Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Potential new herpes therapy studied

05.02.2009
A new therapy being developed at the University of Florida could, in time, produce another weapon for the fight against herpes.

The gene-targeting approach uses a specially designed RNA enzyme to inhibit strains of the herpes simplex virus. The enzyme disables a gene responsible for producing a protein involved in the maturation and release of viral particles in an infected cell.

The technique appears to be effective in experiments with mice and rabbits, but further research is required before it can be attempted in people who are infected with herpes.

"If things worked out the best they could, I think this could be a measure to prevent recurrence, and that would help a lot of people — and even if it just reduced severity, it would give us another therapy in cases where there is drug resistance," said David Bloom, Ph.D., a virologist at the UF College of Medicine who leads the interdisciplinary research team investigating the new therapy.

The work was published in the Journal of Virology in August.

The HSV-1 strain of the herpes virus causes cold sores or fever blisters around the mouth, genital herpes, a deadly but rare type of encephalitis, and keratitis, a scarring of the cornea that leads to vision loss. HSV-2 is the more common cause of genital herpes.

Existing herpes treatments work because the active ingredients target viral building blocks, and become incorporated into the virus' genetic material and shut down its ability to make copies of itself. In so doing, the drugs limit the severity of herpes lesions.

"They work pretty well, and they keep the disease in check, but there's no real cure," said Alfred Lewin, Ph.D., a molecular geneticist on the research team.

Current treatments also can cause inflammation, and in many people the virus becomes resistant and there is no back-up medication. In HSV keratitis, even after a corneal transplant the virus can hide out in nerve cells and cause re-infection.

"Our approach would keep it from popping up again," Lewin said.

The UF team — which also includes researchers and clinicians from obstetrics and gynecology, orthopedics and ophthalmology and the university's Genetics Institute — came up with a way to cut the virus' RNA to prevent reactivation.

By designing special enzymes called hammerhead ribozymes, the researchers were able to target a so-called "late" gene that releases its protein product relatively late after infection. With late genes, partial corruption of the genetic material is sufficient to shut down virus production, as opposed to "early" genes, which would require total inactivation to hinder the process.

"What I think is remarkable with the technology is its versatility — you can design ribozymes that will be effective against any pathogenic virus you're interested in inhibiting," said John M. Burke, a professor of microbiology and molecular genetics at the University of Vermont, who has studied the use of ribozymes for treating viral infections.

Burke, who is not affiliated with the research at UF, said that finding the way to get the ribozyme into an infected cell or animal or person in such a way that it can be active once inside is "the hard part" of these types of experiments.

The University of Florida team packaged the enzyme inside an adenovirus — the type of virus that causes the common cold — and injected it into the mice. Afterward, the animals were infected with potentially lethal doses of the HSV-1 virus. As a control, other mice were injected with green fluorescent protein before being exposed to the virus.

Ninety percent of the mice that were treated with the ribozyme survived, whereas the survival rate was less than 45 percent in mice not given the special enzyme.

Analysis of tissue from treated mice revealed lower viral DNA levels in the feet, nerve cells called dorsal root ganglia and the spinal cord than in mice not treated with the ribozyme.

The approach has also been tested in mouse tissue and in rabbits.

"They have found a very good experimental system in which they can convincingly show significant antiviral activity," Burke said.

But the researchers still need to do more checks to see whether it is safe to move to human testing. Also, they want to develop more than one ribozyme, because having enzymes that attack different places on the viral RNA during replication helps prevent the virus from successfully mutating to resist treatment. They are also trying different ways of delivering the enzyme to the host cells.

One delivery technique for the eye is called iontophoresis, in which a low current pushes the treatment into the cells. The ribozyme could also be formulated into a cream to be used topically on other parts of the body.

"I would like to have it where you put it on once and forget about it," Lewin said.

The work is funded by University of Florida Office of Translational Research, Research to Prevent Blindness and The Burroughs Wellcome Fund.

"I think we've gotten it to the point where it looks promising," Bloom said.

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

More articles from Health and Medicine:

nachricht Indications of Psychosis Appear in Cortical Folding
26.04.2018 | Universität Basel

nachricht GLUT5 fluorescent probe fingerprints cancer cells
20.04.2018 | Michigan Technological University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Why we need erasable MRI scans

New technology could allow an MRI contrast agent to 'blink off,' helping doctors diagnose disease

Magnetic resonance imaging, or MRI, is a widely used medical tool for taking pictures of the insides of our body. One way to make MRI scans easier to read is...

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

World's smallest optical implantable biodevice

26.04.2018 | Power and Electrical Engineering

Molecular evolution: How the building blocks of life may form in space

26.04.2018 | Life Sciences

First Li-Fi-product with technology from Fraunhofer HHI launched in Japan

26.04.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>