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5 December 2013 11:26 am ,
Vol. 342 ,
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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HIV Defense Mechanism Uncovered
11 July 2003 (All day)
The AIDS virus dodges the immune system's barrage of ammunition. Now researchers have uncovered one of its tricks: HIV disables a host protein that otherwise would break the virus into pieces. But the virus can't stop similar proteins in mice. The finding, published in the 11 July issue of Cell, provides a new clue about why HIV infects only humans and may someday lead to better animal models of AIDS.
Last year scientists discovered that a protein made by HIV, called Vif, protects the virus from host attack. But they weren't sure how Vif pulled off this feat. Now AIDS researcher Nathaniel Landau of the Salk Institute for Biological Studies in San Diego, California, and colleagues report that Vif locks down a human protein called APOBEC3G. In the absence of Vif, APOBEC3G slides into the virus and pulls out bits of its DNA, inactivating it. Vif thus protects HIV against extermination in human cells.
Curious how mice fight off HIV so easily, Landau's group checked to see if the rodents have their own version of the APOBEC3G gene. They did, but the mouse protein, the researchers found, is unrecognizable to HIV's defense system. It bypassed the Vif blockade, wiggled into the virus, and knocked it out of commission.
“It's a major breakthrough” to show that APOBEC3G plays a role in humans' unique susceptibility to HIV, says Jeremy Luban, a virologist at Columbia University. For scientists studying HIV drugs and vaccines, "it would be an enormous technical advantage" if this information could help create laboratory mice that can sustain HIV infection, he says. But Luban cautions that such a project is not likely to bear fruit immediately, as there are likely many other obstacles preventing HIV from infecting other species.