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BioMed Research International
Volume 2014 (2014), Article ID 564285, 11 pages
Research Article

Induction of Boosted Immune Response in Mice by Leptospiral Surface Proteins Expressed in Fusion with DnaK

1Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil 1500, 05503-900 São Paulo, SP, Brazil
2Programa Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, USP, Avenida Professor Lineu Prestes 1730, 05508-900 São Paulo, SP, Brazil

Received 20 February 2014; Accepted 6 June 2014; Published 6 July 2014

Academic Editor: Armando Acosta

Copyright © 2014 Marina V. Atzingen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Leptospirosis is an important global disease of human and veterinary concern. Caused by pathogenic Leptospira, the illness was recently classified as an emerging infectious disease. Currently available veterinarian vaccines do not induce long-term protection against infection and do not provide cross-protective immunity. Several studies have suggested the use of DnaK as an antigen in vaccine formulation, due to an exceptional degree of immunogenicity. We focused on four surface proteins: rLIC10368 (Lsa21), rLIC10494, rLIC12690 (Lp95), and rLIC12730, previously shown to be involved in host-pathogen interactions. Our goal was to evaluate the immunogenicity of the proteins genetically fused with DnaK in animal model. The chosen genes were amplified by PCR methodology and cloned into pAE, an E. coli vector. The recombinant proteins were expressed alone or in fusion with DnaK at the N-terminus. Our results demonstrate that leptospiral proteins fused with DnaK have elicited an enhanced immune response in mice when compared to the effect promoted by the individual proteins. The boosted immune effect was demonstrated by the production of total IgG, lymphocyte proliferation, and significant amounts of IL-10 in supernatant of splenocyte cell cultures. We believe that this approach could be employed in vaccines to enhance presentation of antigens of Leptospira to professional immune cells.