Retroviral infections often spread by cell-to-cell transmission, which involves transfer of viruses from infected cells to neighboring uninfected cells via zones of cell-cell contact designated virological synapses. Our laboratory has contributed to the understanding of the biogenesis of virological synapses using a model retrovirus, the Friend murine leukemia virus (F-MLV). Interactions between the viral envelope glycoprotein (Env) in the infected cell and its viral receptor in the target cell drive the establishment of cell-cell contact. The viral Env accumulates in the cell-cell interface and redirects virus assembly to the site of cell-cell contact. Our work has, for the first time, documented the transmission of viruses from one cell to another using time-lapse video microscopy and shown that polarized assembly directly at the cell-cell interface can contribute to the efficient spreading of retroviral infections. While we have made progress in understanding the biogenesis of virological synapses using tissue culture systems, little is known about the mechanism of virus spreading in vivo. To bridge this gap in knowledge, we have established intravital microscopy to visualize the behavior of infected lymphocytes directly in vivo within the lymph node of living mice. We identify a subpopulation of F- MLV-infected B cells that form virological synapses with uninfected lymphocytes. In vivo virological synapses are dependent on the viral envelope glycoprotein and are characterized by a prolonged polarization of viral capsid to the cell-cell interface. Our results suggest that Env-induced virological synapses exist in vivo and can contribute to the spreading of retroviral infections. In this competitive renewal application we will study MLV cell-to-cell transmission in relevant primary lymphocytes. We will explore the role of infected B and T cells in the in vivo spread of MLV. We will elucidate the mechanism of polarized virus assembly in in vivo virological synapses and will identify viral and cellular factors that synergize with the Env-receptor interactions to promote viral spreading to CD4+ T cells. We will also test if migratory T cells contribute to viral spreading by a mechanism that involves more transient cell-cell interactions. Our work will allow critical insights into pathogenesis and the spreading of retroviral infections.

Public Health Relevance

This application proposes to study retroviral cell-to-cell transmission in primary cells. Intravital microscopy will allow the monitoring of retrovially infeced lymphocytes directly within the lymph node of mice. Combined with in vitro assays, the proposed work will allow critical insights into pathogenesis and the spreading of retroviral infections.

National Institute of Health (NIH)
National Cancer Institute (NCI)
Research Project (R01)
Project #
Application #
Study Section
Virology - B Study Section (VIRB)
Program Officer
Read-Connole, Elizabeth Lee
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Yale University
Schools of Medicine
New Haven
United States
Zip Code
Riedel, Christiane; Vasishtan, Daven; Siebert, C Alistair et al. (2017) Native structure of a retroviral envelope protein and its conformational change upon interaction with the target cell. J Struct Biol 197:172-180
Sewald, Xaver; Motamedi, Nasim; Mothes, Walther (2016) Viruses exploit the tissue physiology of the host to spread in vivo. Curr Opin Cell Biol 41:81-90
Kong, Rui; Xu, Kai; Zhou, Tongqing et al. (2016) Fusion peptide of HIV-1 as a site of vulnerability to neutralizing antibody. Science 352:828-33
Sewald, Xaver; Ladinsky, Mark S; Uchil, Pradeep D et al. (2015) Retroviruses use CD169-mediated trans-infection of permissive lymphocytes to establish infection. Science 350:563-567
Agosto, Luis M; Uchil, Pradeep D; Mothes, Walther (2015) HIV cell-to-cell transmission: effects on pathogenesis and antiretroviral therapy. Trends Microbiol 23:289-95
Uchil, Pradeep D; Pawliczek, Tobias; Reynolds, Tracy D et al. (2014) TRIM15 is a focal adhesion protein that regulates focal adhesion disassembly. J Cell Sci 127:3928-42
Li, Fei; Sewald, Xaver; Jin, Jing et al. (2014) Murine leukemia virus Gag localizes to the uropod of migrating primary lymphocytes. J Virol 88:10541-55
Huang, Fang; Hartwich, Tobias M P; Rivera-Molina, Felix E et al. (2013) Video-rate nanoscopy using sCMOS camera-specific single-molecule localization algorithms. Nat Methods 10:653-8
Zhong, Peng; Agosto, Luis M; Munro, James B et al. (2013) Cell-to-cell transmission of viruses. Curr Opin Virol 3:44-50
Li, Fei; Jin, Jing; Herrmann, Christin et al. (2013) Basic residues in the matrix domain and multimerization target murine leukemia virus Gag to the virological synapse. J Virol 87:7113-26

Showing the most recent 10 out of 26 publications