Question

Which of the following are effector functions utilized by NK cells?

a. Activation of B cells within secondary lymphoid tissues.
b. Inducing apoptosis of non-infected cells.
c. Activation of complement.
d. Cytokine secretion to activate macrophages.
e. All of the above.

Answer 1

NK cells primarily use inducing apoptosis and cytokine secretion as effector functions, not activation of B cells or the complement system.

Step-by-step explanation:

Among the options provided, the effector functions utilized by NK cells include inducing apoptosis of infected or tumor cells and secreting cytokines to activate macrophages. Option a, activation of B cells, is typically facilitated by helper T cells, not NK cells. Option c, activation of complement, is not a direct function of NK cells but is part of the innate immune system that can be activated through other pathways.

NK cells detect and destroy cells that have become infected with pathogens or that have become cancerous via contact-dependent cytotoxicity and the secretion of cytotoxic granules containing perforin and granzymes. These substances lead to cell death through the process of apoptosis. Moreover, NK cells can produce interferons and other cytokines to recruit and activate other immune cells, including macrophages, thus playing a role in shaping both innate and adaptive immune responses.