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Barría MI, Alvarez RA, Law K, Wolfson DL, Huser T, Chen BK. Endocytic Motif on a Biotin-Tagged HIV-1 Env Modulates the Co-Transfer of Env and Gag during Cell-to-Cell Transmission. Viruses 2021; 13:v13091729. [PMID: 34578310 PMCID: PMC8471404 DOI: 10.3390/v13091729] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/17/2021] [Accepted: 08/24/2021] [Indexed: 12/24/2022] Open
Abstract
During HIV-1 transmission through T cell virological synapses, the recruitment of the envelope (Env) glycoprotein to the site of cell-cell contact is important for adhesion and for packaging onto nascent virus particles which assemble at the site. Live imaging studies in CD4 T cells have captured the rapid recruitment of the viral structural protein Gag to VSs. We explored the role of endocytic trafficking of Env initiated by a membrane proximal tyrosine motif during HIV transfer into target cells and examined the factors that allow Gag and Env to be transferred together across the synapse. To facilitate tracking of Env in live cells, we adapted an Env tagging method and introduced a biotin acceptor peptide (BAP) into the V4 loop of Env gp120, enabling sensitive fluorescent tracking of V4-biotinylated Env. The BAP-tagged and biotinylated HIVs were replication-competent in cell-free and cell-to-cell infection assays. Live cell fluorescent imaging experiments showed rapid internalized cell surface Env on infected cells. Cell-cell transfer experiments conducted with the Env endocytosis mutant (Y712A) showed increased transfer of Env. Paradoxically, this increase in Env transfer was associated with significantly reduced Gag transfer into target cells, when compared to viral transfer associated with WT Env. This Y712A Env mutant also exhibited an altered Gag/biotin Env fluorescence ratio during transfer that correlated with decreased productive cell-to-cell infection. These results may suggest that the internalization of Env into recycling pools plays an important role in the coordinated transfer of Gag and Env across the VS, which optimizes productive infection in target cells.
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Affiliation(s)
- María Inés Barría
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Puerto Montt 5501842, Chile;
| | - Raymond A. Alvarez
- Division of Infectious Diseases, Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (R.A.A.); (K.L.)
| | - Kenneth Law
- Division of Infectious Diseases, Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (R.A.A.); (K.L.)
| | - Deanna L. Wolfson
- Department of Physics and Technology, UiT The Arctic University of Norway, NO-9037 Tromsø, Norway;
| | - Thomas Huser
- Biomolecular Photonics, Department of Physics, Bielefeld University, 33615 Bielefeld, Germany;
| | - Benjamin K. Chen
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Puerto Montt 5501842, Chile;
- Correspondence:
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Alvarez RA, Maestre AM, Law K, Durham ND, Barria MI, Ishii-Watabe A, Tada M, Kapoor M, Hotta MT, Rodriguez-Caprio G, Fierer DS, Fernandez-Sesma A, Simon V, Chen BK. Enhanced FCGR2A and FCGR3A signaling by HIV viremic controller IgG. JCI Insight 2017; 2:e88226. [PMID: 28239647 DOI: 10.1172/jci.insight.88226] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
HIV-1 viremic controllers (VC) spontaneously control infection without antiretroviral treatment. Several studies indicate that IgG Abs from VCs induce enhanced responses from immune effector cells. Since signaling through Fc-γ receptors (FCGRs) modulate these Ab-driven responses, here we examine if enhanced FCGR activation is a common feature of IgG from VCs. Using an infected cell-based system, we observed that VC IgG stimulated greater FCGR2A and FCGR3A activation as compared with noncontrollers, independent of the magnitude of HIV-specific Ab binding or virus neutralization activities. Multivariate regression analysis showed that enhanced FCGR signaling was a significant predictor of VC status as compared with chronically infected patients (CIP) on highly active antiretroviral therapy (HAART). Unsupervised hierarchical clustering of patient IgG functions primarily grouped VC IgG profiles by enhanced FCGR2A, FCGR3A, or dual signaling activity. Our findings demonstrate that enhanced FCGR signaling is a common and significant predictive feature of VC IgG, with VCs displaying a distinct spectrum of FCGR activation profiles. Thus, profiling FCGR activation may provide a useful method for screening and distinguishing protective anti-HIV IgG responses in HIV-infected patients and in monitoring HIV vaccination regimens.
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Affiliation(s)
- Raymond A Alvarez
- Division of Infectious Diseases, Department of Medicine, Immunology Institute
| | - Ana M Maestre
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Kenneth Law
- Division of Infectious Diseases, Department of Medicine, Immunology Institute
| | - Natasha D Durham
- Division of Infectious Diseases, Department of Medicine, Immunology Institute
| | - Maria Ines Barria
- Division of Infectious Diseases, Department of Medicine, Immunology Institute.,Department of Microbiology, University of Concepcion, Concepcion, Chile
| | - Akiko Ishii-Watabe
- Division of Biological Chemistry and Biologicals, National Institute of Health Sciences, Tokyo, Japan
| | - Minoru Tada
- Division of Biological Chemistry and Biologicals, National Institute of Health Sciences, Tokyo, Japan
| | - Manav Kapoor
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Mathew T Hotta
- Division of Infectious Diseases, Department of Medicine, Immunology Institute
| | | | - Daniel S Fierer
- Division of Infectious Diseases, Department of Medicine, Immunology Institute
| | - Ana Fernandez-Sesma
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Viviana Simon
- Division of Infectious Diseases, Department of Medicine, Immunology Institute.,Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,The Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Benjamin K Chen
- Division of Infectious Diseases, Department of Medicine, Immunology Institute
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HIV-1 Vpu antagonism of tetherin inhibits antibody-dependent cellular cytotoxic responses by natural killer cells. J Virol 2014; 88:6031-46. [PMID: 24623433 DOI: 10.1128/jvi.00449-14] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
UNLABELLED The type I interferon-inducible factor tetherin retains virus particles on the surfaces of cells infected with vpu-deficient human immunodeficiency virus type 1 (HIV-1). While this mechanism inhibits cell-free viral spread, the immunological implications of tethered virus have not been investigated. We found that surface tetherin expression increased the antibody opsonization of vpu-deficient HIV-infected cells. The absence of Vpu also stimulated NK cell-activating FcγRIIIa signaling and enhanced NK cell degranulation and NK cell-mediated antibody-dependent cellular cytotoxicity (ADCC). The deletion of vpu in HIV-1-infected primary CD4(+) T cells enhanced the levels of antibody binding and Fc receptor signaling mediated by HIV-positive-patient-derived antibodies. The magnitudes of antibody binding and Fc signaling were both highly correlated to the levels of tetherin on the surfaces of infected primary CD4 T cells. The affinity of antibody binding to FcγRIIIa was also found to be critical in mediating efficient Fc activation. These studies implicate Vpu antagonism of tetherin as an ADCC evasion mechanism that prevents antibody-mediated clearance of virally infected cells. IMPORTANCE The ability of the HIV-1 accessory factor to antagonize tetherin has been considered to primarily function by limiting the spread of virus by preventing the release of cell-free virus. This study supports the hypothesis that a major function of Vpu is to decrease the recognition of infected cells by anti-HIV antibodies at the cell surface, thereby reducing recognition by antibody-dependent clearance by natural killer cells.
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