Rv2741 Promotes Mycobacterium Survival by Modulating Macrophage Function via the IL-1α-MAPK Axis.

One of the primary healthcare problems in the world today is tuberculosis (TB), a chronic infectious illness brought on by Mycobacterium tuberculosis (M. tuberculosis). A distinct family of PE_PGRS proteins, encoded by the M. tuberculosis genome, has attracted more attention because of their involvement in immune evasion and bacterial pathogenicity. Nevertheless, the specific functions and mechanisms of action for the majority of PE_PGRS proteins remain largely unexplored. This study focuses on the Rv2741 (PE_PGRS47) gene, which is exclusively present in pathogenic mycobacteria. To examine the function of Rv2741 in host-pathogen interactions, we created recombinant strains of Mycobacterium smegmatis (M. smegmatis) that expressed the M. tuberculosis Rv2741 gene. IL-1α was found to be a key mediator of host response modulation by Rv2741. Rv2741 downregulates the secretion of IL-1α and inhibits the MAPK signaling pathway, particularly the p38 and ERK1/2 pathways, thereby cooperatively inhibiting macrophage autophagy and apoptosis. Meanwhile, the decrease in IL-1α secretion directly leads to changes in the cytokine secretion pattern and a reduction in nitric oxide (NO) production. This multifaceted regulatory mechanism ultimately favors the survival of M. smegmatis in macrophages. This research significantly expands our understanding of Rv2741 function, revealing its crucial role as a multifunctional virulence factor in the immune evasion of M. tuberculosis.