P1-068761_E30D_E55A;

[0292] (bb) VH containing the amino acid sequence of VH of P1-068761_E56N_H100G modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068761_E56N_H100G;

[0293] (cc) VH containing the amino acid sequence of VH of P1-068761_E30D_H100G modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068761_E30D_H100G;

[0294] (dd) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing P1-068761_E30D_E56N;

[0295] (ee) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing P1-068761_E100fF;

[0296] (ff) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing P1-068761_E55A_E100fF;

[0297] (gg) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitutions of P1-068761_H100G_E100fF; and VL containing the amino acid sequence of VL containing P1-068761_H100G_E100fF;

[0298] (hh) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing P1-068761_E30D_H100fF;

[0299] (ii) A VH containing the amino acid sequence of a VH modified by K16R and / or T84A substitution; and a VL containing the amino acid sequence of a VL containing a P1-068761_E56N_H100fF;

[0300] (jj) VH containing the amino acid sequence of VH of P1-068761_E32Y modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068761_E32Y;

[0301] (kk) VH containing the amino acid sequence of VH of P1-068761_E32Y_E55A modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068761_E32Y_E55A;

[0302] (ll) VH containing the amino acid sequence of VH of P1-068761_E32Y_E56N modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068761_E32Y_E56N;

[0303] (mm) VH containing the amino acid sequence of VH of P1-068761_E30D_E32Y modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068761_E30D_E32Y;

[0304] (nn) VH containing the amino acid sequence of VH of P1-068761_E32Y_H100G modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068761_E32Y_H100G;

[0305] (oo) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing P1-068761_E32Y_H100fF;

[0306] (pp) VH containing the amino acid sequence of VH of P1-068767_D52N_D102V modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068767_D52N_D102V;

[0307] (qq) VH containing the amino acid sequence of VH of P1-068767_D52N modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068767_D52N;

[0308] (rr) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing P1-068767_D52N_E55A;

[0309] (ss) VH containing the amino acid sequence of VH of P1-068767_E55A_D102V modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068767_E55A_D102V;

[0310] (tt) VH containing the amino acid sequence of VH of P1-068767_D102V modified by K16R and / or T84A substitution; VL containing the amino acid sequence of VL of P1-068767_D102V;

[0311] (uu) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing P1-068767_E55A;

[0312] (vv) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing P1-068767_E30D_D52N;

[0313] (ww) VH containing the amino acid sequence of VH of P1-068767_E30D_D102V modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068767_E30D_D102V;

[0314] (xx) VH containing the amino acid sequence of VH of P1-068767_E30D modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068767_E30D;

[0315] (yy) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing P1-068767_E30D_E55A;

[0316] (zz) VH containing the amino acid sequence of VH of P1-068767_E100fF_D102V modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-068767_E100fF_D102V;

[0317] (aaa) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing P1-068767_E55A_E100fF;

[0318] (bbb) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitutions of P1-068767_D52N_E100fF; and VL containing the amino acid sequence of VL containing P1-068767_D52N_E100fF;

[0319] (ccc) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing P1-068767_E100fF;

[0320] (ddd) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitutions of P1-068767_E30D_E100fF; and VL containing the amino acid sequence of VL containing P1-068767_E30D_E100fF;

[0321] (eee) VH containing the amino acid sequence of VH of P1-061029_F100fE_V102D modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-061029_F100fE_V102D;

[0322] (fff) VH containing the amino acid sequence of VH modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL containing P1-061029_F100fE;

[0323] (ggg) VH containing the amino acid sequence of VH of P1-061029_V102D modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-061029_V102D;

[0324] (hhh) VH containing the amino acid sequence of VH of P1-061029_Y32E modified by K16R and / or T84A substitution; and VL containing the amino acid sequence of VL of P1-061029_Y32E; or

[0325] (iii) A VH containing the amino acid sequence of a VH modified by K16R and / or T84A substitution of P1-061029_Y32E_F100fE; and a VL containing the amino acid sequence of a VL containing P1-061029_Y32E_F100fE.

[0326] Anti-hVISTA Ab may include:

[0327] (a) VH containing the VH CDR of VH in P1-061029 and VL containing the VL CDR of P1-061029; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-061029;

[0328] (b) VH containing the VH CDR of VH in P1-061015 and VL containing the VL CDR of P1-061015; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-061015;

[0329] (c) VH containing the VH CDR of VH in P1-068757 and VL containing the VL CDR of P1-068757; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068757;

[0330] (d) VH containing the VH CDR of VH in P1-068759 and VL containing the VL CDR of P1-068759; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068759;

[0331] (e) VH containing the VH CDR of VH in P1-068761 and VL containing the VL CDR of P1-068761; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068761;

[0332] (f) VH containing the VH CDR of VH in P1-068763 and VL containing the VL CDR of P1-068763; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068763;

[0333] (g) VH containing the VH CDR of VH in P1-068765 and VL containing the VL CDR of P1-068765; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068765;

[0334] (h) VH containing the VH CDR of VH in P1-068767 and VL containing the VL CDR of P1-068767; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068767;

[0335] (i) VH containing the VH CDR of VH in P1-068769 and VL containing the VL CDR of P1-068769; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity with VH and VL in P1-068769;

[0336] (j) VH containing the VH CDR of VH in P1-068771 and VL containing the VL CDR of P1-068771; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068771;

[0337] (k) VH containing the VH CDR of VH in P1-068773 and VL containing the VL CDR of P1-068773; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068773;

[0338] (l) VH containing the VH CDR of VH in P1-068775 and VL containing the VL CDR of P1-068775; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity with VH and VL in P1-068775;

[0339] (m) VH containing the VH CDR of VH in P1-069059 and VL containing the VL CDR of P1-069059; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-069059;

[0340] (n) VH containing the VH CDR of VH in P1-069061 and VL containing the VL CDR of P1-069061; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-069061;

[0341] (o) VH containing the VH CDR of VH in P1-069063 and VL containing the VL CDR of P1-069063; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-069063;

[0342] (p) VH containing the VH CDR of VH in P1-069065 and VL containing the VL CDR of P1-069065; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-069065;

[0343] (q) VH containing the VH CDR of VH in P1-069067 and VL containing the VL CDR of P1-069067; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-069067;

[0344] (r) VH containing the VH CDR of VH in P1-069069 and VL containing the VL CDR of P1-069069; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-069069;

[0345] (s) VH containing the VH CDR of VH in P1-069071 and VL containing the VL CDR of P1-069071; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-069071;

[0346] (t) VH containing the VH CDR of VH in P1-069073 and VL containing the VL CDR of P1-069073; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-069073;

[0347] (u) VH containing the VH CDR of VH in P1-069075 and VL containing the VL CDR of P1-069075; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-069075;

[0348] (v) VH containing the VH CDR of VH in P1-069077 and VL containing the VL CDR of P1-069077; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-069077;

[0349] (w) VH containing the VH CDR of VH in P1-068736 and VL containing the VL CDR of P1-068736; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068736;

[0350] (x) VH containing the VH CDR of VH in P1-068738 and VL containing the VL CDR of P1-068738; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068738;

[0351] (y) VH containing the VH CDR of VH in P1-068740 and VL containing the VL CDR of P1-068740; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068740;

[0352] (z) VH containing the VH CDR of VH in P1-068742 and VL containing the VL CDR of P1-068742; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068742;

[0353] (aa) VH containing the VH CDR of VH in P1-068744 and VL containing the VL CDR of P1-068744; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068744;

[0354] (bb) VH containing the VH CDR of VH in P1-068746 and VL containing the VL CDR of P1-068746; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068746;

[0355] (cc) VH containing the VH CDR of VH in P1-068748 and VL containing the VL CDR of P1-068748; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068748;

[0356] (dd) VH containing the VH CDR of VH in P1-068750 and VL containing the VL CDR of P1-068750; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068750;

[0357] (ee) VH containing the VH CDR of VH in P1-068752 and VL containing the VL CDR of P1-068752; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068752;

[0358] (ff) VH containing the VH CDR of VH in P1-068754 and VL containing the VL CDR of P1-068754; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068754;

[0359] (gg) VH containing the VH CDR of VH in P1-068761_E55A and VL containing the VL CDR of P1-068761_E55A; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068761_E55A;

[0360] (hh) VH containing the VH CDR of VH in P1-068761_H100G and VL containing the VL CDR of P1-068761_H100G; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068761_H100G;

[0361] (ii) VH containing the VH CDR of VH in P1-068761_E56N and VL containing the VL CDR of P1-068761_E56N; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068761_E56N;

[0362] (jj) VH containing the VH CDR of VH in P1-068761_E55A_E56N and VL containing the VL CDR of P1-068761_E55A_E56N; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068761_E55A_E56N;

[0363] (kk) VH containing the VH CDR of VH in P1-068761_E30D and VL containing the VL CDR of P1-068761_E30D; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068761_E30D;

[0364] (ll) VH containing the VH CDR of VH in P1-068761_E30D_E55A and VL containing the VL CDR of P1-068761_E30D_E55A; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068761_E30D_E55A;

[0365] (mm) VH containing the VH CDR of VH in P1-068761_E56N_H100G and VL containing the VL CDR of P1-068761_E56N_H100G; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068761_E56N_H100G;

[0366] (nn) VH containing the VH CDR of VH in P1-068761_E30D_H100G and VL containing the VL CDR of P1-068761_E30D_H100G; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068761_E30D_H100G;

[0367] (oo) VH containing the VH CDR of VH in P1-068761_E30D_E56N and VL containing the VL CDR of P1-068761_E30D_E56N; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068761_E30D_E56N;

[0368] (pp) VH containing VH CDR of VH in P1-068761_E100fF and VL containing VLCDR of P1-068761_E100fF; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068761_E100fF;

[0369] (qq) VH containing the VH CDR of VH in P1-068761_E55A_E100fF and VL containing the VL CDR of P1-068761_E55A_E100fF; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068761_E55A_E100fF;

[0370] (rr) VH containing the VH CDR of VH in P1-068761_H100G_E100fF and VL containing the VL CDR of P1-068761_H100G_E100fF; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068761_H100G_E100fF;

[0371] (ss) VH containing the VH CDR of VH in P1-068761_E30D_E100fF and VL containing the VL CDR of P1-068761_E30D_E100fF; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068761_E30D_E100fF;

[0372] (tt) VH containing the VH CDR of VH in P1-068761_E56N_E100fF and VL containing the VL CDR of P1-068761_E56N_E100fF; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068761_E56N_E100fF;

[0373] (uu) VH containing the VH CDR of VH in P1-068761_E32Y and VL containing the VL CDR of P1-068761_E32Y; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068761_E32Y;

[0374] (vv) VH containing the VH CDR of VH in P1-068761_E32Y_E55A and VL containing the VL CDR of P1-068761_E32Y_E55A; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068761_E32Y_E55A;

[0375] (ww) VH containing the VH CDR of VH in P1-068761_E32Y_E56N and VL containing the VL CDR of P1-068761_E32Y_E56N; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068761_E32Y_E56N;

[0376] (xx) VH containing the VH CDR of VH in P1-068761_E30D_E32Y and VL containing the VL CDR of P1-068761_E30D_E32Y; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068761_E30D_E32Y;

[0377] (yy) contains the VH CDR of VH in P1-068761_E32Y_H100G and the VL contains the VL CDR of P1-068761_E32Y_H100G; and the VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the VH and VL of P1-068761_E32Y_H100G;

[0378] (zz) VH containing the VH CDR of VH in P1-068761_E32Y_E100fF and VL containing the VL CDR of P1-068761_E32Y_E100fF; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068761_E32Y_E100fF;

[0379] (aaa) VH containing the VH CDR of VH in P1-068767_D52N_D102V and VL containing the VL CDR of P1-068767_D52N_D102V; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068767_D52N_D102V;

[0380] (bbb) VH containing the VH CDR of VH in P1-068767_D52N and VL containing the VL CDR of P1-068767_D52N; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the VH and VL of P1-068767_D52N;

[0381] (ccc) VH containing the VH CDR of VH in P1-068767_D52N_E55A and VL containing the VL CDR of P1-068767_D52N_E55A; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068767_D52N_E55A;

[0382] (ddd) VH containing the VH CDR of VH in P1-068767_E55A_D102V and VL containing the VL CDR of P1-068767_E55A_D102V; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068767_E55A_D102V;

[0383] (eee) contains the VH CDR of VH in P1-068767_D102V and the VL contains the VL CDR of P1-068767_D102V; and the VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the VH and VL of P1-068767_D102V;

[0384] (fff) contains the VH CDR of VH in P1-068767_E55A and the VL contains the VL CDR of P1-068767_E55A; and the VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the VH and VL of P1-068767_E55A;

[0385] (ggg) contains the VH CDR of VH in P1-068767_E30D_D52N and the VL CDR of VL in P1-068767_E30D_D52N; and the VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the VH and VL of P1-068767_E30D_D52N;

[0386] (hhh) VH containing the VH CDR of VH in P1-068767_E30D_D102V and VL containing the VL CDR of P1-068767_E30D_D102V; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068767_E30D_D102V;

[0387] (iii) VH containing the VH CDR of VH in P1-068767_E30D and VL containing the VL CDR of P1-068767_E30D; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-068767_E30D;

[0388] (jjj) contains the VH CDR of VH in P1-068767_E30D_E55A and the VL CDR of VL in P1-068767_E30D_E55A; and the VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the VH and VL in P1-068767_E30D_E55A;

[0389] (kkk) contains the VH CDR of VH in P1-068767_E100fF_D102V and the VL CDR of VL in P1-068767_E100fF_D102V; and the VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the VH and VL of P1-068767_E100fF_D102V;

[0390] (lll) VH containing the VH CDR of VH in P1-068767_E55A_E100fF and VL containing the VL CDR of P1-068767_E55A_E100fF; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068767_E55A_E100fF;

[0391] (mmm) VH containing the VH CDR of VH in P1-068767_D52N_E100fF and VL containing the VL CDR of P1-068767_D52N_E100fF; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068767_D52N_E100fF;

[0392] (nnn) VH containing VH CDR of VH in P1-068767_E100fF and VL containing VLCDR of P1-068767_E100fF; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068767_E100fF;

[0393] (ooo) VH containing the VH CDR of VH in P1-068767_E30D_E100fF and VL containing the VL CDR of P1-068767_E30D_E100fF; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-068767_E30D_E100fF;

[0394] (ppp) VH containing the VH CDR of VH in P1-061029_F100fE_V102D and VL containing the VL CDR of P1-061029_F100fE_V102D; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-061029_F100fE_V102D;

[0395] (qqq) VH containing VH CDR of VH in P1-061029_F100fE and VL containing VLCDR of P1-061029_F100fE; and VH and VL amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL of P1-061029_F100fE;

[0396] (rrr) VH containing the VH CDR of VH in P1-061029_V102D and VL containing the VL CDR of P1-061029_V102D; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-061029_V102D;

[0397] (sss) contains the VH CDR of VH in P1-061029_Y32E and the VL CDR of VL in P1-061029_Y32E; and the VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the VH and VL in P1-061029_Y32E;

[0398] (ttt)VH containing the VH CDR of VH in P1-061029_Y32E_F100fE and VL containing the VL CDR of VL in P1-061029_Y32E_F100fE; and VH and VL amino acid sequences that have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with VH and VL in P1-061029_Y32E_F100fE;

[0399] Optionally, the VH in any of (a) to (ttt) contains one or both of K16R substitution and T84A substitution.

[0400] In some of the above embodiments, the sequence difference between VH and / or VL and each of substances (a) to (ttt) may lie in the presence of 1, 2, 3, 4, or 5 amino acid substitutions (e.g., 1, 2, 3, 4, or 5 conserved substitutions). In some embodiments, VH may contain one or both of the K16R substitution and the T84A substitution.

[0401] Anti-hVISTA Ab may include:

[0402] (a) VH composed of the amino acid sequence of VH in P1-061029 and VL composed of VL in P1-061029;

[0403] (b) VH composed of the amino acid sequence of VH in P1-061015 and VL composed of VL in P1-061015;

[0404] (c) VH composed of the amino acid sequence of VH in P1-068757 and VL composed of VL in P1-068757;

[0405] (d) VH composed of the amino acid sequence of VH in P1-068759 and VL composed of VL in P1-068759;

[0406] (e) VH composed of the amino acid sequence of VH in P1-068761 and VL composed of VL in P1-068761;

[0407] (f) VH composed of the amino acid sequence of VH in P1-068763 and VL composed of VL in P1-068763;

[0408] (g) VH composed of the amino acid sequence of VH in P1-068765 and VL composed of VL in P1-068765;

[0409] (h) VH composed of the amino acid sequence of VH in P1-068767 and VL composed of VL in P1-068767;

[0410] (i) VH composed of the amino acid sequence of VH in P1-068769 and VL composed of VL in P1-068769;

[0411] (j) VH composed of the amino acid sequence of VH in P1-068771 and VL composed of VL in P1-068771;

[0412] (k) VH composed of the amino acid sequence of VH in P1-068773 and VL composed of VL in P1-068773;

[0413] (l) VH composed of the amino acid sequence of VH in P1-068775 and VL composed of VL in P1-068775;

[0414] (m) VH, which is composed of the amino acid sequence of VH in P1-069059, and VL, which is composed of VL in P1-069059;

[0415] (n) VH, which is composed of the amino acid sequence of VH in P1-069061, and VL, which is composed of VL in P1-069061;

[0416] (o) VH composed of the amino acid sequence of VH in P1-069063 and VL composed of VL in P1-069063;

[0417] (p) VH, which is composed of the amino acid sequence of VH in P1-069065, and VL, which is composed of VL in P1-069065;

[0418] (q) VH composed of the amino acid sequence of VH in P1-069067 and VL composed of VL in P1-069067;

[0419] (r) VH composed of the amino acid sequence of VH in P1-069069 and VL composed of VL in P1-069069;

[0420] (s) VH, which is composed of the amino acid sequence of VH in P1-069071, and VL, which is composed of VL in P1-069071;

[0421] (t) VH, which is composed of the amino acid sequence of VH in P1-069073, and VL, which is composed of VL in P1-069073;

[0422] (u) VH, which is composed of the amino acid sequence of VH in P1-069075, and VL, which is composed of VL in P1-069075;

[0423] (v) VH composed of the amino acid sequence of VH in P1-069077 and VL composed of VL in P1-069077;

[0424] (w) VH composed of the amino acid sequence of VH in P1-068736 and VL composed of VL in P1-068736;

[0425] (x) VH, which is composed of the amino acid sequence of VH in P1-068738, and VL, which is composed of VL in P1-068738;

[0426] (y) VH composed of the amino acid sequence of VH in P1-068740 and VL composed of VL in P1-068740;

[0427] (z) VH composed of the amino acid sequence of VH in P1-068742 and VL composed of VL in P1-068742;

[0428] (aa) VH is composed of the amino acid sequence of VH in P1-068744 and VL is composed of VL in P1-068744;

[0429] (bb) VH is composed of the amino acid sequence of VH in P1-068746 and VL is composed of VL in P1-068746;

[0430] (cc) VH, which is composed of the amino acid sequence of VH in P1-068748, and VL, which is composed of VL in P1-068748;

[0431] (dd) VH is composed of the amino acid sequence of VH in P1-068750 and VL is composed of VL in P1-068750;

[0432] (ee) VH is composed of the amino acid sequence of VH in P1-068752 and VL is composed of VL in P1-068752;

[0433] (ff) VH, which is composed of the amino acid sequence of VH in P1-068754, and VL, which is composed of VL in P1-068754;

[0434] (gg) VH is composed of the amino acid sequence of VH in P1-068761_E55A and VL is composed of the amino acid sequence of VL in P1-068761_E55A;

[0435] (hh) VH is composed of the amino acid sequence of VH in P1-068761_H100G and VL is composed of the amino acid sequence of VL in P1-068761_H100G;

[0436] (ii) VH, which is composed of the amino acid sequence of VH in P1-068761_E56N, and VL, which is composed of the amino acid sequence of VL in P1-068761_E56N;

[0437] (jj) VH is composed of the amino acid sequence of VH in P1-068761_E55A_E56N and VL is composed of the amino acid sequence of VL in P1-068761_E55A_E56N;

[0438] (kk) VH is composed of the amino acid sequence of VH in P1-068761_E30D and VL is composed of the amino acid sequence of VL in P1-068761_E30D;

[0439] (ll) VH, which is composed of the amino acid sequence of VH in P1-068761_E30D_E55A, and VL, which is composed of the amino acid sequence of VL in P1-068761_E30D_E55A;

[0440] (mm) VH, which is composed of the amino acid sequence of VH in P1-068761_E56N_H100G, and VL, which is composed of the amino acid sequence of VL in P1-068761_E56N_H100G;

[0441] (nn) VH, which is composed of the amino acid sequence of VH in P1-068761_E30D_H100G, and VL, which is composed of the amino acid sequence of VL in P1-068761_E30D_H100G;

[0442] (oo) VH, which is composed of the amino acid sequence of VH in P1-068761_E30D_E56N, and VL, which is composed of the amino acid sequence of VL in P1-068761_E30D_E56N;

[0443] (pp) VH, which is composed of the amino acid sequence of VH in P1-068761_E100fF, and VL, which is composed of the amino acid sequence of VL in P1-068761_E100fF;

[0444] (qq) VH is composed of the amino acid sequence of VH in P1-068761_E55A_E100fF and VL is composed of the amino acid sequence of VL in P1-068761_E55A_E100fF;

[0445] (rr) VH, which is composed of the amino acid sequence of VH in P1-068761_H100G_E100fF, and VL, which is composed of the amino acid sequence of VL in P1-068761_H100G_E100fF;

[0446] (ss) VH is composed of the amino acid sequence of VH in P1-068761_E30D_E100fF and VL is composed of the amino acid sequence of VL in P1-068761_E30D_E100fF;

[0447] (tt) VH is composed of the amino acid sequence of VH in P1-068761_E56N_E100fF and VL is composed of the amino acid sequence of VL in P1-068761_E56N_E100fF;

[0448] (uu) VH is composed of the amino acid sequence of VH in P1-068761_E32Y and VL is composed of the amino acid sequence of VL in P1-068761_E32Y;

[0449] (vv) VH, which is composed of the amino acid sequence of VH in P1-068761_E32Y_E55A, and VL, which is composed of the amino acid sequence of VL in P1-068761_E32Y_E55A;

[0450] (ww) VH is composed of the amino acid sequence of VH in P1-068761_E32Y_E56N and VL is composed of the amino acid sequence of VL in P1-068761_E32Y_E56N;

[0451] (xx) VH, which is composed of the amino acid sequence of VH in P1-068761_E30D_E32Y, and VL, which is composed of the amino acid sequence of VL in P1-068761_E30D_E32Y;

[0452] (yy) VH is composed of the amino acid sequence of VH in P1-068761_E32Y_H100G and VL is composed of the amino acid sequence of VL in P1-068761_E32Y_H100G;

[0453] (zz) VH, which is composed of the amino acid sequence of VH in P1-068761_E32Y_E100fF, and VL, which is composed of the amino acid sequence of VL in P1-068761_E32Y_E100fF;

[0454] (aaa) VH is composed of the amino acid sequence of VH in P1-068767_D52N_D102V and VL is composed of the amino acid sequence of VL in P1-068767_D52N_D102V;

[0455] (bbb) VH is composed of the amino acid sequence of VH in P1-068767_D52N and VL is composed of the amino acid sequence of VL in P1-068767_D52N;

[0456] (ccc) VH is composed of the amino acid sequence of VH in P1-068767_D52N_E55A and VL is composed of the amino acid sequence of VL in P1-068767_D52N_E55A;

[0457] (ddd) VH is composed of the amino acid sequence of VH in P1-068767_E55A_D102V and VL is composed of the amino acid sequence of VL in P1-068767_E55A_D102V;

[0458] (eee) VH is composed of the amino acid sequence of VH in P1-068767_D102V and VL is composed of the amino acid sequence of VL in P1-068767_D102V;

[0459] (fff) VH is composed of the amino acid sequence of VH in P1-068767_E55A and VL is composed of the amino acid sequence of VL in P1-068767_E55A;

[0460] (ggg) VH is composed of the amino acid sequence of VH in P1-068767_E30D_D52N and VL is composed of the amino acid sequence of VL in P1-068767_E30D_D52N;

[0461] (hhh) VH is composed of the amino acid sequence of VH in P1-068767_E30D_D102V and VL is composed of the amino acid sequence of VL in P1-068767_E30D_D102V;

[0462] (iii) VH, which is composed of the amino acid sequence of VH in P1-068767_E30D, and VL, which is composed of the amino acid sequence of VL in P1-068767_E30D;

[0463] (jjj) VH is composed of the amino acid sequence of VH in P1-068767_E30D_E55A and VL is composed of the amino acid sequence of VL in P1-068767_E30D_E55A;

[0464] (kkk) VH is composed of the amino acid sequence of VH in P1-068767_E100fF_D102V and VL is composed of the amino acid sequence of VL in P1-068767_E100fF_D102V;

[0465] (lll) VH is composed of the amino acid sequence of VH in P1-068767_E55A_E100fF and VL is composed of the amino acid sequence of VL in P1-068767_E55A_E100fF;

[0466] (mmm) VH is composed of the amino acid sequence of VH in P1-068767_D52N_E100fF and VL is composed of the amino acid sequence of VL in P1-068767_D52N_E100fF;

[0467] (nnn) VH is composed of the amino acid sequence of VH in P1-068767_E100fF and VL is composed of the amino acid sequence of VL in P1-068767_E100fF;

[0468] (ooo) VH is composed of the amino acid sequence of VH in P1-068767_E30D_E100fF and VL is composed of the amino acid sequence of VL in P1-068767_E30D_E100fF;

[0469] (ppp) VH is composed of the amino acid sequence of VH in P1-061029_F100fE_V102D and VL is composed of the amino acid sequence of VL in P1-061029_F100fE_V102D;

[0470] (qqq) VH is composed of the amino acid sequence of VH in P1-061029_F100fE and VL is composed of the amino acid sequence of VL in P1-061029_F100fE;

[0471] (rrr) VH is composed of the amino acid sequence of VH in P1-061029_V102D and VL is composed of the amino acid sequence of VL in P1-061029_V102D;

[0472] (sss) VH, composed of the amino acid sequence of VH in P1-061029_Y32E, and VL, composed of the amino acid sequence of VL in P1-061029_Y32E; or

[0473] (ttt) VH is composed of the amino acid sequence of VH in P1-061029_Y32E_F100fE and VL is composed of the amino acid sequence of VL in P1-061029_Y32E_F100fE;

[0474] Optionally, the VH in any of (a) to (ttt) contains one or both of K16R substitution and T84A substitution.

[0475] In some implementations, anti-VISTA Ab includes any of the variable regions and / or variable regions CDR 1-3 of the antibody described above and elsewhere herein, for example:

[0476] (1) One or more of VH CDR1, CDR2 and CDR3:

[0477] (2) VH CDR1, CDR2 and CDR3:

[0478] (3) VH:

[0479] (4) One or more of VH CDR1, CDR2 and CDR3 and one or more of VL CDR1, CDR2 and CDR3:

[0480] (5) VH CDR1, CDR2 and CDR3 and VL CDR1, CDR2 and CDR3:

[0481] (6) VH and VL:

[0482] or

[0483] (7) VL and VH, except for one or both of the K16R substitution and T84A substitution in VH (in the case of P1-061029 or its progeny), the moiety is derived from the following substances:

[0484] P1-061029,P1-068757,P1-068759,P1-068761,P1-068763,P1-068765,P1-068767,P1-068769、P1-068771、P1-068773、P1-068775、P1-069059、P1-069061、P1-069063、P1-069065、P1-069067、P1-069069、P1-069071、P1-069073、P1-069075、P1-069077、P1-061015、P1-068736、P1-068738、P1-068740、P1-068742、P1-068744、P1-068766、P1-068748、P1-068750、P1-068752、P1-068754、P1-068761_E55A、P1-068761_H100G、P1-068761_E56N、P1-068761_E55A_E56N、P1-068761_E30D、P1-068761_E30D_E55A、P1-068761_E56N_H100G、P1-068761_E30D_H100G、P1-068761_E30D_E56N、P1-068761_E100fF、P1-068761_E55A_E100fF、P1-068761_H100G_E100fF、P1-068761_E30D_E100fF、P1-068761_E56N_E100fF、P1-068761_E32Y、P1-068761_E32Y_E55A、P1-068761_E32Y_E56N、P1-068761_E30D_E32Y、P1-068761_E32Y_H100G、P1-068761_E32Y_E100fF、P1-068767_D52N_D102V、P1-068767_D52N、P1-068767_D52N_E55A、P1-068767_E55A_D102V、P1-068767_D102V、P1-068767_E55A、P1-068767_E30D_D52N、P1-068767_E30D_D102V、P1-068767_E30D、P1-068767_E30D_E55A、P1-068767_E100fF_D102V、P1-068767_E55A_E100fF、P1-068767_D52N_E100fF、P1-068767_E100fF、P1-068767_E30D_E100fF、P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E, or P1-061029_Y32E_F100fE; and anti-VISTA Ab is also an IgG antibody (e.g., IgG1, IgG2, IgG3, or IgG4 antibody or a modified form thereof), as described in the following sections. In some embodiments, the constant region has effector functionality, and in some embodiments, the constant region is effector-free. In some embodiments, the constant region is the constant region of IgG1.3.

[0485] In some implementations, anti-VISTA Ab includes any of the variable regions and / or variable regions CDR 1-3 of the antibody described above and elsewhere herein, for example:

[0486] (1) One or more of VH CDR1, CDR2 and CDR3:

[0487] (2) VH CDR1, CDR2 and CDR3:

[0488] (3) VH:

[0489] (4) One or more of VH CDR1, CDR2 and CDR3 and one or more of VL CDR1, CDR2 and CDR3:

[0490] (5) VH CDR1, CDR2 and CDR3 and VL CDR1, CDR2 and CDR3:

[0491] (6) VH and VL:

[0492] or

[0493] (7) VL and VH, except for one or both of the K16R substitution and T84A substitution in VH (in the case of P1-061029 and its progeny), the moiety is derived from the following substances:

[0494] P1-061029、P1-068757、P1-068759、P1-068761、P1-068763、P1-068765、P1-068767、P1-068769、P1-068771、P1-068773、P1-068775、P1-069059、P1-069061、P1-069063、P1-069065、P1-069067、P1-069069、P1-069071、P1-069073、P1-069075、P1-069077、P1-061015、P1-068736、P1-068738、P1-068740、P1-068742、P1-068744、P1-068766、P1-068748、P1-068750、P1-068752、P1-068754、P1-068761_E55A、P1-068761_H100G、P1-068761_E56N、P1-068761_E55A_E56N、P1-068761_E30D、P1-068761_E30D_E55A、P1-068761_E56N_H100G、P1-068761_E30D_H100G、P1-068761_E30D_E56N、P1-068761_E100fF、P1-068761_E55A_E100fF、P1-068761_H100G_E100fF、P1-068761_E30D_E100fF、P1-068761_E56N_E100fF、P1-068761_E32Y、P1-068761_E32Y_E55A、P1-068761_E32Y_E56N、P1-068761_E30D_E32Y、P1-068761_E32Y_H100G、P1-068761_E32Y_E100fF、P1-068767_D52N_D102V、P1-068767_D52N、P1-068767_D52N_E55A、P1-068767_E55A_D102V、P1-068767_D102V、P1-068767_E55A、P1-068767_E30D_D52N、P1-068767_E30D_D102V、P1-068767_E30D、P1-068767_E30D_E55A、P1-068767_E100fF_D102V、P1-068767_E55A_E100fF、P1-068767_D52N_E100fF、P1-068767_E100fF、P1-068767_E30D_E100fF、P1-061029_F100fE_V102D, P1-061029_F100fE, P1-061029_V102D, P1-061029_Y32E or P1-061029_Y32E_F100fE,

[0495] Furthermore, it includes one or more of the following characteristics:

[0496] -Specifically binds to hVISTA (e.g., the histidine-rich region of ECD or a polypeptide containing amino acid residues 35-127 of SEQ ID NO:2) at acidic pH (e.g., pH 6.0 or pH 6.5);

[0497] - It does not significantly bind to hVISTA (e.g., histidine-rich regions of ECD or polypeptides containing amino acid residues 35-127 of SEQ ID NO:2) at physiological or neutral pH (e.g., pH 7.4 or pH 7.0);

[0498] - It specifically binds to the VISTA of cynomolgus monkeys (e.g., the histidine-rich region of ECD) at acidic pH (e.g., pH 6.0 or pH 6.5);

[0499] - At physiological or neutral pH (e.g., pH 7.4 or pH 7.0), it does not significantly bind to the VISTA of cynomolgus monkeys (e.g., the histidine-rich region of the ECD);

[0500] - Relative to the hVISTA ECD having SEQ ID NO:2, it is bound to a lesser extent to an hVISTA-ECD having a substitution at one or more of the following amino acids: T35, Y37, K38, T39, Y41, R54, T61, F62, Q63, L65, H66, L67, H68, H69, F97, L115, V117, I119, H121, H122, S124, E125, R127;

[0501] - Cross-competing with P1-061029, P1-068761, P1-068767 and / or P1-061015 to combine into hVISTA;

[0502] - Inhibits the binding of hVISTA to human T cells (e.g., naive or activated T cells) that express VISTA at acidic pH (e.g., pH 6.0 or pH 6.5);

[0503] - Inhibit the binding of hVISTA to PSGL-1 at an acidic pH (e.g., pH 6.0 or pH 6.5) (e.g., inhibit the interaction between H153 and H154 of hVISTA having SEQ ID NO: 1 and tyrosines Y46 and Y48 of PSGL-1), wherein PSGL-1 contains or does not contain sialyl Lewis X, and wherein the tyrosine is preferably sulfotyrosine;

[0504] - The mean residence time (MRT) in cynomolgus monkeys was at least 100, 200, 300, 350, 400, 450, 500, 600 or 700 hours (e.g. at least 350 hours), as measured as described in the examples;

[0505] - Stimulate T cell activation by (for example) enhancing T cell proliferation, enhancing IFN-γ production from T cells and / or stimulating T cell receptor-mediated NF-κB signaling;

[0506] - Inhibit VISTA-mediated cell adhesion;

[0507] -Specifically binds to hVISTA in human tumor cell samples or inflamed human tissue samples that express VISTA;

[0508] - hVISTA is contacted via one or more (e.g., at least 1-3, 1-5, 1-10, 5-10, 5-15 or all) energetically important contact residues Y37, T39, R54, F62, H66, V117, I119 or S124, as determined, for example, using yeast surface display and NGS assays as described in Example 15; and wherein the number is the number of a mature hVISTA;

[0509] - Combined with region 1 of hVISTA having SEQ ID NO:1: 57 LGPVDKGHDVTF 68 (SEQ ID NO:566); Region 2: 86 RRPIRNLTFQDL 97 (SEQ ID NO:567); and region 3: 148 VVEIRHHHSEHRVHGAME 165 (SEQ IDNO:568), and optionally the binding to region 2 is the strongest, as determined by MS-HDX as described in Example 21;

[0510] - The enriched histidine β-sheet extension bound to hVISTA, as determined, for example, by crystallography as illustrated, for example, in the examples;

[0511] - H121, H122 and / or H123 of mature hVISTA are contacted via (e.g.) hydrogen bonding. (or a smaller distance), such as by crystallography as described in the examples;

[0512] - HVISTA is contacted via at least one or more glutamic acid, aspartic acid, or histidine residues located in VH CDR1, CDR2, or CDR3; and

[0513] and any other features stated in the claims and / or embodiments.

[0514] In some embodiments, the anti-hVISTA Ab comprises a heavy chain (HC) containing the amino acid sequence of the heavy chain of any of the anti-hVISTA Abs provided herein. In some embodiments, anti-hVISTA Ab comprises P1-061029 or P1-061015 or its progeny (e.g., P1-061029.IgG1.3 (SEQ ID NO: 69), P1-068757.IgG1.3, P1-068759.IgG1.3, P1-068761.IgG1.3, P1-068763.IgG1.3, P1-068765.IgG1.3, P1-068767.IgG1.3, P1-068769.IgG1.3, P1-068771.IgG1.3, P1-068773.IgG1.3, P1-068775.Ig) containing the IgG1.3 heavy chain constant region shown in the sequence listing below. G1.3, P1-069059.IgG1.3, P1-069061.IgG1.3, P1-069063.IgG1.3, P1- 069065.IgG1.3, P1-069067.IgG1.3, P1-069069.IgG1.3, P1-069071.Ig G1.3, P1-069073.IgG1.3, P1-069075.IgG1.3, P1-069077.IgG1.3, P1- 061015.IgG1.3, P1-068736.IgG1.3, P1-068738.IgG1.3, P1-068740.Ig G1.3, P1-068742.IgG1.3, P1-068744.IgG1.3, P1-068766.IgG1.3, P1- 068748.IgG1.3, P1-068750.IgG1.3, P1-068752.IgG1.3, P1-068754.Ig G1.3, P1-068761_E55A.IgG1.3, P1-068761_H100G.IgG1.3, P1-068761_E56N.IgG1.3, P1-068761_E55 A_E56N.IgG1.3, P1-068761_E30D.IgG1.3, P1-068761_E30D_E55A.IgG1.3, P1-068761_E56N_H100G.Ig G1.3、P1-068761_E30D_H100G.IgG1.3、P1-068761_E30D_E56N.IgG1.3、P1-068761_ E100fF.IgG1.3, P1-068761_E55A_E100fF.IgG1.3, P1-068761_H100G_E100fF.IgG1.3. P1-068761_E30D_E100fF.IgG1.3, P1-068761_E56N_E100fF.IgG1.3, P1-068761_E32Y.IgG1.3, P 1-068761_E32Y_E55A.IgG1.3, P1-068761_E32Y_E56N.IgG1.3, P1-068761_E30D_E32Y.IgG1.3, P1- 068761_E32Y_H100G.IgG1.3, P1-068761_E32Y_E100fF.IgG1.3, P1-068767_D52N_D102V.IgG1.3, P 1-068767_D52N.IgG1.3, P1-068767_D52N_E55A.IgG1.3, P1-068767_E55A_D102V.IgG1.3, P1-0687 67_D102V.IgG1.3, P1-068767_E55A.IgG1.3, P1-068767_E30D_D52N.IgG1.3, P1-068767_E30D_D10 2V.IgG1.3, P1-068767_E30D.IgG1.3, P1-068767_E30D_E55A.IgG1.3, P1-068767_E100fF_D102V.I gG1.3, P1-068767_E55A_E100fF.IgG1.3, P1-068767_D52N_E100fF.IgG1.3, P1-068767_E100fF.Ig G1.3, P1-068767_E30D_E100fF.IgG1.3, P1-061029_F100fE_V102D.IgG1.3, P1-061029_F100fE.Ig The heavy chain of the heavy chain is a heavy chain with an amino acid sequence of G1.3, P1-061029_V102D.IgG1.3, P1-061029_Y32E.IgG1.3, or P1-061029_Y32E_F100fE.IgG1.3, optionally wherein VH contains one or both of K16R substitution and T84A substitution.

[0515] In some embodiments, the anti-hVISTA Ab comprises a heavy chain containing the amino acid sequence of the heavy chain of any anti-hVISTA Ab provided herein (which contains the constant region of the IgG1.3 heavy chain) and the amino acid sequence of the light chain of any anti-hVISTA Ab provided herein. In some embodiments, anti-hVISTA Ab comprises P1-061029 or P1-061015 or its progeny (e.g., P1-061029.IgG1.3 (SEQ ID NO: 69), P1-068757.IgG1.3, P1-068759.IgG1.3, P1-068761.IgG1.3, P1-068763.IgG1.3, P1-068765.IgG1.3, P1-068767.IgG1.3, P1-068769.IgG1.3, P1-068771.IgG1.3, P1-068773.IgG1.3, P1-068775.IgG1.3, P1-069059.Ig) containing the IgG1.3 HC constant region. G1.3, P1-069061.IgG1.3, P1-069063.IgG1.3, P1-069065.IgG1.3, P1- 069067.IgG1.3, P1-069069.IgG1.3, P1-069071.IgG1.3, P1-069073.Ig G1.3, P1-069075.IgG1.3, P1-069077.IgG1.3, P1-061015.IgG1.3, P1- 068736.IgG1.3, P1-068738.IgG1.3, P1-068740.IgG1.3, P1-068742.Ig G1.3, P1-068744.IgG1.3, P1-068766.IgG1.3, P1-068748.IgG1.3, P1-068750.IgG1.3, P1-068752.IgG1.3, P1-068 754.IgG1.3, P1-068761_E55A.IgG1.3, P1-068761_H100G.IgG1.3, P1-068761_E56N.IgG1.3, P1-068761_E55A_E56 N.IgG1.3, P1-068761_E30D.IgG1.3, P1-068761_E30D_E55A.IgG1.3, P1-068761_E56N_H100G.IgG1.3, P1-068761_ E30D_H100G.IgG1.3, P1-068761_E30D_E56N.IgG1.3, P1-068761_E100fF.IgG1.3, P1-068761_E55A_E100fF.IgG1.3. P1-068761_H100G_E100fF.IgG1.3, P1-068761_E30D_E100fF.IgG1.3, P1-068761_E56N_E100fF.IgG1.3, P1-068761_E32Y.I gG1.3, P1-068761_E32Y_E55A.IgG1.3, P1-068761_E32Y_E56N.IgG1.3, P1-068761_E30D_E32Y.IgG1.3, P1-068761_E32Y_H100 G.IgG1.3, P1-068761_E32Y_E100fF.IgG1.3, P1-068767_D52N_D102V.IgG1.3, P1-068767_D52N.IgG1.3, P1-068767_D52N_E55 A.IgG1.3, P1-068767_E55A_D102V.IgG1.3, P1-068767_D102V.IgG1.3, P1-068767_E55A.IgG1.3, P1-068767_E30D_D52N.IgG1. 3. P1-068767_E30D_D102V.IgG1.3, P1-068767_E30D.IgG1.3, P1-068767_E30D_E55A.IgG1.3, P1-068767_E100fF_D102V.IgG1 .3, P1-068767_E55A_E100fF.IgG1.3, P1-068767_D52N_E100fF.IgG1.3, P1-068767_E100fF.IgG1.3, P1-068767_E30D_E100fF. A heavy chain containing the amino acid sequence of VH of IgG1.3, P1-061029_F100fE_V102D.IgG1.3, P1-061029_F100fE.IgG1.3, P1-061029_V102D.IgG1.3, P1-061029_Y32E.IgG1.3 or P1-061029_Y32E_F100fE.IgG1.3), optionally wherein VH contains one or both of K16R substitution and T84A substitution; and a light chain containing the amino acid sequence of the light chain of P1-061029 or P1-061015.

[0516] Anti-hVISTA Ab may include:

[0517] (a) The heavy chain containing the heavy chain amino acid sequence of P1-061029.IgG1.3 (SEQ ID NO:69) and the light chain containing the light chain amino acid sequence of P1-061029 (SEQ ID NO:70);

[0518] (b) The heavy chain containing the heavy chain amino acid sequence of P1-061015.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-061015.

[0519] (c) The heavy chain containing the heavy chain amino acid sequence of P1-068757.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068757.

[0520] (d) The heavy chain containing the heavy chain amino acid sequence of P1-068759.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068759.

[0521] (e) The heavy chain containing the heavy chain amino acid sequence of P1-068761.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761.

[0522] (f) The heavy chain containing the heavy chain amino acid sequence of P1-068763.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068763.

[0523] (g) The heavy chain containing the heavy chain amino acid sequence of P1-068765.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068765.

[0524] (h) The heavy chain containing the heavy chain amino acid sequence of P1-068767.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068767.

[0525] (i) The heavy chain containing the heavy chain amino acid sequence of P1-068769.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068769.

[0526] (j) The heavy chain containing the heavy chain amino acid sequence of P1-068771.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068771.

[0527] (k) The heavy chain containing the heavy chain amino acid sequence of P1-068773.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068773.

[0528] (l) The heavy chain containing the heavy chain amino acid sequence of P1-068775.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068775;

[0529] (m) The heavy chain containing the heavy chain amino acid sequence of P1-069059.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-069059.

[0530] (n) The heavy chain containing the heavy chain amino acid sequence of P1-069061.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-069061.

[0531] (o) The heavy chain containing the heavy chain amino acid sequence of P1-069063.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-069063;

[0532] (p) The heavy chain containing the heavy chain amino acid sequence of P1-069065.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-069065.

[0533] (q) The heavy chain containing the heavy chain amino acid sequence of P1-069067.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-069067.

[0534] (r) The heavy chain containing the heavy chain amino acid sequence of P1-069069.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-069069.

[0535] (s) a heavy chain containing the heavy chain amino acid sequence of P1-069071.IgG1.3 and a light chain containing the light chain amino acid sequence of P1-069071.

[0536] (t) The heavy chain containing the heavy chain amino acid sequence of P1-069073.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-069073;

[0537] (u) The heavy chain containing the heavy chain amino acid sequence of P1-069075.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-069075.

[0538] (v) The heavy chain containing the heavy chain amino acid sequence of P1-069077.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-069077.

[0539] (w) The heavy chain containing the heavy chain amino acid sequence of P1-068736.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068736.

[0540] (x) The heavy chain containing the heavy chain amino acid sequence of P1-068738.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068738;

[0541] (y) Heavy chain containing the heavy chain amino acid sequence of P1-068740.IgG1.3 and light chain containing the light chain amino acid sequence of P1-068740;

[0542] (z) The heavy chain containing the heavy chain amino acid sequence of P1-068742.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068742;

[0543] (aa) The heavy chain containing the heavy chain amino acid sequence of P1-068744.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068744.

[0544] (bb) The heavy chain containing the heavy chain amino acid sequence of P1-068746.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068746.

[0545] (cc) The heavy chain containing the heavy chain amino acid sequence of P1-068748.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068748.

[0546] (dd) Heavy chain containing the heavy chain amino acid sequence of P1-068750.IgG1.3 and light chain containing the light chain amino acid sequence of P1-068750;

[0547] (ee) The heavy chain containing the heavy chain amino acid sequence of P1-068752.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068752.

[0548] (ff) The heavy chain containing the heavy chain amino acid sequence of P1-068754.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068754.

[0549] (gg) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E55A.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E55A;

[0550] (hh) The heavy chain containing the heavy chain amino acid sequence of P1-068761_H100G.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_H100G;

[0551] (ii) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E56N.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E56N;

[0552] (jj) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E55A_E56N.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E55A_E56N;

[0553] (kk) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E30D.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E30D;

[0554] (ll) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E30D_E55A.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E30D_E55A;

[0555] (mm) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E56N_H100G.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E56N_H100G;

[0556] (nn) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E30D_H100G.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E30D_H100G;

[0557] (oo) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E30D_E56N.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E30D_E56N;

[0558] (pp) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E100fF.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E100fF;

[0559] (qq) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E55A_E100fF.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E55A_E100fF;

[0560] (rr) The heavy chain containing the heavy chain amino acid sequence of P1-068761_H100G_E100fF.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_H100G_E100fF;

[0561] (ss) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E30D_E100fF.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E30D_E100fF;

[0562] (tt) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E56N_E100fF.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E56N_E100fF;

[0563] (uu) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E32Y.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E32Y;

[0564] (vv) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E32Y_E55A.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E32Y_E55A;

[0565] (ww) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E32Y_E56N.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E32Y_E56N;

[0566] (xx) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E30D_E32Y.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E30D_E32Y;

[0567] (yy) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E32Y_H100G.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E32Y_H100G;

[0568] (zz) The heavy chain containing the heavy chain amino acid sequence of P1-068761_E32Y_E100fF.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068761_E32Y_E100fF;

[0569] (aaa) The heavy chain containing the heavy chain amino acid sequence of P1-068767_D52N_D102V.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068767_D52N_D102V;

[0570] (bbb) The heavy chain containing the heavy chain amino acid sequence of P1-068767_D52N.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068767_D52N;

[0571] (ccc) The heavy chain containing the heavy chain amino acid sequence of P1-068767_D52N_E55A.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068767_D52N_E55A;

[0572] (ddd) The heavy chain containing the heavy chain amino acid sequence of P1-068767_E55A_D102V.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068767_E55A_D102V;

[0573] (eee) is a heavy chain containing the heavy chain amino acid sequence of P1-068767_D102V.IgG1.3 and a light chain containing the light chain amino acid sequence of P1-068767_D102V.

[0574] (fff) The heavy chain containing the heavy chain amino acid sequence of P1-068767_E55A.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068767_E55A.

[0575] (ggg) The heavy chain containing the heavy chain amino acid sequence of P1-068767_E30D_D52N.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068767_E30D_D52N;

[0576] (hhh) The heavy chain containing the heavy chain amino acid sequence of P1-068767_E30D_D102V.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068767_E30D_D102V;

[0577] (iii) The heavy chain containing the heavy chain amino acid sequence of P1-068767_E30D.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068767_E30D;

[0578] (jjj) The heavy chain containing the heavy chain amino acid sequence of P1-068767_E30D_E55A.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068767_E30D_E55A;

[0579] (kkk) The heavy chain containing the heavy chain amino acid sequence of P1-068767_E100fF_D102V.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068767_E100fF_D102V;

[0580] (lll) The heavy chain containing the heavy chain amino acid sequence of P1-068767_E55A_E100fF.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068767_E55A_E100fF;

[0581] (mmm) The heavy chain containing the heavy chain amino acid sequence of P1-068767_D52N_E100fF.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068767_D52N_E100fF;

[0582] (nnn) The heavy chain containing the heavy chain amino acid sequence of P1-068767_E100fF.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-068767_E100fF; or

[0583] (ooo) The heavy chain containing the heavy chain amino acid sequence P1-068767_E30D_E100fF.IgG1.3 and the light chain containing the light chain amino acid sequence P1-068767_E30D_E100fF.

[0584] (ppp) The heavy chain containing the heavy chain amino acid sequence P1-061029_F100fE_V102D and the light chain containing the light chain amino acid sequence P1-061029_F100fE_V102D;

[0585] (qqq) The heavy chain containing the heavy chain amino acid sequence of P1-061029_F100fE.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-061029_F100fE;

[0586] (rrr) The heavy chain containing the heavy chain amino acid sequence of P1-061029_V102D.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-061029_V102D;

[0587] (sss) The heavy chain containing the heavy chain amino acid sequence of P1-061029_Y32E.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-061029_Y32E; or

[0588] (ttt) The heavy chain containing the heavy chain amino acid sequence of P1-061029_Y32E_F100fE.IgG1.3 and the light chain containing the light chain amino acid sequence of P1-061029_Y32E_F100fE;

[0589] Optionally, the VH in any of (a) to (ttt) contains one or both of K16R substitution and T84A substitution.

[0590] Anti-hVISTA Ab may include:

[0591] (a) The heavy chain (HC) containing the HC CDR of P1-061029 and the light chain (LC) containing the LC CDR of P1-061029; and the amino acid sequences of the HC and LC of P1-061029.IgG1.3 having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity, respectively.

[0592] (b) HC containing the HC CDR of P1-061015 and LC containing the LC CDR of P1-061015; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-061015.IgG1.3, respectively;

[0593] (c) HC containing the HC CDR of P1-068757 and LC containing the LC CDR of P1-068757; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity with the HC and LC of P1-068757.IgG1.3, respectively;

[0594] (d) HC containing the HC CDR of P1-068759 and LC containing the LC CDR of P1-068759; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068759.IgG1.3, respectively.

[0595] (e) HC containing the HC CDR of P1-068761 and LC containing the LC CDR of P1-068761; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761.IgG1.3, respectively.

[0596] (f) HC containing the HC CDR of P1-068763 and LC containing the LC CDR of P1-068763; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068763.IgG1.3, respectively;

[0597] (g) HC containing the HC CDR of P1-068765 and LC containing the LC CDR of P1-068765; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068765.IgG1.3, respectively.

[0598] (h) HC containing the HC CDR of P1-068767 and LC containing the LC CDR of P1-068767; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767.IgG1.3, respectively.

[0599] (i) HC containing the HC CDR of P1-068769 and LC containing the LC CDR of P1-068769; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity with the HC and LC of P1-068769.IgG1.3, respectively;

[0600] (j) HC containing the HC CDR of P1-068771 and LC containing the LC CDR of P1-068771; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068771.IgG1.3, respectively.

[0601] (k) HC containing the HC CDR of P1-068773 and LC containing the LC CDR of P1-068773; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity with the HC and LC of P1-068773.IgG1.3, respectively;

[0602] (l) HC containing the HC CDR of P1-068775 and LC containing the LC CDR of P1-068775; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity with the HC and LC of P1-068775.IgG1.3, respectively;

[0603] (m) HC containing the HC CDR of P1-069059 and LC containing the LC CDR of P1-069059; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-069059.IgG1.3, respectively.

[0604] (n) HC containing the HC CDR of P1-069061 and LC containing the LC CDR of P1-069061; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-069061.IgG1.3, respectively.

[0605] (o) HC containing the HC CDR of P1-069063 and LC containing the LC CDR of P1-069063; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity with the HC and LC of P1-069063.IgG1.3, respectively;

[0606] (p) HC containing the HC CDR of P1-069065 and LC containing the LC CDR of P1-069065; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-069065.IgG1.3, respectively.

[0607] (q) HC containing the HC CDR of P1-069067 and LC containing the LC CDR of P1-069067; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767.IgG1.3, respectively.

[0608] (r) HC containing the HC CDR of P1-069069 and LC containing the LC CDR of P1-069069; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-069069.IgG1.3, respectively.

[0609] (s) HC containing the HC CDR of P1-069071 and LC containing the LC CDR of P1-069071; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-069071.IgG1.3, respectively.

[0610] (t) HC containing the HC CDR of P1-069073 and LC containing the LC CDR of P1-069073; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-069073.IgG1.3, respectively.

[0611] (u) HC containing the HC CDR of P1-069075 and LC containing the LC CDR of P1-069075; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-069075.IgG1.3, respectively.

[0612] (v) HC containing the HC CDR of P1-069077 and LC containing the LC CDR of P1-069077; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-069077.IgG1.3, respectively.

[0613] (w) HC containing the HC CDR of P1-068736 and LC containing the LC CDR of P1-068736; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068736.IgG1.3, respectively.

[0614] (x) HC containing the HC CDR of P1-068738 and LC containing the LC CDR of P1-068738; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068738.IgG1.3, respectively.

[0615] (y) HC containing the HC CDR of P1-068740 and LC containing the LC CDR of P1-068740; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068740.IgG1.3, respectively.

[0616] (z) HC containing the HC CDR of P1-068742 and LC containing the LC CDR of P1-068742; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068742.IgG1.3, respectively.

[0617] (aa) HC containing the HC CDR of P1-068744 and LC containing the LC CDR of P1-068744; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068744.IgG1.3, respectively.

[0618] (bb) HC containing the HC CDR of P1-068746 and LC containing the LC CDR of P1-068746; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068746.IgG1.3, respectively.

[0619] (cc) HC containing the HC CDR of P1-068748 and LC containing the LC CDR of P1-068748; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068748.IgG1.3, respectively.

[0620] (dd) HC containing the HC CDR of P1-068750 and LC containing the LC CDR of P1-068750; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068750.IgG1.3, respectively.

[0621] (ee) HC containing the HC CDR of P1-068752 and LC containing the LC CDR of P1-068752; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity with the HC and LC of P1-068752.IgG1.3, respectively;

[0622] (ff) HC containing the HC CDR of P1-068754 and LC containing the LC CDR of P1-068754; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068754.IgG1.3, respectively.

[0623] (gg) HC containing the HC CDR of P1-068761_E55A.IgG1.3 and LC containing the LCCDR of P1-068761_E55A; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E55A.IgG1.3, respectively.

[0624] (hh) HC containing the HC CDR of P1-068761_H100G.IgG1.3 and LC containing the LC CDR of P1-068761_H100G; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_H100G.IgG1.3, respectively.

[0625] (ii) HC containing the HC CDR of P1-068761_E56N.IgG1.3 and LC containing the LCCDR of P1-068761_E56N; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E56N.IgG1.3, respectively;

[0626] (jj) HC containing the HC CDR of P1-068761_E55A_E56N.IgG1.3 and LC containing the LC CDR of P1-068761_E55A_E56N; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E55A_E56N.IgG1.3, respectively;

[0627] (kk) HC containing the HC CDR of P1-068761_E30D.IgG1.3 and LC containing the LCCDR of P1-068761_E30D; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E30D.IgG1.3, respectively.

[0628] (ll) HC containing the HC CDR of P1-068761_E30D_E55A.IgG1.3 and LC containing the LC CDR of P1-068761_E30D_E55A; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E30D_E55A.IgG1.3, respectively;

[0629] (mm) HC containing the HC CDR of P1-068761_E56N_H100G.IgG1.3 and LC containing the LC CDR of P1-068761_E56N_H100G; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E56N_H100G.IgG1.3, respectively.

[0630] (nn) HC containing the HC CDR of P1-068761_E30D_H100G.IgG1.3 and LC containing the LC CDR of P1-068761_E30D_H100G; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E30D_H100G.IgG1.3, respectively.

[0631] (oo) HC containing the HC CDR of P1-068761_E30D_E56N.IgG1.3 and LC containing the LC CDR of P1-068761_E30D_E56N; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E30D_E56N.IgG1.3, respectively.

[0632] (pp) HC containing the HC CDR of P1-068761_E100fF.IgG1.3 and LC containing the LC CDR of P1-068761_E100fF; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E100fF.IgG1.3, respectively;

[0633] (qq) HC containing the HC CDR of P1-068761_E55A_E100fF.IgG1.3 and LC containing the LC CDR of P1-068761_E55A_E100fF; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E55A_E100fF.IgG1.3, respectively;

[0634] (rr) HC containing the HC CDR of P1-068761_H100G_E100fF.IgG1.3 and LC containing the LC CDR of P1-068761_H100G_E100fF; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_H100G_E100fF.IgG1.3, respectively;

[0635] (ss) HC containing the HC CDR of P1-068761_E30D_E100fF.IgG1.3 and LC containing the LC CDR of P1-068761_E30D_E100fF; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E30D_E100fF.IgG1.3, respectively.

[0636] (tt) HC containing the HC CDR of P1-068761_E56N_E100fF.IgG1.3 and LC containing the LC CDR of P1-068761_E56N_E100fF; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E56N_E100fF.IgG1.3, respectively.

[0637] (uu) HC containing the HC CDR of P1-068761_E32Y.IgG1.3 and LC containing the LCCDR of P1-068761_E32Y; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E32Y.IgG1.3, respectively.

[0638] (vv) HC containing the HC CDR of P1-068761_E32Y_E55A.IgG1.3 and LC containing the LC CDR of P1-068761_E32Y_E55A; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E32Y_E55A.IgG1.3, respectively.

[0639] (ww) HC containing the HC CDR of P1-068761_E32Y_E56N.IgG1.3 and LC containing the LC CDR of P1-068761_E32Y_E56N; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E32Y_E56N.IgG1.3, respectively;

[0640] (xx) HC containing the HC CDR of P1-068761_E30D_E32Y.IgG1.3 and LC containing the LC CDR of P1-068761_E30D_E32Y; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E30D_E32Y.IgG1.3, respectively;

[0641] (yy) HC containing the HC CDR of P1-068761_E32Y_H100G.IgG1.3 and LC containing the LC CDR of P1-068761_E32Y_H100G; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E32Y_H100G.IgG1.3, respectively.

[0642] (zz) HC containing the HC CDR of P1-068761_E32Y_E100fF.IgG1.3 and LC containing the LC CDR of P1-068761_E32Y_E100fF; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068761_E32Y_E100fF.IgG1.3, respectively;

[0643] (aaa) HC containing the HC CDR of P1-068767_D52N_D102V.IgG1.3 and LC containing the LC CDR of P1-068767_D52N_D102V; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767_D52N_D102V.IgG1.3, respectively.

[0644] (bbb) HC containing the HC CDR of P1-068767_D52N.IgG1.3 and LC containing the LC CDR of P1-068767_D52N; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767_D52N.IgG1.3, respectively.

[0645] (ccc) HC containing the HC CDR of P1-068767_D52N_E55A.IgG1.3 and LC containing the LC CDR of P1-068767_D52N_E55A; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767_D52N_E55A.IgG1.3, respectively.

[0646] (ddd) HC containing the HC CDR of P1-068767_E55A_D102V.IgG1.3 and LC containing the LC CDR of P1-068767_E55A_D102V; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767_E55A_D102V.IgG1.3, respectively.

[0647] (eee) HC containing the HC CDR of P1-068767_D102V.IgG1.3 and LC containing the LC CDR of P1-068767_D102V; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767_D102V.IgG1.3, respectively.

[0648] (fff) HC containing the HC CDR of P1-068767_E55A.IgG1.3 and LC containing the LC CDR of P1-068767_E55A; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767_E55A.IgG1.3, respectively;

[0649] (ggg) HC containing the HC CDR of P1-068767_E30D_D52N.IgG1.3 and LC containing the LC CDR of P1-068767_E30D_D52N; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767_E30D_D52N.IgG1.3, respectively.

[0650] (hhh) HC containing the HC CDR of P1-068767_E30D_D102V.IgG1.3 and LC containing the LC CDR of P1-068767_E30D_D102V; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767_E30D_D102V.IgG1.3, respectively.

[0651] (iii) HC containing the HC CDR of P1-068767_E30D.IgG1.3 and LC containing the LC CDR of P1-068767_E30D; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767_E30D.IgG1.3, respectively;

[0652] (jjj) HC containing the HC CDR of P1-068767_E30D_E55A.IgG1.3 and LC containing the LC CDR of P1-068767_E30D_E55A; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767_E30D_E55A.IgG1.3, respectively;

[0653] (kkk) HC containing the HC CDR of HC in P1-068767_E100fF_D102V.IgG1.3 and LC containing the LC CDR of P1-068767_E100fF_D102V; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767_E100fF_D102V.IgG1.3, respectively.

[0654] (lll) HC containing the HC CDR of P1-068767_E55A_E100fF.IgG1.3 and LC containing the LC CDR of P1-068767_E55A_E100fF; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767_E55A_E100fF.IgG1.3, respectively;

[0655] (mmm) HC containing the HC CDR of P1-068767_D52N_E100fF.IgG1.3 and LC containing the LC CDR of P1-068767_D52N_E100fF; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767_D52N_E100fF.IgG1.3, respectively.

[0656] (nnn) HC containing the HC CDR of P1-068767_E100fF.IgG1.3 and LC containing the LC CDR of P1-068767_E100fF; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767_E100fF.IgG1.3, respectively.

[0657] (ooo) HC containing the HC CDR of P1-068767_E30D_E100fF.IgG1.3 and LC containing the LC CDR of P1-068767_E30D_E100fF; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-068767_E30D_E100fF.IgG1.3, respectively.

[0658] (ppp) HC containing the HC CDR of P1-061029_F100fE_V102D.IgG1.3 and LC containing the LC CDR of P1-061029_F100fE_V102D; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-061029_F100fE_V102D.IgG1.3, respectively;

[0659] (qqq) HC containing the HC CDR of P1-061029_F100fE.IgG1.3 and LC containing the LC CDR of P1-061029_F100fE; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-061029_F100fE.IgG1.3, respectively;

[0660] (rrr) HC containing the HC CDR of P1-061029_V102D.IgG1.3 and LC containing the LC CDR of P1-061029_V102D; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-061029_V102D.IgG1.3, respectively;

[0661] (sss) HC containing the HC CDR of P1-061029_Y32E.IgG1.3 and LC containing the LC CDR of P1-061029_Y32E; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-061029_Y32E.IgG1.3, respectively; or

[0662] (ttt) HC containing the HC CDR of P1-061029_Y32E_F100fE.IgG1.3 and LC containing the LC CDR of P1-061029_Y32E_F100fE; and HC and LC amino acid sequences having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity with the HC and LC of P1-061029_Y32E_F100fE.IgG1.3, respectively.

[0663] In some of the above embodiments, the sequence difference between HC and / or LC and each of substances (a) to (ttt) may lie in the presence of 1, 2, 3, 4, or 5 amino acid substitutions (e.g., 1, 2, 3, 4, or 5 conserved substitutions). In some embodiments, for example, HC of P1-061029 or one of its progeny may contain one or both of K16R and T84A substitutions in the VH region of HC (P1-061015 and its progeny have R and A at those positions, respectively).

[0664] In some implementations, anti-hVISTA Ab may include:

[0665] (a) The heavy chain consisting of the heavy chain amino acid sequence of P1-061029.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-061029;

[0666] (b) The heavy chain consisting of the heavy chain amino acid sequence of P1-061015.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-061015;

[0667] (c) The heavy chain consisting of the heavy chain amino acid sequence of P1-068757.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-068757;

[0668] (d) The heavy chain consisting of the heavy chain amino acid sequence of P1-068759.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-068759;

[0669] (e) The heavy chain consisting of the heavy chain amino acid sequence of P1-068761.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-068761;

[0670] (f) The heavy chain consisting of the heavy chain amino acid sequence of P1-068763.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-068763;

[0671] (g) A heavy chain consisting of the heavy chain amino acid sequence of P1-068765.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-068765.

[0672] (h) The heavy chain consisting of the heavy chain amino acid sequence of P1-068767.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-068767.

[0673] (i) The heavy chain consisting of the heavy chain amino acid sequence of P1-068769.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-068769.

[0674] (j) The heavy chain consisting of the heavy chain amino acid sequence of P1-068771.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-068771;

[0675] (k) The heavy chain consisting of the heavy chain amino acid sequence of P1-068773.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-068773;

[0676] (l) The heavy chain consisting of the heavy chain amino acid sequence of P1-068775.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-068775;

[0677] (m) The heavy chain, consisting of the heavy chain amino acid sequence of P1-069059.IgG1.3, and the light chain, consisting of the light chain amino acid sequence of P1-069059;

[0678] (n) The heavy chain consisting of the heavy chain amino acid sequence of P1-069061.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-069061;

[0679] (o) The heavy chain consisting of the heavy chain amino acid sequence of P1-069063.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-069063;

[0680] (p) The heavy chain, consisting of the heavy chain amino acid sequence of P1-069065.IgG1.3, and the light chain, consisting of the light chain amino acid sequence of P1-069065.

[0681] (q) The heavy chain consisting of the heavy chain amino acid sequence of P1-069067.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-069067;

[0682] (r) The heavy chain, consisting of the heavy chain amino acid sequence of P1-069069.IgG1.3, and the light chain, consisting of the light chain amino acid sequence of P1-069069;

[0683] (s) A heavy chain consisting of the heavy chain amino acid sequence of P1-069071.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-069071;

[0684] (t) The heavy chain, consisting of the heavy chain amino acid sequence of P1-069073.IgG1.3, and the light chain, consisting of the light chain amino acid sequence of P1-069073;

[0685] (u) The heavy chain consisting of the heavy chain amino acid sequence of P1-069075.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-069075;

[0686] (v) The heavy chain consisting of the heavy chain amino acid sequence of P1-069077.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-069077;

[0687] (w) The heavy chain consisting of the heavy chain amino acid sequence of P1-068736 and the light chain consisting of the light chain amino acid sequence of P1-068736.

[0688] (x) The heavy chain consisting of the heavy chain amino acid sequence of P1-068738.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-068738;

[0689] (y) The heavy chain consisting of the heavy chain amino acid sequence of P1-068740.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-068740;

[0690] (z) The heavy chain consisting of the heavy chain amino acid sequence of P1-068742.IgG1.3 and the light chain consisting of the light chain amino acid sequence of P1-068742;

[0691] (aa) The heavy chain, consisting of the heavy chain amino acid sequence of P1-068744.IgG1.3, and the light chain, consisting of the light chain amino acid sequence of P1-068744.

[0692] (bb) The heavy chain consists of the heavy chain amino acid sequence of P1-068746.IgG1.3 and the light chain consists of the light chain amino acid sequence of P1-068746.

[0693] (cc) The heavy chain, consisting of the heavy chain amino acid sequence of P1-068748.IgG1.3, and the light chain, consisting of the light chain amino acid sequence of P1-068748;

[0694] (dd) A heavy chain consisting of the heavy chain amino acid sequence of P1-068750.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-068750;

[0695] (ee) consists of a heavy chain composed of the heavy chain amino acid sequence of P1-068752.IgG1.3 and a light chain composed of the light chain amino acid sequence of P1-068752.

[0696] (ff) The heavy chain, consisting of the heavy chain amino acid sequence of P1-068754, and the light chain, consisting of the light chain amino acid sequence of P1-068754.

[0697] (gg) consists of a heavy chain composed of the heavy chain amino acid sequence of P1-068761_E55A.IgG1.3 and a light chain composed of the light chain amino acid sequence of P1-068761_E55A.

[0698] (hh) A heavy chain consisting of the heavy chain amino acid sequence of P1-068761_H100G.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-068761_H100G;

[0699] (ii) A heavy chain consisting of the heavy chain amino acid sequence of P1-068761_E56N.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-068761_E56N;

[0700] (jj) The heavy chain consists of the heavy chain amino acid sequence of P1-068761_E55A_E56N.IgG1.3 and the light chain consists of the light chain amino acid sequence of P1-068761_E55A_E56N;

[0701] (kk) A heavy chain consisting of the heavy chain amino acid sequence of P1-068761_E30D.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-068761_E30D;

[0702] (ll) The heavy chain, consisting of the heavy chain amino acid sequence of P1-068761_E30D_E55A.IgG1.3, and the light chain, consisting of the light chain amino acid sequence of P1-068761_E30D_E55A;

[0703] (mm) The heavy chain consists of the heavy chain amino acid sequence of P1-068761_E56N_H100G.IgG1.3 and the light chain consists of the light chain amino acid sequence of P1-068761_E56N_H100G;

[0704] (nn) The heavy chain, consisting of the heavy chain amino acid sequence of P1-068761_E30D_H100G.IgG1.3, and the light chain, consisting of the light chain amino acid sequence of P1-068761_E30D_H100G;

[0705] (oo) A heavy chain consisting of the heavy chain amino acid sequence of P1-068761_E30D_E56N.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-068761_E30D_E56N;

[0706] (pp) The heavy chain consists of the heavy chain amino acid sequence of P1-068761_E100fF.IgG1.3 and the light chain consists of the light chain amino acid sequence of P1-068761_E100fF;

[0707] (qq) The heavy chain consists of the heavy chain amino acid sequence of P1-068761_E55A_E100fF.IgG1.3 and the light chain consists of the light chain amino acid sequence of P1-068761_E55A_E100fF;

[0708] (rr) The heavy chain, consisting of the heavy chain amino acid sequence of P1-068761_H100G_E100fF.IgG1.3, and the light chain, consisting of the light chain amino acid sequence of P1-068761_H100G_E100fF;

[0709] (ss) The heavy chain consists of the heavy chain amino acid sequence of P1-068761_E30D_E100fF.IgG1.3 and the light chain consists of the light chain amino acid sequence of P1-068761_E30D_E100fF;

[0710] (tt) The heavy chain consists of the heavy chain amino acid sequence of P1-068761_E56N_E100fF.IgG1.3 and the light chain consists of the light chain amino acid sequence of P1-068761_E56N_E100fF;

[0711] (uu) is a heavy chain composed of the heavy chain amino acid sequence of P1-068761_E32Y.IgG1.3 and a light chain composed of the light chain amino acid sequence of P1-068761_E32Y;

[0712] (vv) The heavy chain, consisting of the heavy chain amino acid sequence of P1-068761_E32Y_E55A.IgG1.3, and the light chain, consisting of the light chain amino acid sequence of P1-068761_E32Y_E55A;

[0713] (ww) The heavy chain consists of the heavy chain amino acid sequence of P1-068761_E32Y_E56N.IgG1.3 and the light chain consists of the light chain amino acid sequence of P1-068761_E32Y_E56N;

[0714] (xx) A heavy chain consisting of the heavy chain amino acid sequence of P1-068761_E30D_E32Y.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-068761_E30D_E32Y;

[0715] (yy) is a heavy chain composed of the heavy chain amino acid sequence of P1-068761_E32Y_H100G.IgG1.3 and a light chain composed of the light chain amino acid sequence of P1-068761_E32Y_H100G;

[0716] (zz) A heavy chain consisting of the heavy chain amino acid sequence of P1-068761_E32Y_E100fF.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-068761_E32Y_E100fF;

[0717] (aaa) A heavy chain consisting of the heavy chain amino acid sequence of P1-068767_D52N_D102V.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-068767_D52N_D102V;

[0718] (bbb) A heavy chain consisting of the heavy chain amino acid sequence of P1-068767_D52N.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-068767_D52N;

[0719] (ccc) is a heavy chain consisting of the heavy chain amino acid sequence of P1-068767_D52N_E55A.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-068767_D52N_E55A.

[0720] (ddd) A heavy chain consisting of the heavy chain amino acid sequence of P1-068767_E55A_D102V.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-068767_E55A_D102V;

[0721] (eee) consists of a heavy chain composed of the heavy chain amino acid sequence of P1-068767_D102V.IgG1.3 and a light chain composed of the light chain amino acid sequence of P1-068767_D102V.

[0722] (fff) The heavy chain consists of the heavy chain amino acid sequence of P1-068767_E55A.IgG1.3 and the light chain consists of the light chain amino acid sequence of P1-068767_E55A.

[0723] (ggg) consists of a heavy chain composed of the heavy chain amino acid sequence of P1-068767_E30D_D52N.IgG1.3 and a light chain composed of the light chain amino acid sequence of P1-068767_E30D_D52N;

[0724] (hhh) The heavy chain consists of the heavy chain amino acid sequence of P1-068767_E30D_D102V.IgG1.3 and the light chain consists of the light chain amino acid sequence of P1-068767_E30D_D102V;

[0725] (iii) A heavy chain consisting of the heavy chain amino acid sequence of P1-068767_E30D.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-068767_E30D;

[0726] (jjj) consists of a heavy chain composed of the heavy chain amino acid sequence of P1-068767_E30D_E55A.IgG1.3 and a light chain composed of the light chain amino acid sequence of P1-068767_E30D_E55A;

[0727] (kkk) consists of a heavy chain composed of the heavy chain amino acid sequence of P1-068767_E100fF_D102V.IgG1.3 and a light chain composed of the light chain amino acid sequence of P1-068767_E100fF_D102V;

[0728] (lll) The heavy chain consists of the heavy chain amino acid sequence of P1-068767_E55A_E100fF.IgG1.3 and the light chain consists of the light chain amino acid sequence of P1-068767_E55A_E100fF;

[0729] (mmm) A heavy chain consisting of the heavy chain amino acid sequence of P1-068767_D52N_E100fF.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-068767_D52N_E100fF;

[0730] (nnn) The heavy chain consists of the heavy chain amino acid sequence of P1-068767_E100fF.IgG1.3 and the light chain consists of the light chain amino acid sequence of P1-068767_E100fF;

[0731] (ooo) A heavy chain consisting of the heavy chain amino acid sequence of P1-068767_E30D_E100fF.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-068767_E30D_E100fF;

[0732] (ppp) consists of a heavy chain composed of the heavy chain amino acid sequence of P1-061029_F100fE_V102D.IgG1.3 and a light chain composed of the light chain amino acid sequence of P1-061029_F100fE_V102D;

[0733] (qqq) consists of a heavy chain composed of the heavy chain amino acid sequence of P1-061029_F100fE.IgG1.3 and a light chain composed of the light chain amino acid sequence of P1-061029_F100fE;

[0734] (rrr) A heavy chain consisting of the heavy chain amino acid sequence of P1-061029_V102D.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-061029_V102D;

[0735] (sss) A heavy chain consisting of the heavy chain amino acid sequence of P1-061029_Y32E.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-061029_Y32E; or

[0736] (ttt) A heavy chain consisting of the heavy chain amino acid sequence of P1-061029_Y32E_F100fE.IgG1.3 and a light chain consisting of the light chain amino acid sequence of P1-061029_Y32E_F100fE.

[0737] Optionally, VH in any of (a) to (ttt) contains one or both of K16R substitution and T84A substitution.

[0738] In some embodiments, this disclosure covers anti-VISTA mAb comprising the following:

[0739] A heavy chain consisting of the heavy chain amino acid sequences (a) to (ttt) listed above, followed by a Lys residue; and

[0740] A light chain consisting of the light chain amino acid sequences listed above (a) to (ttt);

[0741] The heavy and light chain amino acid sequences are selected from the same antibody material listed above (a) to (ttt).

[0742] In some embodiments, the anti-hVISTA Ab may comprise a heavy chain amino acid sequence containing the VH amino acid sequence of the antibody material described herein, but excluding the IgG1.3 heavy chain constant region (as provided in the HC sequence in the sequence listing herein, and see SEQ ID NO:163). The antibody may comprise different heavy chain constant region sequences, such as the human wild-type IgG1 constant region (e.g., human IgG1 isotype f (IgG1f) (SEQ ID NO:182)) or a modified human IgG1 constant region (e.g., IgG1.1f (SEQ ID NO:183)) or a modified human IgG1 constant region (e.g., IgG1.P238K (SEQ ID NO:184)). Therefore, embodiments of this disclosure include anti-VISTA Abs containing the following:

[0743] (a) a heavy chain containing the amino acid sequence of VH of (i) P1-061029 (SEQ ID NO:67) and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-061029 (SEQ ID NO:70);

[0744] (b) a heavy chain containing the amino acid sequence of (i) P1-061015 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-061015.

[0745] (c) The heavy chain containing the amino acid sequence of VH of (i) P1-068757 and (ii) the amino acid sequence of SEQ ID NO:182; and the light chain containing the amino acid sequence of the light chain of P1-068757.

[0746] (d) A heavy chain containing the amino acid sequence of (i) P1-068759 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068759.

[0747] (e) a heavy chain containing the amino acid sequence of (i) P1-068761 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068761.

[0748] (f) a heavy chain containing the amino acid sequence of (i) P1-068763 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068763.

[0749] (g) a heavy chain containing the amino acid sequence of (i) P1-068765 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068765.

[0750] (h) a heavy chain containing the amino acid sequence of (i) P1-068767 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068767.

[0751] (i) a heavy chain containing the amino acid sequence of VH of (i) P1-068769 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068769;

[0752] (j) a heavy chain containing the amino acid sequence of VH of (i) P1-068771 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068771.

[0753] (k) a heavy chain containing the amino acid sequence of (i) P1-068773 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068773.

[0754] (l) a heavy chain containing the amino acid sequence of (i) P1-068775 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068775.

[0755] (m) a heavy chain containing the amino acid sequence of (i) P1-069059 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-069059.

[0756] (n) a heavy chain containing the amino acid sequence of (i) P1-069061 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-069061.

[0757] (o) a heavy chain containing the amino acid sequence of (i) P1-069063 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-069063.

[0758] (p) a heavy chain containing the amino acid sequence of (i) P1-069065 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-069065.

[0759] (q) a heavy chain containing the amino acid sequence of (i) P1-069067 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-069067.

[0760] (r) a heavy chain containing the amino acid sequence of (i) P1-069069 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-069069.

[0761] (s) a heavy chain containing the amino acid sequence of VH of (i) P1-069071 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-069071.

[0762] (t) a heavy chain containing the amino acid sequence of (i) P1-069073 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-069073.

[0763] (u) a heavy chain containing the amino acid sequence of (i) P1-069075 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-069075.

[0764] (v) a heavy chain containing the amino acid sequence of (i) P1-069077 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-069077.

[0765] (w) a heavy chain containing the amino acid sequence of (i) P1-068736 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068736.

[0766] (x) a heavy chain containing the amino acid sequence of (i) P1-068738 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068738.

[0767] (y) a heavy chain containing the amino acid sequence of (i) P1-068740 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068740.

[0768] (z) a heavy chain containing the amino acid sequence of (i) P1-068742 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068742.

[0769] (aa) a heavy chain containing the amino acid sequence of (i) P1-068744 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068744.

[0770] (bb) the heavy chain containing the amino acid sequence of VH of P1-068746 and (ii) the amino acid sequence of SEQ ID NO:182; and the light chain containing the amino acid sequence of the light chain of P1-068746.

[0771] (cc) a heavy chain containing the amino acid sequence of (i) P1-068748 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068748.

[0772] (dd) a heavy chain containing the amino acid sequence of (i) P1-068750 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068750.

[0773] (ee) a heavy chain comprising the amino acid sequence of (i) P1-068752 VH and (ii) SEQ ID NO:182; and a light chain comprising the amino acid sequence of P1-068752.

[0774] (ff) a heavy chain containing the amino acid sequence of (i) P1-068754 VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068754.

[0775] (gg) a heavy chain containing the amino acid sequence of (i) P1-068761_E55A VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068761_E55A.

[0776] (hh) a heavy chain containing the amino acid sequence of (i) P1-068761_H100G and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068761_H100G.

[0777] (ii) a heavy chain containing the amino acid sequence of VH of (i) P1-068761_E56N and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068761_E56N;

[0778] (jj) a heavy chain containing the amino acid sequence of (i) P1-068761_E55A_E56N and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068761_E55A_E56N;

[0779] (kk) a heavy chain containing the amino acid sequence of (i) P1-068761_E30D and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068761_E30D.

[0780] (ll) a heavy chain containing the amino acid sequence of VH of (i) P1-068761_E30D_E55A and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068761_E30D_E55A;

[0781] (mm) a heavy chain containing the amino acid sequence of VH of (i) P1-068761_E56N_H100G and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068761_E56N_H100G;

[0782] (nn) a heavy chain containing the amino acid sequence of VH of (i) P1-068761_E30D_H100G and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068761_E30D_H100G;

[0783] (oo) a heavy chain containing the amino acid sequence of VH of (i) P1-068761_E30D_E56N and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068761_E30D_E56N;

[0784] (pp) a heavy chain containing the amino acid sequence of (i) P1-068761_E100fF of VH and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068761_E100fF.

[0785] (qq) a heavy chain containing the amino acid sequence of (i) P1-068761_E55A_E100fF of VH and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068761_E55A_E100fF;

[0786] (rr) a heavy chain containing the amino acid sequence of VH of (i) P1-068761_H100G_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068761_H100G_E100fF;

[0787] (ss) a heavy chain containing the amino acid sequence of VH of (i) P1-068761_E30D_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068761_E30D_E100fF;

[0788] (tt) a heavy chain containing the amino acid sequence of VH of (i) P1-068761_E56N_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068761_E56N_E100fF;

[0789] (uu) a heavy chain containing the amino acid sequence of (i) P1-068761_E32Y and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068761_E32Y;

[0790] (vv) a heavy chain containing the amino acid sequence of (i) P1-068761_E32Y_E55A and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068761_E32Y_E55A;

[0791] (ww) a heavy chain containing the amino acid sequence of (i) P1-068761_E32Y_E56N and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068761_E32Y_E56N;

[0792] (xx) a heavy chain containing the amino acid sequence of VH of (i) P1-068761_E30D_E32Y and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068761_E30D_E32Y;

[0793] (yy) a heavy chain containing the amino acid sequence of VH of (i) P1-068761_E32Y_H100G and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068761_E32Y_H100G;

[0794] (zz) a heavy chain containing the amino acid sequence of VH of (i) P1-068761_E32Y_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068761_E32Y_E100fF;

[0795] (aaa) a heavy chain containing the amino acid sequence of (i) P1-068767_D52N_D102V and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068767_D52N_D102V;

[0796] (bbb) a heavy chain containing the amino acid sequence of (i) P1-068767_D52N of VH and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068767_D52N of light chain;

[0797] (ccc) a heavy chain containing the amino acid sequence of (i) P1-068767_D52N_E55A of VH and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068767_D52N_E55A of light chain;

[0798] (ddd) a heavy chain containing the amino acid sequence of (i) P1-068767_E55A_D102V and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068767_E55A_D102V;

[0799] (eee) a heavy chain containing the amino acid sequence of (i) P1-068767_D102V and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068767_D102V.

[0800] (fff) a heavy chain containing the amino acid sequence of (i) P1-068767_E55A VH and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068767_E55A;

[0801] (ggg) a heavy chain containing the amino acid sequence of (i) P1-068767_E30D_D52N of VH and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068767_E30D_D52N of light chain;

[0802] (hhh) a heavy chain containing the amino acid sequence of (i) P1-068767_E30D_D102V and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068767_E30D_D102V;

[0803] (iii) a heavy chain containing the amino acid sequence of VH of (i) P1-068767_E30D and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068767_E30D;

[0804] (jjj) a heavy chain containing the amino acid sequence of VH of (i) P1-068767_E30D_E55A and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068767_E30D_E55A;

[0805] (kkk) a heavy chain containing the amino acid sequence of (i) P1-068767_E100fF_D102V and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068767_E100fF_D102V;

[0806] (lll) a heavy chain containing the amino acid sequence of (i) P1-068767_E55A_E100fF of VH and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068767_E55A_E100fF;

[0807] (mmm) a heavy chain containing the amino acid sequence of VH of (i) P1-068767_D52N_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068767_D52N_E100fF;

[0808] (nnn) a heavy chain containing the amino acid sequence of (i) P1-068767_E100fF of VH and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-068767_E100fF;

[0809] (ooo) a heavy chain containing the amino acid sequence of VH of (i) P1-068767_E30D_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-068767_E30D_E100fF;

[0810] (ppp) a heavy chain containing the amino acid sequence of VH of (i) P1-061029_F100fE_V102D and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-061029_F100fE_V102D;

[0811] (qqq) a heavy chain containing the amino acid sequence of (i) P1-061029_F100fE of VH and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-061029_F100fE;

[0812] (rrr) a heavy chain containing the amino acid sequence of (i) P1-061029_V102D and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-061029_V102D;

[0813] (sss) a heavy chain containing the amino acid sequence of (i) P1-061029_Y32E (VH) and (ii) SEQ ID NO:182; and a light chain containing the amino acid sequence of P1-061029_Y32E; or

[0814] (ttt) a heavy chain containing the amino acid sequence of VH of (i) P1-061029_Y32E_F100fE and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain containing the amino acid sequence of the light chain of P1-061029_Y32E_F100fE.

[0815] Optionally, the VH in any of (a) to (ttt) contains one or both of K16R substitution and T84A substitution.

[0816] In some embodiments, the LC may be as specified in (a) to (ttt) above, but the HC may differ from the sequence of each of the substances (a) to (ttt) due to the presence of 1, 2, 3, 4, or 5 amino acid substitutions (e.g., 1, 2, 3, 4, or 5 conserved substitutions). In some embodiments, for example, HC of P1-061029 or one of its progeny may contain one or both of the K16R substitution and the T84A substitution in the VH region of the HC (P1-061015 and its progeny already have R at VH position 16 and A at VH position 84).

[0817] Some embodiments of this disclosure include anti-VISTA Ab containing the following:

[0818] (a) A heavy chain consisting of the amino acid sequence of VH of (i) P1-061029 (SEQ ID NO: 67) and (ii) the amino acid sequence of SEQ ID NO: 182; and a light chain consisting of the amino acid sequence of the light chain of P1-061029 (SEQ ID NO: 70);

[0819] (b) A heavy chain consisting of the amino acid sequence of VH of (i) P1-061015 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-061015.

[0820] (c) The heavy chain consisting of the amino acid sequence of VH of (i) P1-068757 and the amino acid sequence of (ii) SEQ ID NO:182; and the light chain consisting of the amino acid sequence of the light chain of P1-068757.

[0821] (d) A heavy chain consisting of the amino acid sequence of VH of (i) P1-068759 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068759.

[0822] (e) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068761 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761.

[0823] (f) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068763 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068763;

[0824] (g) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068765 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068765.

[0825] (h) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068767 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767.

[0826] (i) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068769 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068769;

[0827] (j) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068771 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068771;

[0828] (k) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068773 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068773;

[0829] (l) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068775 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068775.

[0830] (m) a heavy chain consisting of the amino acid sequence of VH of (i) P1-069059 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-069059.

[0831] (n) a heavy chain consisting of the amino acid sequence of VH of (i) P1-069061 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-069061.

[0832] (o) a heavy chain consisting of the amino acid sequence of (i) VH of P1-069063 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-069063;

[0833] (p) a heavy chain consisting of the amino acid sequence of (i) VH of P1-069065 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-069065.

[0834] (q) a heavy chain consisting of the amino acid sequence of VH of (i) P1-069067 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-069067.

[0835] (r) a heavy chain consisting of the amino acid sequence of (i) VH of P1-069069 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-069069.

[0836] (s) a heavy chain consisting of the amino acid sequence of VH of (i) P1-069071 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-069071.

[0837] (t) a heavy chain consisting of the amino acid sequence of (i) VH of P1-069073 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-069073;

[0838] (u) a heavy chain consisting of the amino acid sequence of VH of (i) P1-069075 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-069075.

[0839] (v) a heavy chain consisting of the amino acid sequence of VH of (i) P1-069077 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-069077;

[0840] (w) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068736 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068736;

[0841] (x) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068738 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068738;

[0842] (y) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068740 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068740;

[0843] (z) A heavy chain consisting of the amino acid sequence of VH of (i) P1-068742 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068742;

[0844] (aa) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068744 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068744.

[0845] (bb) a heavy chain consisting of the amino acid sequence of VH of P1-068746 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068746.

[0846] (cc) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068748 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068748.

[0847] (dd) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068750 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068750;

[0848] (ee) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068752 and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068752;

[0849] (ff) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068754 and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068754.

[0850] (gg) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068761_E55A and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E55A.

[0851] (hh) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068761_H100G and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_H100G;

[0852] (ii) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068761_E56N and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E56N;

[0853] (jj) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068761_E55A_E56N and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E55A_E56N;

[0854] (kk) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068761_E30D and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E30D;

[0855] (ll) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068761_E30D_E55A and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E30D_E55A;

[0856] (mm) a heavy chain consisting of (i) the amino acid sequence of VH of P1-068761_E56N_H100G and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E56N_H100G;

[0857] (nn) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068761_E30D_H100G and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E30D_H100G;

[0858] (oo) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068761_E30D_E56N and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E30D_E56N;

[0859] (pp) a heavy chain consisting of (i) the amino acid sequence of VH of P1-068761_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E100fF;

[0860] (qq) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068761_E55A_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E55A_E100fF;

[0861] (rr) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068761_H100G_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_H100G_E100fF;

[0862] (ss) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068761_E30D_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E30D_E100fF;

[0863] (tt) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068761_E56N_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E56N_E100fF;

[0864] (uu) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068761_E32Y and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E32Y;

[0865] (vv) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068761_E32Y_E55A and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E32Y_E55A;

[0866] (ww) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068761_E32Y_E56N and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E32Y_E56N;

[0867] (xx) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068761_E30D_E32Y and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E30D_E32Y;

[0868] (yy) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068761_E32Y_H100G and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E32Y_H100G;

[0869] (zz) A heavy chain consisting of the amino acid sequence of VH of (i) P1-068761_E32Y_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068761_E32Y_E100fF;

[0870] (aaa) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068767_D52N_D102V and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767_D52N_D102V;

[0871] (bbb) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068767_D52N and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767_D52N;

[0872] (ccc) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068767_D52N_E55A and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767_D52N_E55A;

[0873] (ddd) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068767_E55A_D102V and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767_E55A_D102V;

[0874] (eee) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068767_D102V and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767_D102V.

[0875] (fff) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068767_E55A and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767_E55A.

[0876] (ggg) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068767_E30D_D52N and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767_E30D_D52N;

[0877] (hhh) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068767_E30D_D102V and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767_E30D_D102V;

[0878] (iii) A heavy chain consisting of the amino acid sequence of VH of (i) P1-068767_E30D and the amino acid sequence of (ii) SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767_E30D;

[0879] (jjj) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068767_E30D_E55A and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767_E30D_E55A;

[0880] (kkk) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068767_E100fF_D102V and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767_E100fF_D102V;

[0881] (lll) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068767_E55A_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767_E55A_E100fF;

[0882] (mmm) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068767_D52N_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767_D52N_E100fF;

[0883] (nnn) a heavy chain consisting of the amino acid sequence of (i) VH of P1-068767_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767_E100fF;

[0884] (ooo) a heavy chain consisting of the amino acid sequence of VH of (i) P1-068767_E30D_E100fF and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-068767_E30D_E100fF;

[0885] (ppp) a heavy chain consisting of (i) the amino acid sequence of VH of P1-061029_F100fE_V102D and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-061029_F100fE_V102D;

[0886] (qqq) a heavy chain consisting of (i) the amino acid sequence of VH of P1-061029_F100fE and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-061029_F100fE;

[0887] (rrr) a heavy chain consisting of (i) the amino acid sequence of VH of P1-061029_V102D and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-061029_V102D;

[0888] (sss) a heavy chain consisting of the amino acid sequence of (i) VH of P1-061029_Y32E and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-061029_Y32E; or

[0889] (ttt) a heavy chain consisting of the amino acid sequence of (i) VH of P1-061029_Y32E_F100fE and (ii) the amino acid sequence of SEQ ID NO:182; and a light chain consisting of the amino acid sequence of the light chain of P1-061029_Y32E_F100fE.

[0890] The C-terminal amino acid of VH and the N-terminal amino acid of SEQ ID NO:182 form a peptide bond; and

[0891] Optionally, the VH in any of (a) to (ttt) contains one or both of K16R substitution and T84A substitution.

[0892] In some embodiments, this disclosure covers anti-VISTA mAb comprising the following:

[0893] A heavy chain comprising (i) the amino acid sequence of VH listed in (a) to (ttt) above, (ii) the amino acid sequence of SEQ ID NO:182, and (iii) Lys residues, wherein the C-terminal amino acid of VH and the N-terminal amino acid of SEQ ID NO:182 form a peptide bond and wherein the C-terminal amino acid of SEQ ID NO:182 is attached to the N-terminus of Lys; and

[0894] Light chain, which consists of the light chain amino acid sequences (a) to (ttt) listed above;

[0895] The VH and light chain amino acid sequences are selected from the same antibody material listed above (a) to (ttt).

[0896] Some embodiments of this disclosure include anti-VISTA Ab containing the following:

[0897] (a) a heavy chain containing the amino acid sequence of VH of (i) P1-061029 (SEQ ID NO:67) and (ii) the amino acid sequence of SEQ ID NO:183; and a light chain containing the amino acid sequence of P1-061029 (SEQ ID NO:70);

[0898] (b) a heavy chain containing the amino acid sequence of (i) P1-061015 VH and (ii) SEQ ID NO:183; and a light chain containing the amino acid sequence of P1-061015.

[0899] (c) A heavy chain containing the amino acid sequence of VH of (i) P1-068757 and (ii) the amino acid sequence of SEQ ID NO:183; and a light chain containing the amino acid sequence of the light chain of P1-068757.

[0900] (d) A heavy chain containing the amino acid sequence of (i) P1-068759 VH and (ii) SEQ ID NO:183; and a light chain containing the amino acid sequence of P1-068759.

[0901] (e) a heavy chain containing the amino acid sequence of (i) P1-068761 VH and (ii) SEQ ID NO:183; and a light chain containing the amino acid sequence of P1-068761.

[0902] (f) a heavy chain containing the amino acid sequence of (i) P1-068763 VH and (ii) SEQ ID NO:183; and a light chain containing the amino acid sequence of P1-068763.

[0903] (g) a heavy chain containing the amino acid sequence of (i) P1-068765 VH and (ii) SEQ ID NO:183; and a light chain containing the amino acid sequence of P1-068765.

[0904] (h) a heavy chain containing the amino acid sequence of (i) P1-068767 VH and (ii) SEQ ID NO:183; and a light chain containing the amino acid sequence of P1-068767.

[0905] (i) a heavy chain containing the amino acid sequence of (i) P1-068769 and (ii) the amino acid sequence of SEQ ID NO:183; and a light chain containing the amino acid sequence of P1-068769.

[0906] (j) a heavy chain containing the amino acid sequence of (i) P1-068771 VH and (ii) SEQ ID NO:183; and a light chain containing the amino acid sequence of P1-068771.

[0907] (k) a heavy chain containing the amino acid sequence of (i) P1-068773 VH and (ii) SEQ ID NO:183; and a light chain containing the amino acid sequence of P1-068773.

[0908] (l) a heavy chain containing the amino acid sequence of (i) P1-068775 VH and (ii) SEQ ID NO:183; and a light chain containing the amino acid sequence of P1-068775.

[0909] (m) a heavy chain containing the amino acid sequence of (i) P1-069059 VH and (ii) SEQ ID NO:183; and a light chain containing the amino acid sequence of P1-069059.

[0910] (n) a heavy chain containing the amino acid sequence of (i) P1-069061 VH and (ii) SEQ ID NO:183; and a light chain containing the amino acid sequence of P1-069061.

[0911] (o) a heavy chain containing the amino acid sequence of (i) P1-069063 VH and (ii) SEQ ID NO:183; and a light chain containing the amino acid sequence of P1-069063.

[0912] (p) a heavy chain containing the amino acid sequence of (i) P1-069065 VH and (ii) SEQ ID NO:183; and a light cha...

Claims

1. An antibody that specifically binds to human V-domain Ig repressor (hVISTA) for T cell activation under acidic conditions, wherein the antibody comprises heavy chain variable region (VH) complementarity-determining regions 1 (CDR1), 2, and 3, and wherein: a. The VH CDR1 is composed of residues 26-35 shown in SEQ ID NO: 491, the VH CDR2 is composed of residues 50-66 shown in SEQ ID NO: 491, and the VH CDR3 is composed of residues 99-112 shown in SEQ ID NO: 491; b. The VH CDR1 is composed of residues 26-35 shown in SEQ ID NO: 503, the VH CDR2 is composed of residues 50-66 shown in SEQ ID NO: 503, and the VH CDR3 is composed of residues 99-112 shown in SEQ ID NO: 503; c. The VH CDR1 is composed of residues 26-35 shown in SEQ ID NO: 515, the VH CDR2 is composed of residues 50-66 shown in SEQ ID NO: 515, and the VH CDR3 is composed of residues 99-112 shown in SEQ ID NO: 515; d. wherein the VH CDR1 is composed of residues 26-35 as shown in SEQ ID NO: 527, the VH CDR2 is composed of residues 50-66 as shown in SEQ ID NO: 527, and the VH CDR3 is composed of residues 99-112 as shown in SEQ ID NO: 527; or e. wherein the VH CDR1 is composed of residues 26-35 as shown in SEQ ID NO: 539, the VH CDR2 is composed of residues 50-66 as shown in SEQ ID NO: 539, and the VH CDR3 is composed of residues 99-112 as shown in SEQ ID NO: 539; and The antibody comprises a light chain variable region (VL), which includes VL CDR1, CDR2, and CDR3, wherein VL CDR1 is composed of residues 24-35 shown in SEQ ID NO: 68, VL CDR2 is composed of residues 51-57 shown in SEQ ID NO: 68, and VL CDR3 is composed of residues 90-98 shown in SEQ ID NO:

68.

2. The antibody of claim 1, wherein the antibody comprises VH, the VH containing an amino acid sequence having at least 90% identity with SEQ ID NO: 491, 503, 515, 527 or 539.

3. The antibody of claim 2, wherein the antibody comprises VH, the VH comprising the amino acid sequence shown in SEQ ID NO: 491, 503, 515, 527 or 539; or the amino acid sequence shown in SEQ ID NO: 491, 503, 515, 527 or 539, which is modified by one or both of K16R and T84A.

4. The antibody of claim 1, wherein the antibody comprises a VL, the VL comprising an amino acid sequence having at least 90% identity with SEQ ID NO:

68.

5. The antibody of claim 2, wherein the antibody comprises a VL, the VL comprising an amino acid sequence having at least 90% identity with SEQ ID NO:

68.

6. The antibody of claim 4, wherein the antibody comprises VL, the VL comprising the amino acid sequence shown in SEQ ID NO:

68.

7. The antibody of claim 5, wherein the antibody comprises VL, the VL comprising the amino acid sequence shown in SEQ ID NO:

68.

8. The antibody according to any one of claims 1-7, wherein the antibody has one or more of the following properties: a. It specifically binds to hVISTA under acidic conditions, but does not bind significantly under neutral or physiological conditions; b. Under acidic conditions, the antibody binds to hVISTA, whose K D Compared to its K under neutral or physiological conditions D At least 10 times lower; c. The antibody binds to hVISTA under acidic conditions, and its k 解离 Compared to its k under neutral or physiological conditions 解离 At least 5 times lower; d. Inhibits the binding of hVISTA to human T cells at pH values ​​below 7.0; e. Inhibit the binding of hVISTA to huPSGL-1 and / or compete with huPSGL-1 for binding to hVISTA under conditions of pH less than 7.0; f. Inhibits the binding of hVISTA to heparan sulfate proteoglycan; g. Inhibit the binding of hVISTA to heparan sulfate proteoglycan under conditions of pH less than 7.0; h. Stimulation of T cell activation demonstrated by enhancing T cell proliferation under conditions of pH less than 7.0; enhancement of T cell IFN-γ production; and / or stimulation of T cell receptor-mediated NF-κB signaling; i. Reduce VISTA-mediated intercellular adhesion; j. The mean dwell time (MRT) in cynomolgus monkeys was at least 100 hours; k. Does not significantly bind to VISTA-positive cells in the peripheral blood of subjects receiving the treatment; l. It did not significantly deplete VISTA-positive cells in the peripheral blood of the subjects who received the treatment; m. The region or vicinity of histidine-rich areas bound to hVISTA; and n. The region or vicinity of histidine-rich areas that bind to hVISTA under pH conditions of 6.0–6.

5.

9. The antibody of any one of claims 1 to 7, wherein the antibody does not significantly bind to hVISTA modified by mutation of one or more of the following amino acid residues: T35, Y37, K38, T39, Y41, R54, T61, F62, Q63, L65, H66, L67, H68, H69, F97, L115, V117, I119, H121, H122, S124, E125, and R127, wherein the numbers correspond to SEQ ID NO:

2.

10. The antibody of claim 9, wherein the antibody does not significantly bind to hVISTA modified by mutation of two or more of the following amino acid residues: T35, Y37, K38, T39, Y41, R54, T61, F62, Q63, L65, H66, L67, H68, H69, F97, L115, V117, I119, H121, H122, S124, E125, R127, wherein the numbers correspond to SEQ ID NO:

2.

11. The antibody of claim 10, wherein the antibody does not bind to hVISTA modified by mutation of one or more of the following residues: H68, F97, L115, V117, I119, H121, H122, S124, E125, R127, wherein the number corresponds to SEQ ID NO:

2.

12. The antibody of any one of claims 1-7, wherein the antibody inhibits the interaction between hVISTA and (a) T cells and / or (b) PSGL-1, and wherein the antibody contacts hVISTA via one or more amino acids selected from the group consisting of energy-important contact residues: (i) V34, T35, Y37, K38, T39, Y41, S52, R54, T61, F62, Q63, L65, H66, L67, H68, H69, F97, L115, V117, I119, H121, H122, S124, E125, R127; (ii) V34, T35, Y37, T39, Y41, S52, R54, F62, L65, H66, H68, L115, V117, I119, R120, H121, H122, S124, E125; or (iii) Y37, T39, R54, F62, H66, L115 or V117, determined using the yeast surface display method, wherein the number corresponds to SEQ ID NO:

2.

13. The antibody of any one of claims 1-7, wherein the antibody inhibits the interaction between hVISTA and (a) T cells and / or (b) PSGL-1, and wherein the antibody contacts hVISTA via one or more contact residues Y37, T39, R54, F62, H66, V117, I119 or S124, as determined by yeast surface display assay, and wherein the number corresponds to SEQ ID NO:

2.

14. The antibody according to any one of claims 1 to 7, wherein the antibody: a. The FG ring is bound to hVISTA; b. The extension of the enriched histidine β-sheet bound to hVISTA, as determined by crystallography; c. Mature hVISTA H121, H122 and H123 were contacted at a distance of 4.0 Å or less and determined by crystallography, wherein the numbers correspond to SEQ ID NO: 2; d. HVISTA is contacted via VH CDR1 and VH CDR3, and not significantly via VH CDR2 and / or via VL CDR; e. wherein amino acid residues 110 and 112 of the heavy chain of the antibody form hydrogen bonds with H121 and H122 of hVISTA, respectively, and optionally, wherein the amino acid residues of the antibody form hydrogen bonds with H123 of hVISTA, wherein the numbers correspond to SEQ ID NO:

2. f. Contacting hVISTA via at least one or more glutamic acid, aspartic acid, or histidine residues located in VH CDR1, CDR2, or CDR3; g. It does not significantly bind to hVISTA at neutral or physiological pH; h. Under acidic conditions at pH 6.5, K+ bound to hVISTA D and / or the dissociation ratio of K with hVISTA at neutral or physiological pH is higher. D and / or k dissociation is at least 10 times lower; and i. It does not bind significantly to hVISTA at neutral or physiological pH.

15. The antibody according to any one of claims 1-7, wherein the antibody: a. Inhibit the interaction between hVISTA and (a) T cells and / or (b) PSGL-1; b. Enhance T cell activation by increasing T cell proliferation, increasing T cell production of IFN-γ and / or stimulating T cell receptor-mediated NF-κB signaling; c. Contacting hVISTA via one or more energy-important contact residues Y37, T39, R54, F62, H66, V117, I119, or S124, as determined using a yeast surface display method; and wherein the number corresponds to SEQ ID NO: 2; d. The β-sheet extension of histidine enriched in hVISTA was determined by crystallography; e. Mature hVISTA H121, H122 and / or H123 were contacted at a distance of 4.0 Å or less and determined by crystallography, wherein the numbers correspond to SEQ ID NO: 2; f. Binding to region 1 of hVISTA having SEQ ID NO: 1: 57 LGPVDKGHDVTF 68 (SEQ ID NO: 566); Region 2: 86 RRPIRNLTFQDL 97 (SEQ ID NO: 567); and region 3: 148 VVEIRHHHSEHRVHGAME 165 (SEQ IDNO: 568), and the binding to region 2 is the strongest, as determined by MS-HDX; g. Competitively binding to hVISTA with an antibody comprising VH and VL, wherein the VH and VL comprise amino acid sequences as shown in SEQ ID NO: 67 and 68, SEQ ID NO: 51 and 52, or SEQ ID NO: 55 and 56, respectively; h. Contacting hVISTA via at least one or more glutamic acid, aspartic acid, or histidine residues located in VH CDR1, CDR2, or CDR3; and / or i. Low-target-mediated in vivo drug delivery resulted in a mean retention time (MRT) of at least 100 hours in cynomolgus monkeys.

16. The antibody according to any one of claims 1 to 7, wherein the antibody: a. Has an isoelectric point (pI) between 6.5 and 6.8, as measured by icIEF; b. Exhibiting less aggregation than antibodies containing VH and VL, wherein VH and VL comprise amino acid sequences as shown in SEQ ID NO: 67 and 68, SEQ ID NO: 51 and 52, or SEQ ID NO: 55 and 56, respectively; c. Exhibiting a viscosity similar to or lower than that of antibodies containing VH and VL, wherein the VH and VL contain amino acid sequences as shown in SEQ ID NO: 67 and 68, SEQ ID NO: 51 and 52, or SEQ ID NO: 55 and 56, respectively; d. Exhibiting a hydrodynamic radius similar to or lower than that of antibodies containing VH and VL, wherein the VH and VL comprise amino acid sequences as shown in SEQ ID NO: 67 and 68, SEQ ID NO: 51 and 52, or SEQ ID NO: 55 and 56, respectively; e. Exhibiting a melting temperature (Tm1) similar to or higher than that of antibodies containing VH and VL, wherein the VH and VL comprise amino acid sequences as shown in SEQ ID NO: 67 and 68, SEQ ID NO: 51 and 52, or SEQ ID NO: 55 and 56, respectively; and f. Exhibiting amounts of high molecular weight aggregates similar to or lower than those containing antibodies comprising VH and VL, wherein the VH and VL comprise amino acid sequences as shown in SEQ ID NO: 67 and 68, SEQ ID NO: 51 and 52, or SEQ ID NO: 55 and 56, respectively, as measured by size exclusion chromatography (aSEC).

17. The antibody according to any one of claims 1-7, wherein it is an IgG antibody.

18. The antibody of claim 17, wherein the antibody is an IgG1, IgG2, or IgG4 antibody.

19. The antibody of claim 18, wherein the antibody is an IgG4 antibody having an S228P mutation.

20. A nucleic acid encoding an antibody as described in any one of claims 1 to 19.

21. A nucleic acid encoding the heavy and light chains of an antibody as described in any one of claims 1 to 19.

22. A composition comprising a nucleic acid encoding a heavy chain of an antibody as described in any one of claims 1 to 19 and a nucleic acid encoding a light chain of the antibody.

23. A cell comprising the nucleic acid as claimed in claim 20 or 21 or the composition as claimed in claim 22.

24. A method for preparing an antibody, comprising culturing the cells as described in claim 23 under conditions expressing said antibody.

25. A composition comprising an antibody, nucleic acid, composition, or cellular and pharmaceutically acceptable carrier as described in any one of claims 1 to 23.

26. Use of the antibody of any one of claims 1 to 7 in the preparation of a medicament for treating cancer in a subject in need, wherein the cancer is a solid tumor.

27. Use of the composition of claim 25 in the preparation of a medicament for treating cancer in a subject of need, wherein the cancer is a solid tumor.

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