Role of Fcγ receptors in glomerulonephritis

RM Tarzi, HT Cook - Nephron Experimental Nephrology, 2003 - karger.com
RM Tarzi, HT Cook
Nephron Experimental Nephrology, 2003karger.com
Many forms of glomerulonephritis involve immune complex localization in the kidney. Fcγ
receptors (FcγR) expressed on the surface of leukocytes bind the Fc (constant) portion of
IgG. They link immune complex deposition to innate immune responses, including
phagocytosis, cytokine release, formation of reactive oxygen species, and antibody-
dependent cytotoxicity. Activator and inhibitor FcγR co-exist on the surface of cells and set
thresholds for immune responses. Inhibitor FcγR also have a specific role in the …
Abstract
Many forms of glomerulonephritis involve immune complex localization in the kidney. Fcγ receptors (FcγR) expressed on the surface of leukocytes bind the Fc (constant) portion of IgG. They link immune complex deposition to innate immune responses, including phagocytosis, cytokine release, formation of reactive oxygen species, and antibody-dependent cytotoxicity. Activator and inhibitor FcγR co-exist on the surface of cells and set thresholds for immune responses. Inhibitor FcγR also have a specific role in the maintenance of B cell tolerance. Studies of gene-targeted mice lacking specific FcγR have demonstrated that animals lacking activator FcγR on circulating leukocytes were protected from immune complex induced glomerular injury, both in models of systemic lupus erythematosus (SLE) and anti-glomerular basement membrane antibody disease. In contrast, mice lacking inhibitor FcγR developed SLE-like auto-immunity on certain genetic backgrounds and were more susceptible to anti-glomerular basement membrane disease, with evidence of enhanced immune responses and dysregulated effector cells. There is also evidence for FcγR dysfunction in human SLE and for an association of ‘low-binding’polymorphisms of FcγR with SLE. In the future, therapeutic possibilities may exist for the manipulation of the FcγR pathway in the treatment of glomerulonephritis.
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