Intradermal NKT cell activation during DNA priming in heterologous prime-boost vaccination enhances T cell responses and protection against Leishmania

Eur J Immunol. 2008 Mar;38(3):706-19. doi: 10.1002/eji.200737660.

Abstract

Heterologous prime-boost vaccination employing DNA-vaccinia virus (VACV) modality using the Leishmania homologue of receptors for activated C kinase (LACK) (p36) antigen has been shown to elicit protective immunity against both murine cutaneous and visceral leishmaniasis. However, DNA priming is known to have limited efficacy; therefore in the current study the effect of NKT cell activation using alpha-galactosyl-ceramide (alphaGalCer) during intradermal DNAp36 priming was examined. Vaccinated mice receiving alphaGalCer + DNAp36 followed by a boost with VVp36 appeared to be resolving their lesions and had at ten- to 20-fold higher reductions in parasite burdens. NKT cell activation during alphaGalCer + DNAp36 priming resulted in higher numbers of antigen-reactive effector CD4(+) and CD8(+) T cells producing granzyme and IFN-gamma, with lower levels of IL-10. Although immunodepletion studies indicate that both CD4 and CD8 T cells provide protection in the vaccinated mice, the contribution of CD4(+) T cells was significantly increased in mice primed with DNAp36 together with alphaGalCer. Notably 5 months after boosting, mice vaccinated with DNAp36 + alphaGalCer continued to show sustained and heightened T cell immune responses. Thus, heterologous prime-boost vaccination using alphaGalCer during priming is highly protective against murine cutaneous leishmaniasis, resulting in the heightened activation and development of CD4 and CD8 T cells (effector and memory T cells).

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibody Formation / immunology
  • Antigens, Protozoan / genetics
  • Antigens, Protozoan / immunology
  • CD4-Positive T-Lymphocytes / immunology
  • CD4-Positive T-Lymphocytes / metabolism
  • CD8-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / metabolism
  • Galactosylceramides / immunology
  • Genetic Vectors / genetics
  • Granzymes / metabolism
  • Immunity, Cellular / immunology
  • Interferon-gamma / metabolism
  • Interleukin-10 / metabolism
  • Killer Cells, Natural / immunology*
  • Killer Cells, Natural / metabolism
  • Leishmaniasis / immunology
  • Leishmaniasis / pathology
  • Leishmaniasis / prevention & control*
  • Lymphocyte Activation / immunology*
  • Lymphocyte Depletion
  • Mice
  • Mice, Inbred BALB C
  • Mice, Mutant Strains
  • Nitric Oxide / metabolism
  • Protozoan Proteins / genetics
  • Protozoan Proteins / immunology
  • Skin / immunology
  • Skin / parasitology
  • Skin / pathology
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / metabolism
  • Vaccination / methods
  • Vaccines, DNA / immunology*
  • Vaccines, DNA / therapeutic use
  • Vaccinia virus / genetics

Substances

  • Antigens, Protozoan
  • Galactosylceramides
  • Protozoan Proteins
  • Vaccines, DNA
  • alpha-galactosylceramide
  • Interleukin-10
  • LACK antigen, Leishmania
  • Nitric Oxide
  • Interferon-gamma
  • Granzymes