SAP and EAT-2 are downstream signaling molecules of CD244 in CD8+ T cells during active TB infection. PBMCs from patients with active TB were transfected with siRNA targeting CD244 (siRNA-CD244) or siRNA-Ctrl (si-Ctrl) or transfection medium for 48 h and cultured for another 3 d. Cells were then harvested and analyzed for the expression of CD244, SAP, and EAT-2 in CD8+ T cells using ICS/flow cytometry. (A and B) Representative flow cytometric dot plots shows that siRNA-CD244 but not siRNA-Ctrl or transfection medium decreased expression of CD244 (A), SAP (B), and EAT-2 (D) in CD8+ T cells. (C and E) Representative flow cytometric histogram analysis shows that siRNA-CD244 but not siRNA-Ctrl or transfection medium decreased expression of SAP (C) and EAT-2 (E) in CD8+ T cells. Pooled data show the frequency of SAP+CD8+ T cells (F) and EAT-2+CD8+ T cells (G) among total CD8+ T cells after transfection with indicated siRNA. Error bars, SEM (n = 8). Error bars represent SEM from two independent experiments.