Yingying Cui,Yangyang Tang,Mingzhu Shao,Xinxin Zang,Yanyan Jiang,Ziyin Cui,Guanghui Dang,Siguo Liu

Microb Pathog.2022 Dec;173(Pt B):105880.doi: 10.1016/j.micpath.2022.105880. Epub 2022 Nov 17.

Abstract

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb). Mtb can overcome macrophage intracellular killing and lead to persistent infections. The proteases of Mtb are critical virulence factors that participate in immune responses. We determined that Rv3090 is a cell wall-associated protease and a potential pathogenic factor. To characterize the role of Rv3090 in Mtb, recombinant Msg_Rv3090 and Msg_pAIN strains were constructed to infect macrophages and mice. Lactate dehydrogenase assays and flow cytometry results showed that Rv3090 induces late macrophage apoptosis. In vivo infection experiments indicated that Rv3090 could induce hepatocyte and lung cell apoptosis and cause pathological damage to the spleen, livers and lungs. Msg_Rv3090 specifically stimulated the secretion of inflammatory cytokines including TNF-α, IL-6 and IL-1β. Overexpression of Rv3090 significantly promoted the survival of Msg in livers and lungs. Thus, Rv3090 protease triggered late cell apoptosis and contributed to the pathogenicity and dissemination of Mtb.

Keywords: Apoptosis; Macrophage; Mycobacterium tuberculosis; Protease; Rv3090.