1.Department of Pathogenic Biology and Immunology Medical School of Shihezi University / The Key Laboratory of Endemic and Ethnic Diseaseas, Shihezi University, Shihezi 832000,China; 2.Department 1 of Geriatrics, Shihezi People’s Hospital, Shihezi 832000,China
Abstract:In this study, we explored the regulatory mechanisms of PhoPR two-component signal transduction system in Mycobacterium tuberculosis persistence by analyzing the expression levels difference of PhoP gene and PhoR gene at various time in different oxygen conditions of Mycobacterium tuberculosis which were induced persistent state under low-oxygen conditions. The international standard avirulent strains of Mycobacterium tuberculosis (H37Ra) and the international standard virulent strains of Mycobacterium tuberculosis (H37Rv) were cultured under different low-oxygen conditions, then the total RNA extracted from each sample strain and the integrity of the RNA were checked by gel electrophoresis. The expression of PhoP gene and PhoR gene were quantified by using SYBR Green I FQ-PCR. The expression levels difference of these genes were compared in different low-oxygen conditions of Mycobacterium tuberculosis. The expression levels of PhoP gene and PhoR gene of Mycobacterium tuberculosis under low-oxygen conditions were measured at various times. The expression level of PhoP gene and PhoR gene of H37Rv strain and H37Ra strain cultured for 15 days compared with 10 days were significantly up-regulated (P<0.05); and the expression level of PhoP gene and PhoR gene of H37Rv strain cultured for 25 days were up-regulated by 2.34 times compared with H37Ra strain (P<0.05). In this study, there are differences under different low-oxygen conditions in the expression levels of PhoP gene and PhoR gene of Mycobacterium tuberculosis PhoPR two-component signal transduction system at various time and same virulent strains, and there are differences under the same low-oxygen condition in the expression levels of PhoP gene and PhoR gene of Mycobacterium tuberculosis PhoPR two-component signal transduction system at the same time and different virulent strains. Therefore, the system plays a regulatory role in Mycobacterium tuberculosis persistence.
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