title: Complete protection against Plasmodium yoelii by adoptive transfer of a CD8+ cytotoxic T-cell clone recognizing sporozoite surface protein 2.
abstract: BALB/c mice immunized with irradiated Plasmodium yoelii sporozoites produce antibodies and cytotoxic T lymphocytes against the circumsporozoite protein and against a 140-kDa protein, sporozoite surface protein 2 (PySSP2). Approximately 50% of mice immunized with P815 cells transfected with the gene encoding PySSP2 are protected against malaria, and this protection is reversed by in vivo depletion of CD8+ T cells. To determine if CD8+ T cells against PySSP2 are adequate to protect against malaria in the absence of other malaria-specific immune responses, we produced three CD8+ T-cell clones by stimulating spleen cells from mice immunized with irradiated P. yoelii sporozoites with a mitomycin-treated P815 cell clone transfected with the PySSP2 gene. Adoptive transfer of clone TSLB7 protected 100% of mice against P. yoelii. The second clone protected 58% of mice, and the third clone provided no protection. Clone TSLB7 protected even when administered 3 h after sporozoite inoculation at a time when sporozoites had entered hepatocytes, suggesting that it is recognizing and eliminating infected hepatocytes. These studies demonstrate that cytotoxic T lymphocytes against PySSP2 can protect against P. yoelii sporozoite challenge in the absence of other parasite-specific immune responses.
authors.affiliation: Malaria Program, Naval Medical Research Institute, Bethesda, Maryland 20889-5607.
authors.forename: S
authors.initials: S
authors.lastname: Khusmith
authors.forename: M
authors.initials: M
authors.lastname: Sedegah
authors.forename: S L
authors.initials: SL
authors.lastname: Hoffman
mesh_terms: D000818:Animals; D016827:CD8 Antigens / Q000276:immunology; D002999:Clone Cells; D005260:Female; D016219:Immunotherapy, Adoptive / Q000379:methods*; D007371:Interferon-gamma / Q000096:biosynthesis; D007378:Interleukins / Q000096:biosynthesis; D008288:Malaria / Q000276:immunology / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D010967:Plasmodium yoelii / Q000276:immunology*; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
chemical_list: D016827:CD8 Antigens; D007378:Interleukins; D015800:Protozoan Proteins; D011994:Recombinant Proteins; C076139:sporozoite-surface protein 2, Plasmodium yoelli; D007371:Interferon-gamma