These cells are the body’s first line of defense, destroying pathogens and infected cells in their early stages, preventing the spread of infection and disease.
NK cells spread through the bloodstream and settle in tissues and organs, and a deficiency of them leads to weakened immunity and increased susceptibility to disease.
The study involved 60 Saudi female students aged between 17 and 23 years, who answered questionnaires that included social and demographic data and symptoms of anxiety and insomnia. They also provided blood samples to determine the proportions of NK cells and their subtypes.
NK cells are divided into two subtypes:
CD16+CD56dim: The most common, it connects the central nervous system to the rest of the body and is characterized by the ability to kill invading cells.
CD16+CD56high: Less common, and involved in the production and regulation of immune-activating proteins.
The surveys showed that approximately 53% of participants reported sleep disturbances indicative of insomnia, and 75% reported symptoms of anxiety, including 17% and 13% suffering from moderate and severe symptoms respectively.
The study showed that female students suffering from anxiety or insomnia had a lower percentage and number of NK cells and their subtypes in their blood compared to those without these symptoms. It also revealed that the severity of the symptoms had a direct impact: students with moderate to severe anxiety symptoms had a significantly lower number of these cells, while those with mild symptoms showed no statistically significant difference.
Dr. Renad Al-Hamawi, Assistant Professor of Immunology and Immunotherapy at Taibah University and lead author of the study, explained: “Understanding the effect of psychological stress on the activity of immune cells, especially natural killer cells, may help in uncovering the mechanisms of inflammation and tumor formation.”
Researchers suggest that a decrease in NK cells may weaken the immune system, increasing the risk of chronic diseases, cancers, and mental health disorders, including depression. They also emphasized that the study was limited to young women, necessitating future research encompassing diverse age groups, genders, and geographic regions to gain a more comprehensive understanding.
Previous studies have indicated that a healthy lifestyle, including regular exercise, stress reduction, and a balanced diet, can enhance the number and function of NK cells.
The study was published in the journal Frontiers in Immunology.
