Understanding how HIV reproduces is one of the keys to combating AIDS. Michael Summers, an investigator of Howard Hughes Medical Institute at the University of Maryland, Baltimore County, and his colleagues have developed a new technique that will allow scientists to better understand an important early step in the HIV reproduction cycle - a development that could eventually lead to new treatments for AIDS.
"The HIV virus is one of the simplest things in nature that can reproduce," says Summers. "The virus' genetic material, RNA, must be packaged into newly formed viruses in order for those viruses to be infectious and reproduce." Summers and his colleagues have now figured out what a key part of the HIV RNA looks like, and how the RNA "changes its shape" in order to promote reproduction.
Until now, scientists have not had good tools for studying the HIV RNA. Some laboratories, including Dr. Summers' lab, previously focused on tiny pieces of the HIV RNA that, by themselves, don't explain how the RNA works. Larger portions of the HIV RNA have also been studied, but the methods used provided incomplete pictures and led to controversial and often incompatible conclusions among different research teams.
The Summers lab has developed a nuclear magnetic resonance (NMR) technique for studying the entire region of the HIV RNA that is responsible for incorporating it into new viruses. "It's like performing MRI, except we take pictures of the RNA molecules instead of large objects like the human body," says Summers. One exciting finding, Summers says, is that the RNA molecule actually changes its shape, which enables the RNA to perform multiple functions inside the infected cell and promotes its incorporation into new viruses.
Summers says the development of this new method will allow scientists to find out how the HIV proteins interact with the RNA - research that has implications for drug discovery and the development of new therapies for patients with HIV.