Human T-cell clones against Toxoplasma gondii: production of interferon-gamma, interleukin-2, and strain cross-reactivity.
The soluble fraction from a sonicate of Toxoplasma gondii tachyzoites (termed F3) was shown to induce dose-dependent blastic transformation of peripheral-blood mononuclear cells (PBMC) from seropositive individuals only and was used to isolate a panel of T-cell clones from the PBMC of an immune donor. Proliferation assays using F3 showed that 15 (14 CD4+ and 1 CD8+) of the 18 isolated clones were specific for T. gondii. In response to antigen stimulation, 5 of the 15 clones produced detectable levels of interleukin-2 (IL-2, 0.2-15 u/ml) and 9 clones produced significant levels of interferon-gamma (IFN-gamma, 17.5-1400 IU/ml). Seven of the 7 T-cell clones tested reacted with two different Toxoplasma strains (RH and Wiktor). When used as antigen-presenting cells, an autologous B-lymphoblastoid cell line could efficiently present the antigen to only three of the six T-cell clones tested. This study identifies and characterizes cellular probes that could be useful for future vaccine design.
Service de Génétique Appliquée, Université Libre de Bruxelles, Belgium.
R
R
Saavedra
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P
Hérion
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002461:Cell Line, Transformed; D002999:Clone Cells; D003429:Cross Reactions; D004306:Dose-Response Relationship, Immunologic; D006801:Humans; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000096:biosynthesis*; D007376:Interleukin-2 / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D013601:T-Lymphocytes / Q000276:immunology*; D014122:Toxoplasma / Q000276:immunology*
D007376:Interleukin-2; D007371:Interferon-gamma