| There are two branches of the immune response: humoral and cell-mediated.
Humoral immunity involves the activity of B lymphocytes, antibodies, and related cytokines. B cells respond to the presence of antigens and differentiate into antibody-secreting plasma cells. Antibodies can neutralize antigens, activate phagocytic cells, or recruit lytic enzymes to destroy foreign cells. A percentage of B cells differentiate into memory cells, which are implicated in the stronger humoral response upon reexposure to the same antigen.
Cell-mediated immunity involves T cells and related cytokines. Unlike B cells, T cells require antigen presentation via the major histocompatibility complex (MHC) for activation. |