Using Stem Cells for HIV Treatment
Whether a stem cell transplant using an HIV-infected person's own genetically modified immune cells can become a cure for the disease is the focus of a new $20 million, five-year research grant award announced today by the National Institutes of Health to Fred Hutchinson Cancer Research Center.
Hutchinson Center researchers will use the grant to lead a multifaceted team of scientists and institutions to study whether a person's own stem cells can be engineered to deny HIV entry into the body's blood cells. The researchers also will work to develop tools to eradicate existing reservoirs of infection in the body.
"Funding for research to find a cure for HIV-infected persons represents a paradigm shift," said Keith Jerome, M.D., Ph.D., an expert in viral infections and co-principal investigator of the grant. "HIV has been an incurable, lifelong infection that at best sentences people to a lifetime of complex drug therapies. Now the research field is shifting to address the possibility of a cure. No one would have talked about this approach five years ago." Jerome is an associate member of the Hutchinson Center's Vaccine and Infectious Disease Division.
The research projects will focus on ways around a major obstacle to long-term control and cure of HIV: the persistence of HIV provirus in reservoirs throughout the bodies of infected persons. The infected cells in these reservoirs are long lived and remain a threat during the lifespan of infected persons. Highly active antiretroviral therapy (HAART), although successful at keeping the spread of HIV under control by inhibiting viral replication, does not eliminate these reservoirs. If a patient discontinues HAART, the virus rebounds.
One approach under investigation is autologous stem cell transplantation, in which the infected patient's own immune cells are genetically modified to be resistant to HIV by eliminating one of the receptors, called CCR5, which HIV needs to infect new cells. This method builds on the Hutchinson Center's long-standing expertise in using transplantation to treat and cure blood cancers and some autoimmune diseases, a Nobel Prize-winning accomplishment that has boosted survival rates from nearly zero to 90 percent for certain types of leukemia.
Stem cell transplantation to eliminate HIV infection has one intriguing precedent. In 2008, a group of German physicians published results of transplanting an American man who had acute myeloid leukemia and HIV. The so-called "Berlin patient" received a new immune system from donor cells that also carried a rare genetic variation that made them resistant to HIV. The man was able to stop HAART and the virus remained undetectable.
Stem Cells Show Promise in Brain Repair After Cancer Treatment
The Human Brain's "Fountain of Youth" 