HIV-1 disseminates rapidly in infected individuals. This can at least partially be attributed to virus transfer between T lymphocytes, which occurs very efficiently when infected and uninfected T cells directly contact each other, thus forming the so-called virological synapse (VS). While many features of this transient adhesion structure remain undefined, we know that VS formation necessitates an interaction of the viral envelope glycoprotein (Env), which is expressed at the surface of infected (virus producing) cells, with the viral receptor on uninfected (target) cells. It is not understood, however, why such interactions between Env, which mediates fusion of the viral particle with target cell membranes, and the viral receptor/coreceptor do not routinely result in producer-target cell fusion and thus the formation of a syncytium. Small T cell-based syncytia have been observed in lymph nodes of infected individuals and in humanized mice, but it is evident that most encounters between infected and uninfected cells resolve without fusion. Indeed, fusion-less encounters between these cells are a sine qua non for three central features of HIV-1 pathogenesis: cell-to-cell transmission, killing of bystander cells, and establishment and maintenance of a reservoir of latently infected T lymphocytes. Hence, revealing how fusion between infected and uninfected cells is regulated will not only contribute to our knowledge about how the virus can be efficiently transmitted from cell to cell, it will also aid understanding of key aspects of HIV-1 pathogenesis. We thus propose to investigate how both cell-intrinsic and cell-extrinsic factors, together, facilitate disengagement of producer and target cells upon virus transfer. It will also be tested whether enhancing fusion between the cells beyond the normal level is detrimental to virus dissemination.

Public Health Relevance

HIV/AIDS remains an important public health problem. Investigations aimed at understanding how HIV disseminates in infected individuals and how its mode of spread contributes to key features of AIDS may reveal novel targets for intervention.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
3R01GM117839-07S1
Application #
9295126
Study Section
Special Emphasis Panel (ZRG1 (03)M)
Program Officer
Hagan, Ann A
Project Start
2009-04-22
Project End
2019-08-31
Budget Start
2016-09-01
Budget End
2017-08-31
Support Year
7
Fiscal Year
2016
Total Cost
$81,296
Indirect Cost
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
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Zhou, Jia; Chan, Jany; Lambelé, Marie et al. (2017) NEIL3 Repairs Telomere Damage during S Phase to Secure Chromosome Segregation at Mitosis. Cell Rep 20:2044-2056
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