The immunotolerance role of HLA-G.

HLA-G is a non-classical MHC class I molecule involved in immune tolerance. We present our results concerning the effects of HLA-G on the cellular immune response, where it impairs both NK and T cell functions. We describe the NK inhibitory properties of HLA-G ex vivo, demonstrating its role in materno-fetal tolerance, which is supported by our in vitro studies using membrane-bound HLA-G1- and HLA-G2-transfected cells and a full-length soluble HLA-G molecule. We also report how HLA-G interacts at the T cell level, here exemplified by its inhibitory effect on both T cell allogeneic proliferative and Ag-specific CTL responses. Copyright 1999 Academic Press.