A new technique to visualize HIV particles inside infected cells as they make their way to the nucleus is reported in the October 2006 issue of Nature Methods. Pierre Charneau and colleagues show HIV’s internal voyage with unprecedented detail for the first time.
Once HIV has infected a cell, the viral genome makes its way to the nucleus of the cell, where it integrates into a chromosome to complete infection. It is known that some of the viral proteins coating the HIV genome are gradually lost along the way, but it is still unclear how exactly HIV particles go from the periphery of the cell to inside the nucleus. By fluorescently labeling the Integrase protein, a viral protein that remains associated with the HIV genome until integration into a human chromosome, the group succeeded in following the virus all the way from cell entry to inside the nucleus. In addition, they developed sophisticated software that allows them to precisely analyze very small movements of the viral particle. Using this tool, they were able to distinguish different speeds and shapes of movements characteristic of several cytoskeleton transport systems. Their results indicate that HIV particles inside the cell hitchhike on different types of internal cell fibers until reaching the nucleus.
This work sheds light on the mechanism of HIV transport inside the cell and provides a useful tool to understand HIV interaction with the infected cells so that new ways of blocking infection can be envisioned.
Pierre Charneau (Institut Pasteur, Paris, France)
News and Views: David McDonald (Case Western Reserve University School of Medicine, Cleveland, Ohio, USA)
Abstract available online.
(C) Nature Methods press release.
Message posted by: Trevor M. D'Souza