CD47-blocking antibodies restore phagocytosis and prevent atherosclerosis.

Abstract

SummaryAtherosclerosis is the disease process underlying heart attack and stroke1. Advanced lesions at risk for rupture are characterized by the pathological accumulation of diseased vascular cells and apoptotic cellular debris2. Why these cells are not cleared remains unknown3. Here we show that atherogenesis is associated with upregulation of CD47, a key ‘don’t eat me’ molecule known to render malignant cells resistant to programmed cell removal (PrCR), or ‘efferocytosis’4–7. We find that administration of CD47 blocking antibodies reverses this defect in efferocytosis, normalizes the clearance of diseased vascular tissue, and ameliorates atherosclerosis in multiple mouse models. Mechanistic studies implicate the pro-atherosclerotic factor TNF-α as a fundamental driver of impaired PrCR, explaining why this process is compromised in vascular disease. Similar to recent observations in cancer5, impaired efferocytosis appears to play a pathogenic role in cardiovascular disease, but is not a fixed defect and may represent a novel therapeutic target.