Expression of HLA-DR antigens in human fetal pancreas tissue.
The expression of HLA-DR antigens in human fetal pancreas tissue was studied using four independently derived monoclonal antibodies recognizing nonpolymorphic HLA-DR antigens. Immunoperoxidase staining of frozen sections revealed numerous DR-antigen-positive cells. Two major cell types could be distinguished. Large, strongly DR-positive cells with dendritic morphology were distributed throughout the dendritic morphology were distributed throughout the pancreatic parenchyma and interstitial connective tissue. Dual staining of DR antigens and insulin using a two-color immunoperoxidase technique clearly showed that some of these DR-positive dendritic cells were located within and in close association with insulin-producing islets. Also observed as a regular feature of fetal pancreas tissue sections were large clusters of DR-positive cells with lymphoid morphology. Positive staining of many cells within these clusters with monoclonal antibodies against T-cell marker (Leu-1) and T-cell subset markers (Leu-2 and -3) supported their classification as lymphoid cells. In contrast, no positive staining with anti-T-cell antibodies was observed outside of lymphoid cell clusters, confirming the distinction between these cells and the DR-positive cells distributed throughout the pancreas. The presence of other DR-bearing cell types in fetal pancreas could not be excluded, but most endothelial cells appeared to be DR-negative. The demonstration of numerous DR-bearing cells associated with fetal pancreas tissue may require that we alter our views on DR-antigen ontogeny and develop new strategies for fetal pancreas transplantation.
D000911:Antibodies, Monoclonal / Q000276:immunology; D004727:Endothelium / Q000166:cytology / Q000276:immunology; D005333:Fetus; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006801:Humans; D007124:Immunoenzyme Techniques; D007515:Islets of Langerhans / Q000166:cytology / Q000196:embryology / Q000276:immunology; D010179:Pancreas / Q000166:cytology / Q000196:embryology / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
D000911:Antibodies, Monoclonal; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II