HLA-G inhibits the allogeneic proliferative response

HLA-C is a non-classical MHC class I molecule expressed at the fete/materna l interface where it plays a role in materno-fetal tolerance by inhibiting NK cells. Expression of killing inhibitory receptors capable of interacting with HLA-G on T lymphocytes led us to hypothesize that HLA-G molecules cou ld also modulate T cell responses, analyzed here in the context of the allo geneic proliferative response. Using LCL-HLA-G transfectants as stimulators of T cells present among peripheral mononuclear cells and K562-HLA-G1 tran sfectants as inhibitors in a classical mixed lymphocyte reaction, we showed that HLA-G is able to inhibit T cell allo-proliferation. These findings pr ovide new insight into the role of HLA-G in preventing allograft rejection. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.