June 17, 2010
Scientists at City of Hope in Duarte, California have shown that it may be possible to genetically engineer a patient's own adult stem cells to fight HIV. Four patients with AIDS received their own adult stem cells to treat lymphoma, including some of their cells that had been engineered with three genes to fight off HIV infection. One of the gene therapy targets was a protein receptor on immune cells (CCR5) that HIV binds to when infecting a cell, the idea being to prevent infection of the engineered stem cells. The other two engineered genes were designed to attack viral RNA that might make it into the cell, preventing production of viral protein.
While the dose of engineered stem cells was too low to produce an effect on the patients' viral load, the study showed no adverse effects from the procedure and that the cells survived, engrafted, and continued producing the engineered genes for up to two years after the transplant for three of the four patients.
A previous study had treated leukemia in an AIDS patient using donor adult stem cell transplant, in which the donor was selected specifically for lack of the CCR5 receptor on the donor stem cells. The patient recovered from the leukemia and also exhibited no sign of HIV.
The current study was published in Science Translational Medicine.