Pre-exposure of Mycobacterium tuberculosis-infected macrophages to crystalline silica impairs control of bacterial growth by deregulating the balance between apoptosis and necrosis.

ABSTRACT: Inhalation of crystalline silica (CS) particles increases the risk of pulmonary tuberculosis; however, the precise mechanism through which CS exposure facilitates Mycobacterium tuberculosis (Mtb) infection is unclear. We speculate that macrophage exposure to CS deregulates the cell death pathways that could explain, at least in part, the association observed between exposure to CS and pulmonary tuberculosis. We therefore established an in vitro model in which macrophages were exposed to CS and then infected with Mtb. Expression of surface markers was analyzed by flow cytometry, JNK1/2, ASK1, caspase 9, P-p38, Bcl-2 and Mcl-1 were analyzed by Western blot, and cytokines by ELISA. Our results show that exposure to CS limits macrophage ability to control Mtb growth. Moreover, this exposure re

SUBMITTER: Chavez-Galan L 

PROVIDER: S-EPMC3838437 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature