The effectiveness of our immune system could be directly linked to the time of the day it is triggered, new research has shown.
The discovery could in time lead to the development of more useful drugs for targeting autoimmune disease.
The study by scientists at Trinity College Dublin and the Royal College of Surgeons, found that when a particular gene that controls the body clock is removed in mice, it causes a more severe form of an autoimmune disease similar to multiple sclerosis.
The same result happens when autoimmunity is triggered at midday instead of midnight.
Our bodies maintain a 24-hour cycle in tune with our planet, known as the circadian rhythm which is generated by our body clock.
Having a good body clock is important for our health, studies have shown, and certain immune diseases have been linked to the problem.
The master gene that controls circadian rhythm is BMAL1 and it is also responsible for sensing and acting on time-of-the-day cues to suppress inflammation.
"Our exciting findings suggest that our immune system is programmed to respond better to infection and insults encountered at different times in the 24-hour clock," said Kingston Mills, Professor of Experimental Immunology at Trinity College Dublin.
"This has significant implications for the treatment of immune-mediated diseases and suggests there may be important differences in time of day response to drugs used to treat autoimmune diseases such as multiple sclerosis."
The results of the study, published in the journal Nature Communications, also provide fresh insight into how disruption to body clocks may have an impact on autoimmune conditions said Dr Annie Curtis, Research Lecturer in the Department of Molecular and Cellular Therapeutics at RCSI.
"We are really beginning to uncover exactly how important our body clocks are for health and wellbeing."
However, further work will be required to unearth how the circadian rhythm can be optimised to benefit the immune system.