The Fcγ receptor of natural killer cells is a phospholipid-linked membrane protein
Abstract
Three types of receptor for the Fc (constant) region of human immunoglobulin G have been described1,2; FcRI, a high-affinity (Ka~108 M-1) receptor expressed on monocytes3-5 FcRII (CD32), a low-affinity (Ka~106 M-1) receptor expressed on B cells, granulocytes, macrophages and platelets6-9 and FcRIII (CD 16, FcR10), a low-affinity receptor expressed on macrophages, neutrophils, eosinophils, natural killer cells and a subset of T cells believed to comprise the suppresssor cells10-13. Anti-CD 16 anti-bodies block natural killer-cell mediated antibody dependent cellular cytotoxicity (ADCC)14,15. Binding of aggregated IgG to CD 16 on natural killer cells leads to the expression of lymphocyte activation antigens, mediator release, morphological changes and lytic activity16-18. We report here the isolation of a complementary DNA clone encoding CD 16 determinants which gave rise to IgG binding of the expected affinity and subtype specificity in COS cells, and which proved to encode a phospholipid anchored protein. A single messenger RNA transcript was found in all positive RNA samples, and N-glycanase treatment showed the form found in COS cells was identical to the form present on peripheral blood mononuclear cells (PBMCs). We also show that CD 16 is most closely related to the α-form of the murine IgG 2b/l receptor and propose that extracellular contacts mediate the signal initiated by IgG binding.
- Publication:
-
Nature
- Pub Date:
- June 1988
- DOI:
- 10.1038/333568a0
- Bibcode:
- 1988Natur.333..568S