title: Differential expression of HLA-DR, HLA-DP, HLA-DQ and associated invariant chain (Ii) in normal colorectal mucosa, adenoma and carcinoma.
abstract: The expression of MHC class II antigens (HLA-DR, HLA-DP and HLA-DQ) and the associated invariant chain (Ii) was studied in epithelial cells of normal colorectal mucosae, colorectal adenomas and carcinomas, using a sensitive immunoperoxidase technique with monoclonal antibodies on frozen sections. In contrast to class II antigens, Ii was detected in some normal mucosae distant from the tumour. In residual non-neoplastic mucosa adjacent to carcinomas, Ii and class II antigens were induced in the order Ii greater than or equal to HLA-DR greater than or equal to HLA-DP greater than or equal to HLA-DQ, the reactions being most pronounced in cases with inflammatory alteration of the crypts. In 22/37 adenomas and 77/123 carcinomas, Ii expression clearly exceeded class II antigen expression. Class II antigens were found in 20/37 adenomas and 62/123 carcinomas, mostly in a non-coordinate manner, following the above order. A detailed analysis of the expression patterns in normal and neoplastic colon epithelial cells revealed a closer association of HLA-DP with HLA-DQ than of HLA-DR with HLA-DP, or HLA-DQ.
mesh_terms: D000236:Adenoma / Q000276:immunology*; D002277:Carcinoma / Q000276:immunology*; D003106:Colon; D003110:Colonic Neoplasms / Q000276:immunology*; D006681:HLA-D Antigens / Q000032:analysis*; D006682:HLA-DP Antigens / Q000032:analysis*; D006683:HLA-DQ Antigens / Q000032:analysis*; D006684:HLA-DR Antigens / Q000032:analysis*; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006801:Humans; D007124:Immunoenzyme Techniques; D007413:Intestinal Mucosa / Q000276:immunology*; D012004:Rectal Neoplasms / Q000276:immunology*; D012007:Rectum
chemical_list: D006681:HLA-D Antigens; D006682:HLA-DP Antigens; D006683:HLA-DQ Antigens; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II