New insights into how the body´s immune response is switched off could lead to new treatments for rheumatoid arthritis and other inflammatory conditions.
Scientists have discovered how compounds produced by the immune system help to dampen inflammation and prevent damage to healthy tissues.
These compounds, called alpha defensins, help to stop bacteria and other infectious agents from reproducing. Previous studies have suggested that the compounds may also act on cells of the immune system to prevent excessive inflammation but until now it was not clear how the process works.
In the latest study, which was funded by Arthritis Research UK, researchers at the University of Edinburgh found that alpha defensins are released by immune cells called neutrophils when they die. The alpha defensins are then taken up by other immune cells called macrophages and the compounds prevent macrophages from producing messenger molecules called cytokines, which drive inflammation.
The overall effect is to limit excessive inflammation, restricting damage to healthy tissues without compromising the body´s ability to clear the infection, the University of Edinburgh explained.
The researchers believe that therapies based on these compounds could help to treat rheumatoid arthritis, which occurs when the immune system attacks the joints, causing pain and swelling. Such therapies could even prevent the condition from flaring-up in the first place, they predict.
“This discovery opens the door to new approaches for the treatment and prevention of chronic inflammation,” said Dr. Mohini Gray at the University of Edinburgh/Medical Research Council (MRC) Centre for Inflammation Research. “We are hopeful that with further research, these treatments could be exploited in the near future.”
The findings of the study have been published in the journal Proceedings of the National Academy of Sciences.