Fresh insight into the immune system could lead to better understanding of diseases that occur when the system fails.
Scientists have discovered that a key protein linked to autoimmune reactions - which occur when the immune system attacks the body - also helps control the responses to disease.
The protein not only activates the production of cells that attack the cause of potential illnesses - such as an invading virus or bacteria - but also controls when to shut down this response.
In this way, the immune system is prevented from overreacting and attacking itself.
Until now, it wasn’t clear what the role of this protein was in the immune system, but it appears to have a role in policing immune response.
A team of scientists led by the University of Edinburgh studied the immune systems of mice.
They found that when the protein PTPN22 was absent, there was an increase in the immune attack response, but also in the number of cells produced to shut down this response.
The increase indicates that the protein has a role in keeping the immune system under control.
The work, carried out with The National Institute for Medical Research, King’s College London and Lund University, was published in the journal Science Signaling.
It was supported by the Wellcome Trust, Arthritis Research UK and the Swedish Medical Council.
Investigating how this protein functions in humans could tell us a great deal about how our bodies manage disease, and could point towards ways in which we might control autoimmunity in future.