Leptospira Conserved Antigens And Vaccines

Leptopirosis is an important,global human and veterinary health problem caused by pathogenic spirochetes belonging to the genus Leptospira.The severity of this acute febrile illness varies considerably from mild to rapidly fatal,and wide spectrum of symptoms makes clinical diagnosis very unreliable .Laboratory diagnosis and prevention are therefore of the utmost importance for controlling the disease.Commercially available inactivated leptospiral whole cell vaccines and outer membrane proteins vaccines at the stage of clinical test produce incomplete or only short erm immunity, couldn provide cross-protection.In order to study the better methods for diagnosis and prevention of leptospirosis ,four genes flaB,ompLl,lipL4l&lipL32 from Chinese unique Leptospira serovar linhai(56609) encoding the flagellar protein B(F1aB),outer membrane protein 1 (OmpLl ),lipoprotein 41 (LipL4l)and lipoprotein 32 (LipL32)respectively were cloned, sequenced ,ana]ysed and expressed in E.coli;three kind of DNA vaccines pcD-flaB~. pcD-ompLl&pcD-lipL4l were constructed .Protective immunity assay was done in guinea-pigs,mice and young pigs ,and DNA integration test was done in mice and guinea pigs ;lipL32-based PCR was analysed to detect the pathogenic leptospires in pigs kidneys.The results are as follows:(i)the four genes were successfully cloned, and GST-F1aB,GST-LipL4l and GST-LipL32 were expressed in E.coli;(ii).the three kinds of DNA vaccines could provide different degree protection from leptospiral infection ,pcD-flaB showed the best protection effects of the three vaccines ,it didn only provide protection from the same serovar of Leptospira infection ,but also provided protection from the different leptospira serovars of Leptospira infection;(iii)DNA vaccine pcD-flaB showed longer antibody duration than inactivated vaccine and subunit vaccine GST-F1aB;(iv)DNA vaccine pcD-flaB induced both humoral immune response and Thl immune response;(v)integration of DNA vaccine pcD-flaB with genome DNA was not detected by PCR ;(vi)lipL32-based PCR could detect leptospires specificly. 3 It showed that DNA vaccine pcD-flaB has better efficacy and safety ,may serve as one of new hopeful vaccine in future ,lipL32-based PCR is hopeful for diagnosis of pathogenic Leptospira species.