What does Fc mean in immunology?
The fragment crystallizable region (Fc region) is the tail region of an antibody that interacts with cell surface receptors called Fc receptors and some proteins of the complement system. This property allows antibodies to activate the immune system.
Which Fc receptors are involved in ADCC?
Antibody-dependent cell cytotoxicity ADCC is an adaptive immune response largely mediated by NK cells through the CD16 (FCγRIII) receptor that binds the Fc portion of IgG antibodies triggering the lysis of targeted cells.
What is the ligand for Fc gamma receptors?
Fc gamma receptor I (FcγRI) The most distinctive property of FcγRI is its relatively high affinity for ligand. Fc gamma receptor I binds non-complexed monomeric immunoglobulins. Fc gamma receptor I is the only IgG Fc receptor for which the binding of monomeric ligand can be measured directly.
Do T cells express Fc receptors?
The different cell types of the lymphoid-myeloid lineage constitutively express various Fc receptors. The exception is the T-cell lineage where most subsets express Fc receptors only during a narrow window following cellular activation.
What kind of receptor is the Fc gamma receptor?
Fc gamma receptor definition Fc gamma receptor (FcγR) is a receptor for the Fc portion of IgG. All of the Fc gamma receptors (FcγR) belong to the immunoglobulin superfamily.
Where is Fc gamma RI expressed in the body?
The high affinity recognition of IgG by Fc gamma RI permits the triggering of effector responses at low IgG concentrations typical of early immune responses (2). Fc gamma RI is expressed constitutively on monocytes and macrophages and can be induced on neutrophils and eosinophils (1, 4).
Where does the IgG Fc bind to Fc receptors?
The IgG Fc contains distinct Fc receptor (FcR) binding sites: the leukocyte receptors Fc gamma RI and Fc gamma RIIa bind to a region in the Fc distinct from that recognized by neonatal FcR and protein A
How are FcγRI receptors different from other receptors?
This property allows FcγRI to bind a sole IgG molecule (or monomer ), but all Fcγ receptors must bind multiple IgG molecules within an immune complex to be activated. The Fc-gamma receptors differ in their affinity for IgG and likewise the different IgG subclasses have unique affinities for each of the Fc gamma receptors.