Figure 6.

PD-L1 on human innate cells regulates Th1 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. Amounts of secretion of IFN-γ in monocyte–CD4⁺ T cell cocultures (A) and in DC–CD4⁺ T cell cocultures (mean ± SEM, n = 6) (B). *P < 0.05; **P < 0.01; ***P < 0.001; ns, not significant; as determined by one-way ANOVA.