PD-1/PD-ls Pathways Between CD~4+T Cells And Pleural Mesothelial Cells In Human Tuberculous Pleurisy

Objectives To evaluate the immune regulation of PD-1/PD-Ls pathways between pleuralmesothelial cells (PMCs) and CD4+T cells in human tuberculous pleurisy.Methods Concentrations of soluble PD-l and soluble PD-Ls in tuberculous pleural effusion(TPE) were detected by ELISA kits. Expression of PD-1on CD4+T cells and expressions ofPD-Ls on PMCs from TPE were determined by flow cytometry. The impacts of PD-1/PD-Lspathways on proliferation, apoptosis, adhesion, and migration of CD4+T cells were explored.Results It was found that concentrations of soluble PD-1, but not of soluble PD-Ls, weremuch higher in TPE than in the corresponding serum. Expressions of PD-1on CD4+T cells inTPE were significantly higher than those in blood. Expressions of PD-Ls were much higheron PMCs from TPE when compared with those from transudative effusion. IFN-γ not onlyupregulated the expression of PD-1on CD4+T cells, but also upregulated the expressions ofPD-Ls on PMCs. Blockage PD-1/PD-Ls pathways abolished the inhibitory effects onproliferation and adhesion activity of CD4+T cells.Conclusions Our current data showed that PD-1/PD-Ls pathways on PMCs inhibitedproliferation and adhesion activity of CD4+T cells, suggesting that Mycobacteriumtuberculosis might exploit PD-1/PD-Ls pathways to evade host cell immune response inhuman.