钩端螺旋体OmpR家族相关TCS鉴定及功能初探OA北大核心CSTPCD

This study was aimed at establishing a method for identifying the OmpR family two-component system(TCS)in Leptospira interrogans,and to explore the effects of these proteins in regulating changes in the expression of leptospiral major outer membrane protein(OMP)during infection of human macrophages.Bioinformatics methods were used to analyze the do-mains of HK/OmpR-TCS proteins in Leptospira.A kinase activity detection kit and bacterial two-hybrid analysis were used to detect HK kinase activity,and the interactions between HKs and RRs,respectively.Real-time fluorescence quantitative RT-PCR(qRT-PCR)was used to detect changes in the expression of leptospiral OMP genes during infection of macrophages with or without HK-antibody block assay.LA1710 and LA2828 contained the HATPase_c domain,and LA1709 and LA2827 con-tained the Response reg and OmpR functional domain.The recombinant HK-2828 and HK-1710 proteins showed kinase activity and direct interaction with OmpR-2827 and OmpR-1709,respectively.The treatment with HK-2828 antibody partly reversed the infection-based down-regulated mRNA levels of lipL32,lipL41 and ompL1 genes(P＜0.05).The system for identifica-tion and functional investigation of OmpR family TCS was successfully constructed.This study provides a basis for elucidating the regulatory mechanisms of OMP expression changes in leptospires during infection,and developing a new OMP antigen screening strategy for genetically engineered vaccines.