Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers harness the power of plants to fight hemophilia

31.03.2010
Hemophilia, a disease linked with legends of European monarchs, frail heirs and one flamboyant charlatan called Rasputin, still afflicts many people today.

And the very treatments that can help can also put patients' lives at risk.

The standard treatment 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 researchers at the University of Florida and the University of Central Florida have devised 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.

The findings were published Monday in the Proceedings of the National Academy of Sciences.

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.

Many people around the world have the disease — 1 in 5,000 boys are born with hemophilia A, the more common of the two forms.

Hemophilia treatment consists of infusing the missing protein into a patient's blood. But in 25 percent of patients, the immune system rejects the therapy and makes inhibitors that stop the clotting factor from taking effect.

In hemophilia B, up to 4 percent of patients develop inhibitors to the protein therapy and many develop severe systemic allergic reactions, called anaphylaxis, which can be life-threatening.

"If the very protein that you administer to the patient is neutralized, it's as if you haven't administered any protein at all," said Thierry Vandendriessche, Ph.D., an associate professor of medicine at the University of Leuven in Belgium, and president of the European Society of Gene Cell Therapy. He was not involved in the study.

Because treatment itself poses a potential threat to life, it has to be done in a hospital setting under supervision. That makes it an expensive enterprise that often includes blood transfusions and hospital stays costing up to $1 million. Average treatment costs are $60,000 to $150,000 a year, according to the National Hemophilia Foundation.

To help patients tolerate therapy, doctors try to exhaust patients' immune systems by administering the therapeutic protein intravenously at frequent intervals and for long periods until the body no longer responds by producing inhibitors. While that brute force approach works for hemophilia A, it often doesn't for hemophilia B, in which patients risk death from anaphylactic shock if exposed to the protein therapy.

To find a new, gentler approach to developing tolerance, Herzog teamed with Henry Daniell, Ph.D., a Pegasus professor and University Board of Trustees Chair in the College of Medicine at the University of Central Florida, who has spent the last two decades developing transgenic plants for producing and delivering oral vaccines and immune-tolerant therapies.

They inserted the gene responsible for producing the therapeutic protein into the genome of plants. To maximize the amount of protein produced, they inserted thousands of copies of the genes into chloroplasts — the energy-producing centers of plants — using a gene gun.

The research team, including first authors Dheeraj Verma, Ph.D., and Babak Moghimi, M.D., fed the encapsulated protein to hemophilic mice for an extended period. Surrounded by the hardy plant cell walls, the protein was protected from digestive acids and enzymes while traveling through the stomach. Once it arrived safely in the small intestines, however, surrounding bacteria chewed on the cell walls, causing the protein to be released and acted on by the immune system to induce tolerance.

When the mice were later treated intravenously with the clotting factor therapy, they produced little or no inhibitors, and none developed anaphylactic shock.

"We have made them develop tolerance, and removed the allergic part of this treatment," Daniell said.

Not only did the pretreated mice survive the once-deadly treatment — they also had a greater positive effect from therapy than did other mice.

"You may wonder, 'why hasn't this happened before,'" Vandendriessche said. "It's because it was difficult to administer a high amount of protein in the right place and at the right time. I think this is a milestone — nobody has previously achieved such levels of robust immune tolerance by any means using a noninvasive procedure."

The researchers will continue to study how their method works, extend the approach to treating hemophilia A in mice and, ultimately, conduct trials in humans. Protein used in the human trials will be produced in lettuce and formulated to allow delivery of standard doses.

Czerne M. Reid | EurekAlert!
Further information:
http://www.ufl.edu

More articles from Life Sciences:

nachricht The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

nachricht Transforming plant cells from generalists to specialists
07.12.2016 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>