The mast cell IgG receptors and their roles in tissue inflammation

Authors

  • Odile Malbec,

    1. Unité d’Allergologie Moléculaire et Cellulaire, Département d’Immunologie, Institut Pasteur, Paris, France.
    2. Inserm, U.760, Paris, France.
    Search for more papers by this author
  • Marc Daëron

    Corresponding author
    1. Unité d’Allergologie Moléculaire et Cellulaire, Département d’Immunologie, Institut Pasteur, Paris, France.
    2. Inserm, U.760, Paris, France.
    Search for more papers by this author

Marc Daëron
Unité d’Allergologie Moléculaire et Cellulaire
Département d’Immunologie
Institut Pasteur
25 rue du Docteur Roux
75015 Paris, France
Tel.: +33 1 4568 8642
Fax: +33 1 4061 3160
E-mail: daeron@pasteur.fr

Abstract

Summary:  Mast cells are effector cells of the innate immune system, but because they express Fc receptors (FcRs), they can be engaged in adaptive immunity by antibodies. Mast cell FcRs include immunoglobulin E (IgE) and IgG receptors and, among these, activating and inhibitory receptors. The engagement of mast cell IgG receptors by immune complexes may or may not trigger cell activation, depending on the type of mast cell. The coengagement of IgG and IgE receptors results in inhibition of mast cell activation. The Src homology-2 domain-containing inositol 5-phosphatase-1 is a major effector of negative regulation. Biological responses of mast cells depend on the balance between positive and negative signals that are generated in FcR complexes. The contribution of human mast cell IgG receptors in allergies remains to be clarified. Increasing evidence indicates that mast cells play critical roles in IgG-dependent tissue-specific autoimmune diseases. Convincing evidence was obtained in murine models of multiple sclerosis, rheumatoid arthritis, bullous pemphigoid, and glomerulonephritis. In these models, the intensity of lesions depended on the relative engagement of activating and inhibitory IgG receptors. In vitro models of mature tissue-specific murine mast cells are needed to investigate the roles of mast cells in these diseases. One such model unraveled unique differentiation/maturation-dependent biological responses of serosal-type mast cells.

Ancillary