KINETICS OF INTERACTION OF HLA-C LIGANDS WITH NATURAL-KILLER-CELL INHIBITORY RECEPTORS

The recognition of HLA-C molecules by specific inhibitory receptors is a crucial step in the regulation of natural killer (NK) cell function . Using soluble, recombinant HLA-C molecules and NK inhibitory recepto rs (NKIR, members of the immunoglobulin superfamily), we show that HLA -C binds to NKIR molecules with extremely fast association and dissoci ation rates, among the fastest of the immune system interactions so fa r studied. These kinetics may be essential for the biological function of NK cells, i.e., to facilitate the rapid immunosurveillance of cell s for absent or diminished expression of class I MHC proteins.