TY - JOUR
T1 - IgG subclasses and allotypes: from structure to effector functions
AU - Vidarsson, Gestur
AU - Dekkers, Gillian
AU - Rispens, Theo
PY - 2014
Y1 - 2014
N2 - Of the five immunoglobulin isotypes, immunoglobulin G (IgG) is most abundant in human serum. The four subclasses, IgG1, IgG2, IgG3, and IgG4, which are highly conserved, differ in their constant region, particularly in their hinges and upper CH2 domains. These regions are involved in binding to both IgG-Fc receptors (Fc gamma R) and C1g. As a result, the different subclasses have different effector functions, both in terms of triggering Fc gamma R-expressing cells, resulting in phagocytosis or antibody-dependent cell-mediated cytotoxicity, and activating complement. The Fc-regions also contain a binding epitope for the neonatal Fc receptor (FcRn), responsible for the extended half-life, placental transport, and bidirectional transport of IgG to mucosal surfaces. However, FcRn is also expressed in myeloid cells, where it participates in both phagocytosis and antigen presentation together with classical Fc gamma R and complement. How these properties, IgG-polymorphisms and post-translational modification of the antibodies in the form of glycosylation, affect IgG-function will be the focus of the current review
AB - Of the five immunoglobulin isotypes, immunoglobulin G (IgG) is most abundant in human serum. The four subclasses, IgG1, IgG2, IgG3, and IgG4, which are highly conserved, differ in their constant region, particularly in their hinges and upper CH2 domains. These regions are involved in binding to both IgG-Fc receptors (Fc gamma R) and C1g. As a result, the different subclasses have different effector functions, both in terms of triggering Fc gamma R-expressing cells, resulting in phagocytosis or antibody-dependent cell-mediated cytotoxicity, and activating complement. The Fc-regions also contain a binding epitope for the neonatal Fc receptor (FcRn), responsible for the extended half-life, placental transport, and bidirectional transport of IgG to mucosal surfaces. However, FcRn is also expressed in myeloid cells, where it participates in both phagocytosis and antigen presentation together with classical Fc gamma R and complement. How these properties, IgG-polymorphisms and post-translational modification of the antibodies in the form of glycosylation, affect IgG-function will be the focus of the current review
U2 - https://doi.org/10.3389/fimmu.2014.00520
DO - https://doi.org/10.3389/fimmu.2014.00520
M3 - Review article
C2 - 25368619
SN - 1664-3224
VL - 5
SP - 520
JO - Frontiers in immunology
JF - Frontiers in immunology
ER -