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Updated: Jul 31, 2025

Dissecting Innate Immune Signaling in Viral Evasion of Cytokine Production
Published on: March 2, 2014
An Aging-Susceptible Circadian Rhythm Controls Cutaneous Antiviral Immunity
Abstract:
Aged skin is prone to viral infections, but the mechanisms responsible for this immunosenescent immune risk are unclear. We observed that aged murine and human skin expressed reduced antiviral proteins (AVPs) and circadian regulators including Bmal1 and Clock. Bmal1 and Clock were found to control rhythmic AVP expression in skin and such circadian-control of AVPs was diminished by disruption of immune cell interleukin 27 signaling and deletion of Bmal1/Clock genes in mouse skins, as well as siRNA-mediated knockdown of CLOCK in human primary keratinocytes. We found that treatment of circadian enhancing agents, nobiletin and SR8278, reduced infection of herpes simplex virus 1 (HSV1) in epidermal explants and human keratinocytes in a Bmal1/Clock-dependent manner. Circadian enhancing treatment also reversed susceptibility of aging murine skin and human primary keratinocytes to viral infection. These findings reveal an evolutionarily conserved and age-sensitive circadian regulation of cutaneous antiviral immunity, underscoring circadian restoration as an antiviral strategy in aging populations.
Insights
Aging skin
Area of Science:
- Immunology
- Dermatology
- Chronobiology
Background:
- Aged skin exhibits increased susceptibility to viral infections.
- The underlying mechanisms of this immunosenescence-related immune risk are not fully understood.
Conclusions:
- Aged skin's antiviral immunity is regulated by an evolutionarily conserved, age-sensitive circadian mechanism.
- Restoring circadian function presents a promising antiviral strategy for combating infections in aging individuals.
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