Regulation of class II MHC molecules on human endothelial cells. Effects of IFN and dexamethasone
Manyak, C.L.; Tse, H.; Fischer, P.; Coker, L.; Sigal, N.H.; Koo, G.C.
Journal of Immunology 140(11): 3817-3821
1988
ISSN/ISBN: 0022-1767 PMID: 2453556 Document Number: 321868
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.