Novel roles for the IgG Fc glycan

RM Anthony, F Wermeling… - Annals of the New York …, 2012 - Wiley Online Library
Annals of the New York Academy of Sciences, 2012Wiley Online Library
IgG antibodies trigger leukocyte activation and inflammation by forming immune complexes
that crosslink activating Fcγ receptors (FcγRs). This is essential to combat infection, but
detrimental if antibodies target or cross‐react with autoantigens. The high specificity and
long serum half‐life of IgG antibodies confers tremendous therapeutic potential. Indeed,
antibodies have been successfully employed to target cancers, autoreactive B cells, and pro‐
inflammatory cytokines. Conversely, IgG antibodies can also initiate anti‐inflammatory …
IgG antibodies trigger leukocyte activation and inflammation by forming immune complexes that crosslink activating Fcγ receptors (FcγRs). This is essential to combat infection, but detrimental if antibodies target or cross‐react with autoantigens. The high specificity and long serum half‐life of IgG antibodies confers tremendous therapeutic potential. Indeed, antibodies have been successfully employed to target cancers, autoreactive B cells, and pro‐inflammatory cytokines. Conversely, IgG antibodies can also initiate anti‐inflammatory responses. In the form of intravenous immunoglobulin (IVIG), IgGs are routinely administered to treat inflammatory autoimmune diseases. Importantly, the N‐linked glycans on the IgG Fc are absolutely required for initiating these IgG effector functions. In fact, the Fc glycan composition dictates IgG affinity to individual FcγRs, and in a broader sense, binding to different FcγRs classes: activating, inhibitory, and anti‐inflammatory (dendritic cell‐specific ICAM‐3 grabbing nonintegrin, DC‐SIGN). The Fc glycan requirements to initiate and suppress inflammation will be discussed herein.
Wiley Online Library