Elimination of P. berghei liver stages is independent of Fas (CD95/Apo-I) or perforin-mediated cytotoxicity

Parasite Immunol. 1997 Mar;19(3):145-8. doi: 10.1046/j.1365-3024.1997.d01-190.x.

Abstract

Immunization of mammals with irradiated malaria sporozoites protects from a subsequent contact with the parasite. Protective immunity is directed against the pre-erythrocytic stages of the parasite, sporozoites and liver stages. Specific antibodies neutralize part of the infectious sporozoites infected by the mosquito vector, while liver stages are the target of a cellular immune response which is mediated by T cells. In this study, we evaluated the T-cell dependent protection induced by the infection of P. berghei irradiated sporozoites and the contribution of perforin and of the receptor/ligand system CD95/CD95L, two T cell-dependent mechanisms known to mediate elimination of target cells. Wild type, perforin deficient, CD95 mutant, CD95L mutant and perforin deficient/CD95L mutant mice were immunized with P. berghei irradiated sporozoites and submitted to a challenge with infectious sporozoites. All mice immunized with P. berghei irradiated sporozoites were protected against a sporozoite challenge, including perforin deficient/CD95L mutant animals. These results indicate that T cells do not kill malaria-infected hepatocytes via one of the known pathways, but rather that activated parasite-specific T cells produce cytokines which activate in cascade other mechanisms responsible for the intracellular elimination of the parasite.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cytotoxicity, Immunologic
  • Immunization
  • Liver / parasitology
  • Malaria / immunology
  • Malaria / parasitology
  • Malaria / prevention & control
  • Malaria Vaccines / immunology
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Perforin
  • Plasmodium berghei / growth & development
  • Plasmodium berghei / immunology*
  • Pore Forming Cytotoxic Proteins
  • T-Lymphocytes, Cytotoxic / immunology
  • fas Receptor* / genetics

Substances

  • Malaria Vaccines
  • Membrane Glycoproteins
  • Pore Forming Cytotoxic Proteins
  • fas Receptor
  • Perforin