Sorry for the Inconvenience

Life, the Universe, Everything

Herpes Cure?

Well, not exactly. But this is a great example of new approaches to preventing disease using the tools of modern biology. It’s even cooler because it comes out of the lab that I’m working in.

Judy Lieberman, professor of pediatrics and a senior investigator at the Immune Disease Institute, has overseen the development of the treatment that uses RNA interference, or RNAi, to disable key genes necessary for herpes virus transmission. That cripples the virus in a molecular two-punch knockout, simultaneously disabling its ability to replicate, as well as the host cell’s ability to take up the virus.

This isn’t my project, but RNAi is closely related to microRNAs (which is what my project is). Both involve double-stranded RNA in the cell that interferes with the expression of particular proteins in a specific way. The only difference is that microRNAs are endogenously encoded (the code for them exists on a cell’s own DNA) and RNAi uses RNA introduced from an outside source. Once the RNA is out in the cell though, they both use the same molecular mechanisms to block translation of their targets. Since it’s discovery, RNAi has been extremely useful in studying what particular genes do (the best way to learn about something is to break it and see what else goes wrong), but it’s potential for theraputic use has been elusive.

Many in the field think RNAi-based drugs may be the next important new class of drugs. By introducing tiny RNA molecules into cells, researchers can target a gene of interest and, in effect, throw a wrench into that gene’s ability to build protein molecules. For all intents and purposes, that gene is now disabled.

While RNAi has profoundly accelerated the ability of scientists to probe and interrogate cells in the petri dish, therapeutic breakthroughs have proved far more problematic. Researchers have had a difficult time delivering these tiny RNA molecules and ensuring that they actually penetrate the desired cells and tissues in a living organism.

Modifying a delivery technique that Lieberman developed in 2005, she and postdoctoral fellow Yichao Wu and junior researcher Deborah Palliser (who now heads her own laboratory at Albert Einstein College of Medicine) treated mice with strands of RNA that were fused to cholesterol molecules, which made it possible for the molecules to pass through the cell membranes.

This approach works well in mice, but now needs to be developed for humans. The other problem is that it’s prophylactic, meaning it’s just a preventative measure and would not be able to treat people that are already infected, but it could be the first step in generating preventative tools for any number of STDs.

27 January, 2009 Posted by | Science | , , , | Leave a comment