title: Enhancement of peptide antigen presentation by a second peptide.
abstract: The influence of nonstimulatory "competitor" peptides on the binding of an antigenic peptide to a major histocompatibility complex (MHC) class II molecule was investigated. Using high-performance size-exclusion chromatography and fluorescein-labeled peptides, we show that the presence of the peptides dynorphin A-(1-13) and poly(L-lysine) results in enhancement rather than inhibition of the binding of hen egg lysozyme peptide-(107-116) [HEL-(107-116)] to the detergent-solubilized mouse class II molecule IEd. In parallel, dynorphin A-(1-13) and poly(L-lysine) were found to enhance the specific activation of an IEd-restricted T-cell hybridoma by HEL-(107-116). A molecular mechanism involving an intermediate two peptide-MHC class II protein complex is proposed to explain the enhancement of peptide binding to class II molecules by an irrelevant second peptide.
authors.affiliation: Department of Chemistry, Stanford University, CA 94305.
authors.forename: A I
authors.initials: AI
authors.lastname: de Kroon
authors.forename: H M
authors.initials: HM
authors.lastname: McConnell
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000941:Antigens / Q000276:immunology / Q000378:metabolism*; D001667:Binding, Competitive; D002460:Cell Line; D002645:Chickens; D004398:Dyneins / Q000494:pharmacology; D004399:Dynorphins / Q000494:pharmacology; D000949:Histocompatibility Antigens Class II / Q000302:isolation & purification / Q000378:metabolism*; D006825:Hybridomas / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008969:Molecular Sequence Data; D009113:Muramidase / Q000276:immunology / Q000378:metabolism*; D010446:Peptide Fragments / Q000494:pharmacology; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D011107:Polylysine / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology
chemical_list: D000941:Antigens; D000949:Histocompatibility Antigens Class II; D010446:Peptide Fragments; D010455:Peptides; D011107:Polylysine; C026843:dynorphin (1-13); D004399:Dynorphins; D009113:Muramidase; D004398:Dyneins