Natural killer (NK) cells are cytotoxic immune cells with an innate capacity for eliminating cancer cells and virus- infected cells. NK cells are critical effector cells in the immunosurveillance of cancer and viral infections. Patients with low NK cell activity or NK cell deficiencies are predisposed to increased risks of cancer and severe viral infections. However, functional alterations of human NK cells are associated with lifestyles and aging. Personal lifestyles, such as cigarette smoking, alcohol consumption, stress, obesity, and aging are correlated with NK cell dysfunction, whereas adequate sleep, moderate exercise, forest bathing, and listening to music are associated with functional healthy NK cells. Therefore, adherence to a healthy lifestyle is essential and will be favorable for immunosurveillance of cancer and viral infections with healthy NK cells.
Keywords: NK cell; aging; cancer; immunosurveillance; lifestyle; viral infection.