AUTHOR=Fan Xiangyu , Liu Zichen , Wan Zhibin , Zou Hanlu , Ji Mengzhi , Sun Kaili , Gao Rongfeng , Li Zhongfang , Li Wu 

TITLE=Prophage Gene Rv2650c Enhances Intracellular Survival of Mycobacterium smegmatis

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.819837

DOI=10.3389/fmicb.2021.819837

ISSN=1664-302X

ABSTRACT=<sec><title>Background</title><p>Induced by the pathogen <italic>Mycobacterium tuberculosis</italic>, tuberculosis remains one of the most dangerous infectious diseases in the world. As a special virus, prophage is domesticated by its host and are major contributors to virulence factors for bacterial pathogenicity. The function of prophages and their genes in <italic>M. tuberculosis</italic> is still unknown.</p></sec><sec><title>Methods</title><p><italic>Rv2650c</italic> is a prophage gene in <italic>M. tuberculosis genome</italic>. We constructed recombinant <italic>Mycobacterium smegmatis</italic> (<italic>M. smegmatis</italic>) to observe bacteria morphology and analyze the resistance to various adverse environments. Recombinant and control strains were used to infect macrophages, respectively. Furthermore, we performed ELISA experiments of infected macrophages.</p></sec><sec sec-type="results"><title>Results</title><p>Rv2650c affected the spread of colonies of <italic>M. smegmatis</italic> and enhanced the resistance of <italic>M. smegmatis</italic> to macrophages and various stress agents such as acid, oxidative stress, and surfactant. ELISA experiments revealed that the Rv2650c can inhibit the expression of inflammatory factors TNF-α, IL-10, IL-1β, and IL-6.</p></sec><sec sec-type="conclusion"><title>Conclusion</title><p>This study demonstrates that the prophage gene <italic>Rv2650c</italic> can inhibit the spread of colonies and the expression of inflammatory factors and promote intracellular survival of <italic>M. smegmatis</italic>. These results build the foundation for the discovery of virulence factors of <italic>M. tuberculosis</italic>, and provide novel insights into the function of the prophage in <italic>Mycobacterium</italic>.</p></sec>