Corporate Banner
Satellite Banner
Immunology
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Therapy Repairs Ravaged Immune System

Published: Tuesday, October 02, 2012
Last Updated: Tuesday, October 02, 2012
Bookmark and Share
Gene therapy can safely restore immune function in children with severe combined immunodeficiency and allow some to stop taking painful weekly injections.

Children with severe combined immunodeficiency (SCID) can't produce healthy microbe-fighting white blood cells called lymphocytes. As a result, these children are susceptible to a wide range of infections. Most die by the age of 2 if untreated.

One type of SCID arises from a faulty gene for the enzyme adenosine deaminase (ADA). Without this enzyme, toxic compounds build up in the body and inhibit the production of lymphocytes. Once- or twice-weekly injections of ADA can partly restore immune function. But this therapy is expensive and must continue for a lifetime.

For 2 decades, researchers have been exploring an alternative approach that uses gene therapy to replace the damaged ADA gene in the blood-forming stem cells found in bone marrow. But they've had trouble developing a method that effectively raises ADA levels and leads to lasting improvements in immune function.

An 11-year effort to test 2 different gene therapy regimens was led by Dr. Donald B. Kohn of the University of California, Los Angeles, and Dr. Fabio Candotti of NIH's National Human Genome Research Institute (NHGRI). The research was supported in part by several NIH components, including the National Heart, Lung and Blood Institute (NHLBI). The results appeared on September 11, 2012, in the online edition of Blood.

Ten patients with ADA-deficient SCID were treated at either the NIH Clinical Center or the Children's Hospital Los Angeles. Blood-forming stem cells were isolated from their bone marrow. The cells were treated with retroviral vectors, which delivered healthy ADA genes. The corrected cells were then infused back into the patients’ bloodstream.

The first 4 patients remained on ADA replacement therapy throughout the gene therapy procedure and follow-up. Although the gene therapy had no negative effect, it didn't improve ADA function. The scientists suspect that ongoing enzyme replacement therapy might have diluted the numbers of corrected lymphocytes in the patients' immune systems. As a result, the corrected cells couldn't establish themselves.

For the 6 additional patients, the doctors modified the treatment. Enzyme-replacement therapy was stopped before the procedure, and patients received low-dose chemotherapy, which depletes bone marrow stem cells. “This step proved to be important,” says Candotti. “By adjusting the chemotherapy dosage, we found its optimal level for enhancing the efficacy of the corrected stem cells.”

Three children who received the refined procedure have had improved health for up to 5 years and haven't needed enzyme replacement injections. The other 3 patients didn't have lasting improvements from the procedure. Now that the scientists have identified a regimen that can be effective, 8 children have been added to a second phase of the study.

“We are encouraged by the outcome of our gene therapy trial,” Candotti says. “We will continue to follow the progress of our patients and to enroll those who can benefit from this promising gene therapy strategy.”


Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,500+ scientific posters on ePosters
  • More than 3,700+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Test Reliably Detects Inherited Immune Deficiency in Newborns
NIH-supported study suggests that early diagnosis of severe combined immunodeficiency leads to high survival rates.
Wednesday, August 20, 2014
Gene Variants Found Associated With Human Immune System, Autoimmune Disease
Numerous studies have reported that certain diseases are inherited. But genetics also plays a role in immune response, affecting our ability to stave off disease.
Friday, September 27, 2013
Scientific News
Inciting an Immune Attack on Cancer Cells
A new minimally invasive vaccine that combines cancer cells and immune-enhancing factors could be used clinically to launch a destructive attack on tumors.
Inflammation Linked to Colon Cancer Metastasis
A new Arizona State University research study led by Biodesign Institute executive director Raymond DuBois has identified for the first time the details of how inflammation triggers colon cancer cells to spread to other organs, or metastasize.
New Strategy for Combating Adenoviruses
Using an animal model they developed, Saint Louis University and Utah State university researchers have identified a strategy that could keep a common group of viruses called adenoviruses from replicating and causing sickness in humans.
Major Advance Toward More Effective, Long-Lasting Flu Vaccine
Collaboration shows vaccine candidate can produce powerful ‘broadly neutralizing antibodies’ in animal models.
Immune System: Help for Killer Cells
A study from the University of Bonn may show the way to more effective vaccines.
Protein Found to Control Inflammatory Response
A new Northwestern Medicine study shows that a protein called POP1 prevents severe inflammation and, potentially, diseases caused by excessive inflammatory responses.
A Leap Forward in Vaccinating Against HIV
A team of scientists has developed an experimental vaccine candidate that successfully stimulates the immune system activity in animal models necessary to stop HIV infection.
MRI Scanners Can Steer Therapeutics to Specific Target Sites
Scientists from the University of Sheffield have discovered MRI scanners, normally used to produce images, can steer cell-based, tumour busting therapies to specific target sites in the body.
Agricultural Intervention Improves HIV Outcomes
A multifaceted farming intervention can reduce food insecurity while improving HIV outcomes in patients in Kenya, according to a randomized, controlled trial led by researchers at UC San Francisco.
Team Finds Early Inflammatory Response Paralyzes T Cells
Findings could have enormous implications for immunotherapy, autoimmune disorders, transplants and other aspects of immunity.
SELECTBIO

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!