Does protein kinase C control receptor-mediated phagocytosis in human neutrophils?

FEBS Lett. 1988 Nov 7;239(2):371-5. doi: 10.1016/0014-5793(88)80954-2.


It was previously demonstrated that C3bi- but not IgG-mediated phagocytosis in human neutrophils is a Ca2+-independent process [(1985) Nature 315, 509-511]. The objective of this study was to elucidate the nature of an additional messenger signal(s) that may be involved in receptor-mediated phagocytosis in these cells. The C3bi- and IgG-mediated phagocytic ability of neutrophils was inhibited by forskolin, a potent activator of adenylate cyclase. It was found that forskolin induced a 3-fold increase in cAMP levels and simultaneously reduced the uptake of both C3bi- and IgG-opsonized particles by 65%. This inhibition was reversed by exposure to either phorbol myristate acetate (PMA) or diacylglycerol (OAG), which are both activators of protein kinase C, but not by the inactive analog 4 alpha-PMA. PMA could also restore the phagocytic ability of neutrophils with an experimentally impaired calcium response. These results suggest that activation of protein kinase C might be an important transducing signal controlling receptor-mediated phagocytosis in human neutrophils.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cyclic AMP / blood
  • Diglycerides / pharmacology
  • Humans
  • In Vitro Techniques
  • Neutrophils / drug effects
  • Neutrophils / immunology
  • Neutrophils / physiology*
  • Phagocytosis*
  • Protein Kinase C / blood*
  • Protein Kinase C / physiology
  • Receptors, Immunologic / physiology*
  • Tetradecanoylphorbol Acetate / pharmacology


  • Diglycerides
  • Receptors, Immunologic
  • 1-oleoyl-2-acetylglycerol
  • Cyclic AMP
  • Protein Kinase C
  • Tetradecanoylphorbol Acetate