St. Jude Research Study Shows Advances in Gene Therapy Transfer

St. Jude Children's Research Hospital (ALSAC)
Tuesday, 30 May 2000

Lead investigator to present preliminary results at national gene therapy meeting

(Memphis, Tennessee, May 30, 2000) Researchers at St. Jude Children's Research Hospital have developed new methods that appear to remove certain gene transfer barriers in blood diseases, showing gene transfer rates 10 to 20 times greater than previously reported. Lead investigator Patrick Kelly, M.D., Division of Experimental Hematology, will present preliminary results of the six-month study at the American Society of Gene Therapy's annual meeting in Denver on June 2.

Scientists from all over the world have been trying to efficiently insert a desired gene into hematopoietic stem cells (the primitive cells that give rise to red and white blood cells and platelets). Until now, this type of gene transfer has been difficult to achieve. Most laboratories and clinical trials have resulted in only 1 to 2 percent of the blood cells carrying the desired gene after transfer.

According to Kelly, there are two recognized barriers to high levels of gene transfer. First, the cells need to be dividing, and secondly, the proper receptor needs to be present on the target cell to allow the virus (carrying the desired gene) to bind and enter the cell.

The St. Jude research team developed lab cultures that allow the hematopoietic stem cells to divide without losing the ability to make white blood cells, red blood cells or platelets. The gene transfer is then performed, using a retrovirus coated with a unique envelope protein that allows the virus to bind to the cell. This retrovirus contains a green fluorescent protein gene, which then turns the successfully transferred cells to the same color. This helps to distinguish what has happened.

Gene therapy is the process of using genes to cause cells to behave in a certain manner, and to potentially cure genetic diseases. "Our goal is to improve gene therapy techniques so people can use them for various needs," Kelly said. "This level of gene transfer expression has never been described before and these results hold great promise for blood diseases. If successful, genetic diseases that affect the blood, such as sickle cell disease, chronic granulomatous disease (CGD) or Fanconi's anemia, could be cured. Additionally, genes could be inserted into blood cells to make the cells resistant to infections (such as the AIDS virus), or resistant to chemotherapy."

St. Jude collaborators of the study also include: Elio F. Vanin, Ph.D.; Jody Vandergriff; Arthur Nienhuis, M.D.; and Amit Nathwani, M.D., Ph.D.

St. Jude, founded by the late entertainer Danny Thomas, is an internationally recognized biomedical research center dedicated to finding cures for catastrophic diseases of childhood. The hospital's work is supported through funds raised by ALSACâ (American Lebanese Syrian Associated Charitiesâ .) All St. Jude patients are treated regardless of their ability to pay. ALSAC covers all costs of treatment beyond those reimbursed by third party insurers, and total costs for families who have no insurance.

For more information, or to contact St. Jude Children's Research Hospital (ALSAC), see their website at: www.stjude.org