Cell-mediated immunity

Cell-mediated immunity is immune defense carried out chiefly by T lymphocytes and other cells that detect and control infected, abnormal, or foreign cells.

Antigen presentation: The display of antigen fragments by cell-surface molecules for recognition by lymphocytes. T cells typically detect infected cells through peptide antigens displayed on their surfaces.
T cell: A lymphocyte that develops in the thymus and participates in antigen-specific adaptive immunity. T cells are the principal adaptive immune cells behind this form of defense.
Antiviral immunity: Immune mechanisms that prevent or control viral infection in a host. Cytotoxic T cells recognize and remove cells producing viral proteins.
Humoral immunity: Adaptive immunity mediated mainly by antibodies produced by B cells and plasma cells. It targets extracellular pathogens and toxins rather than relying chiefly on cellular killing.
Major histocompatibility complex: A group of genes encoding cell-surface proteins that present peptide antigens to T cells. MHC molecules provide the display platform that lets T cells inspect cells.
Natural killer cell: An innate lymphocyte that kills stressed or abnormal cells without antigen-specific T-cell receptors. NK cells provide cellular killing that complements T-cell recognition.
Tumor immunology: The study of interactions between the immune system and cancer. T-cell surveillance and killing can restrain tumors, while cancers evolve ways to evade it.
B cell: A lymphocyte that can differentiate into antibody-secreting plasma cells or memory cells. B cells anchor antibody-mediated defense, the major adaptive counterpart to T-cell responses.
T-cell receptor: A receptor on T cells that recognizes specific peptide antigens bound to MHC molecules. Its antigen-specific binding initiates many cell-mediated immune responses.
Macrophage: A phagocytic immune cell that engulfs microbes and can present antigens to T cells. Activated macrophages kill microbes that helper T cells identify as threats.

Linked from 12 pages