Antigen-specific CD8+ T cell clone protects against acute Toxoplasma gondii infection in mice.
Encephalitis caused by the obligate intracellular protozoan, Toxoplasma gondii, is a major cause of morbidity and mortality in those afflicted with AIDS. The cell-mediated response is critical for host immunity against this parasite. A panel of T cell clones that proliferate in response to a major parasite protein, p30 (SAG-1) were isolated from mice. One of these clones (C3) bearing the CD8+ phenotype was able to induce nearly 100% protection against acute infection when adoptively transferred into naive mice. In contrast, an Ag-specific CD4+ T cell clone (C2) failed to show significant protection in spite of its ability to produce similar quantities of IFN-gamma. Depletion of host CD4+ T cells with mAb had no effect on CD8(+)-mediated adoptive protection, whereas treatment with anti-IFN-gamma completely abrogated this protection. These results indicate that Ag-specific CD8+ T cells in combination with IFN-gamma are able to induce significant protection against acute toxoplasmosis in the experimental murine model.
Khan
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Department of Microbiology, Dartmouth Medical School, Hanover, NH 03756.
Ely
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Kasper
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D000208:Acute Disease; D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology; D016827:CD8 Antigens / Q000032:analysis*; D002999:Clone Cells; D016207:Cytokines / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D015800:Protozoan Proteins / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D014124:Toxoplasmosis, Animal / Q000517:prevention & control*
D000953:Antigens, Protozoan; D016827:CD8 Antigens; D016207:Cytokines; D015800:Protozoan Proteins; C047168:SAG1 antigen, Toxoplasma