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Antigen Presentation by Toxoplasma gondii-Infected Cells to CD4 + Proliferative T Cells and CD8 + Cytotoxic Cells

1989; American Society of Parasitologists; Volume: 75; Issue: 3 Linguagem: Inglês

10.2307/3282598

1937-2345

Akihiko Yano, F Aosai, M. Ohta, Hayato HASEKURA, Kazuo Sugane, Shigeo Hayashi,

Herpesvirus Infections and Treatments

Cytotoxic cells specific for Toxoplasma gondii-infected cells were detected in the peripheral blood leukocytes from a patient with acute toxoplasmosis. The cytotoxicity was mediated by CD5+, CD4-, CD8+ cells. The cytotoxic T cells lysed Toxoplasma-infected target cells with HLA class I restriction. Two types of T cell clones were established from peripheral blood leukocytes of a patient with chronic toxoplasmosis; one was a CD5+, CD4-, CD8+ cytotoxic cell specific for Toxoplasma-infected cells, and the other was a CD5+, CD4+, CD8- proliferative cell that responded to Toxoplasma antigen. Toxoplasma-infected cell-specific cytotoxic cloned T cells recognize the infected target cells in the context of the HLA class I molecules, and the CD8 molecule was involved in the cytotoxicity. Toxoplasma antigen-specific proliferative cloned T cells were stimulated by Toxoplasma antigen-pulsed or Toxoplasma-infected cells in conjunction with HLA-DR molecule on the target cells. Thus, antigen presentation by Toxoplasma-infected cells for activation of both cytotoxic and proliferative T cells has been demonstrated.