Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: 5/23/1996
Publication Date: N/A
Technical Abstract: The survival of pathogenic Leptospira involves adaptation between two different environments: inside the host and the outside environment. Experiments were conducted to evaluate environmental regulation of leptospiral outer membrane protein (OMP) expression. Genes encoding four OMPs of L. kirschneri were cloned and sequenced. Rabbit antiserum specific for each of these OMPs was generated with recombinant His6-OMP fusion proteins. Immunoblot analysis revealed that OmpL1, LipL36, and LipL41 were expressed by L. kirschneri grown in Johnson-Harris bovine serum albumin Tween-80 medium, while OmpL2 was not. To determine which leptospiral OMPs were expressed in vivo we studied the humoral immune response of hamsters infected with virulent, culture-adapted or host-adapted L. kirschneri. During the acute phase of infection, numerous spirochetes were detected in the liver and kidney. During the convalescent phase of infection, organisms were found within renal tubules. Serum from hamsters surviving after challenge contained antibodies to all four OMPs. However, hamsters infected with host-adapted L. kirschneri had a weaker antibody response to LipL36 and leptospiral oligosaccharide than hamsters infected with culture- both in vivo and in vitro, OmpL2 expression was upregulated in vivo, and LipL36 expression was down-regulated in vivo.