Researchers say they have found clues in DNA that may explain what causes the auto-immune disease multiple sclerosis (MS).
Published in the journal Immunity, the study was led by the University of Geneva (UNIGE). They identified something called TOX in humans, a DNA-binding factor, which was only found in cells when activated by a viral pathogen.
The team had used two pathogens – another being bacterial – to study the immune system of healthy mice. It was only the mice infected with the viral pathogen, however, that developed a brain disease similar to MS. Removing TOX from the healthy mice given the viral pathogen, the team found they did not develop the disease.
“We decided to analyse the infectious factors by studying the auto-immune reactions provoked by different pathogens," Doron Merkler from UNIGE, a co-author on the study, said in a statement. "This was to try to pinpoint an element that might influence the development of multiple sclerosis where there has been an infection".
MS affects 1 in every 1,000 people, and can cause a number of symptoms include problems with vision, movement, and balance. Although sometimes mild, it is a lifelong condition that can be extremely debilitating. There is no cure for the condition, although its symptoms can sometimes be treated.
The cause of it is not clear, although genetic factors are thought to play a part, as are things like smoking and other infections. This research, however, sought to hone in on the genetic component, and find what was at play.
"We found that the inflammation environment influences the expression of TOX in T lymphocytes, and that it could play a role in triggering the illness," Nicolas Page, also from UNIGE and the study’s lead author, said in the statement.
The reason TOX may play a part is due to our brains “limited regenerative capacity,” according to Merkler. When it tries to fight the virus, it sets up barriers to stop T lymphocytes. But TOX allows cells to cross the barrier and attack the brain, causing the onset of MS.
The team now plan to investigate the role TOX plays in other auto-immune diseases and cancer on the back of this research.