Cell-mediated immunity is a type of adaptive immune response that involves the activation of T cells to directly target and destroy infected cells or cancer cells.

Helper T cells activate other immune cells and cytotoxic T cells directly kill infected or cancerous cells.

Helper T cells secrete cytokines that activate cytotoxic T cells and B cells, which then carry out the immune response.

Cytotoxic T cells release cytotoxic molecules that directly kill infected or cancerous cells.

T cells recognize antigens presented on the surface of antigen-presenting cells (APCs) via major histocompatibility complex (MHC) molecules.

MHC molecules bind to antigens and present them on the surface of APCs, allowing T cells to recognize and respond to the antigens.

MHC class I molecules present antigens to CD8+ cytotoxic T cells, which are responsible for killing infected or cancerous cells.

MHC class II molecules present antigens to CD4+ helper T cells, which activate other immune cells and help B cells produce antibodies.

Memory T cells remain in the body after an infection and can quickly respond to the same pathogen if it is encountered again, providing long-term immunity.

Cell-mediated immunity involves T cells and targets intracellular pathogens, while humoral immunity involves B cells and targets extracellular pathogens. Cell-mediated immunity also provides long-term immunity through memory T cells.

Interleukin-2 (IL-2) is a cytokine produced by helper T cells that activates cytotoxic T cells and promotes their proliferation.

Natural killer (NK) cells are a type of innate immune cell that can directly kill infected or cancerous cells without prior sensitization.

CD8 is a molecule expressed on the surface of cytotoxic T cells that binds to MHC class I molecules on target cells, allowing the cytotoxic T cell to kill the target cell.

Regulatory T cells (Tregs) are a type of T cell that suppresses the immune response to prevent excessive inflammation and autoimmune reactions.

Interferon-gamma (IFN-γ) is a cytokine produced by helper T cells that activates macrophages and promotes phagocytosis, helping to clear intracellular pathogens.