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Updated: Sep 29, 2026

Investigating Mast Cell Secretory Granules; from Biosynthesis to Exocytosis
Published on: January 26, 2015
Inhibition of anaphylactic inflammation by the gp49B1 receptor on mast cells
1Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA. hrkatz@mbcrr.harvard.edu
Abstract:
gp49B1 is a member of the immunoglobulin (Ig) superfamily expressed on the surface of mast cells, macrophages, and activated natural killer cells. gp49B1 inhibits FcepsilonRI-induced activation of mast cells in vitro by virtue of two immunoreceptor, tyrosine-based inhibitory motifs that recruit the SHP-1 tyrosine phosphatase to the plasma membrane. We created gp49B1 null mice by targeted gene disruption, and found that IgE-dependent mast cell activation is augmented in these animals. Moreover, the ensuing anaphylactic reactions and inflammation are enhanced in the absence of gp49B1. Thus, gp49B1 innately counter-regulates mast cell activation mediated by Ig generated through the adaptive immune response in vivo.
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