In their recent study, scientist Christopher Hall and his team at the University of Auckland concentrated on neutrophils, a specific type of white blood cell significant for antibacterial defense.
yi du et al. We identified a photoresponsive endometrial timer that regulates time variations in antibacterial activity. Image credit: Summerstock.
The researchers employed zebrafish as a model organism due to its similar genetic composition to humans, and its capability of being raised with a transparent body, facilitating real-time observation of biological processes.
“Previous research has noted heightened immune responses in the morning during the initial stages of active fish,” Dr. Hall explained.
“I believe this reflects an evolutionary adaptation where the host is more vigilant during daylight, thus more prone to encounter bacterial infections.”
Nevertheless, the team aimed to determine how immune responses align with sunlight exposure.
The findings revealed that neutrophils have a circadian clock that activates during the day, boosting their bacterial-killing efficacy.
Most cells in our body maintain a circadian clock to synchronize with external time, thus regulating bodily functions.
Light plays a crucial role in resetting these circadian clocks.
“Given that neutrophils are the first immune cells to respond to inflammatory sites, our results carry significant implications for therapeutic advancements in many inflammatory diseases,” Dr. Hall remarked.
“This discovery opens avenues for developing drugs aimed at neutrophil circadian clocks to enhance our capability to fight infectious diseases.”
Study will be featured in the journal Scientific Immunology.
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Lucia Yi du et al. 2025. Light-regulated circadian timers optimize the bactericidal function of neutrophils and enhance daytime immunity. Scientific Immunology 10 (107); doi: 10.1126/Sciimmunol.Adn3080
Source: www.sci.news
