FIGURE 4: Immunofluorescence (IF) staining of THP-1 cells treated with MTB-related materials. THP-1 cells were treated with H37Rv whole cell lysate (10 µg/ml) and EsxA protein (1 µg/ml) for 24 hours. IF staining demonstrated increased expression of PD-L1 (red) overlapped with TET1 (green) in THP-1 cells. PD-L1, programmed death-ligand 1; TET1, ten eleven translocation methylcytosine dioxygenase 1.