Regulation of class II MHC molecules on human endothelial cells. Effects of IFN and dexamethasone.
Human vascular endothelial cells normally do not express class II MHC molecules in culture. IFN-gamma has been shown to induce expression of class I and class II MHC molecules on endothelial cell cultures from umbilical cord. We could detect these Ag by FACS analysis when endothelial cells were cultured for 3 days in the presence of 200 to 1000 U/ml of rIFN-gamma. Among the class II MHC molecules, HLA-DR and -DP but not -DQ were consistently induced. Addition of rIFN-alpha-D/A to IFN-gamma-treated cells inhibited the expression of class II MHC but not class I MHC molecules. Furthermore, the inhibition was more pronounced when IFN-alpha-D/A was added before or simultaneously as IFN-gamma. Natural IFN-alpha also exhibited similar inhibition and its suppressive effect was abolished in the presence of anti-IFN-alpha antibody. On the contrary, dexamethasone, a known inhibitor of class II MHC molecules on murine macrophages, showed a slight enhancing effect on class II MHC Ag. These results suggest an immunoregulatory role for IFN-alpha on non-lymphoid cells and that controlling elements for expression of class II MHC molecules may be different on various cell types as well as species.
D003907:Dexamethasone / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D006681:HLA-D Antigens / Q000096:biosynthesis*; D006682:HLA-DP Antigens / Q000096:biosynthesis; D006683:HLA-DQ Antigens / Q000096:biosynthesis; D006684:HLA-DR Antigens / Q000096:biosynthesis; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007370:Interferon Type I / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D007372:Interferons / Q000494:pharmacology*; D013997:Time Factors
D006681:HLA-D Antigens; D006682:HLA-DP Antigens; D006683:HLA-DQ Antigens; D006684:HLA-DR Antigens; D007166:Immunosuppressive Agents; D007370:Interferon Type I; D003907:Dexamethasone; D007371:Interferon-gamma; D007372:Interferons