Category Archives: Gene therapy

Six kids are healthy, up to three years after treatment

By Tina Hesman Saey

Web edition: July 11, 2013

A virus derived from HIV can safely fix broken immune systems and correct genetic diseases, suggest two new studies involving children with rare conditions.

For both studies, researchers put healthy genes into the childrens own DNA using lentiviruses, in this case genetically engineered versions of HIV that can no longer cause disease. Earlier gene therapy trials using different viruses had a flaw: When the viruses plunked themselves into the patients DNA, they sometimes amped up activity of neighboring cancer-causing genes, leading to leukemia. That side effect, along with the death of a young man participating in another clinical trial, nearly halted gene therapy in the United States in the early 2000s.

Now, researchers led by Luigi Naldini of the San Raffaele Telethon Institute for Gene Therapy in Milan have altered the lentiviruses so that they wont accidently turn on nearby genes. The researchers then infect bone marrow stem cells with lentiviruses carrying the appropriate gene and transplant the stem cells into patients.

In one study, three boys with Wiskott-Aldrich syndrome, an inherited disease that disables the immune system, received gene therapy. Now, two to three years after the therapy, the former bubble boys have healthy immune systems, Naldini and colleagues report July 11 in Science. The boys also show no signs of developing leukemia which should help allay concerns about the teams gene therapy approach, says Todd Rosengart, a surgeon and gene therapy researcher at Baylor College of Medicine in Houston.

In the second trial, Naldini and his colleagues treated three children with a metabolic disease called metachromatic leukodystrophy. Children with the disease lack an important enzyme. As a result, they gradually become paralyzed and suffer damage to their ability to think, dying within a couple of years. Up to two years after the therapy, the children in the study are still making enough of the enzyme to keep their brain and spinal cord working normally with no sign of leukemia, the researchers report in the same issue of Science.

The results are encouraging, says Uta Griesenbach, a gene therapist at Imperial College London. Even after fairly long-term follow up, it appears to be safe and effective. The boys arent out of the woods yet some of the patients in the original gene therapy trials didnt develop cancer until four years after treatment. But Griesenbach says that the children in the new studies dont have warning signs of cancer.

Because the lentiviruses appear safe and work so well, scientists may start doing gene therapy for more common conditions such as Parkinsons disease, says Senlin Li, a medical researcher at the University of Texas Health Science Center at San Antonio.

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Gene therapy treats children with rare diseases

Scientists have developed a genetic therapy to treat two rare childhood diseases using a component of the HIV virus.

The research, which was detailed in two studies published in Science on June 11, showed that scientists were able to use an HIV virus vector -- which acts as a tool to help put genetic material into cells -- on three children with metachromatic leukodystrophy and three others with Wiskott-Aldrich syndrome. Their diseases have stopped progressing and some of the patients have stopped showing symptoms for 18 to 32 months following the therapy.

Using a vector of the virus, the mechanism in which it gets into cells, is not the same as giving the children the actual HIV virus.

"Three years after the start of the clinical trial, the results obtained from the first six patients are very encouraging. The therapy is not only safe, but also effective and able to change the clinical history of these severe diseases," author Luigi Naldini, a researcher from the San Raffaele Telethon Institute for Gene Therapy, said in a press release.

Metachromatic leukodystrophy is an inherited genetic mutation that causes fats called sulfatides to collect in cells, especially in those that produce a substance that surrounds and protects nerves, called myelin. In patients with the disorder, the sulfatide collection ends up destroying the white matter that makes up part of the nervous system. This affects the brain, spinal chord and sensory cells that registered touch, pain, heat and sound.

Eventually the patients no longer have cognitive functions or motor skills, and they cannot feel different sensations. Other symptoms include seizures, paralysis, inability to speak, blindness, hearing loss and eventually loss of awareness. There is currently no cure.

About one out of 40,000 to 160,000 people worldwide have the disorder, the National Institutes of Health reports. The most common form of the condition, called late infantile form, affects 50 to 60 percent of people with the disorder starting at about 2 years old. Twenty to 30 percent of patients will have a juvenile form which begins to manifest around the age of 4 through adolescence. The adult form affects 15 to 20 percent of patients with metachromatic leukodystrophy, and starts appearing during teenage years or later.

People with Wiskott-Aldrich syndrome do not have a normal immune system and have a harder time creating blood clots. The disease, which is caused by an inherited genetic mutation on the X chromosome, causes abnormal or nonfunctional white blood cells, which puts the patients at risk of immune and inflammatory disorders.

The condition is typically found in males, and has an incidence of 1 to 10 cases per one million males, the NIH said. It is rarely found in women. Wiskott-Aldrich can be treated if the patients receive a bone marrow or stem cell transplant, which can work very well if the donation is a close match.

The researchers used an HIV virus vector to insert a corrected form of defective genes at the root of these diseases into the patients' own blood stem cells. Then, the healthy blood stem cells were surgically implanted in to the subject.

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Gene therapy using part of HIV virus treats two rare childhood diseases

Italian researchers have used a defanged version of HIV to replace faulty genes and eliminate devastating symptoms in children suffering two rare and fatal genetic diseases.

Improved gene therapy techniques prevented the onset of metachromatic leukodystrophy in three young children and halted the progression of Wiskott-Aldrich syndrome in three others.

The advance represents a major stride for a field that has struggled to translate experimental successes in lab animals into safe and effective treatments for people, experts said. Researchers may be able to use the team's method as a template, modifying it to treat a variety of diseases.

This is "ammunition for the gene therapy world," said Dr. Theodore Friedmann, a pediatric gene therapist at UC San Diego, who was not part of the study. "The field is slowly but surely making impressive advances against quite untreatable diseases."

The scientists published results from the two clinical trials Thursday in the journal Science.

Metachromatic leukodystrophy affects just 1 in 40,000 to 1 in 160,000 people worldwide; Wiskott-Aldrich syndrome, only 1 to 10 per million males. But both illnesses are devastating. Children with late infantile metachromatic leukodystrophy, the most common form of that disease, begin having trouble walking about a year old and soon after experience muscle deterioration, developmental delays, paralysis and dementia. Most die within a few years of onset.

Kids with Wiskott-Aldrich syndrome suffer from eczema, bruising, nosebleeds and recurrent infections. Most develop at least one autoimmune disorder. A third get cancers, such as lymphoma and leukemia. Life expectancy ranges from 15 to 20 years.

The disorders are challenging when not impossible to treat. No therapy exists for metachromatic leukodystrophy. A bone marrow transplant can stop disease progression for the few Wiskott-Aldrich patients with an immunologically matched sibling, but they may experience severe side effects or death if the donor is not as close a match.

Both diseases are caused by inherited genetic mutations that disrupt the body's ability to produce crucial enzymes. In each trial, researchers took the normal form of the faulty gene and attached it to a virus derived from HIV that had been modified so that it could no longer cause AIDS.

The researchers removed bone marrow stem cells from the patients and then used the lentivirus to infect those cells with the normal genes.

Link:
Gene therapy using HIV helps children with fatal diseases, study says

'Grinder' can listen to music player by wearing a loose wire coil around his neckDon't offer Rich Lee a pair of headphones to listen to music: he's already got a pair, even though you can't see them. They're implanted in his ears – a procedure carried out by a "body modification" expert.Now, by connecting his music player to a loose wire coil around his neck (which he can tuck under his shirt), Lee can listen to music without blocking out the outside world. The tiny magnets implanted invisibly in his outer ears pick up the signal and generate sound.But that's only the beginning. Lee, 34, who works as a salesman, intends to hook it up to an ultrasonic rangefinder – effectively giving himself bat-like echolocation. And he would like to have X-ray vision, super-strength, and anything else...

Source:
http://www.medworm.com/index.php?rid=7397462&cid=c_449_58_f&fid=36473&url=http%3A%2F%2Fwww.guardian.co.uk%2Ftechnology%2F2013%2Fjul%2F04%2Fheadphones-implanted-ear-grinder-rich-lee

'Grinder' can listen to music player by wearing a loose wire coil around his neckDon't offer Rich Lee a pair of headphones to listen to music: he's already got a pair, even though you can't see them. They're implanted in his ears – a procedure carried out by a "body modification" expert.Now, by connecting his music player to a loose wire coil around his neck (which he can tuck under his shirt), Lee can listen to music without blocking out the outside world. The tiny magnets implanted invisibly in his outer ears pick up the signal and generate sound.But that's only the beginning. Lee, 34, who works as a salesman, intends to hook it up to an ultrasonic rangefinder – effectively giving himself bat-like echolocation. And he would like to have X-ray vision, super-strength, and anything else...

Source:
http://www.medworm.com/index.php?rid=7397462&cid=c_449_58_f&fid=36473&url=http%3A%2F%2Fwww.guardian.co.uk%2Ftechnology%2F2013%2Fjul%2F04%2Fheadphones-implanted-ear-grinder-rich-lee

Newswise Researchers at UCLAs Eli & Edythe Broad Center of Regenerative Medicine & Stem Cell Research have successfully established the foundation for using hematopoietic (blood-producing) stem cells (HSC) from the bone marrow of patients with sickle cell disease (SCD) to treat the disease. The study was led by Dr. Donald Kohn, professor of pediatrics and microbiology, immunology and molecular genetics in the life sciences.

Kohn introduced an anti-sickling gene into the HSC to capitalize on the self-renewing potential of stem cells and create a continual source of healthy red blood cells that do not sickle. The breakthrough gene therapy technique for sickle cell disease is scheduled to begin clinical trials by early 2014. The study was published online ahead of press today in Journal of Clinical Investigation.

Gene Therapy Kohns gene therapy approach using HSC from patients own blood is a revolutionary alternative to current SCD treatments as it creates a self-renewing normal blood cell by inserting a gene that has anti-sickling properties into HSC. This approach also does not rely on the identification of a matched donor, thus avoiding the risk of rejection of donor cells. The anti-sickling HSC will be transplanted back into the patients bone marrow and multiplies the corrected cells that make red blood cells without sickling.

The results demonstrate that our technique of lentiviral transduction is capable of efficient transfer and consistent expression of an effective anti-sickling beta-globin gene in human SCD bone marrow progenitor cells, which improved the physiologic parameters of the resulting red blood cells. Kohn said.

Kohn and colleagues found that in the laboratory the HSC produced new non-sickled blood cells at a rate sufficient for significant clinical improvement for patients. The new blood cells survive longer than sickled cells, which could also improve treatment outcomes. The success of this technique will allow Kohn to begin clinical trials in patients with SCD by early next year.

Sickle Cell Disease Affecting more than 90,000 patients in the US, SCD mostly affects people of Sub-Saharan African descent. It is caused by an inherited mutation in the beta-globin gene that makes red blood cells change from their normal shape, which is round and pliable (like a plastic bag filled with corn oil), into a rigid sickle-shaped cell (like a corn flake). Normal red blood cells are able to pass easily through the tiniest blood vessels, called capillaries, carrying oxygen to organs such as the lungs, liver and kidneys. But due to their rigid structure, sickled blood cells get stuck in the capillaries and deprive the organs of oxygen, which causes organ dysfunction and failure.

Current treatments include transplanting patients with donor HSC, which is a potential cure for SCD, but due to the serious risks of rejection, only a small number of patients have undergone this procedure and it is usually restricted to children with severe symptoms.

CIRM Disease Team Program This study was supported in part by a Disease Team I Award from the California Institute for Regenerative Medicine (CIRM), the states stem cell research agency created by voter initiative in 2004. The purpose of the disease team program is to support research focused on one particular disease that leads to the filing of an investigational new drug application with the FDA within four years. The program is designed to encourage translational research, which means to take scientific discoveries from the laboratory to the patient bedside as quickly as possible. This requires new levels of collaboration between basic laboratory scientists, medical clinicians, biotechnology experts and pharmacology experts, to name a few.

Other support came from the UCLA Broad Stem Cell Research Center and Jonsson Comprehensive Cancer Center and the Ruth L. Kirschstein National Research Service Award.

The stem cell center was launched in 2005 with a UCLA commitment of $20 million over five years. A $20 million gift from the Eli and Edythe Broad Foundation in 2007 resulted in the renaming of the center. With more than 200 members, the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research is committed to a multi-disciplinary, integrated collaboration of scientific, academic and medical disciplines for the purpose of understanding adult and human embryonic stem cells. The center supports innovation, excellence and the highest ethical standards focused on stem cell research with the intent of facilitating basic scientific inquiry directed towards future clinical applications to treat disease. The center is a collaboration of the David Geffen School of Medicine, UCLAs Jonsson Cancer Center, the Henry Samueli School of Engineering and Applied Science and the UCLA College of Letters and Science. To learn more about the center, visit our web site at http://www.stemcell.ucla.edu

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UCLA Stem Cell Gene Therapy for Sickle Cell Disease Advances Toward Clinical Trials

July 1, 2013 Researchers at UCLA's Eli & Edythe Broad Center of Regenerative Medicine & Stem Cell Research have successfully established the foundation for using hematopoietic (blood-producing) stem cells (HSC) from the bone marrow of patients with sickle cell disease (SCD) to treat the disease. The study was led by Dr. Donald Kohn, professor of pediatrics and microbiology, immunology and molecular genetics in the life sciences.

Kohn introduced an anti-sickling gene into the HSC to capitalize on the self-renewing potential of stem cells and create a continual source of healthy red blood cells that do not sickle. The breakthrough gene therapy technique for sickle cell disease is scheduled to begin clinical trials by early 2014. The study was published online in the Journal of Clinical Investigation.

Gene Therapy

Kohn's gene therapy approach using HSC from patient's own blood is a revolutionary alternative to current SCD treatments as it creates a self-renewing normal blood cell by inserting a gene that has anti-sickling properties into HSC. This approach also does not rely on the identification of a matched donor, thus avoiding the risk of rejection of donor cells. The anti-sickling HSC will be transplanted back into the patient's bone marrow and multiplies the corrected cells that make red blood cells without sickling.

"The results demonstrate that our technique of lentiviral transduction is capable of efficient transfer and consistent expression of an effective anti-sickling beta-globin gene in human SCD bone marrow progenitor cells, which improved the physiologic parameters of the resulting red blood cells." Kohn said.

Kohn and colleagues found that in the laboratory the HSC produced new non-sickled blood cells at a rate sufficient for significant clinical improvement for patients. The new blood cells survive longer than sickled cells, which could also improve treatment outcomes. The success of this technique will allow Kohn to begin clinical trials in patients with SCD by early next year.

Sickle Cell Disease

Affecting more than 90,000 patients in the US, SCD mostly affects people of Sub-Saharan African descent. It is caused by an inherited mutation in the beta-globin gene that makes red blood cells change from their normal shape, which is round and pliable (like a plastic bag filled with corn oil), into a rigid sickle-shaped cell (like a corn flake). Normal red blood cells are able to pass easily through the tiniest blood vessels, called capillaries, carrying oxygen to organs such as the lungs, liver and kidneys. But due to their rigid structure, sickled blood cells get stuck in the capillaries and deprive the organs of oxygen, which causes organ dysfunction and failure.

Current treatments include transplanting patients with donor HSC, which is a potential cure for SCD, but due to the serious risks of rejection, only a small number of patients have undergone this procedure and it is usually restricted to children with severe symptoms.

CIRM Disease Team Program

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Stem cell gene therapy for sickle cell disease advances toward clinical trials

Researchers at UCLA's Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research have successfully established the foundation for using hematopoietic (blood-producing) stem cells from the bone marrow of patients with sickle cell disease to treat the disease. The study was led by Dr. Donald Kohn, professor of pediatrics and of microbiology, immunology and molecular genetics.

Sickle cell disease causes the body to produce red blood cells that are formed like the crescent-shaped blade of a sickle, which hinders blood flow in the blood vessels and deprives the body's organs of oxygen.

Kohn introduced an anti-sickling gene into the hematopoietic stem cells to capitalize on the self-renewing potential of stem cells and create a continual source of healthy red blood cells that do not sickle. The breakthrough gene therapy technique for sickle cell disease is scheduled to begin clinical trials by early 2014. The study was published online today ahead of press in the Journal of Clinical Investigation.

Kohn's gene therapy approach, which uses hematopoietic stem cells from a patient's own blood, is a revolutionary alternative to current sickle cell disease treatments as it creates a self-renewing normal blood cell by inserting a gene that has anti-sickling properties into hematopoietic stem cells. This approach also does not rely on the identification of a matched donor, thus avoiding the risk of rejection of donor cells. The anti-sickling hematopoietic stem cells are transplanted back into the patient's bone marrow and multiply the corrected cells that make red blood cells without sickling.

"The results demonstrate that our technique of lentiviral transduction is capable of efficient transfer and consistent expression of an effective anti-sickling beta-globin gene in human sickle cell disease bone marrow progenitor cells, which improved the physiologic parameters of the resulting red blood cells," Kohn said.

Kohn and colleagues found that in the laboratory the hematopoietic stem cells produced new non-sickled blood cells at a rate sufficient for significant clinical improvement for patients. The new blood cells survive longer than sickled cells, which could also improve treatment outcomes.

Sickle cell disease mostly affects people of Sub-Saharan African descent, and more than 90,000 patients in the U.S. have been diagnosed. It is caused by an inherited mutation in the beta-globin gene that makes red blood cells change from their normal shape, which is round and pliable, into a rigid, sickle-shaped cell. Normal red blood cells are able to pass easily through the tiniest blood vessels, called capillaries, carrying oxygen to organs such as the lungs, liver and kidneys. But due to their rigid structure, sickled blood cells get stuck in the capillaries.

Current treatments include transplanting patients with donor hematopoietic stem cells, which is a potential cure for sickle cell disease, but due to the serious risks of rejection, only a small number of patients have undergone this procedure and it is usually restricted to children with severe symptoms.

This study was supported in part by a Disease Team I Award from the California Institute for Regenerative Medicine, the state's stem cell research agency, which was created by a voter initiative in 2004. The purpose of the disease team program is to support research focused on one particular disease that leads to the filing of an investigational new drug application with the FDA within four years. The program is designed to speed translational research - research that takes scientific discoveries from the laboratory to the patient bedside. This requires new levels of collaboration between basic laboratory scientists, medical clinicians, biotechnology experts and pharmacology experts, to name a few.

Other support came from UCLA's Broad Stem Cell Research Center and Jonsson Comprehensive Cancer Center, and from the Ruth L. Kirschstein National Research Service Award.

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Stem-cell gene therapy for sickle-cell disease advances

MOUNTAIN VIEW, Calif., June 17, 2013 /PRNewswire/ --In an effort to aid progress in gene therapy clinical research, representatives of Clontech laboratories, Inc. and its parent company Takara Bio Inc. announce the availability of clinical grade RetroNectin reagent for direct supply to biomedical researchers.

RetroNectin reagent is designed to enable efficient retroviral transduction of genes into hematopoietic stem cells as well as lymphocytes and other blood cells. The RetroNectin method has been recognized as a standard gene transduction method in ex vivo gene therapy around the world. In addition, RetroNectin reagent has another remarkable feature that can also be useful for cell therapies: during the expansion culture of human T lymphocytes, RetroNectin reagent helps to increase proportion of nave T cells. This RetroNectin induced T cell method has already become available as a cancer therapy in three Japanese clinics under technical support from Takara Bio.

Takara Bio is the exclusive supplier of RetroNectin reagent, a recombinant human fibronectin fragment developed in 1995 by Takara Bio in collaboration with Indiana University. It has been used in 68 gene therapy clinical trials in 44 institutes and hospitals in 10 countries to date.

Previously, access to clinical-grade RetroNectin reagent required a Material Transfer Agreement (MTA) between a research institution and Takara Bio. Researchers may now submit direct orders to Clontech or local Takara Bio subsidiaries for RetroNectin (GMP), which is manufactured as a quality-assured product according to guidelines for Good Manufacturing Practice (GMP). The Drug Master File for RetroNectin (GMP) has been filed with the U.S. Food and Drug Administration. In a recent study published in Science Translational Medicine in March 2013, scientists at Memorial Sloan-Kettering Cancer Center reported an immunotherapy strategy for the treatment of five adult patients with acute lymphoblastic leukemia. Each patient's T cells were extracted, altered by introduction of DNA that would cause the cells to attack tumor cells, and infused back into the patient's bloodstream. According to researchers, all patients achieved tumor eradication and complete remission. RetroNectin reagent was used during T cell transduction.

Corresponding author Dr. Renier J. Brentjens said, "It was very clear to us even 10 years ago that the use of RetroNectin coated plates markedly, massively improved gene transfer." Dr. Brentjens continued, "The methodologies that many of us now use have been developed over a number of years. Once you have a system that works, you become very reliant and dependent on those reagents."

"RetroNectin reagent has become a standard reagent for many gene transfer protocols worldwide," said Carol Lou, General Manager of Clontech. "We are sure that such direct access to RetroNectin (GMP) without MTA execution will make this reagent available much more easily to any scientists or clinicians interested in RetroNectin clinical applications, which aligns with Takara Bio's mission of contributing to the health of mankind through gene therapy."

About Clontech Laboratories, Inc.Clontech Laboratories, Inc., a wholly-owned subsidiary of Takara Bio Inc., develops, manufactures, and distributes a wide range of life science research reagents under the Clontech and Takara brands. Key products include the Living Colors fluorescent proteins; high-performance qPCR and PCR reagents (including theTaKaRa Ex Taq,TaKaRa LA Taq, Titanium, and Advantage enzymes); RT enzymes and SMART library construction kits; the innovative In-Fusion cloning system; Tet-based inducible gene expression systems; and a range of Macherey-Nagel nucleic acid purification tools. These and other products support applications including gene discovery, regulation, and function; protein expression and purification; RNAi and stem cell studies; and plant and food research. For more information, visit http://www.clontech.com.

About Takara Bio Inc.Takara Bio Inc. is an innovative biotechnology company based in Shiga, Japan. As a world leader in biotechnology research and development, Takara Bio was the first company to market PCR technology in Japan and is also the developer of the RetroNectin reagent, which is used as a world-standard in gene therapy protocols. In addition to providing research reagents and equipment to the life science research market, Takara Bio has active research and product development activities in the fields of gene and cell-based therapy, and agricultural biotechnology; and is committed to preventing disease and improving the quality of life for all people through the use of biotechnology. Through strategic alliances with other industry leaders, the Company aims to extend its reach around the world. More information is available athttp://www.takara-bio.com.

For more information, contact:

Lorna Neilson, Ph.D. Director, Business Development Clontech Laboratories, Inc. A TakaraBio Company lorna_neilson@clontech.com (650) 919-7372

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Clinical Grade RetroNectin® Reagent Available To Support Gene Therapy Clinical Research

June 12, 2013 Researchers at UC Berkeley have developed an easier and more effective method for inserting genes into eye cells that could greatly expand gene therapy to help restore sight to patients with blinding diseases ranging from inherited defects like retinitis pigmentosa to degenerative illnesses of old age, such as macular degeneration.

Unlike current treatments, the new procedure is quick and surgically non-invasive, and it delivers normal genes to hard-to-reach cells throughout the entire retina.

Over the last six years, several groups have successfully treated people with a rare inherited eye disease by injecting a virus with a normal gene directly into the retina of an eye with a defective gene. Despite the invasive process, the virus with the normal gene was not capable of reaching all the retinal cells that needed fixing.

"Sticking a needle through the retina and injecting the engineered virus behind the retina is a risky surgical procedure," said David Schaffer, professor of chemical and biomolecular engineering and director of the Berkeley Stem Cell Center at UC Berkeley. "But doctors have no choice, because none of the gene delivery viruses can travel all the way through the back of the eye to reach the photoreceptors -- the light sensitive cells that need the therapeutic gene.

"Building upon 14 years of research, we have now created a virus that you just inject into the liquid vitreous humor inside the eye, and it delivers genes to a very difficult-to-reach population of delicate cells in a way that is surgically non-invasive and safe. "It's a 15-minute procedure, and you can likely go home that day."

The engineered virus works far better than current therapies in rodent models of two human degenerative eye diseases, and can penetrate photoreceptor cells in monkeys' eyes, which are like those of humans.

Schaffer said he and his team are now collaborating with physicians to identify the patients most likely to benefit from this gene delivery technique and, after some preclinical development, hope soon to head into clinical trials.

Schaffer and John Flannery, UC Berkeley professor of molecular and cell biology and of optometry, along with colleagues from UC Berkeley's Helen Wills Neuroscience Institute and the Flaum Eye Institute at the University of Rochester in New York, published the results of their study on June 12 in the journal Science Translational Medicine.

Harnessing a benign virus for gene therapy

Three groups of researchers have successfully restored some sight to more than a dozen people with a rare disease called Leber's congenital amaurosis, which leads to complete loss of vision in early adulthood. They achieved this by inserting a corrective gene into adeno-associated viruses (AAV), and injecting these common but benign respiratory viruses directly into the retina. The photoreceptor cells take up the viruses and incorporate the functional gene into their chromosomes to make a critical protein that the defective gene could not, rescuing the photoreceptors and restoring sight.

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Easy and effective therapy to restore sight: Engineered virus will improve gene therapy for blinding eye diseases