Final answer:
CD8 T Cells and NK cells both contribute to immune defense by targeting infected or abnormal cells, with CD8 T Cells being part of the adaptive immune system and requiring activation by APCs, and NK cells as innate immune components acting without prior activation. Both cell types release cytokines to amplify the immune response but differ in their recognition and engagement strategies.
Step-by-step explanation:
CD8 T Cells and NK cells are both crucial to the immune system, but they function in different ways. CD8 T Cells, also known as cytotoxic T lymphocytes (CTLs), express the CD8 glycoprotein on their surfaces and interact with antigen-presenting cells (APCs) by binding to antigen-embedded MHC I molecules. They play a significant role in the adaptive immune response by directly killing infected cells through induction of apoptosis, in addition to releasing cytokines.
NK cells, part of the innate immune system, do not require antigen presentation to target infected or abnormal cells. They have the ability to induce apoptosis by releasing proteins such as granzymes and perforins without prior sensitization. Unlike T cells, NK cells do not have antigen-specific receptors but rather rely on a balance of activating and inhibiting signals to determine whether to engage a potential target.
Both CD8 T Cells and NK cells have cytotoxic capabilities; however, NK cells act without the need for a prior activation event. Regarding similarities, both cell types release cytokines that contribute to the immune response amplification. Additionally, they both are involved in the detection and elimination of virally infected cells and tumor cells through different mechanisms.