Murine CD8+ cytotoxic T lymphocytes lyse Toxoplasma gondii-infected cells.
Studies were performed to determine whether CTL against Toxoplasma gondii-infected cells could be induced in a murine model of T. gondii infection in which CD8+ T lymphocytes have been shown to play a major role in resistance against this parasite. In 51Cr release assays, nylon wool nonadherent spleen cells from BALB/c (H-2d) mice immunized with the temperature-sensitive (ts-4) mutant strain of T. gondii were cytotoxic for T. gondii-infected P815 (H-2d) mastocytoma cells but not for uninfected cells. This cytotoxic activity was remarkably increased after in vitro stimulation with T. gondii-infected syngeneic spleen cells. The effector cells were shown to be CD8+ T lymphocytes, because the cytotoxicity was significantly inhibited by depletion of CD8+ T lymphocytes but not by depletion of CD4+ T lymphocytes. This cytotoxic activity was genetically restricted. Spleen cells from T. gondii-immune BALB/c mice were not cytotoxic for T. gondii-infected EL4 (H-2b) thymoma cells, whereas spleen cells from T. gondii-immune C57B1/6 (H-2b) mice were cytotoxic for T. gondii-infected EL4 cells but not for T. gondii-infected P815 cells. The cytolytic activity of CD8+ T lymphocytes against T. gondii-infected cells might be a mechanism whereby these cells confer resistance against T. gondii.
Department of Immunology and Infectious Diseases, Palo Alto Medical Foundation, CA 94301.
C S
CS
Subauste
A H
AH
Koniaris
J S
JS
Remington
D000818:Animals; D016827:CD8 Antigens / Q000032:analysis*; D003602:Cytotoxicity, Immunologic; D007111:Immunity, Cellular; D066298:In Vitro Techniques; D051379:Mice; D008815:Mice, Inbred Strains; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014122:Toxoplasma / Q000276:immunology*
D016827:CD8 Antigens