Are NK cells part of innate or adaptive immunity? Explain.
Are NK cells part of innate or adaptive immunity? Explain.
Answered
Natural Killer (NK) cells are part of the innate immune system. They play a crucial role in the body’s initial response to infection and tumor formation. Unlike cells of the adaptive immune system (such as T cells and B cells), which require antigen-specific recognition and prior activation, NK cells can recognize and kill infected or transformed cells directly and without the need for antigen presentation.
NK cells detect stressed, infected, or malignant cells through a balance of activating and inhibitory receptors. They can kill these target cells through the release of cytotoxic granules that induce apoptosis (programmed cell death). Additionally, NK cells produce cytokines, such as interferon-gamma (IFN-γ), which help to shape the immune response. Their ability to act quickly and without prior sensitization makes them a key component of the innate immune defense.