What is the primary function of B lymphocytes?

B lymphocytes, also known as B cells, play a crucial role in the adaptive immune response primarily by producing antibodies. When B cells encounter a specific antigen, they differentiate into plasma cells that secrete antibodies tailored to target that particular antigen. These antibodies circulate in the bloodstream and bind to pathogens, marking them for destruction by other immune cells or neutralizing their ability to infect other cells.

This antibody-mediated response is vital for recognizing and remembering pathogens, providing long-term immunity and protection against re-infection. The ability to produce a diverse array of antibodies enables the immune system to respond effectively to a vast number of different pathogens, making B cells essential for adaptive immunity.