KILLER-CELL INHIBITORY RECEPTOR INTERACTIONS WITH HLA CLASS-I MOLECULES - IMPLICATIONS FOR ALLOREACTIVITY AND TRANSPLANTATION

Human killer cell inhibitory receptors (KIR) are novel members of the immunoglobulin superfamily of cell surface glycoproteins, which are ex pressed by lymphocytes with natural killer (NK) and cytotoxic T-cell ( CTL) phenotypes. These receptors have specificity for relatively conse rved epitopes of HLA-A, -B, and -C class I antigens. Recent studies ha ve identified KIR as being involved in the transmission of negative, i nhibitory signaling events to the cytotoxic cell which prevent or dimi nish target cell lysis. KIR are thus likely to play an important role in the responses of alloreactive NK cells and CTL to allogeneic HLA an tigens. In this article, we review the known structural and functional characteristics of KIR, suggest a possible mechanism for the transmis sion of intracellular negative signaling by these receptors, and discu ss the relevance of KIR function and HLA specificity to the clinical t ransplantation of allogeneic tissues. (C) American Society Jar Histoco mpatibility and Immunogenetics, 1997.