CD47-mediated efferocytosis in diseases: A comprehensive review.

Efferocytosis is a vital process by which phagocytes, such as macrophages, recognize and clear apoptotic cells, making it essential for maintaining tissue homeostasis and promoting the resolution of inflammation. Impaired efferocytosis can lead to the secondary necrosis of apoptotic cells and the continuous release of inflammatory factors, thereby contributing to the occurrence and development of various diseases, including tumors, atherosclerosis (AS), autoimmune diseases, and neurodegenerative diseases. CD47, a transmembrane glycoprotein widely expressed on the cell surface, binds to signal regulatory protein α (SIRPα) on the macrophage surface to transmit the classic "don't eat me" signal, which negatively regulates the efferocytic process. Under pathological conditions, abnormally high CD47 expression helps abnormal cells evade immune clearance; as a result, the CD47/SIRPα axis has gradually become an important immune checkpoint in the regulation of efferocytosis. Focusing on CD47-mediated efferocytosis, this paper reviews its molecular mechanisms and recent research progress in diseases like tumors and AS, with the aim of providing new insights for the immunotherapy and clinical translation of related disorders.