Fig. 7

Blockade of PVRIG enhances human NK cell cytotoxicity and inhibits tumor growth in NK cell- or PBMC-reconstituted xenograft mice. a Representative histogram of PVRIG expression in human NKG cell line. b NKG cells were co-cultured with SW620 cells at 2.5:1 ratio for 24 h in the presence of anti-hPVRIG antibody or mIgG1 control antibody. The expression of NKG2D, CD107a and perforin in NKG cells was analyzed by flow cytometry. c Cytotoxicity of NKG cells against human colon cancer cell line SW620 in the presence of anti-hPVRIG antibody (red) or mIgG1 control antibody (blue) at E/T ratios of 1:1 and 5:1. d Flow cytometric analysis of PVRIG expression in CD56⁺ NK cells, CD8⁺ T cells and CD4⁺ T cells from healthy human PBMCs (n = 21). e Human PBMCs were co-cultured with SW620 cells at an E/T ratio of 25:1 for 24 h in the presence of anti-hPVRIG antibody or mIgG1 control antibody. The expression of IFN-γ (n = 47), TNF-α (n = 47) and CD107a (n = 26) in NK cells was analyzed by flow cytometry. f Cytotoxicity of purified human NK cells against SW620 cells in the presence of anti-hPVRIG antibody or mIgG1 control antibody at indicated E/T ratios. g Cytotoxicity of human PBMCs against SW620, A375 and SK-OV-3 tumor cells in the presence of anti-hPVRIG antibody or mIgG1 control antibody at various E/T ratios was analyzed, respectively. h Representative histogram of PVRIG expression in expanded human NK cells. i B-NDG mice were inoculated subcutaneously with SW620 colon cancer cells on day 0. Mice were grouped randomly and expanded NK cells were injected intravenously (i.v.) on days 7, 12 and 17. Mice were then treated with anti-hPVRIG mAb (n = 9) or isotype-matched control mAb (mouse IgG) (n = 9) intraperitoneally (i.p.) every three days starting on day 7 for five times. All mice were injected intraperitoneally with 50,000 IU recombinant human IL-2 every two days starting on day 7. And median tumor size was shown on the right. j B-NDG mice were inoculated subcutaneously with SW620 colon cancer cells on day 0. Mice were grouped randomly and human PBMCs were injected intravenously (i.v.) on day 7. Mice were then treated with PBS (n = 9), anti-hPVRIG mAb (n = 9) or isotype-matched control mAb (mouse IgG) (n = 7) intraperitoneally (i.p.) every three days starting on day 8 for five times. And median tumor size was shown on the right. Each symbol represents an individual health donor (d, e, g) or B-NDG mouse (i, j). Data are representative of at least two independent experiments. Error bars represent means ± s.e.m. Statistical significance was determined using unpaired two-tailed t test (b, c, f, g), paired two-tailed t test (e) or two-way ANNOVA (i, j). *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001