Cell-mediated immunity is a type of immune response that involves the activation of specific immune cells to target and destroy infected or abnormal cells. It is distinct from humoral immunity, which involves the production of antibodies to target foreign substances. Cell-mediated immunity is important for protecting the body against infectious diseases caused by viruses and intracellular bacteria. The immune response is initiated when antigen-presenting cells present foreign antigens to T cells, which then become activated and differentiate into effector cells that can recognize and kill infected or abnormal cells. Cell-mediated immunity also involves the production of cytokines, which help regulate the immune response, and it is involved in the development and progression of autoimmune diseases