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Updated: Jun 18, 2026
06:50
The Use of Mouse Splenocytes to Assess Pathogen-associated Molecular Pattern Influence on Clock Gene Expression
Published on: July 24, 2018
A circadian clock in macrophages controls inflammatory immune responses
Maren Keller1, Jeannine Mazuch, Ute Abraham
1Laboratory of Chronobiology, Institute for Medical Immunology, Charité-Universitätsmedizin, 10117 Berlin, Germany.
Summary
The study reveals that macrophages possess intrinsic circadian clocks regulating immune responses, independent of systemic factors. This finding deepens our understanding of how the body's internal clock influences innate immunity.
Area of Science:
- Immunology
- Chronobiology
- Molecular Biology
Background:
- Time of day influences immune system parameters, a phenomenon known as circadian variation.
- The circadian clock is implicated in coordinating these immune variations, but the underlying molecular mechanisms are not fully understood.
Purpose of the Study:
- To systematically investigate the link between the circadian clock and rhythmic immune functions.
- To elucidate the molecular basis of circadian rhythms in innate immune responses.
Main Methods:
- Investigated intrinsic circadian clockworks in mouse spleen, lymph nodes, and peritoneal macrophages.
- Stimulated isolated spleen cells and primary macrophage cultures with bacterial endotoxin at different circadian times.
- Analyzed macrophage transcriptome oscillations.
Main Results:
- Mouse immune organs and macrophages exhibit autonomous circadian clockworks.
- Circadian rhythms in inflammatory cytokine (TNF-alpha and IL-6) secretion were observed in spleen cells.
- These rhythms are governed by local macrophage circadian clocks, not systemic glucocorticoids or spleen cell composition.
- Over 8% of the macrophage transcriptome shows circadian oscillation, including genes involved in pathogen recognition and cytokine secretion.
Conclusions:
- The circadian clock, particularly within macrophages, plays a crucial role in regulating innate immune functions.
- Understanding the interplay between the circadian clock and the immune system is vital for comprehending physiological and pathophysiological immune responses.
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