Recombinant gamma interferon induces HLA-DR expression on cultured human keratinocytes.
In normal human epidermis, expression of HLA-DR antigen is restricted to Langerhans cells (LC) and acrosyringial epithelium. However, in diseases such as lichen planus and graft-vs.-host, HLA-DR antigen appears to be expressed by keratinocytes, although the exact source of the HLA-DR is unclear. Two possibilities are that (1) the HLA-DR is shed by neighboring immunocompetent cells, or (2) that the keratinocytes are synthesizing the antigen themselves. Recently, gamma interferon has been shown to induce HLA-DR biosynthesis and expression on human malignant melanoma cells lines and on normal vascular endothelium. We report here that pure recombinant human gamma interferon (100 units/ml) induces HLA-DR expression on 60-70% of cultured human adult keratinocytes depleted of LC within 2-4 days of culture as determined by fluorescence-activated cell sorter (FACS) analysis using monoclonal antibodies. No residual LC or lymphocytes could be detected in these cultures. This is the first demonstration of HLA-DR expression by cultured human keratinocytes. This expression may be of functional significance in antigen presentation and cell-mediated cytotoxicity involving the epidermis.
D000911:Antibodies, Monoclonal / Q000032:analysis; D002469:Cell Separation; D002478:Cells, Cultured; D000078404:Epidermal Cells; D004817:Epidermis / Q000276:immunology*; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology*; D007633:Keratins / Q000096:biosynthesis; D007801:Langerhans Cells / Q000276:immunology
D000911:Antibodies, Monoclonal; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D007633:Keratins; D007371:Interferon-gamma