Clonal analysis of B and T cell responses to Ia antigens. IV. Proliferative T cell clones recognizing E beta and/or E alpha allodeterminants.
The allospecific T cell recognition of the I-Ek molecule was assessed by using eight A. TH anti-A. TL proliferative T cell clones, all of which expressed the Thy-1-2+, Lyt-1+, Lyt-2-, Ia-, and p94,180+ cell surface phenotype. The use of panels of stimulating cells from homozygous of F1 hybrid strains indicated each T cell clone exhibited specificity for distinct alloactivating determinants including: i) a private E beta k-controlled determinant expressed in cis- or trans-complementing E beta kE alpha strains; ii) an apparently nonpolymorphic E alpha determinant resembling the serologic specificity Ia.7, i.e., present in all strains carrying E alpha and E beta expressor alleles; and iii) a series of conformational I-E determinants, the expression of which required a precisely defined combinatorial association of E beta plus E alpha chains. Two clones were found to be reactivated by cis- but not trans-complementing E beta k E alpha k strains, and another recognized an allodeterminant shared by the I-Ab molecule. Various I-Ek-reactive monoclonal antibodies (mAb) directed to epitopes presumably expressed on either E alpha (epitope clusters I and II) or E beta (epitope cluster III) chains inhibited the proliferative responses of seven clones recognizing private E beta k or unique E beta E alpha conformational activating determinants. By contrast, the restimulation of the clone directed to a nonpolymorphic E alpha determinant was selectively blocked by anti-Ia.7 mAb defining epitopes on the E alpha chains but not by those directed to the E beta chain. On the basis of these data, it was concluded that the recognition sites of most anti-I-Ek proliferative T cells were expressed on the E beta chain or the E beta plus E alpha interaction products, and that a minority of such alloreactive T cells could be activated through recognition of the E alpha chain per se.
D000483:Alleles; D000818:Animals; D000911:Antibodies, Monoclonal / Q000502:physiology; D001402:B-Lymphocytes / Q000276:immunology; D002999:Clone Cells / Q000276:immunology; D000939:Epitopes / Q000235:genetics*; D005260:Female; D006649:Histocompatibility Antigens / Q000235:genetics / Q000276:immunology*; D000949:Histocompatibility Antigens Class II; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D010641:Phenotype; D051381:Rats; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000939:Epitopes; D006649:Histocompatibility Antigens; D000949:Histocompatibility Antigens Class II; C024138:I-E-antigen