title: Idiotypic determinants on T-cell subpopulations.
abstract: Killer T cells with specificity for major histocompatibility antigens have been shown in mice and rats to display idiotypic receptors allowing the lysis of such cells at the effector phase by anti-idiotypic antibodies and complement. A comparison was made between idiotypes displayed by Lyt-1-2+3+ and Lyt-1+2-3- T blasts, generated in the same mixed leucocyte culture (MLC), across an entire H-2 locus barrier. This was done by absorption of anti-idiotypic antibodies with respective T blasts, followed by estimation of the ability of the absorbed antiserum to inhibit MLC or killer T-cell function. Further, the capacity of Lyt-purified, MLC-generated T blasts to provoke specific unresponsiveness via anti-idiotypic immunity in syngeneic recipients was analyzed. Taken together, the results demonstrate that Lyt-1+2-3- T blasts responsible for the major part of MLC proliferation have distincly different idiotypes from those on the Lyt 1-2+3+ killer T cells. That the idiotypes on the killer T-cell presursors can serve as triggering sites for induction of effector T-cell function was then suggested by experiments with Lyt-1-2+3+-purified, normal T cells as precursor cells in vitro. The fact that autoanti-idiotypic antibodies may circumvent the need for helper Lyt-1+2-3- T cells in the generation of allospecific killer T cells indicates that the former cells may normally function partly via such anti-idiotypic reactions.
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic; D000918:Antibody Specificity; D000954:Antigens, Surface / Q000032:analysis; D001665:Binding Sites; D003602:Cytotoxicity, Immunologic; D000939:Epitopes; D006183:H-2 Antigens; D006649:Histocompatibility Antigens; D007130:Immunoglobulin Idiotypes / Q000032:analysis*; D007694:Killer Cells, Natural / Q000276:immunology; D008211:Lymphocyte Cooperation; D051379:Mice; D051381:Rats; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000954:Antigens, Surface; D000939:Epitopes; D006183:H-2 Antigens; D006649:Histocompatibility Antigens; D007130:Immunoglobulin Idiotypes