The frequency and dynamics of CD4+ mucosal‐associated invariant T (MAIT) cells in active pulmonary tuberculosis

•Patients with Pulmonary Tuberculosis had declined CD4- MAIT and elevated CD4+ MAIT cells in their peripheral blood.•Increased CD69+ and decreased LAG-3+ expression were observed in Mtb-reactive CD4+ MAIT cells in peripheral blood of patients with Pulmonary Tuberculosis.•IFN-γ and granzyme B expression on MAIT cells were increased in patients with Pulmonary Tuberculosis, and decreased after anti-tuberculosis chemotherapy.•CD4+ MAIT cells might play a role in anti-tuberculosis immunity by increasing IFN-γ and Granzyme B secretion.