What role do B cells play in the immune response?

B cells play a critical role in the immune response primarily by producing antibodies. When B cells encounter a pathogen, they can differentiate into plasma cells, which are responsible for generating antibodies specific to the antigens present on the pathogen. These antibodies bind to the pathogens, neutralizing them or marking them for destruction by other immune cells. This process is vital for the humoral immune response, providing long-term immunity by creating memory B cells that can quickly respond to future infections by the same pathogen.

While B cells do contribute to other aspects of immune function, such as assisting in antigen presentation to T cells, their primary and most defining role is the production of antibodies. This function distinguishes them from other components of the immune system, such as T cells, which play a direct role in killing infected cells and regulating the immune response through cytokine release.