Monocytic myeloid-derived suppressor cells reflect tuberculosis severity and are influenced by cyclooxygenase-2 inhibitors

[摘要] Myeloid-derived suppressor cells (MDSCs) increase in tuberculosis (TB) and may be targets for host-directed therapy (HDT). In this study, we use flow cytometry to analyze the effects of cyclooxygenase-2 inhibitors (COX-2i) on monocytic (M)-MDSCs in blood from TB patients attending a clinical trial of COX-2i. The effects of COX-2i on M-MDSCs and mycobacterial uptake were also studied by an in vitro mycobacterial infection model. We found that M-MDSC frequencies correlated with TB disease severity. Reduced M-MDSC ( P  = 0.05) and IDO ( P  = 0.03) expression was observed in the COX-2i group. We show that peripheral blood-derived M-MDSCs successfully internalized Mycobacterium bovis and that in vitro mycobacterial infection increased COX-2 ( P  = 0.002), PD-L1 ( P  = 0.01), and Arginase-1 ( P  = 0.002) expression in M-MDSCs. Soluble IL-1β, IL-10, and S100A9 were reduced in COX-2i-treated M-MDSCs cultures ( P  < 0.05). We show novel data that COX-2i had limited effect in vivo but reduced M-MDSC cytokine production in vitro. The relevance of COX-2i in a HDT strategy needs to be further explored.

[学科分类] 生理学

[关键词] Mycobacteria;M-MDSC;cyclooxygenase-2 inhibitor;host directed therapy;innate immunity