Protein immunity linked to muscular dystrophy

An unintended result of a small study into muscular dystrophy has opened up a new frontier for national gene therapy research.

As part of the first clinical trial addressing gene therapy, researchers studying muscular dystrophy were attempting to use a virus to safely provide patients with the disease a genetic protein that could treat them.

To their surprise, researchers found some patients already had a version of the protein, said R. Jude Samulski, director of the Gene Therapy Center and an author of the study.

He said researchers were puzzled when patients’ bodies mounted an autoimmune response that attacked the good protein as if it were bad.

They hypothesized that the existing protein caused the patients’ bodies to create an immunity to it , similar to immunity to the flu after a shot, he said.

“The body has already seen these fibers, and the immune response is to attack them,” Samulski said.

The discovery means patients in future research trials will need to be screened and treated based on their results, providing researchers with a clearer idea of which course of treatment might be better.

“People hypothesize that this may be seen in all genetic disorders,” Samulski said. “That’s where all the hoopla is coming from.”

Tara Britt, director of research at the Gene Therapy Center, said more projects — even some unrelated to muscular dystrophy — will see increased funding as a result of the new findings.

“I think it will make a significant impact on future funding for the center,” she said.

The University also has one of six Wellstone Centers for Muscular Dystrophy Research in the U.S. These centers focus on curing the disease, with UNC’s center focusing on genetic and cell-based therapy research.

Samulski said the findings in the study will be incorporated into future research studies on patients with the disease.

He said researchers will generate models based on their observations to determine whether suppressing patients’ immune systems or inducing a tolerance to the protein will be most beneficial.

“We would have to model this in the research lab and come back and say, ‘This is the best way to do it,’” Samulski said.
The study is also making waves outside the University.

Jim Brown, spokesman of the Muscular Dystrophy Association, said the study was important not only because of its results but also because of how it was conducted.

“You have a small safety trial that can teach us a tremendous amount,” he said. “It underscores the importance of safety trials.”
Brown said the results will affect future studies.

“When you find a somewhat surprising immune response to a protein that is needed to treat or cure the disease, you are able to refine the approaches you are using,” he said.

“The good news is that all across the world there are elegant minds working on solutions, and they will help zero in on what will work best to keep moving forward.”

Contact the University Editor at udesk@unc.edu.