U.S. researchers are preparing to begin human clinical trials of a novel therapy that uses genetically modified stem cells to fight HIV, the virus that causes AIDS. The therapy would populate a patient's diseased immune system with healthy new cells resistant to HIV infection.
Scientists believe the new therapy could mean a functional cure for patients infected with the AIDS virus. The technique involves genetically altering stem cells, master cells that can be manipulated to become any type of cell. In this experiment, researchers engineered into stem cells a trio of genes resistant to an attack by HIV.
The research was led by Joseph Anderson, a stem cell researcher at the University of California's Institute for Regenerative Cures in Davis. Anderson says he and his colleagues "humanized" mice by breeding them with a human immune system and then injecting them with the genetically modified stem cells. Then they infected the mice with HIV.
"They were able to block HIV infection, maintain a normal immune system in the mice even though the virus was still there. We were able to still detect virus that was replicating inside of the mice. However, because we put in genetically modified stem cells, the resistant immune cells were able to maintain a normal immune cell's level and maintain a functional immune system," Anderson said.
Anderson says the immune system in the mice behaved normally, with the HIV-resistant cells reproducing and thriving. Anderson says the experiments confirmed the safety and effectiveness of the therapy. He now hopes to conduct clinical trials of the genetically-modified, HIV-resistant immune cells in human patients infected with the AIDS virus.
"Hopefully in a patient, if this moves forward into human clinical trials, we would be able to maintain a normal human immune system in patients that have HIV infection. Hopefully, they'll be able to stop taking the antiretroviral drugs that they normally take because the genetically-resistant stem cells will be able to fight off the virus in the body of the patients," Anderson said.
An article by the University of California's Joseph Anderson and colleagues on genetically-modified HIV-resistant immune cells is published in the May issue of Journal of Virology.
