Brugia malayi: comparison of protective immune responses induced by Bm-alt-2 DNA, recombinant Bm-ALT-2 protein and prime-boost vaccine regimens in a jird model

Exp Parasitol. 2007 Aug;116(4):483-91. doi: 10.1016/j.exppara.2007.02.017. Epub 2007 Mar 6.

Abstract

Immunization of jirds with Bm-alt-2 elicited partial protection against challenge infection with the filarial parasite Brugia malayi. In this study, we initially compared the protective immune responses elicited following immunization with recombinant Bm-ALT-2 protein regimen and Bm-alt-2 DNA regimen. These studies showed that protein vaccination conferred approximately 75% protection compared to DNA vaccination that conferred only 57% protection. Analysis of the protective immune responses showed that the protein immunization promoted a Th2-biased response with an increase in IL-4, IL-5 and IgG1 responses, whereas, the DNA vaccine promoted a Th1-biased response with profound IFN-gamma and IgG2a responses. Since protein vaccination gave better results than DNA vaccination, we then wanted to evaluate whether a prime-boost vaccination that combined DNA prime and protein boost will significantly increase the protective responses induced by the protein vaccine. Our results suggest that prime-boost vaccination had no added advantage and was comparatively less effective (64% protection) than the Bm-ALT-2 protein alone vaccination. Prime boost vaccination generated mixed Th1/Th2 responses with a slightly diminished Th2 responses compared to protein vaccination. Thus, our results suggest that Bm-ALT-2 protein vaccination regimen may be slightly better than prime-boost vaccine regimen and the mechanism of protection appears to be largely mediated by a Th2-biased response.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Helminth / biosynthesis*
  • Antibodies, Helminth / blood
  • Antigens, Helminth / genetics
  • Antigens, Helminth / immunology*
  • Brugia malayi / immunology*
  • Cytokines / biosynthesis
  • Cytokines / genetics
  • DNA, Helminth / immunology
  • Diffusion Chambers, Culture
  • Disease Models, Animal
  • Elephantiasis, Filarial / prevention & control*
  • Gerbillinae
  • Helminth Proteins / genetics
  • Helminth Proteins / immunology*
  • Immunity, Cellular
  • Immunization / methods
  • Lymphocyte Activation
  • Male
  • Recombinant Proteins / genetics
  • Recombinant Proteins / immunology*
  • Th2 Cells / immunology
  • Vaccines / immunology*
  • Vaccines, DNA / immunology
  • Vaccines, Synthetic / immunology

Substances

  • ALT-2 protein, Brugia malayi
  • Antibodies, Helminth
  • Antigens, Helminth
  • Cytokines
  • DNA, Helminth
  • Helminth Proteins
  • Recombinant Proteins
  • Vaccines
  • Vaccines, DNA
  • Vaccines, Synthetic