Differential effector pathways regulate memory CD8 T cell immunity against Plasmodium berghei versus P. yoelii sporozoites

J Immunol. 2010 Mar 1;184(5):2528-38. doi: 10.4049/jimmunol.0903529. Epub 2010 Jan 22.

Abstract

Malaria results in >1,000,000 deaths per year worldwide. Although no licensed vaccine exists, much effort is currently focused on subunit vaccines that elicit CD8 T cell responses directed against Plasmodium parasite liver stage Ags. Multiple immune-effector molecules play a role in antimicrobial immunity mediated by memory CD8 T cells, including IFN-gamma, perforin, TRAIL, Fas ligand, and TNF-alpha. However, it is not known which pathways are required for memory CD8 T cell-mediated immunity against liver stage Plasmodium infection. In this study, we used a novel immunization strategy to generate memory CD8 T cells in the BALB/c mouse model of P. berghei or P. yoelii sporozoite infection to examine the role of immune-effector molecules in resistance to the liver stage infection. Our studies reveal that endogenous memory CD8 T cell-mediated protection against both parasite species is, in part, dependent on IFN-gamma, whereas perforin was only critical in protection against P. yoelii. We further show that neutralization of TNF-alpha in immunized mice markedly reduces memory CD8 T cell-mediated protection against both parasite species. Thus, our studies identify IFN-gamma and TNF-alpha as important components of the noncytolytic pathways that underlie memory CD8 T cell-mediated immunity against liver stage Plasmodium infection. Our studies also show that the effector pathways that memory CD8 T cells use to eliminate liver stage infection are, in part, Plasmodium species specific.

Publication types

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

MeSH terms

  • Animals
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / metabolism
  • Culicidae / parasitology
  • Dendritic Cells / immunology
  • Dendritic Cells / metabolism
  • Fas Ligand Protein / immunology
  • Fas Ligand Protein / metabolism
  • Female
  • Immunologic Memory / immunology
  • Interferon-gamma / deficiency
  • Interferon-gamma / genetics
  • Interferon-gamma / immunology
  • Listeria monocytogenes / immunology
  • Liver Diseases, Parasitic / immunology
  • Liver Diseases, Parasitic / parasitology
  • Malaria / immunology*
  • Malaria / parasitology
  • Malaria / prevention & control
  • Malaria Vaccines / administration & dosage
  • Malaria Vaccines / immunology*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Knockout
  • Perforin / deficiency
  • Perforin / genetics
  • Perforin / immunology
  • Plasmodium berghei / immunology*
  • Plasmodium yoelii / immunology*
  • Signal Transduction / immunology
  • Sporozoites / immunology*
  • TNF-Related Apoptosis-Inducing Ligand / deficiency
  • TNF-Related Apoptosis-Inducing Ligand / genetics
  • TNF-Related Apoptosis-Inducing Ligand / immunology
  • Tumor Necrosis Factor-alpha / immunology
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Fas Ligand Protein
  • Fasl protein, mouse
  • Malaria Vaccines
  • TNF-Related Apoptosis-Inducing Ligand
  • Tnfsf10 protein, mouse
  • Tumor Necrosis Factor-alpha
  • Perforin
  • Interferon-gamma