Three-Dimensional Structural Characterization of HIV-1 Tethered to Human Cells

• Type of Material: Article
• Authors: Joshua D. Strauss, Emory University; Jason Hammonds, Emory University; Hong Yi, Emory University; Lingmei Ding, Emory University; Paul Spearman, Emory University; Elizabeth Wright, Emory University
• Language: English
• Date: 2016-01-15
• Publisher: American Society for Microbiology
• Publication Version: Final Published Version
• Copyright Statement: © 2016, American Society for Microbiology.
• Final Published Version (URL): http://dx.doi.org/10.1128/JVI.01880-15
• Title of Journal or Parent Work: Journal of Virology
• ISSN: 0022-538X
• Volume: 90
• Issue: 3
• Start Page: 1507
• End Page: 1521
• Grant/Funding Information: National Institutes of Health (NIH) http://dx.doi.org/10.13039/100000002 F32GM112517 to . HHS; This work was supported in part by Emory University, Children's Healthcare of Atlanta, the Center for AIDS Research at Emory University (P30 AI050409), and the Georgia Research Alliance to E.R.W.; NSF grant 0923395 to E.R.W; the James B. Pendleton Charitable Trust to P.S. and E.R.W.; and public health service grants F32GM112517 to J.D.S and NIH AI058828 to P.S.; Children's Healthcare of Atlanta to . James B. Pendleton Charitable Trust to . HHS; National Institutes of Health (NIH) http://dx.doi.org/10.13039/100000002 R01AI058828 to . National Science Foundation (NSF) http://dx.doi.org/10.13039/100000001 0923395 to . Emory University http://dx.doi.org/10.13039/100006939 to . Center for AIDS Research, Emory University (CFAR) http://dx.doi.org/10.13039/100008374 P30 AI050409 to . Georgia Research Alliance (GRA) http://dx.doi.org/10.13039/100008065.
• Keywords: VIRAL GLYCOPROTEINS; BST-2/TETHERIN; Science & Technology; INHIBITS HIV-1; RESTRICTION; IN-VIVO; PARTICLE RELEASE; Life Sciences & Biomedicine; Virology; ELECTRON-MICROSCOPY; VPU PROTEIN; CRYOELECTRON TOMOGRAPHY; SIMPLEX-VIRUS 1
• Research Categories: Biology, Cell; Health Sciences, Immunology; Biology, Virology

Abstract

Tetherin (BST2, CD317, or HM1.24) is a host cellular restriction factor that prevents the release of enveloped viruses by mechanically linking virions to the plasma membrane. The precise arrangement of tetherin molecules at the plasma membrane site of HIV-1 assembly, budding, and restriction is not well understood. To gain insight into the biophysical mechanism underlying tetherin-mediated restriction of HIV-1, we utilized cryo-electron tomography (cryo-ET) to directly visualize HIV-1 virus-like particles (VLPs) and virions tethered to human cells in three dimensions (3D). Rod-like densities that we refer to as tethers were seen connecting HIV-1 virions to each other and to the plasma membrane. Native immunogold labeling showed tetherin molecules located on HIV-1 VLPs and virions in positions similar to those of the densities observed by cryo-ET. The location of the tethers with respect to the ordered immature Gag lattice or mature conical core was random. However, tethers were not uniformly distributed on the viral membrane but rather formed clusters at sites of contact with the cell or other virions. Chains of tethered HIV-1 virions often were arranged in a linear fashion, primarily as single chains and, to a lesser degree, as branched chains. Distance measurements support the extended tetherin model, in which the coiled-coil ectodomains are oriented perpendicular with respect to the viral and plasma membranes.