Cell-mediated vs Humoral Immunity
(Similarities and Differences between Cell-Mediated and Humoral Immunity)
The immunity induced in an organism by the exposure of a foreign antigen is called Active Immunity. The active immunity is mediated through two distinct mechanisms, and they are named as (1) Cell-mediated immunity and (2) Humoral immunity. These two immune pathways show considerable differences in their components, their targets, and the method of killing of pathogens.
Cell-mediated immunity: The cell-mediated immunity is facilitated by the activated TH cells (T-Helper cells) and Cytotoxic T Lymphocytes (CTLs). Cytokines secreted by the TH cells activate the phagocytic cells. These activated phagocytic cells then phagocytosis and kill the microbes. The cell-mediated immunity is particularly important against the bacterial and protozoan pathogens.
Humoral Immunity (antibody-mediated immunity): The Humoral immunity is mediated through antibodies. Antibodies are produced by the B cells. These antibodies bound to specific microbial antigens. Binding of antibodies to antigens neutralize the microbes and target them for elimination by various effector mechanisms. The humoral immunity is the major defense mechanism against the extracellular microbes trying to invade the host systems.