Cloning and expressing a conserved region of surface protein VlsE gene from a Chinese Borrelia afzelii strain GDsh1 and analyzing antigenicity of rVlsE protein
LIU Wei, ZHANG Lin, HOU Xue-xia, LIU Hui-xin, HAO Qin, WAN Kang-lin
State Key Laboratory for Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
Abstract:We cloned and expressed a conserved region of surface protein VlsE gene from a Chinese Borrelia afzelii strain GDsh1, and analyzed the antigenicity of the rVlsE protein to support the development of Chinese ELISA recombinant antigen detection kit for Lyme disease. According to literature, we downloaded and aligned VlsE sequences of all B. afzelii strains from PubMed to identify conserved segment and design primers. The target fragment was amplified and inserted into an expression vector PET-32a and expressed in E. coli B21. The expressed protein was identified by SDS-PAGE, western blot and gene sequence. ELISA was performed with the rVlsE protein to test 83 Lyme disease sera, 90 negative serum samples and 90 samples of syphilis serum, thereby to determine the sensitivity and specificity of the rVlsE protein. SDS-PAGE analysis showed the conserved region was successful expressed in E. coli. Western blot results confirmed that recombinant protein was able to response with immune rabbit serum. ELISA results showed that the sensitivity of rVlsE protein and the whole borrelia burgdorferi protein were 60.2% and 92.8%(P<0.001), the specificity were 73.3% and 68.9%(P=0.511). The specificity of this method in the detection of syphilis serum was 83.3%, much higher than that using the whole bacterial protein(18.9% specificity)(P<0.001). The method using conserved fragments of VlsE protein has certain sensitivity and specificity in the distinguishing of syphilis and Lyme serum samples, its specificity is much higher than the whole cell protein. Therefore, the conserved fragments of VlsE in Lyme disease serological detection should not be ignored.
刘炜, 张琳, 侯学霞, 刘慧鑫, 郝琴, 万康林. 中国B.afzelii基因型莱姆病螺旋体GDsh1表面蛋白VlsE保守区段的克隆表达及抗原性分析[J]. 中国人兽共患病学报, 2016, 32(1): 13-16.
LIU Wei, ZHANG Lin, HOU Xue-xia, LIU Hui-xin, HAO Qin, WAN Kang-lin. Cloning and expressing a conserved region of surface protein VlsE gene from a Chinese Borrelia afzelii strain GDsh1 and analyzing antigenicity of rVlsE protein. Chinese Journal of Zoonoses, 2016, 32(1): 13-16.
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