Journal of Vaccines & Vaccination

Abstract

Failure of LIC13435 Protein of Leptospira interrogans Serovar Copenhageni to Confer Protection in Immunized Hamsters

Vivian L Hashimoto, Zenaide M Moraes, Amane P Gonçales, Silvio A Vasconcellos and Paulo L Ho

Leptospirosis is a re-emergent zoonosis characterized by an acute febrile and systemic illness in humans caused by pathogenic spirochetes belonging to the genus Lepstospira. This disease has global distribution, and it is more frequent in tropical and subtropical areas. The complete genomic sequence of Leptospira species offered the possibility to identify potential vaccine candidates for leptospirosis, since environmental control measures are difficult to implement and there is not an ideal vaccine available for human use. Secreted and surface exposed molecules are potential targets for inducing protective immune response in the host. Although we selected six predicted sequences coding for putative outer membrane proteins with unknown function to be analyzed as vaccinal candidates against leptospirosis and for biological characterization, only the lic13435 gene was expressed and purified. The lic13435 gene is specific for pathogenic leptospires suggesting a possible virulence and/or pathogenicity associated function. The recombinant protein was purified and tested as vaccine candidate against leptospirosis. The immunization with the recombinant protein was able to produce a significant immune response in hamsters. Nevertheless, the animals were not protected against leptospirosis.