What is the main purpose of B cells in the immune response?

The primary role of B cells in the immune response is to produce antibodies against specific antigens. When B cells encounter an antigen that matches their specific receptor, they undergo activation and differentiation into plasma cells, which are responsible for the synthesis and secretion of antibodies. These antibodies are crucial for identifying and neutralizing pathogens, such as bacteria and viruses, by binding to them and marking them for destruction or preventing them from entering and infecting healthy cells.

Antibodies serve various functions in the immune response, including neutralization of toxins, opsonization (marking pathogens for phagocytosis), and activating the complement system, which aids in the elimination of pathogens. This specialized response is essential for adaptive immunity, providing long-lasting protection and immunological memory against specific infections.

In contrast, the other roles listed, such as killing infected cells (which is primarily performed by cytotoxic T cells), activating T cells (a function typically executed by antigen-presenting cells), and detecting pathogens (usually done by innate immune cells like macrophages and dendritic cells), do not capture the main function of B cells within the immune landscape.