Abstract

From bacteria to mammals, nearly all organisms have adapted their physiology and behavior to a daily rhythm. These circadian (daily) rhythms influence virtually all aspects of physiological architecture (i.e., from gene expression to organismal behavior). Therefore, it is not surprising that several features of the immune response are regulated in a time-of-day dependent manner. The field of chrono-immunology has expanded tremendously over the past decade. In this abridged review, we present studies from the past five years that have revealed new parameters of the immune system that demonstrate daily variations in the control of pathogens and response to microbial components. These studies analyzed how the disruption of circadian rhythms impairs immune function, how microbial components alter the circadian clock, and how immune responses demonstrate daily variations in human subjects. Further elucidating the intricate connections between the circadian clock and the immune system will hopefully provide opportunities for chrono-immunotherapy in disease treatment and prevention.

https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC6585517/

The post Time is on the Immune System’s Side, Yes it is appeared first on EMFSA.

Date: November 24, 2021

Source: RCSI

Summary: New research has demonstrated the significant role that an irregular body clock plays in driving inflammation in the body’s immune cells, with implications for the most serious and prevalent diseases in humans.

Snippet:

Dr George Timmons, lead author on the study, said: “Our results add to the growing body of work showing why disruption of our body clock leads to inflammatory and infectious disease, and one of the aspects is fuel usage at the level of key immune cells such as macrophages.”

Dr Annie Curtis, Senior Lecturer at RCSI School of Pharmacy and Biomolecular Sciences and senior author on the paper, added: “This study also shows that anything which negatively impacts on our body clocks, such as insufficient sleep and not enough daylight, can impact on the ability of our immune system to work effectively.”

Journal Reference:

1. George A. Timmons, Richard G. Carroll, James R. O’Siorain, Mariana P. Cervantes-Silva, Lauren E. Fagan, Shannon L. Cox, Eva Palsson-McDermott, David K. Finlay, Emma E. Vincent, Nicholas Jones, Annie M. Curtis. The Circadian Clock Protein BMAL1 Acts as a Metabolic Sensor In Macrophages to Control the Production of Pro IL-1β. Frontiers in Immunology, 2021; 12 DOI: 10.3389/fimmu.2021.700431

https://www.sciencedaily.com/releases/2021/11/211124154033.htm

The post Researchers find new link between a disrupted body clock and inflammatory diseases appeared first on EMFSA.

Abstract

Night shift work is a risk factor for viral infection, suggesting that night shift schedules compromise host defense mechanisms. Prior studies have investigated changes in the temporal profiles of circulating cytokines important for priming and restraining the immune response to infectious challenges from night shift work, but not by way of a 24-h constant routine of continuous wakefulness devoid of behavioral or environmental influences. Hence the true endogenous pattern of cytokines, and the combined effect of sleep loss and circadian misalignment on these cytokines remains unknown. Here, 14 healthy young men and women underwent three days of either a simulated night shift or a simulated day shift schedule under dim light in a controlled in-laboratory environment. This was followed by a 24-h constant routine protocol during which venous blood was collected at 3-h intervals. Those who had been in the night shift schedule showed lower mean circulating TNF-α (t₁₃ = -6.03, p < 0.001), without any significant differences in IL-1β, IL-8 and IL-10, compared with those who had been in the day shift (i.e., control) schedule. Furthermore, circulating IL-6 increased with time awake in both shift work conditions (t₁₃ = 6.03, p < 0.001), such that temporal changes in IL-6 were markedly shifted relative to circadian clock time in the night shift condition. These results indicate that night shift work compromises host defense by creating cytokine conditions that initially impede anti-viral immunity (lower TNF-α) and may eventually promote autoimmunity (mistimed rise in IL-6).

https://www.sciencedirect.com/science/article/pii/S2451994421000043?via%3Dihub

The post Night shift schedule alters endogenous regulation of circulating cytokines appeared first on EMFSA.