Gene Therapy Using Lentivirus to Treat Wiskott-Aldrich Syndrome Promising

Wiskott–Aldrich syndrome (WAS) is a rare X-linked recessive disease. This condition primarily affects males. It is characterized by abnormal immune system function (immune deficiency) and a reduced ability to form blood clots. This condition primarily affects males. 

It is caused by a mutation in a gene that encodes the protein WASP. This protein is found in all blood cells. WASP is involved in relaying signals from the surface of blood cells to the actin cytoskeleton, which is a network of fibers that make up the cell's structural framework. WASP signaling activates the cell when it is needed and triggers its movement and attachment to other cells and tissues (adhesion). In white blood cells, this signaling allows the actin cytoskeleton to establish the interaction between cells and the foreign invaders that they target (immune synapse).

Treatment of Wiskott–Aldrich syndrome is currently based on correcting symptoms. Management can accomplished through 'Cord blood & Bone marrow transplant' . It can be curative for some patients, those who have a strongly matching donor.

An alternative is to obtain blood stem cells from patient, and, in the laboratory, use gene therapy involving a form of retrovirus to take the normal gene into the cells to correct the defect. The patients are then given back the genetically changed blood cells back. This approach has been successful . However, over the long term, patients developed blood cancers.

Researchers now have developed a new gene therapy approach to the treatment of Wiskott-Aldrich Syndrome. They used a partially inactivated lentivirus to take the normal gene into the cell, while reducing the risk of cancer by inserting gene next to a cancer-promoting gene.

For their research they took the patients own blood stem cells in the laboratory, and used the lentiviral vector combined with the normal WASP gene to correct the genetic defect in the blood.

After a special treatment to eliminate their defective immune system, they received their own blood cells that had been altered to contain the normal WASP gene.

The research was published in Science Express.