CD16 Receptor Overview
CD16, also known as Fc gamma receptor III (FcγRIII), is a low-affinity receptor for the Fc portion of immunoglobulin G (IgG). It plays a central role in immune regulation, particularly in mediating antibody-dependent cellular cytotoxicity (ADCC). CD16 exists in two main isoforms: CD16a (FcγRIIIA) and CD16b (FcγRIIIB). CD16a is a transmembrane protein expressed on NK cells, macrophages, some monocytes, and mast cells, while CD16b is a GPI-anchored protein primarily found on neutrophils. Upon binding to IgG, CD16 triggers ADCC by NK cells, induces phagocytosis and oxidative burst in neutrophils/macrophages, and promotes cytokine production. Genetic variants in CD16A affect the strength of ADCC responses. CD16 is a key mediator in therapeutic antibody mechanisms against cancer.
Mechanism of Action
Binding to Fc region of IgG antibodies, triggering ADCC, phagocytosis, and cytokine production.
Biological Functions
Disease Associations
Safety Considerations
- Potential for off-target effects with therapeutic antibodies
- Variability in ADCC response due to CD16A polymorphisms
Interacting Drugs
Associated Biomarkers
Biomarker |
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CD16A allelic variants (Val158/Phe158) |
CD16 expression levels on NK cells and other immune cells |