Human NK cells are large granular lymphocytes that kill neoplastic or viral
ly infected targets using perforin-dependent mechanisms. CD16 or Fc gamma R
III is one of the cell surface molecules that can trigger the killing machi
nery following binding of the Fc portion of IgG to the receptor: a mechanis
m known as antibody dependent cell-mediated cytotoxicity (ADCC). We have re
cently shown that some individuals express an additional Fc gamma R on thei
r NK cells, CD32 or Fc gamma RII. This receptor has now been characterized
at the molecular, biochemical and functional level. The present review outl
ines our findings to date on the features of this novel receptor. These fin
dings suggest that the presence of a functional Fc gamma RII on the surface
of NK cells could have important clinical consequences in both turner immu
notherapy and autoimmune disease.