Natural killer (NK) cells are a type of lymphocyte that plays a critical role in the immune system's early response to viral infections. They recognize and destroy cells infected by viruses without the need for prior antigen exposure or activation by other immune cells. NK cells release cytotoxic granules that induce apoptosis (programmed cell death) in the target cell.

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Natural Killer Cells

Question 20

Multiple Choice

Natural killer cells

A) recognize, ingest, and destroy antigens.
B) contribute to inflammatory and allergic reactions.
C) assist in the activation of T cells through the secretion of cytokine.
D) attack and destroy cells infected by viruses.

Correct Answer: