study, published in PNAS, found that T cells decrease the inflammatory response of macrophages.
Regulatory T cells can reverse the role of macrophages, which are normally involved in causing inflammation, report scientists at King’s College London.
Under normal circumstances, the immune system creates sustained inflammation around a dangerous pathogen or injury, which tells the body that there is a problem. However, in the case of tumors, certain cellular mechanisms counteract inflammation, which can cause the tumor to go undetected, making it even harder for the body to expel.
“A relatively harmless stimulus, such as a small cut, will automatically be treated by the body as something dangerous and will cause macrophages to promote inflammation. We discovered that it is then the regulatory T cells’ responsibility to make the macrophages promote anti-inflammation to counteract the initial response, as it is not a real danger. This helps keep the immune system stable and prevents the body from overreacting to everything in its environment,” says Leonie Taams, Ph.D., research leader.
“However problems can occur with tumors, where many regulatory T cells promoting a strong anti-inflammatory response are present. Neutralizing an inflammatory response in this scenario can cause the tumor to fall under the radar of the body’s immune system and trick it into believing that there is no problem,” noted Dr. Taams
The findings will be published online in the Proceedings of the National Academy of Sciences.