Faculty Collaboration Database

Environmental circadian disruption elevates the IL-6 response to lipopolysaccharide in blood. J Biol Rhythms 2013 Aug;28(4):272-7

Date

08/10/2013

Pubmed ID

23929554

Pubmed Central ID

PMC4097096

DOI

10.1177/0748730413494561

Scopus ID

2-s2.0-84881471131 (requires institutional sign-in at Scopus site)   47 Citations

Abstract

The immune system is regulated by circadian clocks within the brain and immune cells. Environmental circadian disruption (ECD), consisting of a 6-h phase advance of the light:dark cycle once a week for 4 weeks, elevates the inflammatory response to lipopolysaccharide (LPS) both in vivo and in vitro. This indicates that circadian disruption adversely affects immune function; however, it remains unclear how the circadian system regulates this response under ECD conditions. Here, we develop an assay using ex vivo whole-blood LPS challenge to investigate the circadian regulation of immune responses in mice and to determine the effects of ECD on these rhythms. LPS-induced IL-6 release in whole blood was regulated in a circadian manner, peaking during subjective day under both entrained and free-running conditions. This LPS-induced IL-6 release rhythm was associated with daily variation in both white blood cell counts and immune cell responsiveness. ECD increased the overall level of LPS-induced IL-6 release by increasing immune cell responsiveness and not by affecting immune cell number or the circadian regulation of this rhythm. This indicates that ECD produces pathological immune responses by increasing the proinflammatory responses of immune cells. Also, this newly developed whole blood assay can provide a noninvasive longitudinal method to quantify potential health consequences of circadian disruption in humans.

Author List

Adams KL, Castanon-Cervantes O, Evans JA, Davidson AJ

Author

Jennifer A. Evans PhD Assistant Professor in the Biomedical Sciences department at Marquette University

MESH terms used to index this publication - Major topics in bold

Animals
Blood Cell Count
Cell Separation
Circadian Rhythm
Environment
Enzyme-Linked Immunosorbent Assay
Interleukin-6
Leukocyte Count
Lipopolysaccharides
Macrophages
Male
Mice
Mice, Inbred C57BL
Motor Activity
Neutrophils