Immune System Affected By Body Clock
Feb 17th, 2012
Our vulnerability to infection can vary at different times of the day, a recent study in the U.S. found.
The study, published in the journal Immunity, was based on the findings about a specific protein in the immune system which was affected by changes in body chemistry throughout the day. The study showed that the severity of an infection changes at different times of the day.
Experts believe that new drugs can be desigend to take advantage of the body clock.
Animals, plants, and even bacteria undergo a 24-hour daily routine otherwise known as circadian rhythm. Our bodies experience jet lag when we get out of sync with our environment every time we cross time zones.
The researchers from Yale University School of Medicine are trying to pin down the details of how the immune system changes throughout the day.
Before fighting off an infection, the immune system needs to detect it first. The study focused on one of the proteins responsible in the detection process, Toll-like receptor nine (TLR9). This receptor can identify DNA from bacteria and viruses.
Lab experiments on mice showed that the production and function of TLR9 depended on body clock and differed throughout the day.
Researchers found that immunization during the peak of TLR9 activity significantly improved the immune response.
Experts say that humans with sepsis or systemic infection, have a greater risk of dying between 2 and 6 AM.
The study showed that the severity of infection depend on the specific time of its onset and also changed along with TLR9 activity.
Research leader Prof Erol Fikrig of Yale University, claimed that circadian rhythms and the immune system can now be linked directly at a molecular level. “These findings have important implications in medicine especially with the treatment and prevention of diseases,” he said.
“It seems that the interruptions in circadian rhythms can affect our vulnerability to pathogens.
Dr. Akhilesh Reddy of the University of Cambridge, who is also doing a research on circadian rhythms, said it is already known that timing can influence the immune system’s behavior, but this is one of the first attempts to find out the reasons why.
This could mean that drugs may have to be given at specific times of the day to maximize their effectivity, or they can be designed to target the body clock in order to increase the immune system’s response.
“Pharmaceutical companies are all looking into this and are in the process of screening drugs at specific times of the day,” said Dr. Reddy. “Body clock can have a huge impact on medicine within the next ten years.”