CD64 (biology)

CD64 is a type of protein that in humans is encoded by the FCGR1A gene. It is also known as Fc-gamma RI and is a member of the immunoglobulin superfamily. CD64 is a high-affinity Fc receptor and plays a crucial role in the immune system.

Structure

CD64 is a type of integral membrane glycoprotein that consists of a single polypeptide chain of about 72 kDa. It is composed of three extracellular immunoglobulin-like domains, a hydrophobic transmembrane region, and a short cytoplasmic tail.

Function

CD64 plays a vital role in the immune response. It is a receptor for the Fc region of IgG antibodies and can bind to both monomeric and aggregated forms of IgG. This binding triggers a variety of immune functions, including phagocytosis, antibody-dependent cell-mediated cytotoxicity, and release of inflammatory cytokines and chemokines.

Clinical significance

CD64 is expressed on the surface of monocytes and macrophages and is upregulated in response to inflammation or infection. It is therefore used as a marker for sepsis and other inflammatory conditions. In addition, CD64 expression is also increased in certain types of cancer, including leukemia and lymphoma, making it a potential target for immunotherapy.

See also

• Fc receptor
• Immunoglobulin G
• Monocyte
• Macrophage
• Sepsis
• Leukemia
• Lymphoma