Isolation and functional characterization of murine T cell lines and clones specific for the protozoan parasite Trypanosoma cruzi.
Murine T cell lines responsive to the protozoan parasite Trypanosoma cruzi were generated in vitro by stimulating hyperimmune C57BL/6 lymphoid cells with trypomastigote stage antigen. A spleen-derived line designated ST1 and eight clones derived from ST1 were characterized. All lines bear the surface phenotype Thy-1.2+, Ly-1.2+, 2.2- and respond to T. cruzi antigen only in the presence of antigen-presenting cells matched at the I-A subregion of the H2 locus. Clonal specificity analyses indicated that these T. cruzi-selected T cells are species specific and recognize antigenic determinants that are expressed predominantly in the trypomastigote stage. On the basis of their distinct patterns of response to a panel of different T. cruzi strains, clones recognizing strain-specific, shared, or common determinants were identified. Functional studies indicated that ST1 and some but not all of the clones are capable of expressing antigen-specific T helper function in vitro and in vivo. In addition, co-incubation of T. cruzi-specific T cells with cultured T. cruzi-infected syngeneic macrophages led to the dose-dependent destruction of intracellular parasites. Most notably, ST1 and several of the cloned T. cruzi-specific T cell lines were able to passively protect syngeneic recipients from lethal T. cruzi challenge infection. Efforts to identify the parasite antigens recognized by these T cell lines, particularly the protective clones, are currently in progress.
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology*; D002460:Cell Line; D002999:Clone Cells; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D007116:Immunization, Passive; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D013045:Species Specificity; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D014301:Trinitrobenzenes / Q000276:immunology; D014349:Trypanosoma cruzi / Q000276:immunology*
D000953:Antigens, Protozoan; D000949:Histocompatibility Antigens Class II; D014301:Trinitrobenzenes