What is an "antigen-presenting cell"?

An Antigen-presenting cell refers to a diverse group of immune cells that play a crucial role in the immune response by capturing, processing, and presenting antigens to activate other immune cells, such as T cells. They help initiate and regulate immune responses, aiding in the recognition and elimination of pathogens or abnormal cells in the body. Examples of antigen-presenting cells include dendritic cells, macrophages, and B cells.