title: Enhanced dissociation of HLA-DR-bound peptides in the presence of HLA-DM.
abstract: Human leukocyte antigen (HLA)-DM is a critical participant in antigen presentation that catalyzes the release of class II-associated invariant chain-derived peptides (CLIP) from newly synthesized class II histocompatibility molecules, freeing the peptide-binding site for acquisition of antigenic peptides. The mechanism for the selective release of CLIP but not other peptides is unknown. DM was found to enhance the rate of peptide dissociation to an extent directly proportional to the intrinsic rate of peptide dissociation from HLA-DR, regardless of peptide sequence. Thus, CLIP is rapidly released in the presence of DM, because its intrinsic rate of dissociation is relatively high. In antigen presentation, DM has the potential to markedly enhance the rate of peptide exchange, favoring the presentation of peptides with slower intrinsic rates of dissociation.
authors.affiliation: Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Weber
authors.forename: B D
authors.initials: BD
authors.lastname: Evavold
authors.forename: P E
authors.initials: PE
authors.lastname: Jensen
mesh_terms: D000595:Amino Acid Sequence; D017951:Antigen Presentation; D000944:Antigens, Differentiation, B-Lymphocyte / Q000378:metabolism*; D001665:Binding Sites; D006681:HLA-D Antigens / Q000378:metabolism*; D006684:HLA-DR Antigens / Q000276:immunology / Q000378:metabolism*; D000949:Histocompatibility Antigens Class II / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism
chemical_list: D000944:Antigens, Differentiation, B-Lymphocyte; C416189:H2-M antigens; D006681:HLA-D Antigens; C084245:HLA-DM antigens; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D010455:Peptides; D011993:Recombinant Fusion Proteins; C045084:invariant chain