CD47

CD47, also known as integrin-associated protein (IAP), is a transmembrane protein that in humans is encoded by the CD47 gene. It is a member of the immunoglobulin superfamily and is ubiquitously expressed on the surface of cells. CD47 plays a crucial role in a variety of cellular processes, including apoptosis, proliferation, adhesion, and migration. It is involved in the regulation of innate and adaptive immune responses and acts as a "don't eat me" signal to the immune system, particularly to macrophages and other phagocytic cells.

Function

CD47 interacts with several ligands, including thrombospondin-1 (TSP-1) and signal-regulatory protein alpha (SIRPα). Through its interaction with SIRPα, which is predominantly expressed on macrophages and dendritic cells, CD47 delivers a signal that inhibits phagocytosis. This interaction is critical for the self-recognition mechanism of the immune system, preventing the immune system from attacking the body's own cells. However, this mechanism is also exploited by cancer cells to avoid being phagocytosed and destroyed by the immune system.

In addition to its role in immune evasion, CD47 is involved in the regulation of cell migration and adhesion, processes that are essential for wound healing and the response to inflammation. CD47 also plays a role in the cardiovascular system, where its interaction with TSP-1 regulates blood pressure and has implications for cardiovascular disease.

Clinical Significance

The "don't eat me" signal provided by CD47 is exploited by various types of cancer cells to avoid destruction by the immune system. This has led to the development of therapeutic strategies aimed at blocking the CD47-SIRPα interaction to enhance the phagocytosis of cancer cells. Antibodies targeting CD47 have shown promise in preclinical models and are currently being evaluated in clinical trials for the treatment of multiple types of cancer.

Moreover, the role of CD47 in cardiovascular diseases and its potential as a therapeutic target in conditions such as atherosclerosis and myocardial infarction is an area of active research. Targeting CD47 could potentially offer new avenues for the treatment of these conditions.

Genetics

The CD47 gene is located on human chromosome 3q13.2 and consists of four exons. Variants and mutations in the CD47 gene have been studied in the context of their potential association with disease susceptibility, particularly in cancer and cardiovascular diseases.

See Also

• Immunoglobulin superfamily
• Macrophage
• Phagocytosis
• Cancer
• Cardiovascular disease
• Thrombospondin-1
• Signal-regulatory protein alpha