title: Induction of minor alloantigen-specific T cell subsets in vivo: recognition of processed antigen by helper but not by cytotoxic T cell precursors.
abstract: Primary cytotoxic T lymphocyte (CTL) and helper T (Th) cell responses were generated from regional lymph nodes of heterozygous mice sensitized in the footpad with spleen cells of parental H-2 genotype but differing for multiple minor alloantigens of the B10 background. Cytotoxic and helper responses were read after a short in vitro culture period, which did not influence the restriction specificities of in vivo sensitized T cells. We show that under these conditions, Th cell responses appear unrestricted, whereas CTL responses are restricted to the immunizing parental H-2 genotype. Furthermore, we present evidence that these two functions are mediated by distinct T cell subsets and that the in vivo induction of Lyt-2- Th cells has the appearance of being unrestricted whereas that of Lyt-2+ CTL is restricted by H-2. These findings suggest that in a primary immune response, in vivo precursors of Th cells recognize processed antigen on F1 antigen-presenting cells (clones restricted to each parental H-2 genotype are cross-sensitized) under conditions in which those of CTL only respond directly to foreign minor alloantigens on the injected stimulator cells (clones restricted to parental H-2 genotypes are not cross-immunized). This dichotomy is taken to suggest the possibility that processing of cell membrane-bound antigens is controlled at their association step with products of the major histocompatibility complex.
mesh_terms: D000818:Animals; D000950:Antigens, Ly / Q000235:genetics; D000954:Antigens, Surface / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D000939:Epitopes / Q000235:genetics / Q000276:immunology; D006183:H-2 Antigens / Q000235:genetics; D007376:Interleukin-2 / Q000502:physiology; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D008912:Minor Histocompatibility Loci; D013234:Stem Cells / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D000950:Antigens, Ly; D000954:Antigens, Surface; D000939:Epitopes; D006183:H-2 Antigens; D007376:Interleukin-2