Modulation of immune complex-induced inflammation in vivo by the coordinate expression of activation and inhibitory Fc receptors

Raphael Clynes, Jay S. Maizes, Rodolphe Guinamard, Masao Ono, Toshiyuki Takai, Jeffrey V. Ravetch

Research output: Contribution to journalArticlepeer-review

323 Citations (Scopus)

Abstract

Autoantibodies and immune complexes are major pathogenic factors in autoimmune injury, responsible for initiation of the inflammatory cascade and its resulting tissue damage. This activation results from the interaction of immunoglobulin (Ig)G Fc receptors containing an activation motif (ITAM) with immune complexes (ICs) and cytotoxic autoantibodies which initiates and propagates an inflammatory response. In vitro, this pathway can be interrupted by coligation to FcγRIIB, an IgG Fc receptor containing an inhibitory motif (ITIM). In this report, we describe the in vivo consequences of FcγRII deficiency in the inflammatory response using a mouse model of IC alveolitis. At subthreshold concentrations of ICs that fail to elicit inflammatory responses in wild-type mice, FcγRII-deficient mice developed robust inflammatory responses characterized by increased hemorrhage, edema, and neutrophil infiltration. Bronchoalveolar fluids from FcγRII(-/-) stimulated mice contain higher levels of tumor necrosis factor and chemotactic activity, suggesting that FcγRII deficiency lowers the threshold of IC stimulation of resident cells such as the alveolar macrophage. In contrast, complement- and complement receptor-deficient mice develop normal inflammatory responses to suprathreshold levels of ICs, while FcRγ(-/-) mice are completely protected from inflammatory injury. An inhibitory role for FcγRII on macrophages is demonstrated by analysis of FcγRII(-/-) macrophages which show greater phagocytic and calcium flux responses upon FcγRIII engagement. These data reveal contrasting roles for the cellular receptors for IgG on inflammatory cells, providing a regulatory mechanism for setting thresholds for IC sensitivity based on the ratio of ITIM to ITAM FcγR expression. Exploiting the FcγRII inhibitory pathway could thus provide a new therapeutic approach for modulating antibody-triggered inflammation.

Original languageEnglish
Pages (from-to)179-185
Number of pages7
JournalJournal of Experimental Medicine
Volume189
Issue number1
DOIs
Publication statusPublished - 1999 Jan 4

Keywords

  • Chemokine
  • Complement
  • Cytokine
  • Fc receptor
  • Immune complex

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

Fingerprint Dive into the research topics of 'Modulation of immune complex-induced inflammation in vivo by the coordinate expression of activation and inhibitory Fc receptors'. Together they form a unique fingerprint.

Cite this