Power of plants harnessed to fight hemophilia

Researchers at the University of Florida and the University of Central Florida have modified plants to fight hemophilia, a disease linked with legends of European monarchs.

The standard treatment for the disease is infusion with an expensively produced protein that helps the blood to clot. But in some patients the immune system fights the therapy, and in a subset of those, it sets off an allergic reaction that can result in death.

Now boffins at the universities have come up with a way that potentially could help patients develop tolerance to the therapeutic protein before they are in need of treatment.

They genetically modified plants to encapsulate the tolerance-inducing protein within cell walls so that when ingested, it can travel unscathed through the stomach and be released into the small intestines where the immune system can act on it.

The low-cost plant-based system, now being tested in mice, eventually could help improve the lives of many people who have hemophilia and dramatically reduce related health-care costs. The approach also has the potential for use with other conditions such as food allergies and autoimmune diseases.

"We're hoping that our research will, in the future, result in better and more cost-effective therapies," said Roland Herzog, Ph.D., an associate professor of pediatrics, molecular genetics and microbiology in the UF College of Medicine and a member of the UF Genetics Institute, who was one of the study's leaders.

Hemophilia is characterized by defects in the gene that produces a protein required for blood to clot. People with hemophilia can suffer from spontaneous internal bleeding or severe bleeding resulting from minor injuries. Males get the disease, which is linked to the X chromosome, while females are "carriers" who rarely exhibit symptoms. The two forms of the disease - hemophilia A and B - are associated with the absence of proteins called factor VIII and factor IX, respectively.

The findings have been published in the Proceedings of the National Academy of Sciences .