Fc gamma receptor III induces actin polymerization in human neutrophils and primes phagocytosis mediated by Fc gamma receptor II.

Academic Article

Abstract

  • Human polymorphonuclear leukocytes (PMN) express two classes of Fc gamma R: Fc gamma RII the 42-kDa receptor with a traditional membrane spanning domain and cytoplasmic tail and Fc gamma RIIIPMN the 50- to 80-kDa receptor with a glycosyl-phatidylinositol membrane anchor expressed on PMN. To explore the capacity of Fc gamma RIIIPMN to generate intracellular signals, we have analyzed the ability of Fab and F(ab')2 anti-Fc gamma R mAb to induce actin filament assembly, a prerequisite for motile behaviors. Multivalent ligation of Fc gamma RIIIPMN, independent of Fc gamma RII, results in an increase in F-actin content that is [Ca2+]i dependent. Multivalent ligation of Fc gamma RII also initiates actin polymerization but uses a [Ca2+]i-independent initial pathway. In addition to providing a mechanism for Fc gamma RIIIPMN triggered effector functions, the increase in F-actin and [Ca2+]i generated by Fc gamma RIIIPMN ligation also serves as a "priming" signal to modify PMN responses to other stimuli. Experiments using erythrocytes specifically coated with anti-Fc gamma RII Fab demonstrate that cross-linking of Fc gamma RIIIPMN with anti-Fc gamma RIII F(ab')2 enhances phagocytosis mediated by Fc gamma RII. Thus, Fc gamma RIIIPMN, a glycosyl-phosphatidylinositol anchored protein, may contribute directly to an intracellular program of actin assembly that may trigger and prime neutrophil effector functions.
  • Published In

    Keywords

  • Actins, Antigen-Antibody Complex, Antigens, Differentiation, Calcium, Humans, Immunoglobulin G, Neutrophils, Phagocytosis, Polymers, Receptors, Fc, Receptors, IgG, Signal Transduction
  • Author List

  • Salmon JE; Brogle NL; Edberg JC; Kimberly RP
  • Start Page

  • 997
  • End Page

  • 1004
  • Volume

  • 146
  • Issue

  • 3