March 28, 2011
University of Pennsylvania researchers are still recruiting HIV-positive participants for a trial of a gene therapy approach intended to block HIV from entering human immune cells. The trial's initial results, presented at the recent 18th Conference on Retroviruses and Opportunistic Infections in Boston, were promising.
In the study, launched in July 2009, Penn scientists remove T-cells from HIV-positive patients' blood, genetically alter them to lack a receptor HIV uses to infect the cells, and re-inject the cells into their donors.
"We separate the cells in the lab, and the protein in the membrane of the cell where the HIV virus uses to enter the cells is taken out," Dr. Pablo Tebas said. "So we remove that particular gene from the cells and then monitor the patients to see if the HIV continues to expand or not."
"We've seen that it is doable," Tebas said. "We can take cells and genetically modify them and re-infuse them and it's safe, nothing bad has happened to the patients. The cells are alive when they go back into the patient and, while we don't have all the data yet, the cells have expanded so far as normal cells as we can tell, which means that they are protected from HIV infection."
Despite the good results, scientists are a long way from freeing HIV patients from the need for life-long antiretroviral therapy, Tebas said. "In order for there to be an actual cure, we'd need all cells in the patient to have this gene removed, and we can't do that yet -- we've only removed a small fraction."
For more information about the study, telephone Penn's AIDS Clinical Trials Unit, 215-349-8092.