The presence of HLA-DR antigens on lactating human breast epithelium and milk fat globule membranes.
HLA-DR antigens have been demonstrated on the secretory epithelia of lactating breast using rabbit anti-p28,33 ('Ia-like') and mouse monoclonal anti-HLA-DR 'framework'. Normal non-lactating breast, benign or malignant tumours, epithelial cells from normal breast or isolated from milk and a presumptive breast carcinoma cell line (MCF-7) were all HLA-DR-negative. HLA-DR, HLA (ABC 'framework') and beta 2-microglobulin determinants were also demonstrated on the surface of milk fat globules (MFG) which were unreactive with monoclonal antibodies to thymus cells or leucocytes. A monoclonal antibody detecting allelic HLA-DR determinants (HLA-DRw 1,2,6) was positive on 40% of MFG samples tested, positive reactions being concordant, when tested, with blood B lymphocytes. Antisera raised against MFG membranes also contain anti-HLA-DR activity. Whether the breast epithelial cells synthesize HLA-DR molecules or acquire these passively from mononuclear cells which infiltrate during lactation is not yet resolved.
D001940:Breast / Q000276:immunology*; D002478:Cells, Cultured; D004848:Epithelium / Q000276:immunology; D005260:Female; D005455:Fluorescent Antibody Technique; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006801:Humans; D007774:Lactation; D008055:Lipids / Q000276:immunology; D008895:Milk, Human / Q000276:immunology*; D011247:Pregnancy
D000949:Histocompatibility Antigens Class II; D008055:Lipids