In a review published May 17 in the journal Trends in Immunology , researchers discuss how time of day affects the severity of afflictions ranging from allergies to heart attacks.
Researchers in Switzerland compiled studies, predominantly in mice, that looked at the connection between circadian rhythms and immune responses. For example, studies showed that adaptive immune responses--in which highly specialized, pathogen-fighting cells develop over weeks--are under circadian control. This is "striking," says senior author Christoph Scheiermann, an immunologist at the University of Geneva, "and should have relevance for clinical applications, from transplants to vaccinations."
The body reacts to cues such as light and hormones to anticipate recurring rhythms of sleep, metabolism, and other physiological processes. In both humans and mice, the numbers of white blood cells also oscillate in a circadian manner, raising the question of whether it might be possible one day to optimize immune response through awareness and utilization of the circadian clock.
In separate studies that compared immune cell time-of-day rhythms under normal conditions, inflammation, and disease, researchers found that:
"Investigating circadian rhythms in innate and adaptive immunity is a great tool to generally understand the physiological interplay and time-dependent succession of events in generating immune responses," Scheiermann says. "The challenge lies in how to channel our growing mechanistic understanding of circadian immunology into time-tailored therapies for human patients."
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This work was supported by the German Research Foundation, the European Research Council, and the Swiss National Science Foundation.
Trends in Immunology , Pick and He et al.: "Time-of-Day-Dependent Trafficking andFunction of Leukocyte Subsets" https://www.cell.com/trends/immunology/fulltext/S1471-4906(19)30074-2
Trends in Immunology ( @TrendsImmuno ), published by Cell Press, is a monthly review journal that plays an essential role in monitoring advances in the various fields of immunology, bringing together developments in basic and clinical immunology in a readable and lucid form. Visit: http://www.cell.com/trends/immunology . To receive Cell Press media alerts, contact press@cell.com .
Trends in Immunology