PDCD1 and tuberculosis: On the other hand, PD-1 and PD-L1 expression on bronchoalveolar lavage-derived CD3+ T cells and CD14+ monocytes obtained from TB patients, suggested that PD-1 was associated with a diminished number of cells producing IFN-γ and TNF-α and IL-2, and blocking the PD-1/PD-L pathway could restores protective T cell responses (185).