Figure 1: IFN-γ production in MAIT cells from tuberculous pleural effusions and peripheral blood.

(A) Representative flow cytometric plot showing gating of MAIT cells with phenotypes of CD3⁺Vα7.2⁺CD161^high. (B) Representative flow cytometric plots showing IFN-γ production in MAIT cells from peripheral blood (PB) and from tuberculous pleural effusion (PE) of patient with tuberculous pleurisy in the absence of antigen stimulation. (C) Representative flow cytometric plots showing IFN-γ production in MAIT cells from peripheral blood (PB) and from tuberculous pleural effusion (PE) of patient with tuberculous pleurisy after Mtb antigen stimulation. (D) MAIT cells in tuberculous pleural effusions had greatly enhanced IFN-γ response to Mtb antigens compared with those in peripheral blood. Horizontal Bars in the scatter plots indicate median. (E) The ratio of patients with tuberculous pleurisy only (PE), with accompanied pulmonary TB with lesions located within one lung (PE & pTB1), with accompanied pulmonary TB with lesions located in both lungs (PE & pTB2), and with accompanied pulmonary TB and other extrapulmonary TB (PE & mTB) in the high IFN-γ-producing MAIT cell group. (F) The ratio of patients with different extent of TB infections in the low IFN-γ-producing MAIT cell group. (G) Correlation analysis showed that the frequency of IFN-γ-producing MAIT cells was inversely correlated with the extent of TB infection. The extend of TB infection was graded from 1 to 4, representing PE, PE&pTB1, PE&pTB2 and PE&mTB respectively, as described in legend in Fig. 1E. The nonparametric Mann-Whitney test was used for statistical analysis in Fig. 1D.