Immune cells mobilized in muscles during physical exercise fight inflammation and boost endurance.
- Regulatory T cells (Tregs) improve the ability of muscles to use energy for fuel and overall endurance during physical exercise.
- In mice that played sports, these cells suppress exercise-induced skeletal muscle inflammation, which is counterproductive to improving performance.
- The latter also promoted muscular metabolic reprogramming.
“We have long known that physical exertion causes inflammation, but we do not fully understand the immune processes involved,” said Kent Langston, a researcher in the laboratory of Diane Mathis, who works at Harvard Medical School (United States). This is why scientists conducted a study published in the journal Science Immunology.
Physical activity: regulatory T cells suppress inflammation in muscles
As part of their work, the team focused on anti-inflammatory T cells, called “regulatory T cells (Tregs)”. These improve the muscles’ ability to use energy as fuel and overall endurance during physical exercise. For the purposes of the research, the scientists analyzed what was happening in these cells taken from the muscles of the hind legs of mice that ran once on a treadmill and of rodents that ran regularly. Then, the authors compared them to muscle cells obtained from sedentary animals.
Muscle cells from mice that ran on treadmills, either once or regularly, showed classic signs of inflammation: greater activity of genes that regulate various metabolic processes and higher levels of chemicals that promote inflammation, including interferon. According to the results, regulatory T cells suppress skeletal muscle inflammation induced by physical activity, which is counterproductive for performance improvement. None of these changes were observed in the muscle cells of sedentary mice.
“It is possible that exercise stimulates Treg activity elsewhere in the body”
In contrast, the metabolic and performance benefits of exercise were only apparent in mice that ran repeatedly. In this group, regulatory T cells also modified muscle metabolism and muscle performance. “Our research suggests that with exercise we have a natural way to stimulate the body’s immune responses to reduce inflammation. We only looked at muscle, but it is possible that exercise stimulates also the activity of Tregs elsewhere in the body”, concluded Diane Mathis, author of the study, in a statement.