Protein kinase C is crucial in signal transduction during IFN-γ induction in endothelial cells

Abstract

We have demonstrated that IFN-γ, a potent peptide mediator in inflammatory responses, operates via the protein kinase C dependent transduction pathway in the induction of class II MHC antigens on rat microvascular endothelial cells. Stimulators of protein kinase C, like PMA, replaced IFN-γ in the induction of MHC class II on endothelial cells in a dose-dependent manner. Selective enzyme inhibitors of protein kinase C, H-7 as well as sphingosine down-regulated the IFN-γ induced class II expression in a dose-dependent manner. Addition of cAMP or cGMP in the culture, had no effect on the class II expression on the endothelial cells. Transient rise of cytosolic Ca 2+ by calcium ionophore A23187, or a calmodulin antagonist W-7, had no effect on the IFN-γ induced class II expression.