What is the role of an antigen in the immune system?

An antigen plays a crucial role in the immune system by inducing the formation of antibodies. Antigens are typically foreign substances, such as proteins on the surface of pathogens like bacteria and viruses, or even allergens, that trigger an immune response when recognized by the body.

When antigens are detected, the immune system responds by activating B cells, which are a type of white blood cell. These B cells then produce specific antibodies that bind to the antigens. This binding helps neutralize pathogens, marking them for destruction by other components of the immune system. Therefore, the ability of antigens to stimulate the production of antibodies is fundamental to the body’s defense mechanism against infections.

The other options highlight different aspects of immune responses or physiological functions but do not accurately reflect the primary role of antigens in the context of the immune system. For instance, while some components of the immune system can signal inflammation or destroy pathogens directly, these processes are not the direct role of antigens themselves. Similarly, regulating blood pressure is unrelated to the function of antigens within immune responses.