title: Cross-reactive recognition by antigen-specific, major histocompatibility complex-restricted T cells of a mitogen derived from Mycoplasma arthritidis is clonally expressed and I-E restricted.
abstract: In order to determine whether or not the major histocompatibility complex (MHC)-encoded restriction element used by a T cell in the recognition of its primary antigen affected its ability to be cross-reactively stimulated by MAS (a soluble product of Mycoplasma arthritidis), a panel of cloned, soluble antigen-specific I-A- and I-E-restricted T cells were tested for their ability to cross-reactively recognize and respond to MAS. Initial studies indicated that all of the cloned T cells tested were capable of responding to MAS in the presence of genetically E alpha E beta-expressing (I-E+), but not E alpha E beta-non-expressing (I-E-) accessory cells (AC). However, subsequent studies demonstrated that the ability of most of these T cell clones to mount proliferative responses to MAS in the presence of I-E+ AC was dependent upon the presence of Lyt-1+2- T cells in the irradiated spleen cells which were used as AC sources. When T cell-depleted, I-E+ populations of spleen cells or an I-E+ antigen-presenting line (WEHI-5) were used as AC sources, only 6 of the 34 clones tested were found to be directly responsive to MAS. Subsequent to stimulation by MAS plus I-E product, these MAS-reactive T cell clones were capable of "recruiting" bystander T cells to proliferate. Finally, the ability of a given T cell clone to respond to MAS plus I-E product did not appear to be influenced by the restriction element used by that clone in its response to other antigens since both I-A-restricted and I-E-restricted T cell clones were responsive to MAS plus I-E in equivalent proportions. Thus, the data presented indicated that I-E-restricted T cell reactivity to MAS is a clonally expressed property of T cells that is independent of their conventional antigen specificities and MHC restriction patterns.
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D002999:Clone Cells / Q000276:immunology; D003429:Cross Reactions; D006649:Histocompatibility Antigens / Q000276:immunology; D000949:Histocompatibility Antigens Class II; D008285:Major Histocompatibility Complex; D051379:Mice; D008815:Mice, Inbred Strains / Q000276:immunology; D008934:Mitogens / Q000276:immunology* / Q000302:isolation & purification; D009174:Mycoplasma / Q000032:analysis*; D013601:T-Lymphocytes / Q000276:immunology* / Q000528:radiation effects
chemical_list: D006649:Histocompatibility Antigens; D000949:Histocompatibility Antigens Class II; C024138:I-E-antigen; D008934:Mitogens