Receptors for the Fc fragment of IgG on natural killer cells.
Natural killer (NK) cells are capable of binding to immune-complexed IgG via CD16-Fc gamma RIIIA molecules on their surface. This interaction activates the NK cell lytic mechanism and induces production of lymphokines by the activated cells. The exact molecular basis for CD16-mediated NK cell activation remains unclear; however, a number of recent studies have provided a framework for future research. It has been shown that CD16 perturbation on NK cells evokes a variety of early signal transduction events in these cells, such as polyphosphatidylinositol hydrolysis, [Ca2+]i increases and protein tyrosine kinase activation. Furthermore, the identification, of CD3-zeta/eta and/or Fc epsilon RI-gamma polypeptides complexed with CD16 in NK cells suggests a signal transduction mechanism analogous to those studied for the T cell receptor and Fc epsilon-receptor complexes. Therefore, research on each of these receptor complexes should now be viewed in light of a potential common signal transduction mechanism. Comparison of the similarities and differences observed should yield valuable insight into the complex network of molecular interactions apparently necessary for CD16-mediated NK cell activation.
Trinchieri
G
G
Wistar Institute of Anatomy and Biology, Philadelphia, Pa 19104.
Valiante
N
N
D000818:Animals; D000920:Antibody-Dependent Cell Cytotoxicity / Q000276:immunology; D006412:Hematopoietic Stem Cells / Q000276:immunology; D006801:Humans; D007128:Immunoglobulin Fragments / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology*; D008222:Lymphokines / Q000235:genetics; D011961:Receptors, Fc / Q000276:immunology*; D017452:Receptors, IgG / Q000235:genetics
D007128:Immunoglobulin Fragments; D007074:Immunoglobulin G; D008222:Lymphokines; D011961:Receptors, Fc; D017452:Receptors, IgG