Tuesday, March 31, 2009

Quantitative 3D Video Microscopy of HIV Transfer Across T Cell Virological Synapses

Science 27 March 2009:
Vol. 323. no. 5922, pp. 1743 - 1747
DOI: 10.1126/science.1167525


Wolfgang Hübner,1 Gregory P. McNerney,3 Ping Chen,1 Benjamin M. Dale,1 Ronald E. Gordon,2 Frank Y. S. Chuang,3 Xiao-Dong Li,4 David M. Asmuth,4 Thomas Huser,3,4 Benjamin K. Chen1*

The spread of HIV between immune cells is greatly enhanced by cell-cell adhesions called virological synapses, although the underlying mechanisms have been unclear. With use of an infectious, fluorescent clone of HIV, we tracked the movement of Gag in live CD4 T cells and captured the direct translocation of HIV across the virological synapse. Quantitative, high-speed three-dimensional (3D) video microscopy revealed the rapid formation of micrometer-sized "buttons" containing oligomerized viral Gag protein. Electron microscopy showed that these buttons were packed with budding viral crescents. Viral transfer events were observed to form virus-laden internal compartments within target cells. Continuous time-lapse monitoring showed preferential infection through synapses. Thus, HIV dissemination may be enhanced by virological synapse-mediated cell adhesion coupled to viral endocytosis.

1 Division of Infectious Diseases, Department of Medicine, Immunology Institute, Mount Sinai School of Medicine, New York, NY 10029, USA.
2 Department of Pathology, Mount Sinai School of Medicine, New York, NY 10029, USA.
3 NSF Center for Biophotonics Science and Technology, University of California Davis (UCD), Sacramento, CA 95817, USA.
4 Department of Internal Medicine, University of California Davis Medical Center, Sacramento, CA 95817, USA.

* To whom correspondence should be addressed. E-mail: ben.chen@mssm.edu


  • An interesting informative presentation with numerous videos:

It turns out that HIV doesn't work like this (mostly). In fact, it operates more much more sneakily -- like special forces -- viral ninjas, if you will. Instead of spreading out in the blood, HIV viruses transfer between infected cells through a structure called a virological synapse. (To be accurate, HIV does infect cells in a cell-free form -- this is discussed in the Introduction of the paper. However, cell-to-cell transfer of HIV is up to a thousand times more efficient and inhibiting it inhibits viral replication.)