Saturday, Sep. 29, 2012
NAGOYA — A team of Japanese researchers has identified the structure of an immune-cell protein targeted by HIV, increasing hope for the development of new medicines that could block attacks by the virus.
The discovery by researchers at the National Hospital Organization Nagoya Medical Center and at Nagoya University was published Sept. 23 in the online edition of the U.S. journal Nature Structural & Molecular Biology.
A central part of the human immune system is lymphocyte cells that have virus-fighting proteins on their surface. But an HIV protein called Vif (viral infectivity factor) is able to bind to and destroy these proteins, allowing the AIDS-causing virus to enter the cells and multiply.
The researchers analyzed the molecular structure of an antivirus protein called APOBEC3C, and found that it contains a cavity that Vif can bind to. They confirmed the process through which this phenomenon occurs, and found that the APOBEC3C protein disintegrates once the two combine, their report in Nature said.
While existing medicines to combat HIV often cause side effects or become less potent if used over a long period, the team's finding raises "the possibility for the development of a new AIDS treatment that taps into the human body's own defense mechanism," said Yasumasa Iwatani, who heads the medical center's laboratory of infectious diseases.
The team said it now plans to look for compounds that can fit into the protein cavity and block attacks by HIV to study the effectiveness of different candidate compounds.