Signal transduction via MHC class I molecules in endothelial and smooth muscle cells.

MHC class I molecules have long been recognized for their ability to stimulate intracellular signals in T and B lymphocytes. More recently, it has become clear that MHC class I molecules can also initiate intracellular signals in endothelial and smooth muscle cells, which synergize with growth factor receptors to elicit cell proliferation. This review describes our current knowledge of class I-mediated signaling pathways in human endothelial and smooth muscle cells. The role of the class I signaling pathway in modulating cell growth and the clinical significance of this pathway in chronic allograft rejection are discussed.