The IL-6-deficient mouse exhibits impaired lymphocytic responses to a vaccine combining live Leishmania major and CpG oligodeoxynucleotides

Can J Microbiol. 2009 Jun;55(6):705-13. doi: 10.1139/w09-017.

Abstract

We have previously reported that vaccination with CpG oligodeoxynucleotides delivered concomitantly with live Leishmania major (Lm/CpG) eliminates lesions associated with live vaccination in C57BL/6 mice. The absence of lesions is at least in part a result of the CpG DNA-mediated activation of dermal dendritic cells to produce cytokines such as interleukin (IL)-6. Wild-type C57BL/6 mice and IL-6-/- mice were immunized with the Lm/CpG vaccine and monitored for the development of lesions. IL-6-/- mice developed extensive, nonhealing lesions following live vaccination. The analysis of the inoculation site and draining lymph nodes of the IL-6-/- mice revealed a constitutive reduction in lymphocyte numbers, particularly CD4+ T cells. Live vaccination resulted in the specific expansion of CD4+Foxp3+ regulatory T cells in the knockout mice, and in a decrease of CD4+ IFN-gamma -producing cells. These results indicate that IL-6-/- mice may have collateral immune defects that could influence the development of the natural immune response to pathogens, vaccines, or other inflammatory stimuli.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Interleukin-6 / deficiency*
  • Interleukin-6 / genetics
  • Leishmania major / immunology*
  • Leishmaniasis, Cutaneous / immunology*
  • Leishmaniasis, Cutaneous / parasitology
  • Lymphocyte Count
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Oligodeoxyribonucleotides / administration & dosage
  • Oligodeoxyribonucleotides / immunology*
  • Protozoan Vaccines / administration & dosage
  • Protozoan Vaccines / immunology*
  • Vaccination
  • Vaccines, Attenuated / administration & dosage
  • Vaccines, Attenuated / immunology

Substances

  • CPG-oligonucleotide
  • Interleukin-6
  • Oligodeoxyribonucleotides
  • Protozoan Vaccines
  • Vaccines, Attenuated