Homology Analysis,Cross-immunogenicity And Toxicity Study Of OmpA From Pathogenic Yersinia

Yersinia, a member of enterobacteriaceae, currently have been typed into 17 species, among which three kinds of them were pathogenic for human beings and rodents: Yersinia enterocolitica, Yersinia pestis and Yersinia pseudotuberculosis. Yersinia pestis is the pathogen of the plague that is deadly infectious disease; Yersinia enterocolitica and Yersinia pseudotuberculosis can cause human diarrhea, can also cause some sequelas, such as erythema nodosum, reactive arthritis, endocarditis,and even can cause sepsis to death. Researching and developing of safe and effective vaccine of Yersinia, and looking for the right antigen as a candidate of subunit vaccine is imperative to prevent and control pathogenic Yersinia infection.The outer membrane protein A (OmpA) is one of the intra-species conserved proteins with immunogenicity widely found in the family of Enterobacteriaceae. It is previously conformed that OmpA served as the dorminant immunogenic protein of Yersinia enterocolitica; the ompA genes of pathogenic Yersinia enterocolitica were highly homogeneous among different serotype; the OmpA of Y. pestis was a immune protective antigen and promoted intracellular survival and virulence in mice. So this study is to confirm the homology of the ompA genes of pathogenic Yersinia, to testify the cross immunogenicity between Pathogenic Yersinia and explore virulence changes induced by ompA gene mutation.Identity analysis of ompA included 615 pathogenic Yersinia strains from the 1960s up to the present, containing 219 pathogenic Y.enterocoltitica strains,262 Y. pestis strains and 134 Y.pseudotuberculosis strains. We sequenced and analyzed these included strains to verify the homology within and between the three kinds of pathogenic Yersinia. Three kinds of representative OmpA were expressed and purified to test the cross-immunogenicity by Western blot. The virulence test was performed by compared spleen colony count of the ompA deletion strain and the wild strain of pathogenic Y.enterocolitica with a nonpathogenic Y.enterocolitica.The identity of ompA sequences for 262 Y. pestis strains,134 Y. pseudotuberculosis strains and 219 pathogenic Y. enterocolitica strains are 100%, 98.8% and 97.7% similar. The main pattern of OmpA of pathogenic Yersinia are 86.2% and 88.8% identical at the nucleotide and amino acid sequence levels, respectively. Immunological analysis showed the immunogenicity of each OmpA and cross-immunogenicity of OmpA for pathogenic Yersinia.We found that the elimination speed of ompA gene deletion strain was lower than that of the wild strain within the spleen, and confirmed ompA gene was related to virulence by a virulence experiment of ompA gene deletion of pathogenic Yersinia strain.Here we first confirmed OmpA is conserved in the three pathogenic Yersinia:Y. pestis, Y pseudotuberculosis and pathogenic Y. enterocolitica, with high homology at the nucleotide level and at the amino acid sequence level. We found OmpA was a mutually immunogenic antigen among pathogenic Yersinia where OmpA may be a vaccine candidate for Y. pestis and other pathogenic Yersinia. This study also suggested that ompA gene is related to the virulence of pathogenic of Y. enterocolitica.