Which of the following activities is most closely associated with NK cells?

Options:

production of antibodies

release of reactive oxygen intermediates

production of IL-6

killing of virus-infected cells

phagocytosis of bacteria

killing of virus-infected cells

Explanation:

Natural killer (NK) cells is the major component of immune system and a type of white blood cells that play an important role in immunity. Protease enzyme is present in the NK cells.

Natural killer cells can identify the virus infected cells and activates the cascade mechanism to kill the virus cells. Natural killer cells release cytokines that can kill the virus infected cells.

Thus, the correct answer is option 4.