RESEARCHERS in California have found a potential new direction for treatments for baldness with the discovery of a connection between regulatory T-cells, a type of immune system cell, and healthy hair growth.
The study by scientists at the University of California San Francisco published online this week showed that without regulatory T-cells, or Tregs, stem cells in the skin cannot regenerate hair follicles, leading to baldness.
Conversely, replacing the Tregs can reverse baldness, as well as possibly help treat numerous other autoimmune disorders ranging from allergies to serious conditions like lupus, the study suggested.
Michael Rosenblum, an assistant professor of dermatology at UCSF and senior author of the study explained, “Our hair follicles are constantly recycling: when a hair falls out, the whole hair follicle has to grow back. This has been thought to be an entirely stem cell-dependent process, but it turns out Tregs are essential. If you knock out this one immune cell type, hair just doesn’t grow.”
The study said that Tregs normally function as “diplomats,” differentiating between harmful and benign cells and substances and preventing the immune system from attacking the body. If the Tregs are missing or not functioning properly, autoimmune disorders can result.
The Tregs are usually found in the lymph nodes, but the researchers discovered some live permanently in the skin and other tissue, where they have an expanded role in metabolic functions, the study said.
To study their function, the team developed a technique for temporarily removing Tregs from the skin. When they shaved patches of hair from mice to make observations of the affected skin, “We quickly noticed that the shaved patches of hair never grew back, and we thought, ‘that’s interesting,’” Rosenblum was quoted as saying in a news release from the university.
The research, led by UCSF postdoctoral fellow and first author Niwa Ali, suggested that Tregs play a role in triggering hair follicle regeneration.
“It’s as if the skin stem cells and Tregs have co-evolved, so that the Tregs not only guard the stem cells against inflammation but also take part in their regenerative work,” Rosenblum said. “Now the stem cells rely on the Tregs completely to know when it’s time to start regenerating.”