Expression of mammalian cell entry genes in clinical isolates of M. tuberculosis and the cell entry potential and immunological reactivity of the Rv0590A protein

AbstractMammalian cell entry (mce) operons play a vital role in cell invasion and survival ofM. tuberculosis. Of themce genes, the function ofRv0590A is still unknown. The present study was performed to investigate the function and immunogenic properties of the protein Rv0590A. Human leukemia monocytic cell line (THP-1) derived macrophages were infected withM. tuberculosis H37Rv at 3, 6, and 24  h of infection. The maximum colony forming units (CFU) were observed at 6 h (p <  0.005), followed by 3 h after infection.M. tuberculosis H37Rv and clinical isolates representative of Delhi/CAS, EAI, Beijing, Haarlem and Euro-American-superlineage were included in the study for expression analysis ofmce1A, mce2A, mce3A, mce4A, andRv0590A genes. Maximum upregulation of allmce genes was observed at 3  h of infection. All the five clinical isolates and H37Rv upregulatedRv0590A at various time points. Macrophage infection withM. tuberculosis H37Rv-overexpressingRv0590A gene showed higher intracellular CFU as compared to that of wild-type H37Rv. Further, purified Rv0590A protein stimulated the production of TNF α, IFNγ, and IL-10 in macrophages. Thus, Rv0590A was found to be involved in cell invasion and showed good immunological response.
Source: Medical Microbiology and Immunology - Category: Microbiology Source Type: research