Selection Of OMPs And Flagella As Leptospirosis Vaccine Candidates

Leptospirosis, caused by the pathogenic leptospires, is one of the most widespread zoonotic diseases known (1,2). Commercially available vaccines, which consist of heat- or formalin-killed leptospires, only produce incomplete, short-term immunity. Outer membrane proteins (OMPs) exposed on the cell surface where bacteria interact with the host, so they are of interest as vaccine candidates. There are some differences in this work from other earlier documents. We selected and analyzed the OMPs using bioinformatics and genomics, and screened out the potential efficacious leptospiral vaccines by many immunity experimental techniques.There are more than 100 ORFs encoding outer membrane proteins sequences of L. interrogans serogroup Icterohaemorrhagiae serovar Lai predicted (http://www.chgc.sh.cn/lep/). Part â…  of this work is to develop efficacious and broad-spectrum leptospiral vaccines from these OMPs. Thereinto eleven OMPs sequences were analyzed by bioinformatic tools and proteomic strategies. These OMPs were expressed and purified using molecule clone methods and polyclonal antisera were gamed by immunizing rabbits separately. The eleven OMPs all express in virulent or avirulent L. interrogans strain Lai cultured in vitro, almost all in other pathogenic leptospires and only some in apathogenic leptospires, which showed the high conservation in pathogenic leptospires. In these eleven OMPs, nine were found being strong reactivity with sera from patients with leptospirosis caused by L.interrogans strain Lai and by other pathogenic Leptospires by comparing the ELISA. Among these nine outer membrane proteins mentioned above three outer membrane proteins showed effective protective effect, in other words, guinea pigs had better survival treated with these three OMPs than with the other OMPs by the immunoprotection experiment. And then, these three OMPs were studied in immunology level. Antibodies against these three proteins by immunizing guinea pigs were detected by MAT, and 100% positive result of the protein encoded by LAO136 gene was...