Fig. 7: αPD-L2 efficacy exhibits host age and tumour type specificity.

a Overall tumour growth curve of B16 melanoma tumours from IL-17^KO aged mice harboring subcutaneous B16 melanoma tumours given 1×10⁶ naive wild type aged CD4⁺ T cells day -1 before tumour challenge treated with isotype (200 µg/mouse) or αPD-L2 (200 µg/mouse) intraperitoneally every 4 days starting on day 3 ± α-IL-17R (25 μg/mouse intraperitoneally on day 18 post-tumour challenge) (isotype n = 3 mice, αPD-L2 n = 4 mice). b Tumour growth curves of wild type young mice challenged subcutaneously with B16 melanoma and treated with αPD-L2 (200 µg/mouse), isotype control (200 µg/mouse) intraperitoneally every 4 days starting on day 3 ± recombinant IL-17A (rIL17 1 µg/mouse) daily from day -10 to day +11 pre- and post-tumour challenge. (isotype n = 4 mice, αPD-L2 n = 5 mice, rIL-17 n = 4 mice, rIL-17 + αPD-L2 n = 4 mice). Flow cytometry data of intratumoural prevalence of c CXCR3⁺CD8⁺ T cells (CD45⁺CD3⁺B220^-), d CXCR3⁺CD4⁺ T cells (CD45⁺CD3⁺B220^-), and e CXCR3⁺γδ TCR⁺ γδ T cells (CD45⁺CD3⁺B220^-) from tumours in b. f NY-ESO-1 TCR expressing HLA-A2⁺ human T cells cultured with HLA-A2⁺ U251-nGFP-NY-ESO-1⁺ human glioblastoma cells treated with isotype control (50 μg/mL) or αPD-L2 (50 μg/mL) with GFP expression quantified (n = 3 human donors). g Tumour growth curve of wild type aged mice challenged subcutaneously with PD-L2^KO B16 murine melanoma and treated with αPD-L2 or isotype control as above (isotype n = 7 mice; αPD-L2 n = 6 mice).Standard error of mean indicated. p-values (a, b, g) two-way ANOVA (c–f) unpaired Student’s t-test.