Fig. 5: Host γδ T cells are required for αPD-L2 efficacy.

a–e Flow cytometry data for wild type aged (isotype n = 4 mice, αPD-L2 n = 4 mice), wild type young (isotype n = 5 mice, αPD-L2 n = 4 mice), and IL-17^KO aged mice (isotype n = 5 mice, αPD-L2 n = 4 mice) challenged subcutaneously with B16 melanoma and treated with αPD-L2 (200 µg/mouse) or isotype control (200 µg/mouse) intraperitoneally every 4 days starting on day 3. f Tumour growth curve (isotype n = 8 mice, αPD-L2 n = 8 mice) and g–i flow cytometry data of tumour-infiltrating g CD8⁺ T cells (CD45⁺CD3⁺B220^-) h IFNγ⁺CD8⁺ T cells and i mean fluorescence intensity (MFI) of IFNγ in CD8⁺ T cells from δTCR^KO aged mice (isotype n = 4 mice; αPD-L2 n = 4 mice) as indicated harboring B16 melanomas treated with αPD-L2 or isotype control as above. j MFI of Granzyme B in tumour-infiltrating CD8⁺ T cells from wild type aged (isotype n = 4 mice, αPD-L2 n = 4 mice), wild type young (isotype n = 5 mice, αPD-L2 n = 4 mice), IL-17^KO aged mice (isotype n = 5 mice, αPD-L2 n = 4 mice), and δTCR^KO aged mice (isotype n = 4 mice, αPD-L2 n = 4 mice) as indicated harboring B16 melanomas treated with αPD-L2 or isotype control as above. k Tumour growth curve and l–n flow cytometry data of tumour-infiltrating l CD8⁺ T cells (CD45⁺CD3⁺B220^-), m IFNγ⁺CD8⁺ T cells (CD45⁺CD3⁺B220^-), and n MFI of IFNγ in CD8⁺ T cells (CD45⁺CD3⁺B220^-) from wild type young mice harboring subcutaneous MB49 murine bladder cancer tumours treated with αPD-L2 or isotype control as above ± α-δTCR (500 μg/mouse loading dose followed by 200 μg/mouse for remaining doses) or respective isotype control administered every 3 days beginning on day 2 (α-δTCR n = 5 mice, α-δTCR + αPD-L2 n = 5 mice). Standard error of mean indicated; p-values by (a–e, g–j, l–n) unpaired Student’s t-test (f, k) two-way ANOVA.