Interfering with HIV

A special form of RNA developed by a team that included MIT biologists could one day lead to new treatments for HIV, the virus that causes AIDS. RNA is the molecule that carries the blueprint for translating DNA code into proteins. In a study published in the July issue of Nature Medicine, researchers inserted the special RNA into HIV-infected cells, significantly decreasing the production of new virus.

The team, led by Nobel laureate and MIT biology professor Phillip A. Sharp HM, included researchers from MIT, Harvard Medical School, and the University of Pennsylvania School of Medicine. The group created several versions of the special RNA molecules, called short interfering RNAs (siRNAs). These molecules, which consist of short, double-stranded segments of RNA, were targeted to RNAs that carry the blueprints for specific HIV proteins. When put inside cells, the siRNAs bind to the cellular messengers, triggering the degradation of the whole complex. This prevents the proteins from being made, thus blocking the virus from replicating.

While the technique worked on cells in culture dishes, MIT postdoc Carl Novina, first author of the study, says "there is a long distance between siRNAs working in cells in a dish and siRNAs effectively working in a whole organism." One problem that must be solved is the creation of a way to deliver the molecules to cells in animals or humans.