What is the primary function of B cells in the immune system?

B cells play a crucial role in the immune system primarily through the production of antibodies. These specialized lymphocytes develop from stem cells in the bone marrow and, upon encountering a specific antigen, they undergo activation and differentiation. Once activated, B cells can transform into plasma cells that secrete large amounts of antibodies into the bloodstream.

These antibodies are proteins specifically designed to recognize and bind to particular antigens, such as those found on pathogens like bacteria and viruses. This binding facilitates various immune responses, including neutralizing the pathogen directly, marking it for destruction by other immune cells, or preventing it from entering and infecting host cells.

The capacity to produce highly specific antibodies is a key aspect of the acquired immune response, enabling the body to remember past infections and mount a faster and more effective response upon re-exposure to the same pathogen. This functionality underscores the importance of B cells in both immediate immune defense and long-term immunity.