Key protein appears to kill off HIV food supply in certain cells
Today, we're one small but significant step closer to figuring out how to get certain cells to fight back against HIV infection. Specifically, scientists with the NYU Langone Medical Center and colleagues in Rochester, NY, and France have determined how a little protein known as SAMHD1 appears to resist HIV in certain cells. The key? Starvation.
This discovery, detailed online in the journal Nature Immunology, is the kind of finding that will matter more years from now, as future researchers try to figure out new drug targets. In theory, another team of scientists could build a vaccine or pill that harnesses SAMHD1 throughout the body to completely beat back HIV, now that they know how the proteins resist the virus. But it may be years before we know whether this is possible in humans.
Their finding links two previously known discoveries. The virus grows by eating a cell's deoxynucleotide triphosphates (dNTPs)--DNA building blocks--to replicate itself. And they already know immune cells called dendritic cells containing SAMHD1 appear to resist HIV infection. They've also been experimenting with HIV vaccines and have recently generated some promising results, at least in monkeys.
So the big question was: How does SAMHD1 work? It turns out it protects the immune cell from such viruses as HIV by wiping out the food supply--the dNTP--so the HIV starves. The discovery reveals the challenge and opportunity implicit in treatment development. The belief is HIV has evolved so it tries to infect cells that don't have SAMHD1 but have plenty of dNTPs--CD4 T-cells, according to the researchers.
Co-lead investigator Nathaniel Landau of the NYU School of Medicine explains the discovery aided by researchers at the University of Rochester Medical Center and The Cochin Institute in Paris as a bid to decipher HIV in order to anticipate its moves and defeat it.
"We want to understand how the enemy fights so that we can outsmart it in the end," he said in a statement announcing the news.