Fc receptor

Fc receptors are membrane receptors for different immunoglobulin isotypes. All molecules other than the FcRn receptor belong to the immunoglobulin superfamily. The name is based on the binding specificity of the receptors to which a portion of an antibody Fc fragment ( fragment Sheet crystallisable ) is called.

The Fcα receptor ( CD89 ) binding the Fc domain of IgA. The receptor is found on the surface of monocytes, macrophages, neutrophils and eosinophils.

The Fcε receptors bind the Fc domain of free IgE. They are found on the surface of mast cells and basophils. By the binding of antigens to these bound antibodies there is an activation of the mast cell. This process plays a critical role in type I allergy. There are two types in mammals of Fcε receptors distinguished FcεRI with high affinity and low affinity FcεRII to IgE.

The Fcy receptors bind the Fc domain of IgG. They are found on the surface of phagocytes, B- lymphocytes, NK cells and dendritic cells. These receptors can recognize aggregated IgG molecules and bind them. The binding triggers depending on the cell type, different reactions: eg opsonization or ADCC ( NK ​​) cells. There are different types of structure of the Fcy receptor ( FcγRI or CD64, FcγRII or FcγRIII or CD32 and CD16 ).

Neonatal Fcy receptor ( FcRn ) belongs to the MHC superfamily and binds IgG with low affinity.

• Receptor
• Immunology
• Protein group