Immunization with Leishmania infantum released proteins confers partial protection against parasite infection with a predominant Th1 specific immune response

Vaccine. 2007 Jun 6;25(23):4525-32. doi: 10.1016/j.vaccine.2007.04.003. Epub 2007 Apr 19.

Abstract

In this study, protective effect and immune response elicited by protein fractions LiRic1 (>75 kDa) and LiRic2 (<37 kDa) released by Leishmania infantum promastigotes were analysed in challenged BALB/c mice. Viable parasites were quantified in spleen and isolated CD4(+) and CD8(+) T cells were stimulated for evaluation of proliferative response and cytokine production. Immunization triggered 50.4-66.9% of parasite reduction. Stimulated CD4(+) T cells from challenged animals revealed high proliferation. IL-12 and IFN-gamma were released by CD4(+) T cells whereas IL-4 and IL-10 were impaired. LiRic1 and LiRic2 immunization gave partial protection and a CD4(+) Th1 response. LiRic2 generated IL-12 by CD8(+) T cells pointing to its participation in protective response. These results encourage further research on the development of a vaccine that provides long-lasting protection against zoonotic visceral leishmaniasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD4-Positive T-Lymphocytes / immunology
  • Immunization*
  • Interferon-gamma / biosynthesis
  • Interleukin-12 / biosynthesis
  • Leishmania infantum / immunology*
  • Leishmaniasis, Visceral / immunology
  • Leishmaniasis, Visceral / prevention & control*
  • Lymphocyte Activation
  • Mice
  • Mice, Inbred BALB C
  • Protozoan Proteins / immunology*
  • Spleen / parasitology
  • Th1 Cells / immunology*

Substances

  • Protozoan Proteins
  • Interleukin-12
  • Interferon-gamma