PDCD1 and tuberculosis: To verify this assumption, experiments were performed in order to compare B7-H1 expression in IFN-α-induced dendritic cells from donors and TB patients, to investigate the correlation between B7-H1 expression and IL-10 endogenous production level, and to evaluate DCs capability to induce T-cell apoptosis/anergy, as well as the role of the PD-1/B7-H1 signaling pathway in negative regulation of T-lymphocytes.