THE PRESENCE OF HLA-DR ANTIGENS ON LACTATING HUMAN-BREAST EPITHELIUM AND MILK-FAT GLOBULE MEMBRANES

  • 1 January 1980
    • journal article
    • research article
    • Vol. 41  (3) , 478-486
Abstract
HLA-DR antigens were demonstrated on the secretory epithelia of [human] lactating breast using rabbit anti-p2833 (Ia-like) and mouse monoclonal anti-HLA-DR framework. Normal non-lactating breast, benign or malignant tumors, epithelial cells from normal breast or isolated from milk and a presumptive [human] breast carcinoma cell line (MCF-7) were all HLA-DR-negative. HLA-DR, HLA (ABC framework) and .beta.2-microglobulin determinants were demonstrated on the surface of milk fat globules (MFG) which were unreactive with monoclonal antibodies to thymus cells or leukocytes. 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 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.