Correlation study between Mycobacterium tuberculosis PhoPR two-component system and pathogenicity of different virulent Mycobacterium tuberculosis / 中国免疫学杂志

ABSTRACT

Objective:To explore the correlation between Mycobacterium tuberculosis PhoPR two-component system and the pathogenicity of different virulent MTB by analysing the expression levels difference of PhoP gene and PhoR gene in BCG ,H37Ra, H37Rv and XJ-MTB respectively.Methods:Total RNA extracted from four different virulent MTB strains and the integrity of total RNA were identified by using agarose 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 virulent MTB strains .Results: The relative expression levels of PhoP gene in between four different virulent MTB strains from high to low were XJ -MTB(9.05),H37Rv(1.00), H37Ra(0.25),BCG(0.08) respectively ,and the expression levels difference of PhoP gene were statistically significant in different virulent MTB strains ( P＜0.05 );the relative expression levels of PhoR gene in four different virulent MTB strains from high to low were XJ-MTB(5.72),H37Rv(1.00),H37Ra(0.18),BCG(0.07) respectively,and the expression levels difference of PhoR gene were sta-tistically significant in different virulent MTB strains ( P＜0.05 ).The expression levels of PhoP gene and PhoR gene at XJ-MTB were statistically significant difference compared with BCG ,H37Rv,H37Ra respectively (P＜0.05);the expression levels of PhoP gene and PhoR gene at H37Rv were statistically significant difference compared with BCG ,H37Ra respectively (P＜0.05);the expression levels of PhoP and PhoR gene at BCG were not statistically significant difference compared with H 37Ra (P>0.05).Conclusion:Significant expression levels difference of PhoP gene and PhoR gene are confirmed in different virulent MTB strains .Therefore,the Mycobacterium tuberculosis PhoPR two-component system is correlated with the pathogenicity in different virulent MTB strains.