HIV transfer caught on video

The transfer of HIV from infected to uninfected immune system T-cells has been captured on video for the first time, in an achievement that could lead to new ways to block the transmission of HIV, researchers say.

"Most prior studies of HIV dissemination have focused on free-roaming viruses, but this study shows us how direct T-cell-to-T-cell contact could, in fact, be the predominant mode of dissemination within the body," said Dr Benjamin Chen, an assistant professor of medicine and infectious diseases at Mount Sinai School of Medicine in New York City.

The team of researchers from Mount Sinai and the University of California, Davis, Center for Biophotonics Science and Technology, discovered that HIV moves between T-cells through structures called virological synapses.

"Direct T-cell-to-T-cell transfer through virological synapses is a highly efficient avenue of HIV infection. Our recent experiments show that the viral structural protein moves with surprising speed in infected cells, and that the cell machinery actively participates in the transport of virus between T-cells. This suggests there are many targets for interfering with the process," Chen said.

How they did it
To capture the transfer of HIV from T-cell to T-cell on video, the researchers created a molecular clone on infectious HIV that contained a green fluorescent jellyfish protein. Quantitative, high-speed, 3D video microscopy was used to record both viral particle formation and HIV transmission between T-cells.

"We found that the transfer of HIV is highly co-ordinated between T-cells, and that the transfer is rapid and massive. Future efforts to block HIV transmission may be designed to specifically exploit and block this cell-to-cell mode of infection," Chen said.

The study appears in the March 27 issue of Science. – (HealthDay News, March 2009)

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