( Vector improved in two ways creates a s...)Gene therapy advance treats hemophilia in mouse models

A virus that typically infects insects could help with the development of gene therapy treatment for Hemophilia A, a condition in which even a bump on the knee can cause serious internal bleeding in people.

Researchers at the University of Iowa Roy J. and Lucille A. Carver College of Medicine improved a vector -- a vehicle that delivers gene therapy to cells -- in two ways to create a sustained, partial correction to bleeding problems in mice engineered to have Hemophilia A, which is also known as factor VIII deficiency. The findings appear in the Sept. 1 issue of the journal Blood (published Aug. 19 online).

The team adapted the outer layer, or "coat," from a baculovirus, a virus that infects butterflies and moths, onto another modified virus. This hybrid vehicle could more easily attach to certain liver cells and allow the genes within the vehicle to enter the cells. The genes then caused the liver cells to make the protein that prevents bleeding.

The researchers also modified the vehicle so that it would express these therapeutic genes only in liver cells, thus reducing the likelihood of negative side effects.

The laboratory findings have significant potential for developing improved treatment for hemophilia but are not yet applicable to people, cautioned Paul McCray, UI professor of pediatrics and the study's corresponding author. "It's an exciting finding, but we are still many steps away from a possible gene therapy for people with hemophilia," he said.

Hemophilia A is the leading sex-linked bleeding disorder, affecting one in 5,000 to 10,000 males. People with the condition have a genetic mutation that leaves them with little to no factor VIII protein to prevent uncontrolled bleeding. Individuals with the severe form of the disease have less than 1 percent of the normal amount of protein. However, only a rela
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Source:University of Iowa