Many physiological and behavioral functions, including the immune system, exhibit circadian rhythms. We know that circadian rhythms are generated by “clock genes” that affect most organs and cells – including those of the immune system, whose function varies with the time of day.
Research results show that T cells are more prone to being activated at certain times of the day. Identifying the mechanisms by which the biological clock modulates T cell response is helpful to better understand the processes that regulate optimal T cell responses and contribute to improvements in vaccination strategies and cancer immunotherapies.
T cells respond more or less strongly to a foreign body depending on the time of day, but the role of the biological clock in this phenomenon remained unknown. Using a mouse vaccination model, the scientists discovered that the strength of the CD8 T cell response after vaccination varied depending on the time of day. Conversely, in mice whose CD8 T cells for the clock gene were deficient, this circadian rhythm was abolished and the response to the vaccine was lower during the day. CD8 T cells, which are essential for fighting infection and cancer, function very differently depending on the time of day.
Research from the RCSI University of Medicine and Health Sciences has provided new insight into the mechanism behind how our 24-hour circadian body clock affects our immune response to vaccines depending on the time of day. The study examined the changes taking place in the mitochondria of a key immune cell involved in the vaccine response and could help to improve the design and timing of future vaccines to maximize efficacy.
https://www.chronobiology.com/immune-response-to-vaccination-the-role-of-the-circadian-rhythm/
