Figure 1.

Signaling events occurring after binding of the IgG immune complex to the FcγR immune complex and receptor interactions result in phosphorylation of the immunoreceptor tyrosine activating motifs (ITAMs), followed by activation of the spleen tyrosine kinase (SYK)-mediated PI3K/PKB activation, and SRC family kinases result in the influx of Ca²⁺, which also promotes actin remodeling, which is important for the immune complex phagocytosis and internalization of the receptor. Eventually, the activation of transcription through NF-kB and IRF-3 leads to the expression of pro-inflammatory cytokines.