Navigation Links
Researchers develop gene therapy that could correct a common form of blindness

A new gene therapy method developed by University of Florida researchers has the potential to treat a common form of blindness that strikes both youngsters and adults. The technique works by replacing a malfunctioning gene in the eye with a normal working copy that supplies a protein necessary for light-sensitive cells in the eye to function. The findings are published today (Monday, Jan. 23) in the Proceedings of the National Academy of Sciences online.

Several complex and costly steps remain before the gene therapy technique can be used in humans, but once at that stage, it has great potential to change lives.

"Imagine that you can't see or can just barely see, and that could be changed to function at some levels so that you could read, navigate, maybe even drive it would change your life considerably," said study co-author William W. Hauswirth, Ph.D., the Rybaczki-Bullard professor of ophthalmology in the UF College of Medicine and a professor and eminent scholar in department of molecular genetics and microbiology and the UF Genetics Institute. "Providing the gene that's missing is one of the ultimate ways of treating disease and restoring significant visual function."

The researchers tackled a condition called X-linked retinitis pigmentosa, a genetic defect that is passed from mothers to sons. Girls carry the trait, but do not have the kind of vision loss seen among boys. About 100,000 people in the U.S. have a form of retinitis pigmentosa, which is characterized by initial loss of peripheral vision and night vision, which eventually progresses to tunnel vision, then blindness. In some cases, loss of sight coincides with the appearance of dark-colored areas on the usually orange-colored retina.

The UF researchers previously had success pioneering the use of gene therapy in clinical trials to reverse a form of blindness known as Leber's congenital amaurosis. About 5 percent of people who have retinitis pigmentosa have this form, which affects the eye's inner lining.

"That was a great advance, which showed that gene therapy is safe and lasts for years in humans, but this new study has the potential for a bigger impact, because it is treating a form of the disease that affects many more people," said John G. Flannery, Ph.D., a professor of neurobiology at the University of California, Berkeley who is an expert in the design of viruses for delivering replacement genes. Flannery was not involved in the current study.

The X-linked form of retinitis pigmentosa addressed in the new study is the most common, and is caused by degeneration of light-sensitive cells in the eyes known as photoreceptor cells. It starts early in life, so though affected children are often born seeing, they gradually lose their vision.

"These children often go blind in the second decade of life, which is a very crucial period," said co-author Alfred S. Lewin, Ph.D., a professor in the UF College of Medicine department of molecular genetics and microbiology and a member of the UF Genetics Institute. "This is a compelling reason to try to develop a therapy, because this disease hinders people's ability to fully experience their world."

Both Lewin and Hauswirth are members of UF's Powell Gene Therapy Center.

The UF researchers and colleagues at the University of Pennsylvania performed the technically challenging task of cloning a working copy of the affected gene into a virus that served as a delivery vehicle to transport it to the appropriate part of the eye. They also cloned a genetic "switch" that would turn on the gene once it was in place, so it could start producing a protein needed for the damaged eye cells to function.

After laboratory tests proved successful, the researchers expanded their NIH-funded studies and were able to cure animals in which X-linked retinitis pigmentosa occurs naturally. The injected genes made their way only to the spot where they were needed, and not to any other places in the body. The study gave a good approximation of how the gene therapy might work in humans.

"The results are encouraging and the rescue of the damaged photoreceptor cells is quite convincing," said Flannery, who is on the scientific advisory board of the Foundation Fighting Blindness, which provided some funding for the study. "Since this type of study is often the step before applying a treatment to human patients, showing that it works is critical."

The researchers plan to repeat their studies on a larger scale over a longer term, and make a version of the virus that proves to be safe in humans. Once that is achieved, a pharmaceutical grade of the virus would have to be produced and tested before moving into clinical trials in humans. The researchers will be able to use much of the technology they have already developed and used successfully to restore vision.

Contact: Czerne M. Reid
University of Florida

Related biology news :

1. Researchers meet to refine carbon budget for US East Coast
2. Penn researchers help solve questions about Ethiopians high-altitude adaptations
3. Notre Dame researchers report fundamental malaria discovery
4. Researchers find gene critical to sense of smell in fruit fly
5. Native forest birds in unprecedented trouble, according to University of Hawaii at Manoa researchers
6. Researchers discover green pesticide for citrus pests
7. 2-timing and hybrids: RUB researchers look back on 100 million years of evolution
8. Researchers identify possible receptor for key breast cancer regulator
9. UH Manoa researchers discover novel chemical route to form organic molecules
10. Researchers: Honeybee deaths linked to seed insecticide exposure
11. Worm seeks worm: Caltech researchers find chemical cues driving aggregation in nematodes
Post Your Comments:
(Date:11/9/2015)... JOSE, Calif. , Nov. 9, 2015  Synaptics ... human interface solutions, today announced broader entry into the ... vehicle-specific solutions that match the pace of consumer electronics ... and biometric sensors are ideal for the automotive industry ... vehicle. Europe , ...
(Date:10/29/2015)... , Oct. 29, 2015  The J. Craig ... report titled, "DNA Synthesis and Biosecurity: Lessons Learned and ... Department of Health and Human Services guidance for synthetic ... 2010. --> --> ... also has the potential to pose unique biosecurity threats. ...
(Date:10/29/2015)... 2015 NXTD ) ("NXT-ID" ... on the growing mobile commerce market and creator ... a leading marketplace to discover and buy innovative ... wallet on StackSocial for this holiday season.   ... "Company"), a biometric authentication company focused on the ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... 25, 2015 Studies reveal the ... plaque and pave the way for more effective treatment for ...     --> --> ... health problems in cats, yet relatively little was understood about ... studies have been conducted by researchers from the WALTHAM Centre ...
(Date:11/25/2015)... DIEGO , Nov. 25, 2015  Neurocrine Biosciences, ... Kevin Gorman , President and CEO of Neurocrine Biosciences, ... Healthcare Conference in New York . ... to visit the website approximately 5 minutes prior to ... A replay of the presentation will be available on ...
(Date:11/25/2015)... ... November 25, 2015 , ... ... Organization of Black Aerospace Professionals (OPBAP) has been formalized with the signing of ... team leaders met with OPBAP leaders Capt. Karl Minter and Capt. Albert Glenn ...
(Date:11/25/2015)... PORTLAND, Oregon , November 25, 2015 /PRNewswire/ ... Deep Market Research Report is a professional and ... Genomics industry.      (Logo: ... basic overview of the industry including definitions, classifications, ... analysis is provided for the international markets including ...
Breaking Biology Technology: