Muscle regeneration is helped by regulatory T-lymphocytes

Immune cells treat muscles

Kirill Stasevich, Compulenta

Among the great variety of immune cells, there are those that help keep immune reactions in check: if you let the immune system get carried away, it will provoke full–scale inflammation and begin, for good, to destroy healthy cells - and this is an autoimmune disease. To prevent this from happening, the immune system itself limits militancy with the help of so-called regulatory T-cells.

For a long time, these cells have been studied as brakes for other cells fighting bacteria and viruses. Their role has been studied in allergies, autoimmune disorders, and the immune response to cancer. However, as scientists from Harvard Medical School (USA) found out, regulatory T cells have another, rather unexpected function: they take an active part in muscle recovery.

It's true, oddities in the behavior of regulatory T cells were discovered a few years ago. In 2009, Diane Mathis and her colleagues noticed that T-regulators show some strange craving for certain tissues, while demonstrating functions that are not quite characteristic of them. So, in adipose tissue, these cells participated in the regulation of tissue sensitivity to insulin and glucose.

In a new paper published in the journal Cell, researchers describe the behavior of cells in skeletal muscles of mice (Burzyn et al., A Special Population of Regulatory T Cells Potentiates Muscle Repair). If they were damaged, then sooner or later regulatory T-cells appeared in them – which was quite natural, because it was necessary to somehow muffle the immune reaction that began in response to the wound. However, these cells remained in the muscles even after the inflammation subsided, and remained for a long time, which is not quite usual.

Interestingly, these same cells settled in the muscles of those mice in which the researchers provoked muscular dystrophy or whose muscles ached due to another genetic mutation. In all cases, the muscle regulatory T cells differed from the usual regulatory T cells: those in the muscles actively produced proteins that helped the muscle tissue to recover. If there were no T cells in the muscles, then the damage was eliminated more slowly: stem cells could not multiply in the muscles as they should for tissue repair.

It turns out that regulatory T cells are needed not only to control the immune response, but also to guide repair work, to control stem cells.

Naturally, it is impossible not to think about possible use in the clinic, but researchers cannot yet say whether human regulatory T cells are capable of controlling the regenerative processes in muscle tissue. Of course, I would like our immune cells not to be limited only to muscles, but to take care wherever possible: with their help, you see, it would be possible to make our stem cells demonstrate their regenerative functions more energetically.

Prepared based on the materials of the Harvard University Medical School:
Under Repair. New research implicates immune system cells in muscle healing.

Portal "Eternal youth" http://vechnayamolodost.ru10.12.2013