Macrophages

Macrophages are large white blood cells which act as a first line of defense against infection by engulfing and destroying bacteria, viruses, and dead or abnormal cells. Macrophages play an important role in the body's immune system as they are able to identify and eliminate potentially harmful foreign particles. They also play a role in tissue repair, as they phagocytose (ingest) damaged cells and debris and signal other cells to migrate to the site of injury. Macrophages have various other functions in the body such as regulating inflammation, controlling cholesterol metabolism, and supporting angiogenesis (formation of new blood vessels).