Scientists have uncovered an unusual link between the immune system and hair growth

© Illustration RIA Novosti . Alina Polarisavenue found that immune cells are the main conductors of hair growthScientists have uncovered an unusual link between the immune system and hair growth© Illustration RIA Novosti . Alina Polyanina

The cause of alopecia or problems with hair growth can be not only excess testosterone, but the improper functioning of immune cells, according to a paper published in the journal Cell.

«Our hair follicles constantly recycled when a hair falls out, the whole structure of the bulb should actually grow again. We always thought that this process depends solely on themselves stem cells, but found that regulatory T cells play a key role in this process. If they are «disable», the hair just stops growing,» explains Michael Rosenblum (Michael Rosenblum) University of California, San Diego (USA).

Many men and some women often begin to lose hair on the forehead or the crown in middle age and often become partially or completely bald by the age of 40. As shown by experiments and observations in recent years, baldness is called two sets of reasons: malfunction of the male hormones that suppress the activity of cells in the hair follicles, and mutations in genes controlling hair growth on the face and other parts of the body.

Rosenblum and his colleagues found one more unexpected participant in this process, watching what you do special immune cells that live permanently inside the skin and actually never leave its borders.

To answer this question, scientists have grown a special breed of mice, immune cells which they could kill at an arbitrary point of the body, to introducing a toxin produced by bacteria — the causative agents of diphtheria. Using these mice, scientists have tried to the skin, purified from immune cells in a similar way.

This led biologists to the idea that immune cells can play a critical role in hair growth. To test this idea, scientists have made the immune cells and stem cells of hair follicles to glow and followed their relationship with the help of microscopes.

It turned out that the so-called regulatory T cells were directly involved in hair growth. They produced chemical signals, protein molecules Jag1, which made follicle’s stem cells to grow and form new hair.

This «skill» of immune cells, as shown by further experiments, it was not related to their core functions of protecting the skin from the development of inflammation. Scientists believe this indicates the joint evolution of such kind of immune cells and hair of mammals, unable to rise again without their help.

According to Rosenblum, disruption of T-cells may be associated with the development of some forms of baldness in people with normal levels of testosterone and violations of the regeneration of the skin while tightening wounds and scratches.