Circadian Rhythm and Immunity

I was reading an article the other day about how the time of day can affect how well you fight off bacterial and viral infections.  Blood cells that fight infection have a peak and lag, one such cell is TLR9.  They did an experiment with mice where the mice were infected at times of the day that correlated to certain ebb and flow of the blood cell.  When the TLR9 was high, the mice survived much longer, when it was low, the infected mice died much sooner.  Another part of the study, the part I was interested in, was that mice that were vaccinated at the TLR9 peak had a stronger immune response then those vaccinated at the circadian low point.

It ties in how, if you get sick, the feeling of lethargy happens, how people that have jet lag are much more predisposed to get sick.  A few things you can do to influence your circadian rhythm in a positive manner is to go to bed at regular times, reduce the amount of light you start to take in an hour before bed and try to get natural sunlight on your eyes within an hour of waking.

Here is the article, "Your Body Clock Can Determine When You Get Sick."

Here are a few studies, "Biologic Rhythms in the Immune System."

Effects of Sleep and Circadian Rhythms on Human Immune System.