EsxA mainly contributes to the miR-155 overexpression in human monocyte-derived macrophages and potentially affect the immune mechanism of macrophages through miRNA dysregulation.

Background/purpose: Mycobacterium tuberculosis is a successful intracellular pathogen that uses multiple proteins to survive within macrophages, one of the most remarkable is the virulence factor EsxA. In this study, we evaluate the participation of EsxA in the miRNAs expression profile of human monocyte-derived macrophages (hMDM), to mapping out the contribution of this virulence factor in the miRNA profile and how these changes can influence and alter immune-related processes and pathways.

Methods: The cytotoxic effect of rEsxA on hMDM was evaluated by the neutral red assay.

Infection of J774A.1 with different Mycobacterium species induces differential immune and miRNA-related responses.

Macrophages act as a reservoir for Mycobacterium tuberculosis, producing latent infection in approximately 90% of infected people. In this study, J774A.1 mouse macrophage cell line response and microRNA (miRNA) expression during infection with the most relevant mycobacterial strains for humans (M.