Health Market Science

A recent study published in the journal, Immunity found the success of host immune defense partially depends on an organism's body clock. By further understanding the impact of the circadian clock, researchers aim to develop therapeutic strategies designed to optimize the immune response and protect patients when the response is low and they are more vulnerable.

According to the study conducted at Yale University, many organisms have an evolved endogenous timing system known as a circadian clock that regulates metabolic activities on a 24 hour cycle. Disruption of daily rhythms, such as lack of sleep, can significantly affect the body's immune response.

Dr. Erol Fokrig who led the study said the team was investigating whether circadian clocks can control the immune system's ability to detect a pathogen, and if there are any time-associated consequences for the immune response.

By examining the expression and function of an immune system protein that can sense bacterial and viral DNA, the researchers found the circadian clocked was able to control the protein. Mice immunized when the immune system protein was most responsive showed an enhanced immune response, and the disease severity of sepsis was dependent on the timing of induction, directly correlated to the changes in the immune system protein. Therefore, septic patients might be at an increased risk of mortality between 2 a.m. and 6 a.m., and should be monitored.

Fikrig said the results of the study illustrate the power of the circadian clock over the body's immune system, as well as opens up doors as to how patients should be treated in response to this cycle.

"Furthermore, patients in the ICU often have disturbed sleep patterns, due to noise, nocturnal light exposure and medications; it will be important to investigate how these factors influence (immune system protein) expression levels and immune responses," Fikrig said.

Also studying circadian rhythms at the University of Cambridge, Dr. Akhilesh Reddy told BBC that it was understood in the medical community that the immune system's response had to do with timing, but this study explains why that is true. Implications of the study suggest drugs could be more effective when administered at certain times of the day, or drugs could be developed to activate the circadian clock to push the immune system into its most active phase on command.