Stem cells can be tweaked to hunt and kill HIV

WASHINGTON: In a major breakthrough in the fight against AIDS, scientists claim to have for the first time shown that human stem cells can be genetically engineered to seek out and kill HIV-infected cells in a living organism.

The study demonstrates for the first time that engineering stem cells to form immune cells that target HIV is effective in suppressing the virus in living tissues in an animal model, said lead scientist Scott G Kitchen. He added: "We believe that this study lays the groundwork for the potential use of this type of an approach in combating HIV infection in infected individuals , in hopes of eradicating the virus from the body."

In their previous research, the scientists took CD8 cytotoxic T lymphocytes - the "killer" T cells that help fight infection - from an HIV-infected individual and identified the molecule known as the T cell receptor, which guides T cell in recognizing and killing HIV-infected cells.

In their latest research, the scientists at California University similarly engineered human blood stem cells and found that they can form mature T cells that can attack HIV in tissues where the virus resides and replicates.

They did so by using a surrogate model, the humanized mouse, in which HIV infection closely resembles the disease and its progression in humans . In a series of tests on the mice's peripheral blood, plasma and organs conducted two weeks and six weeks after introducing the engineered cells, the scientists found that the number of CD4 "helper" T cells - which become depleted as a result of HIV infection - increased, while levels of HIV in the blood decreased.

CD4 cells are white blood cells that are an important component of immune system , helping to fight off infections . These results indicated that the engineered cells were capable of developing and migrating to the organs to fight infection there, the 'PLoS Pathogens' journal reported.

"We believe that this is the first step in developing a more aggressive approach in correcting the defects in the human T cell responses that allow HIV to persist in infected people," Kitchen said.

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