What is a B cell?

A B cell is a type of lymphocyte that plays a crucial role in the adaptive immune response by differentiating into plasma cells, which are responsible for producing antibodies. When B cells encounter an antigen, they can undergo a process of activation and maturation that allows them to develop into plasma cells. These plasma cells then secrete large amounts of antibodies specific to the antigen, helping to neutralize pathogens or mark them for destruction by other immune cells.

The focus on plasma cell differentiation is significant because it highlights the primary function of B cells in the humoral immune response, which is distinct from other immune processes. This differentiation also underscores their importance in immunological memory; once activated, some B cells can become memory cells, which provide long-lasting immunity by responding more rapidly and effectively upon future exposures to the same antigen.