IgG-mediated anaphylaxis in mice

In a mouse model of anaphylaxis, allergen interacts with allergen-specific IgG on the surface of macrophages, through the IgG receptor Fc-gamma-RIII. Cross-linking of multiple IgG molecules by allergen initiates intracellular signaling and macrophage activation. In mice, macrophage-derived platelet-activating factor and other inflammatory mediators trigger signs and symptoms similar to those of IgE-mediated anaphylaxis in humans.