March 27, 2007
Some researchers are exploring new strategies to fight viruses, including HIV, that aim to "wipe them out by luring them to their destruction," the New York Times reports. According to the Times, viruses such as HIV invade a cell by latching onto certain proteins on the cell's surface. Once inside a cell, viruses manipulate the cell into making new copies of themselves. Viruses cannot infect red blood cells because as these cells develop into bone marrow, they lose their DNA. If a virus enters a red blood cell, there are no genes it can use to replicate itself, the Times reports. In one strategy, Paul Turner, an evolutionary biologist at Yale University, and colleagues created a mathematical model to predict how a virus called phi-6 -- which normally infects a species of bacteria called Pseudomonas phaseolica -- would survive if they added a mutant form of P. phaseolica that attracts viruses but does not allow it to enter and replicate. The researchers found that after introducing three rounds of mutant colonies, the virus disappeared. According to the Times, Turner is using the results to study the effects on HIV. He is adding CD4+ T cells to the surface of red blood cells with the aim of developing an HIV trap, the Times reports. "Once we have [an HIV trap], we can test whether they truly attract HIV," Turner said, adding, "And then we can set up experiments like the ones we've done with" P. phaseolica. According to the Times, the next step in Turner's research is to mix engineered red blood cells with normal CD4 cells in the laboratory and determine if they can trap HIV. Turner said that it might be possible to provide HIV-positive people with transfusions of engineered red blood cells, which would lure the virus away from CD4 cells and allow their immune systems to recover. Dominik Wodarz -- an expert on virus ecology at the University of California-Irvine who was not involved in the research -- said that although it is a "very exciting concept," the ultimate success of such a strategy would depend on the details of HIV infection. According to Wodarz, one milliliter of blood can contain as many as 10 million copies of HIV at some stages of infection. "I don't know if it would be possible to put enough traps in," he added. Turner said that the "data are exciting, but there are all these other intricacies that you have to address." He added that even if the virus is not completely destroyed, reducing viral loads would have significant benefits (Zimmer, New York Times, 3/27).
Reprinted with permission from kaisernetwork.org. You can view the entire Kaiser Daily HIV/AIDS Report, search the archives, or sign up for email delivery at www.kaisernetwork.org/dailyreports/hiv. The Kaiser Daily HIV/AIDS Report is published for kaisernetwork.org, a free service of the Kaiser Family Foundation, by The Advisory Board Company. © 2007 by The Advisory Board Company and Kaiser Family Foundation. All rights reserved.