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Mice vitiligo

Photos courtesy of Loyola University Chicago Stritch School of Medicine

Mice with vitiligo, characterized by white patches of fur (shown left), were treated with a mutant protein, HSP70i. The results offered a complete restoration of color to the fur (right).

Loyola researchers engineer protein to combat the skin disorder vitiligo

by Jason Peterson
Feb 28, 2013

The disfiguring skin disorder vitiligo could be reversed using a genetically modified protein engineered by researchers at Loyola University Chicago’s Stritch School of Medicine.

According to Chicago dermatologist Jeffrey Karaban, the findings would be “life-altering” if a consistently effective treatment using the protein can be produced. Karaban isn't associated with the research.

The research was announced Wendesday in the the journal Science Translational Medicine.
If the university’s pending application for a patent is cleared, the researchers hope to gain approval for funding clinical trials in humans. The research has so far been limited to mice but preliminary tests on human skin tissue samples have also yielded promising results, according to Loyola researcher Caroline Le Poole.

Le Poole, a professor in Loyola's Oncology Institute, and her colleagues scoured through the 641 amino acids that make up the protein HSP70i, known to play a vital role in autoimmune responses causing vitiligo. The skin disorder robs skin of pigment, leaving irregular white patches with the same texture as normal skin.

“We were looking for the region of the molecule that would be responsible for activating vitiligo,” Le Poole said. “That’s where we introduced our mutation to find out which ones would have an effect on the immune response that follows and which ones totally interfered with the response. This was a one of the ones that if you modified it, it had a totally different effect.”

Le Poole injected the mutated version of the protein in a group of dark-colored mice that developed vitiligo, characterized by distinctive, white patches of fur. The mutant protein replaced the normal HSP70i found in the mice and within a matter of weeks, the color was fully restored.

Le Poole has been studying vitiligo and the melanin-producing skin cells called melanocytes for more than 20 years and considers her most recent findings a milestone in her career.

“I don’t know if anybody else has set out to do that,” said Le Poole, who came from the Netherlands to Loyola as a research assistant in 1999. “It’s really because of the questions we ask that has led us in this direction.

“We’re trying to understand why is it autoimmune?” she continued. “Why is the immune system attacking your own skin cells? What is it they recognize? What’s the initial trigger that sets off the response?”

According to the National Institutes of Health, vitiligo appears to occur when immune cells destroy the pigment-producing melanocytes because the body’s immune system sees them as a threat. It affects one in 100 Americans and symptoms may be hereditary.

“We know it’s a genetic predisposition,” Le Poole said. “But certain chemicals and other environmental factors can also play into it.”

Prominent names with vitiligo include pop singer Michael Jackson, actor and comedian Joe Rogan and former Chicago Bears fullback J.D. Runnels.

Karaban, of Lincoln Park Dermatology, said vitiligo is among the more stressful conditions he sees in his patients.

“It is depressing for some of them and some get used to it,” he said. “But I think most people who don’t have it are more uncomfortable about it than people who have it.”

Karaban said the effects of vitiligo are increased among people of color, causing a greater contrast between the person’s skin and the depigmented patches.

“In some ethnic groups, the people are sort of alienated because of it,” he said.

Dermatologists rely on a variety of tools to treat vitiligo, none of which are long-term solutions: steroid creams, ultraviolet light therapy, vitamin D therapy, Protopic, a prescription drug, and skin grafts, which can be painful and expensive.

Le Poole said there are a number of steps to be taken before the mutant protein can be approved for commercial treatment.

“We’d need to figure out what it does to other immune responses or if there are some undesirable effects,” she said. “It takes a lot of time and money. If everything falls into place, we could do that in two years."

Of course, the need to treat vitiligo, otherwise a harmless condition, depends on the individual. Some people may be perfectly fine with it.

“Everyone has a different level of acceptance with their bodies,” Karaban said. “It’s a part of their life.”

Loyola scientists, the primary researchers, collaborated with Rush University Medical Center and other insitutions.