Fig. 1: PD-L1 on DCs is important for T cell priming during antitumor immune responses.
a WT B6 mice (n = 8) were inoculated with 5 × 105 MC38 cells and analyzed by flow cytometry on day 14 after inoculation. PD-L1 expression levels on CD8+ T (CD3+CD8+), CD4+ T (CD3+CD4+), B (CD19+), macrophage (CD11b+F4/80+), MDSC (CD11b+Gr-1+), DC (CD11c+MHC II+), and tumor (CD45−) cells were shown. FMO, fluorescence minus one; MFI, mean fluorescent intensities. b Knockout strategy. LoxP sites were inserted flanking exons 2 and 3. c PD-L1 expression on DCs and control cells (CD11c−MHC II+) were measured by flow cytometry in CD11c-cre;Pdl1fl/fl and control mice. d CD11c-cre;Pdl1fl/fl or control mice (n = 4) were inoculated with 5 × 105 MC38 cells. Tumor sizes were measured twice a week. e MC38 tumor tissues were collected from CD11c-cre;Pdl1fl/fl or control mice (n = 6 Cre-, 7 Cre+) on day 14 after inoculation. PD-L1 levels on tumor cells were measured by flow cytometry. f CD11c-cre;Pdl1fl/fl or control mice (n = 5) were inoculated with E.G7 cells. Percentages of OVA-specific CD8+ T cells in PBMC were stained by tetramer on day 12. *p = 0.0399. g CD11c-cre;Pdl1fl/fl or control mice (n = 5) were inoculated with MC38-SIY cells. DCs were isolated from dLNs on day 14 and incubated with purified 2C T cells with or without SIY peptide restimulation. Forty-eight hours later, IFN-γ production was measured by ELISPOT. n.d., not detected. *p = 0.0172. Data are shown as mean ± SEM (a, e, f, and g) or mean + SEM (d) and are representative of two (d, e, f, and g) or three (a and c) independent experiments. n.s., not significant; *p < 0.05 determined by unpaired two-tailed Student’s t test. Source data are provided as a Source Data file.
