Functional characteristics of the high affinity IgG receptor, FcgammaRI.

摘要

IgG FcRs are important mediators of immunity and play a key role during Ab-based immunotherapy. Within the leukocyte IgG receptor family, only FcgammaRI is capable of IgG binding with high affinity. FcgammaRI exists as a complex of a ligand binding alpha-chain and an FcR gamma-chain. The receptors' alpha-chain can, furthermore, elicit several functions independent of the ITAM-bearing FcR gamma-chain. Functional implications of high-affinity IgG binding and mechanisms underlying FcR gamma-chain-independent signaling remain unclear to this day. In this paper, we provide an overview of past literature on FcgammaRI and address the implications of recently described interactions between cytosolic proteins and the FcgammaRI alpha-chain, as well as cytokine-enhanced FcgammaRI immune complex binding. Furthermore, an analysis of potential polymorphisms within the FCGR1A gene is provided.