Abstract

The regulatory mechanisms of pathogenic bacteria contribute to their survival under stress conditions in the host environment, which allows them to avoid the immune system of the macroorganism. Small, noncoding RNAs were previously found to regulate some metabolic processes of Mycobacterium tuberculosis. We have revealed that the viability of M. tuberculosis in host-like conditions depends on the expression level of small RNAs. Strains overexpressing small RNA MTS1338 and MTS0997 in M. tuberculosis were produced, and their survival under stressful conditions in vitro and in infected human macrophages were studied. We found that overexpression of the small, noncoding RNA MTS1338 increased bacterial resistance to the stressful effects of hydrogen peroxide, nitric oxide, an acidic environment, and a long-term lack of nutrients at different growth phases and contributed to the viability of bacteria in infected macrophages. An overexpression of the small, noncoding RNA MTS0997 did not significantly affect cell viability under stress conditions. Thus, the two studied small RNAs play different roles in the mycobacterial adaptation to intracellular stresses during infection.

中文翻译：

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结核分枝杆菌的小RNA在体外适应宿主样应激条件

摘要

病原菌的调节机制有助于它们在宿主环境中的应激条件下存活，这使它们能够避免大生物的免疫系统。先前发现小的非编码RNA可以调节结核分枝杆菌的某些代谢过程。我们已经揭示，结核分枝杆菌在宿主样条件下的生存能力取决于小RNA的表达水平。在结核分枝杆菌中过表达小RNA MTS1338和MTS0997的菌株产生，并研究了它们在体外和在感染的人类巨噬细胞中在压力条件下的存活率。我们发现小的非编码RNA MTS1338的过表达增加了细菌对过氧化氢，一氧化氮，酸性环境以及长期处于不同生长阶段的营养缺乏的胁迫作用的抵抗力，并有助于细菌在感染后的生存能力巨噬细胞。小的非编码RNA MTS0997的过表达在应激条件下不会显着影响细胞活力。因此，这两个研究小RNA在感染过程中在分枝杆菌对细胞内应激的适应中发挥了不同的作用。