Arsonate-specific murine T cell clones. V. Antigen presentation by L cells transfected with normal and mutant class II genes.
Class II-restricted murine T cell clones specific for the immunogenic determinant L-tyrosine-p-azobenzenearsonate failed to proliferate to Ag presented by L cell lines transfected with and expressing the appropriate class II genes, but are activated to kill the APC in an Ag-dependent, MHC-restricted manner. Inhibition of APC proliferation was used as an assay to determine the relative contributions of polymorphic sites on the class II alpha- and beta-chains to MHC-restricted activation of I-A beta k-restricted cloned T cells. Transfectants expressing A beta k in conjunction with the alpha chain of k, u, or d were equally effective APCs, whereas transfectants expressing A beta u were completely ineffective, implicating the beta-chain as more critical for the presentation of L-tyrosine-p-azobenzenearsonate. Site-directed mutagenesis of polymorphic positions in the beta chain revealed a remarkable stringency for the k haplotype, in contrast to the relaxed alpha-chain requirement. These results, in conjunction with others, indicate that the relative contribution of polymorphic sites on class II alpha- and beta-chains to T cell Ag recognition can differ markedly, and, furthermore, may vary as a function of the Ag.
Norton
F L
FL
Department of Microbiology and Immunology, University of California, San Francisco 94143.
Davis
C B
CB
Jones
P P
PP
Goodman
J W
JW
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D001391:Azo Compounds / Q000276:immunology*; D002999:Clone Cells / Q000145:classification / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D000939:Epitopes / Q000276:immunology; D005802:Genes, MHC Class II; D000949:Histocompatibility Antigens Class II / Q000235:genetics; D007739:L Cells / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008805:Mice, Inbred A; D009154:Mutation; D011487:Protein Conformation; D013602:T-Lymphocytes, Cytotoxic / Q000145:classification / Q000276:immunology*; D014162:Transfection; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000276:immunology; D010132:p-Azobenzenearsonate / Q000031:analogs & derivatives / Q000276:immunology*
D001391:Azo Compounds; D000939:Epitopes; D000949:Histocompatibility Antigens Class II; C000229:tyrosine-4-azobenzenearsonate; D014443:Tyrosine; D010132:p-Azobenzenearsonate