Leukocyte surface antigen CD47 (CD47)

CD47, also known as Integrin-associated protein (IAP), is a ubiquitously expressed transmembrane glycoprotein belonging to the immunoglobulin superfamily (UniProt: Q08722). It serves as a critical "don't eat me" signal by interacting with Signal Regulatory Protein Alpha (SIRPα) on the surface of phagocytes, such as macrophages and dendritic cells, to inhibit phagocytosis (PubMed: 23045607). In many cancers, CD47 is overexpressed as a mechanism of immune evasion, allowing malignant cells to avoid clearance by the innate immune system (NCBI Gene: 961). Therapeutic strategies targeting CD47, including monoclonal antibodies, decoy receptors, and mRNA-silencing techniques like siRNA, aim to disrupt the CD47-SIRPα axis to restore pro-phagocytic signaling and enhance anti-tumor immunity. While promising, targeting CD47 faces challenges such as "antigen sink" effects and off-target toxicity, particularly hemolytic anemia, due to the high expression of CD47 on aged red blood cells (PubMed: 31110134).

Other names

Integrin-associated proteinIAPMER6OA3Protein MER6Antigenic surface determinant protein OA3

Inhibition of the "don't eat me" signal by blocking the interaction between CD47 and Signal Regulatory Protein Alpha (SIRPα) on macrophages, thereby enhancing phagocytosis of tumor cells. mRNA-targeted approaches utilize RNA interference (siRNA) to reduce CD47 protein expression.