Osmosis video - B-cell activation, differentiation, and contraction

B cells are activated when they encounter an antigen that they recognize. The antigen binds to the B cell's surface receptors, which activates and triggers it to divide and differentiate into an antibody-secreting plasma cell. Plasma cells produce antibodies that bind to the antigen and neutralize it.

The differentiation process is controlled by various factors, including cytokines, lymphokines, and chemokines. Each of these molecules signals the B cells to differentiate into a certain type of plasma cell.