antigen presenting cells (APC)

Antigen-presenting cells (APCs) are immune system cells that help identify and activate other immune cells to fight infections. They do this by engulfing invading microbes or infected cells, processing these foreign substances, and then displaying small pieces called antigens on their surface. These displayed antigens act as flags, signaling to T cells (a type of immune cell) that there's a threat. This coordination triggers a targeted immune response, helping the body recognize and destroy harmful pathogens effectively. APCs are essential for initiating and directing adaptive immunity, ensuring a precise and coordinated defense.