title: Induction of murine cytotoxic T lymphocytes against Plasmodium falciparum sporozoite surface protein 2.
abstract: Sporozoite surface protein 2 has been identified as a target of malaria vaccines designed to produce protective CD8+ cytotoxic T lymphocytes (CTL) because mice immunized with mastocytoma cells expressing a fragment of Plasmodium yoelii sporozoite surface protein 2 (PySSP2) are protected against malaria by an immune response that requires CD8+ CTL. To define CTL epitopes in the Plasmodium falciparum sporozoite surface protein 2 (PfSSP2), spleen cells (SC) from mice immunized with irradiated sporozoites (irr spz) were stimulated with synthetic peptides, and these effectors were tested for cytolytic activity against peptide-pulsed, major histocompatibility complex (MHC)-matched targets. Two peptides containing CTL epitopes, A6 (Pf SSP2 3D7 214-233) and BH1 (Pf SSP2 3D7 3-11) were identified in bulk cultures of SC from immune C57BL/6 mice, and by production of CTL lines. Immunization with recombinant vaccinia expressing the full length PfSSP2 induced antigen specific, MHC-restricted, CD8+ T cell-dependent cytolytic activity against these two peptides. Finally, CTL were induced by immunization with a bacteria-derived recombinant fragment of PfSSP2 (rPfSSP2) mixed with a liposomal formulation containing a cationic lipid (Lipofectin Reagent, LPF). Induced CTL lysed target cells pulsed with peptide A6 or with LPF/rPfSSP2, but not targets pulsed with only rPfSSP2. These studies demonstrate that CTL specific to PfSSP2 are present in C57BL/6 mice and that immunization with purified rPfSSP2 delivered with LPF induces a cytotoxic T cell response.
authors.affiliation: Malaria Program, Naval Medical Research Institute, Bethesda, MD.
authors.forename: B
authors.initials: B
authors.lastname: Wizel
authors.forename: W O
authors.initials: WO
authors.lastname: Rogers
authors.forename: R A
authors.initials: RA
authors.lastname: Houghten
authors.forename: D E
authors.initials: DE
authors.lastname: Lanar
authors.forename: J A
authors.initials: JA
authors.lastname: Tine
authors.forename: S L
authors.initials: SL
authors.lastname: Hoffman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016827:CD8 Antigens; D003601:Cytotoxicity Tests, Immunologic; D000939:Epitopes; D005260:Female; D007114:Immunization / Q000379:methods; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010714:Phosphatidylethanolamines / Q000276:immunology; D010963:Plasmodium falciparum / Q000276:immunology*; D015800:Protozoan Proteins / Q000276:immunology*; D011994:Recombinant Proteins; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014407:Tumor Cells, Cultured; D014616:Vaccinia virus / Q000235:genetics
chemical_list: D016827:CD8 Antigens; D000939:Epitopes; D010714:Phosphatidylethanolamines; D015800:Protozoan Proteins; D011994:Recombinant Proteins; C069428:thrombospondin-related adhesive protein, protozoan; C020888:1,2-dielaidoylphosphatidylethanolamine