Immunoprotection of recombinant leptospiral immunoglobulin-like protein A against Leptospira interrogans serovar Pomona infection.
We previously reported the cloning and characterization of leptospiral immunoglobulin-like proteins LigA and LigB of Leptospira interrogans. LigA and LigB are conserved at the amino-terminal region but are variable at the carboxyl-terminal region. Here, we evaluate the potential of recombinant LigA (rLigA) as a vaccine candidate against infection by L. interrogans serovar Pomona in a hamster model. rLigA was truncated into conserved (rLigAcon) and variable (rLigAvar) regions and expressed in Escherichia coli as a fusion protein with glutathione-S-transferase (rLigA). Golden Syrian hamsters were immunized at 3 and 6 weeks of age with rLigA (rLigAcon and rLigAvar) with aluminum hydroxide as an adjuvant. Hamsters given recombinant glutathione-S-transferase (rGST)-adjuvant and phosphate-buffered saline-adjuvant served as nonvaccinated controls. Three weeks after the last vaccination, all animals were challenged intraperitoneally with 10(8) L. interrogans serovar Pomona bacteria (NVSL 1427-35-093002). All hamsters immunized with recombinant LigA survived after challenge and had no significant histopathological changes. In contrast, nonimmunized and rGST-immunized hamsters were subjected to lethal doses, and the hamsters that survived showed severe tubulointerstitial nephritis. All vaccinated animals showed a rise in antibody titers against rLigA. Results from this study indicate that rLigA is a potential vaccine candidate against L. interrogans serovar Pomona infection.
Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
Raghavan U M
RU
Palaniappan
Sean P
SP
McDonough
Thomas J
TJ
Divers
Chia-Sui
CS
Chen
Ming-Jeng
MJ
Pan
Mitsuharu
M
Matsumoto
Yung-Fu
YF
Chang
D000276:Adjuvants, Immunologic; D000818:Animals; D000942:Antigens, Bacterial / Q000008:administration & dosage* / Q000276:immunology; D006224:Cricetinae; D004195:Disease Models, Animal; D007136:Immunoglobulins; D007668:Kidney / Q000166:cytology; D041401:Leptospira interrogans serovar pomona / Q000276:immunology*; D007922:Leptospirosis / Q000276:immunology / Q000517:prevention & control*; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000276:immunology; D013205:Staphylococcal Protein A / Q000276:immunology*; D014614:Vaccines, Synthetic
D000276:Adjuvants, Immunologic; D000942:Antigens, Bacterial; D007136:Immunoglobulins; C487006:LigB-m protein, Leptospira interrogans; D011994:Recombinant Proteins; D013205:Staphylococcal Protein A; D014614:Vaccines, Synthetic