Sangamo Biosciences Creates Genetically Modified Immune Cells That Resist HIV Infection in Lab Tests
Human immune cells genetically modified by the Richmond, Calif.-based biotechnology company Sangamo Biosciences have been able to stave off HIV infection in laboratory tests, the company announced on Saturday at the 45th Annual Interscience Conference on Antimicrobial Agents and Chemotherapy in Washington, D.C, the Oakland Tribune reports. Scientists in the 1990s found that a small number of HIV-negative injection drug users who "routinely" were exposed to HIV had cellular CCR5 receptors that contained genetic mutations, according to the Tribune. Sangamo's new process aims to replicate such genetic mutations of the CCR5 receptors -- which are what HIV uses to enter human immune cells -- to prevent HIV from further infecting and destroying an HIV-positive individuals' cells. "What we're trying to do is give [HIV] patient cells this mutation and give them back to the patient so they can mount an immune response," Sangamo Chief Medical Officer Dale Ando said on Friday (Hoffman, Oakland Tribune, 12/18). Pfizer, GlaxoSmithKline and Schering-Plough are working on developing a new class of antiretroviral drugs called CCR5 inhibitors that would block the virus from entering cells through the receptor, rather than genetically modifying the cells (Kaiser Daily HIV/AIDS Report, 4/13).
Next Steps, Reaction
"It's certainly an interesting approach, but my sense is the virus is smarter than that," Richard Sutton, a professor of molecular virology and microbiology at Baylor College of Medicine, said, adding that if CCR5 receptors are blocked or eliminated "my feeling is the virus is just going to ignore it and go on to another receptor" (Oakland Tribune, 12/18). However, Ando said Sangamo's process "could potentially provide HIV-[positive] individuals with a reservoir of healthy and uninfectable T cells that would be available to fight both opportunistic infections and HIV itself" (Sangamo release, 12/17). Sangamo plans to file an FDA investigational new drug application in the second half of next year, Forbes.com reports (Kang, Forbes.com, 12/17).