title: Antigen-Ia interaction and the proteolytic processing of antigen: the structure of the antigen determines its restriction to the A or E molecule of the major histocompatibility complex.
abstract: The effect of a protease inhibitor, leupeptin, on the presentation of hen egg lysozyme (HEL) to cloned T cells was investigated. We found that leupeptin-sensitive thiol proteases are apparently less involved when HEL is presented by the I-Ad molecule, than when it is presented by the I-Ed molecule. This selectivity was more of a function of the antigen than that of the Ia molecule because presentation of denatured or fragmented HEL was not sensitive to leupeptin whereas antigen presentation to a number of I-A-restricted T cell clones specific to other antigens was sensitive to leupeptin. These data demonstrate that the particular combination of major histocompatibility complex/nominal antigen recognized by a certain T cell clone may require processing of the antigen molecule through a certain group of proteases and that other combinations are independent of that particular processing pathway. Furthermore, there is a preference for a certain type of processing depending on the Ia molecule involved.
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000187:drug effects / Q000378:metabolism*; D000941:Antigens; D002999:Clone Cells; D000939:Epitopes / Q000032:analysis; D006183:H-2 Antigens / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000502:physiology*; D007976:Leupeptins / Q000494:pharmacology; D008285:Major Histocompatibility Complex; D051379:Mice; D008815:Mice, Inbred Strains; D009113:Muramidase / Q000276:immunology / Q000378:metabolism; D010447:Peptide Hydrolases / Q000502:physiology*; D013601:T-Lymphocytes / Q000378:metabolism
chemical_list: D000941:Antigens; D000939:Epitopes; D006183:H-2 Antigens; D000949:Histocompatibility Antigens Class II; D007976:Leupeptins; D009113:Muramidase; D010447:Peptide Hydrolases; C032854:leupeptin