Immune cells engineered in lab to resist HIV infection
Researchers at the Stanford University School of Medicine have found a novel way to engineer key cells of the immune system so they remain resistant to infection with HIV, the virus that causes AIDS.
They have described the use of a kind of molecular scissors to cut and paste a series of HIV-resistant genes into T cells, specialized immune cells targeted by the AIDS virus.
The genome editing was made in a gene that the virus uses to gain entry into the cell. By inactivating a receptor gene and inserting additional anti-HIV genes, the virus was blocked from entering the cells, thus preventing it from destroying the immune system, said Matthew Porteus, MD, an associate professor of pediatrics at Stanford and a pediatric hematologist/oncologist at Lucile Packard Children's Hospital.
"We inactivated one of the receptors that HIV uses to gain entry and added new genes to protect against HIV, so we have multiple layers of protection - what we call stacking. We can use this strategy to make cells that are resistant to both major types of HIV," said Porteus, the study's principal investigator.
He said the new approach, a form of tailored gene therapy, could ultimately replace drug treatment, in which patients have to take multiple medications daily to keep the virus in check and prevent the potentially fatal infections wrought by AIDS.
The work was done in the laboratory, and clinical trials would still be needed to determine whether the approach would work as a therapy.
Porteus said he hopes to begin clinical trials within three to five years.
"Providing an infected person with resistant T cells would not cure their viral infection. However, it would provide them with a protected set of T cells that would ward off the immune collapse that typically gives rise to AIDS," said Sara Sawyer, PhD, assistant professor of molecular genetics and microbiology at the University of Texas-Austin and a co-author of the study.
The study will be published in the latest issue of Molecular Therapy.