Evaluation of Lsa46 and Lsa77 Leptospiral Proteins for Their Immunoprotective Activities in Hamster Model of Leptospirosis

Author(s)

Teixeira, Aline F. ; Fernandes, Luis G. V. ; Souza Filho, Antonio ; Souza, Gisele O. ; Vasconcellos, Silvio A. ; Heinemann, Marcos B. ; Nascimento, Ana L. T. O.

• Document type: Journal article
• Source: BIOMED RESEARCH INTERNATIONAL; v. 2018, p. 13-pg., 2018-01-01.

Abstract

Leptospirosis is a neglected tropical disease caused by pathogenic Leptospira spp. The lack of an effective vaccine favors the increase of the disease. Currently, surface-exposed proteins are the main targets for the search of vaccine candidates. In this study, we examined whether the surface Lsa46 and Lsa77 proteins, previously identified as laminin and plasminogen binding proteins, have the capacity of inducing protection and sterilizing immunity against challenge with virulent Leptospira in hamster model. Animals were subcutaneously immunized with Lsa46, Lsa77, or a combination of both in Alum adjuvant and challenged intraperitoneally with L. interrogans serovar Kennewicki strain Pomona Fromm. Hamster immunization with Lsa46 or Lsa77 or both promoted a strong IgG response. Th2- and Th1-biased immune responses were observed when Lsa46 and Lsa77 were individually administered, respectively, as detected by the IgG1/IgG2/3 ratio. Immunized hamsters with the combined proteins induced a Th1-biased immune response. Although the immunization with Lsa46 and Lsa77 stimulated protective immunity with reduction of bacterial burden, when compared to animals individually immunized with the proteins, the data was not statistically significant. Thus, although promising, more studies are needed before the role of these proteins in stimulating sterilizing immunity in mammals is conclusively determined. (AU)

• FAPESP's process: 14/50981-0 - Search for surface proteins among the genome sequences of Leptospira interrogans: functional and immunological characterization to understanding mechanisms involved in the bacterial pathogenesis
• Grantee: Ana Lucia Tabet Oller do Nascimento
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/11541-0 - Evaluation of the vaccine potential of antigenic fractions obtained in Leptospira interrogans serovar Copenhageni using hamsters as an animal model
• Grantee: Aline Florencio Teixeira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 17/06731-8 - Application of CRISPR-interference for elucidating leptospirosis pathogenesis and development of novel strategies for knockout mutant's obtainment
• Grantee: Luis Guilherme Virgílio Fernandes
• Support Opportunities: Scholarships in Brazil - Post-Doctoral