circadian cycle tagged posts

Ability of immune system to destroy Alzheimer’s-related protein oscillates with daily circadian rhythm. The brain’s ability to clear a protein closely linked to Alzheimer’s disease is tied to our circadian cycle, according to research published today in PLOS Genetics. The research underscores the importance of healthy sleep habits in preventing the protein Amyloid-Beta 42 (AB42) from forming clumps in the brain, and opens a path to potential Alzheimer’s therapies.

“Circadian regulation of immune cells plays a role in the intricate relationship between the circadian clock and Alzheimer’s disease,” said Jennifer Hurley, an expert in circadian rhythms, and associate professor of biological science at Rensselaer Polytechnic Institute...

The body’s ability to prevent food poisoning by producing a natural antimicrobial compound increases during the day, when exposure to noxious bacteria is most likely, a new study by UT Southwestern scientists suggests. The findings, published online in Cell, could eventually lead to timed therapies and vaccination regimens designed to maximize this immune response.

“This study shows that our immune systems are not turned on all the time, which is an unexpected result,” says study leader John F. Brooks II, Ph.D., a postdoctoral fellow in the laboratory of Lora Hooper, Ph.D., study co-leader and professor of immunology and microbiology at UTSW. “Our findings suggest that there are peak times in which the body is more primed to fight infections.”

Researchers have long known that vi...

A microscopic image of a mouse lymph node. Credit: Image courtesy of Kazuhiro Suzuki

Researchers in Japan have discovered that the adrenergic nervous system controls when white blood cells circulate through the body, boosting the immune response by retaining T and B cells in lymph nodes at the time of day when they are most likely to encounter foreign antigens. On their way around the body, T and B cells pass through lymph nodes, where specialized cells may present them with antigens from bacteria or other pathogens. The T and B cells then reenter the bloodstream in search of these pathogens so that they can kill them. Previous studies have suggested that number of T and B cells present in the bloodstream varies over the course of the day.

Kazuhiro Suzuki and colleagues from the WPI Immuno...