Figure 5.

PD-L1 on human innate cells is dispensable for regulating Th17 response to M. tuberculosis. Monocytes or DCs were cocultured with autologous CD4⁺ T cells either alone or with γ-irradiated M. tuberculosis. After 18 h, PD-L1 blocking mAb or isotype control mAb were added, and cultures were maintained for 5 days. Th17 cells were analyzed by flow cytometry by combination of surface staining for CD4 and intracellular staining for IL-17A. IL-17A in the cell-free supernatants was quantified by ELISA. (A–C) Representative dot plots showing the frequencies of CD4⁺IL-17A⁺ T cells (A), frequencies of CD4⁺IL-17A⁺ T cells (mean ± SEM, n = 5) (B), and amounts of IL-17A production (mean ± SEM, n = 6) (C) in monocyte–CD4⁺ T cell cocultures. (D–F) Representative dot plots showing the frequencies of CD4⁺IL-17A⁺ T cells (D), frequencies of CD4⁺IL-17A⁺ T cells (mean ± SEM, n = 6) (E), and amounts of IL-17A production (mean ± SEM, n = 6) (F) in DC–CD4⁺ T cell cocultures. *P < 0.05; **P < 0.01; ***P < 0.001; ns, not significant; as determined by one-way ANOVA.