In a promising new finding that could help anti-HIV therapy, researchers in the US have discovered how a genetic circuit in HIV controls whether the virus turns on or stays dormant.Researchers at the University of California, San Diego, and Oak Ridge National Laboratory have also succeeded in forcing the virus towards dormancy. The authors say that their study shows how a developmental decision between HIV’s two “replication fates” is made. The scientists were able to measure the level of “noise” or randomness in HIV gene expression and use this noise to probe how HIV decides to replicate or remain dormant. This method is somewhat like finding a radio station by honing in on regions with the most static. It provides a new tool for probing cellular, as well as viral, regulation, and for understanding how other biological decisions are made, notably how stem cells choose between different developmental fates, the researchers say. The reserchers explored the genetic master circuit of HIV, the Tat circuit, and built upon previous work by Leor S. Weinberger, professor of chemistry and biochemistry at UC San Diego, which showed that it did not function like a standard on-off switch (a light switch, for example). Weinberger’s previous work found that the HIV circuit is driven by cellular noise.
