A prime-boost strategy using the novel vaccine candidate, LemA, protects hamsters against leptospirosis

Clin Vaccine Immunol. 2013 May;20(5):747-52. doi: 10.1128/CVI.00034-13. Epub 2013 Mar 20.

Abstract

Toward developing an effective vaccine capable of conferring heterologous protection, the putative lipoprotein LemA, which presents an M3 epitope similar to that of Listeria, was evaluated as a vaccine candidate in the hamster model of leptospirosis. LemA is conserved (>70% pairwise identity) among the pathogenic Leptospira spp., indicating its potential in stimulating a cross-protective immune response. Using different vaccination strategies, including prime-boost, DNA vaccine, and a subunit preparation, recombinant LemA conferred different levels of protection in hamsters. Significant protection against mortality was observed for the prime-boost and the DNA vaccine strategies, which showed 87.5% (P < 0.01) and 62.5% (P < 0.05) efficacy, respectively. Although the subunit vaccine preparation protected 50.0% of immunized hamsters, the level of protection was not significant. None of the hamsters in the control groups survived challenge with a virulent strain of Leptospira interrogans serogroup Icterohaemorrhagiae. Characterization of the immune response found that the strongest antibody response was stimulated by the subunit vaccine preparation, followed by the prime-boost strategy. The DNA vaccine failed to elicit an antibody response in immunized hamsters.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Bacterial / biosynthesis
  • Antibodies, Bacterial / immunology
  • Antigens, Bacterial / immunology
  • Bacterial Proteins / administration & dosage
  • Bacterial Proteins / immunology*
  • Bacterial Vaccines / immunology*
  • Cricetinae
  • Disease Models, Animal
  • Immunization, Secondary
  • Leptospira interrogans serovar icterohaemorrhagiae / immunology*
  • Leptospirosis / immunology*
  • Leptospirosis / prevention & control
  • Transcription Factors / administration & dosage
  • Transcription Factors / immunology*
  • Vaccination
  • Vaccines, DNA / immunology
  • Vaccines, Subunit / immunology
  • Vaccines, Synthetic / immunology

Substances

  • Antibodies, Bacterial
  • Antigens, Bacterial
  • Bacterial Proteins
  • Bacterial Vaccines
  • Transcription Factors
  • Vaccines, DNA
  • Vaccines, Subunit
  • Vaccines, Synthetic
  • lemA protein, bacterial