CD47

1. 본문

CD47, also known as integrin-associated protein (IAP), is a transmembrane protein encoded by the *CD47* gene in humans. It belongs to the immunoglobulin superfamily and interacts with various ligands, including integrins, thrombospondin-1 (TSP-1), and signal-regulatory protein alpha (SIRPα).

Here's a breakdown of key aspects of CD47:
Function:

• "Don't eat me" signal: CD47 is widely recognized for its role in sending an anti-phagocytic "don't eat me" signal to macrophages. It achieves this by binding to SIRPα, a protein expressed on macrophages and dendritic cells. This interaction inhibits phagocytosis, the process by which immune cells engulf and destroy other cells.
• Cellular processes: It is involved in several cellular functions, including apoptosis, proliferation, adhesion, cell migration, and immune responses. It also plays a part in insulin secretion and angiogenesis.
• Regulation of immune system: CD47 helps regulate the innate immune system by acting as an inhibitory signal to phagocytic cells such as macrophages, dendritic cells, and neutrophils.
• Thrombospondin-1 (TSP-1) receptor: CD47 acts as receptor for TSP-1, influencing cellular processes, that include cell migration, adhesion, proliferation, apoptosis, and angiogenesis.

• Ubiquitous expression: CD47 is expressed on the surface of many cell types.
• Overexpression in cancer: It is found to be overexpressed in many types of tumor cells. The overexpression of CD47 on cancer cells helps them evade detection and destruction by the immune system.

• Self-recognition: CD47 plays a crucial role in self-recognition. It signals to the immune system which cells are healthy and should be protected.
• Aging and clearance of cells: It helps in the disposal of aged or diseased cells. For example, young red blood cells have high levels of CD47, which decrease as they age, eventually leading to their clearance by macrophages.
• Cancer therapy target: Due to its role in helping cancer cells evade the immune system, CD47 has become a target for cancer immunotherapy. Blocking CD47 with targeted monoclonal antibodies can enable macrophages to phagocytose tumor cells.
• Pulmonary Fibrosis: CD47 is being investigated as a potential therapeutic target for the treatment of pulmonary fibrosis.
• Lymphohematopoietic system: CD47 is a marker of self on red blood cells and important for neutrophil transendothelial migration during inflammation. CD47 is also needed for the expansion and persistence of T-cells.