Cell Mediated Immunity Introduction Cytokines Components of Cell Mediated Immunity

Cell Mediated Immunity Introduction Involves specialized lymphocytes call T-cells T-cells mature in thymus Response to intracellular viruses, multicellular parasites, transplanted tissues and cancer

Cell Mediated Immunity Cytokines are chemical messengers Interleukins are cytokines that allow leukocytes to communicate Interferons are cytokines that protect against viruses Chemokines cause leukocytes to move to site of infection

Cell Mediated Immunity Components Helper T Cells (TH ) Cytotoxic T Cells (TC ) Delayed Hypersensitivity T Cells (TD) Suppressor T Cells (TS) Activated Macrophages Natural Killer Cells

Cell Mediated Immunity Helper T Cells Activate B-cells Activate cytotoxic T cells Activate other helper T cells

Cell Mediated Immunity Cytotoxic T Cells Used to attack intracellular pathogens such as viruses, some bacteria, multicellular parasites Attaches to target cell Releases protein perforin which pokes holes in target cell inducing lysis T cells continue as long as antigen is present

Cell Mediated Immunity Delayed Hypersensitivity T Cells Involved in allergic reactions like response to poison ivy and transplanted tissue rejection Originally named because transfer of cell transferred immunity to TB Probably a subpopulation TH cells and TC cells

Cell Mediated Immunity Suppressor T Cells Appears to regulate immune response Probably a subpopulation of helper cells

Cell Mediated Immunity Activated Macrophages Stimulated by ingestion antigens and cytokines from helper T cells Acquire enhanced ability to digest via phagocytosis virus infected cells and intracellular bacteria infected cells Can be antigen presenting cells

Cell Mediated Immunity Nautral Killer Cells Kill virus infected cells, tumor cells and large parasites Not immunologically specific like cytotoxic T cells