Functional CD32 Molecules on Human NK Cells

Abstract

Human NK cells are large granular lymphocytes that kill neoplastic or virally infected targets using perforin-dependent mechanisms. CD16 or FcγRIII is one of the cell surface molecules that can trigger the killing machinery following binding of the Fc portion of IgG to the receptor: a mechanism known as antibody dependent cell-mediated cytotoxicity (ADCC). We have recently shown that some individuals express an additional FcγR on their NK cells, CD32 or FcγRII. This receptor has now been characterized at the molecular, biochemical and functional level. The present review outlines our findings to date on the features of this novel receptor. These findings suggest that the presence of a functional FcγRII on the surface of NK cells could have important clinical consequences in both tumor immunotherapy and autoimmune disease.

Key Words:

• Natural killer cells
• Fq receptors
• ADCC
• signal transduction