Poster Sessions

SB -2

Richard Felts

R. Felts, A. Bennett, D. Shi, E. Freed, J. Lifson, B. Lowekamp, T. Yoo, D. Bliss, S. Subramaniam, , , , , , , , , , ,

3D imaging of HIV transmission and entry

HIV transfer from dendritic cells to CD4+ T-cells is believed to take place via a complex mechanism that involves contact between the two cells at the “virological synapse.” Using 3D electron microscopy, we have imaged the distribution of HIV at the virological synapse. Electron tomography of 200nm thick sections and ion abrasion scanning electron microscopy of the entire cell-cell region (approximately 5 microns thick) reveal the presence of an intricate scaffold formed by cell surface protrusions from the dendritic cells and the CD4+ T-cells at the synapse. An extended network of virus-containing compartments is found inside the dendritic cell. Remarkably, these compartments appear to be connected to the virological synapse via channels that are about 100 nm wide that frequently contain viruses. We presume these viruses are in transit to the virological synapse. Similar channels are also found in virus-infected macrophages. Our results thus suggest a novel mechanism for delivery of HIV from the interior of antigen-presenting cells to CD4+ T-cells in “virion channels” that are likely to be much more effective at viral delivery then by the release of virus into the extracellular media via budding.