Signaling transduction by IgG receptors

【Abstract】 To review and summarize literature regarding stimulatory and inhibitory signaling pathways from different types of Fc gamma r eceptors (FcγRs).Data source Articles were obtained from Medline from January 1 991 to April 2002. Study selection Over 100 English language papers and reviews pu blished over the last 11 years were selected.Results and Conclusions Stimulatory Fcγ receptors include Fc γRI, FcγRIIA, FcγRIIC, and FcγRIII A. They transduce signals through the imm unoreceptor tyrosine-based activation motif (ITAM) in subunits or in the cytopl asmic domain. Inhibitory Fcγ receptors, such as FcγRIIB, are single chain receptors, transducing signals through an immunoreceptor tyrosine-based inhibi tory motif (ITIM) in cytoplasmic domains. Stimulatory signals include protein ph osphorylation, increase in intracellular free calcium, the production of 1,4,5- triphosphate inositol (IP 3) and diacylglycerol (DAG) mainly through the Src-f amily kinases, phosphoinositide 3-kinase (PI3-K) and phospholipase C (PLC). In hibitory signaling has been implicated in the repression of the above activities as well as inhibition of B cell responses through Src homology 2-containing in ositol phosphatase (SHIP).更多还原