title: Cellular and molecular aspects of antigen processing and the function of class II MHC molecules.
abstract: Antigen processing is the conversion of native antigen molecules into short peptides that can then bind to major histocompatibility complex (MHC) molecules. Class II MHC (MHC-II) molecules target to endocytic compartments, where they bind peptides that are produced by internalization of extracellular antigens and subsequent antigen catabolism. The resulting peptide-MHC complexes are displayed on the surface of antigen-presenting cells for recognition by T cells. Thus, MHC-II molecules first serve as peptide receptors that rescue peptides from total lysosomal degradation and transport them to the plasma membrane; the MHC-II molecules then form a composite peptide-MHC-II determinant that is recognized by the T cell receptor. Recent work has begun to clarify the molecular events and transport mechanisms that govern antigen processing.
authors: Institute of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106.
authors: C V
authors: CV
authors: Harding
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism; D000941:Antigens / Q000378:metabolism*; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D006681:HLA-D Antigens / Q000502:physiology*; D006801:Humans; D015388:Organelles / Q000378:metabolism; D011485:Protein Binding; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D000941:Antigens; D006681:HLA-D Antigens