Cell death caused by the action of perforin, which is produced by cytotoxic T lymphocytes in certain cell-mediated immune reactions, is associated with
A. activation of initiating and effector caspases
B. inhibition of adenosine triphosphate (ATP)-dependent sodium/potassium pump
C. increased water content of the cytoplasm
D. influx of sodium into the cytoplasm
E. activation of growth factor XORs on the cell surface
A
Through the action of perforin, T lymphocytes induce apoptosis, a form of cell death, characterized by activation of "suicide pathway enzymes," the most notable of which are caspases. Inhibition of the ATP-dependent sodium/potassium pump, resulting in an influx of water and sodium into the cell cytoplasm, is typical of ischemic or toxic cell injury leading to vacuolar (hydropic) change or necrosis. Cell surface growth factor receptors are not activated by perforin.
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