Cell mediated immunity

Pathogens invade body cell or is engulfed by phagocyte

phagocyte places antigens from pathogen on cell membrane

receptors on a specific helper t-cell are complementary to these antigens

stimulates t-cell to divide rapidly via mitosis, forms genetically identical cells

one type of cloned t-cell stimulates B-cells to divide and secrete antibodies

one type of cloned t-cell stimulates phagocytosis by phagocytes

T-memory cells: enable a rapid response to future infections by same pathogen

divides into cytotoxic t-cell which punch holes in membrane of pathogen

produces a protein called perforin which punches holes in pathogen cell

these holes mean the pathogen is freely permeable to any substances and quickly dies as a result. T-cells are most effective against viruses as they use body cells to replicate