Successful dissemination of HIV-1 in infected individuals depends on efficient transmission of viral particles from infected (producer) to uninfected (target) cells. In vitro propagation studies have established that HIV-1 particles are most effectively transmitted to target cells if they bud into the cleft of the so-called virological synapse (VS) that forms between producer and target cells. The events leading to the formation, maintenance and disassembly of this synapse are poorly understood. Previously, we and other laboratories have established that HIV-1 particles exit from cells at sites that are enriched in tetraspanins. These cellular membrane proteins normally function as organizers of plasma membrane-based processes, including cell-cell fusion and adhesion. Our preliminary data suggest that individual members of the tetraspanin family are not required for virus release, but they point to a role of these proteins in regulating virus transfer to target cells. We thus propose to evaluate if tetraspanins in producer cells are regulatory cofactors necessary for efficient cell-to-cell transmission of HIV-1 particles. We will also analyze the effects of virus-mediated downregulation of tetraspanins. Altogether, these studies will provide further insight into the molecular mechanisms underlying HIV-1 spread and thus pathogenesis. In the Specific Aims of this proposal we propose: 1) To test the hypothesis that tetraspanins inhibit HIV-1-induced membrane fusion, thus allowing cell-to-cell transfer without fusion of producer and target cell. 2) To determine if tetraspanins in HIV-1 producer cells promote efficient transmission of viral particles to target cells by supporting the formation, the organization and the disassembly of the VS. 3) To examine the kinetics, determinants and potential consequences of HIV-1-induced tetraspanin downregulation in infected cells.

Public Health Relevance

The proposed analyses are aimed at elucidating HIV-1 transmission from cell-to-cell, a step in the viral replication cycle that remains poorly understood. Hence, the results may reveal novel targets for intervention with HIV-1 spread in infected individuals.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI080302-04
Application #
8240242
Study Section
AIDS Molecular and Cellular Biology Study Section (AMCB)
Program Officer
Sharma, Opendra K
Project Start
2009-04-22
Project End
2014-03-31
Budget Start
2012-04-01
Budget End
2013-03-31
Support Year
4
Fiscal Year
2012
Total Cost
$368,763
Indirect Cost
$123,738
Name
University of Vermont & St Agric College
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
066811191
City
Burlington
State
VT
Country
United States
Zip Code
05405
Symeonides, Menelaos; Murooka, Thomas T; Bellfy, Lauren N et al. (2015) HIV-1-Induced Small T Cell Syncytia Can Transfer Virus Particles to Target Cells through Transient Contacts. Viruses 7:6590-603
Lambelé, Marie; Koppensteiner, Herwig; Symeonides, Menelaos et al. (2015) Vpu is the main determinant for tetraspanin downregulation in HIV-1-infected cells. J Virol 89:3247-55
Wei, Quan; Zhang, Feng; Richardson, Mekel M et al. (2014) CD82 restrains pathological angiogenesis by altering lipid raft clustering and CD44 trafficking in endothelial cells. Circulation 130:1493-504
Symeonides, Menelaos; Lambelé, Marie; Roy, Nathan H et al. (2014) Evidence showing that tetraspanins inhibit HIV-1-induced cell-cell fusion at a post-hemifusion stage. Viruses 6:1078-90
Roy, Nathan H; Lambelé, Marie; Chan, Jany et al. (2014) Ezrin is a component of the HIV-1 virological presynapse and contributes to the inhibition of cell-cell fusion. J Virol 88:7645-58
Roy, Nathan H; Chan, Jany; Lambelé, Marie et al. (2013) Clustering and mobility of HIV-1 Env at viral assembly sites predict its propensity to induce cell-cell fusion. J Virol 87:7516-25
Sateriale, Adam; Roy, Nathan H; Huston, Christopher D (2013) SNAP-tag technology optimized for use in Entamoeba histolytica. PLoS One 8:e83997
Klaus, Joseph P; Eisenhauer, Philip; Russo, Joanne et al. (2013) The intracellular cargo receptor ERGIC-53 is required for the production of infectious arenavirus, coronavirus, and filovirus particles. Cell Host Microbe 14:522-34
Thali, Markus (2011) Tetraspanin functions during HIV-1 and influenza virus replication. Biochem Soc Trans 39:529-31
Dillingham, Mark S (2011) Superfamily I helicases as modular components of DNA-processing machines. Biochem Soc Trans 39:413-23

Showing the most recent 10 out of 15 publications