Arthritis and other inflammatory conditions could be helped by new insights into how the immune response is switched off.
Scientists have discovered how compounds produced by the body’s immune system help to dampen inflammation and prevent damage to healthy tissues.
Their findings suggest 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.
The research could also lead to new treatments for sepsis, where a body-wide immune response causes life-threatening tissue damage.
This discovery opens the door to new approaches for the treatment and prevention of chronic inflammation. We are hopeful that with further research, these treatments could be exploited in the near future.
The compounds – called alpha defensins – are part of the body’s first line of defence against infection. They help to stop bacteria and other infectious agents from reproducing.
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 a study involving human cells, researchers at the University of Edinburgh have shown 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. The team found that 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.
Researchers say their findings could lead to new treatments for chronic inflammatory disorders including rheumatoid arthritis. Such therapies could even prevent the condition from flaring-up in the first place, the team predicts.
There are over 400,000 people living with rheumatoid arthritis in the UK, a painful and debilitating inflammatory condition which can severely impact on the way people live their lives affecting their ability to walk, sit or move.
The study, funded by the Medical Research Council and Arthritis UK, is published in the journal Proceedings of the National Academy of Sciences.