1
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Umthong S, Timilsina U, D’Angelo MR, Salka K, Stavrou S. MARCH2, a T cell specific factor that restricts HIV-1 infection. PLoS Pathog 2024; 20:e1012330. [PMID: 39074162 PMCID: PMC11309421 DOI: 10.1371/journal.ppat.1012330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 08/08/2024] [Accepted: 06/07/2024] [Indexed: 07/31/2024] Open
Abstract
Membrane-associated RING-CH (MARCH) 2 is a member of the MARCH protein family of RING-CH finger E3 ubiquitin ligases that play important roles in regulating the levels of proteins found on the cell surface. MARCH1, 2 and 8 inhibit HIV-1 infection by preventing the incorporation of the envelope glycoproteins into nascent virions. However, a better understanding of the mechanism utilized by MARCH proteins to restrict HIV-1 infection is needed. In this report, we identify an amino acid in human MARCH2, absent in mouse MARCH2, critical for its antiretroviral function. Moreover, we map the domains of human MARCH2 critical for restricting as well as binding to the HIV-1 envelope glycoproteins. In addition, we demonstrate that MARCH2 is present inside nascent virions and reduces particle infectivity by blocking virus entry in a RING-CH-independent manner. Finally, we show that MARCH2 acts as an HIV-1 restriction factor only in primary CD4+ T cells and can prevent cell-to-cell transmission of HIV-1. Our findings reveal important new aspects of the antiviral mechanism utilized by human MARCH2 to restrict HIV-1 that have potential implications to all MARCH proteins with antiviral functions and their viral targets.
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Affiliation(s)
- Supawadee Umthong
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
- Department of Biochemistry and Microbiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Uddhav Timilsina
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Mary R. D’Angelo
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Kyle Salka
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Spyridon Stavrou
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
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2
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Iida N, Kawahara M, Hirota R, Shibagaki Y, Hattori S, Morikawa Y. A Proteomic Analysis of Detergent-Resistant Membranes in HIV Virological Synapse: The Involvement of Vimentin in CD4 Polarization. Viruses 2023; 15:1266. [PMID: 37376566 DOI: 10.3390/v15061266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/19/2023] [Accepted: 05/24/2023] [Indexed: 06/29/2023] Open
Abstract
The cell-cell contact between HIV-1-infected and uninfected cells forms a virological synapse (VS) to allow for efficient HIV-1 transmission. Not only are HIV-1 components polarized and accumulate at cell-cell interfaces, but viral receptors and lipid raft markers are also. To better understand the nature of the HIV-1 VS, detergent-resistant membrane (DRM) fractions were isolated from an infected-uninfected cell coculture and compared to those from non-coculture samples using 2D fluorescence difference gel electrophoresis. Mass spectrometry revealed that ATP-related enzymes (ATP synthase subunit and vacuolar-type proton ATPase), protein translation factors (eukaryotic initiation factor 4A and mitochondrial elongation factor Tu), protein quality-control-related factors (protein disulfide isomerase A3 and 26S protease regulatory subunit), charged multivesicular body protein 4B, and vimentin were recruited to the VS. Membrane flotation centrifugation of the DRM fractions and confocal microscopy confirmed these findings. We further explored how vimentin contributes to the HIV-1 VS and found that vimentin supports HIV-1 transmission through the recruitment of CD4 to the cell-cell interface. Since many of the molecules identified in this study have previously been suggested to be involved in HIV-1 infection, we suggest that a 2D difference gel analysis of DRM-associated proteins may reveal the molecules that play crucial roles in HIV-1 cell-cell transmission.
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Affiliation(s)
- Naoyuki Iida
- School of Pharmacy, Kitasato University, Shirokane 5-9-1, Minato-ku, Tokyo 108-8641, Japan
| | - Madoka Kawahara
- Omura Satoshi Memorial Institute and Graduate School for Infection Control, Kitasato University, Shirokane 5-9-1, Minato-ku, Tokyo 108-8641, Japan
| | - Riku Hirota
- Omura Satoshi Memorial Institute and Graduate School for Infection Control, Kitasato University, Shirokane 5-9-1, Minato-ku, Tokyo 108-8641, Japan
| | - Yoshio Shibagaki
- School of Pharmacy, Kitasato University, Shirokane 5-9-1, Minato-ku, Tokyo 108-8641, Japan
| | - Seisuke Hattori
- School of Pharmacy, Kitasato University, Shirokane 5-9-1, Minato-ku, Tokyo 108-8641, Japan
| | - Yuko Morikawa
- Omura Satoshi Memorial Institute and Graduate School for Infection Control, Kitasato University, Shirokane 5-9-1, Minato-ku, Tokyo 108-8641, Japan
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3
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Mulherkar TH, Gómez DJ, Sandel G, Jain P. Co-Infection and Cancer: Host–Pathogen Interaction between Dendritic Cells and HIV-1, HTLV-1, and Other Oncogenic Viruses. Viruses 2022; 14:v14092037. [PMID: 36146843 PMCID: PMC9503663 DOI: 10.3390/v14092037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/08/2022] [Accepted: 09/12/2022] [Indexed: 11/16/2022] Open
Abstract
Dendritic cells (DCs) function as a link between innate and adaptive immune responses. Retroviruses HIV-1 and HTLV-1 modulate DCs to their advantage and utilize them to propagate infection. Coinfection of HTLV-1 and HIV-1 has implications for cancer malignancies. Both viruses initially infect DCs and propagate the infection to CD4+ T cells through cell-to-cell transmission using mechanisms including the formation of virologic synapses, viral biofilms, and conduits. These retroviruses are both neurotrophic with neurovirulence determinants. The neuropathogenesis of HIV-1 and HTLV-1 results in neurodegenerative diseases such as HIV-associated neurocognitive disorders (HAND) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Infected DCs are known to traffic to the brain (CNS) and periphery (PNS, lymphatics) to induce neurodegeneration in HAND and HAM/TSP patients. Elevated levels of neuroinflammation have been correlated with cognitive decline and impairment of motor control performance. Current vaccinations and therapeutics for HIV-1 and HTLV-1 are assessed and can be applied to patients with HIV-1-associated cancers and adult T cell leukemia/lymphoma (ATL). These diseases caused by co-infections can result in both neurodegeneration and cancer. There are associations with cancer malignancies and HIV-1 and HTLV-1 as well as other human oncogenic viruses (EBV, HBV, HCV, HDV, and HPV). This review contains current knowledge on DC sensing of HIV-1 and HTLV-1 including DC-SIGN, Tat, Tax, and current viral therapies. An overview of DC interaction with oncogenic viruses including EBV, Hepatitis viruses, and HPV is also provided. Vaccines and therapeutics targeting host–pathogen interactions can provide a solution to co-infections, neurodegeneration, and cancer.
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Affiliation(s)
- Tania H. Mulherkar
- Department of Microbiology and Immunology, Drexel University, College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Daniel Joseph Gómez
- Department of Microbiology and Immunology, Drexel University, College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
- Department of Biological Sciences, California State University, 25800 Carlos Bee Blvd, Hayward, CA 94542, USA
| | - Grace Sandel
- Department of Microbiology and Immunology, Drexel University, College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Pooja Jain
- Department of Microbiology and Immunology, Drexel University, College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
- Correspondence:
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4
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Hoffman HK, Aguilar RS, Clark AR, Groves NS, Pezeshkian N, Bruns MM, van Engelenburg SB. Endocytosed HIV-1 Envelope Glycoprotein Traffics to Rab14 + Late Endosomes and Lysosomes to Regulate Surface Levels in T-Cell Lines. J Virol 2022; 96:e0076722. [PMID: 35770989 PMCID: PMC9327703 DOI: 10.1128/jvi.00767-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 06/06/2022] [Indexed: 11/20/2022] Open
Abstract
Production of infectious HIV-1 particles requires incorporation of the viral envelope glycoprotein (Env) at the plasma membrane (PM) of infected CD4+ T cells. Env trafficking to the PM exposes viral epitopes that can be exploited by the host immune system; however, HIV-1 can evade this response by endocytosis of excess Env from the PM. The fate of Env after internalization remains unclear, with evidence suggesting several different vesicular trafficking steps may be involved, including recycling pathways. To date, there have been very few studies documenting the trafficking pathways of native Env in infected T cells. Furthermore, it remains unclear whether there are T-cell-specific endosomal pathways regulating the fate of endocytic Env. Here, we use a pulse-labeling approach with a monovalent anti-Env Fab probe to characterize the trafficking of internalized Env within infected CD4+ T-cell lines, together with CRISPR/Cas9-mediated endogenous protein tagging, to assess the role of host cell Rab GTPases in Env trafficking. We show that endocytosed Env traffics to Rab14+ compartments that possess hallmarks of late endosomes and lysosomes. We also demonstrate that Env can recycle back to the PM, although we find that recycling does not occur at high rates when compared to the model recycling protein transferrin. These results help to resolve open questions about the fate and relevance of endocytosed Env in HIV-infected cells and suggest a novel role for Rab14 in a cell-type-specific late-endosomal/lysosomal trafficking pathway in T cells. IMPORTANCE HIV-1 envelope glycoprotein (Env) evades immune neutralization through many mechanisms. One immune evasion strategy may result from the internalization of excess surface-exposed Env to prevent antibody-dependent cellular cytotoxicity or neutralization. Characterization of the fate of endocytosed Env is critical to understand which vesicular pathways could be targeted to promote display of Env epitopes to the immune system. In this study, we characterize the endocytic fate of native Env, expressed from infected human T-cell lines. We demonstrate that Env is rapidly trafficked to a late-endosome/lysosome-like compartment and can be recycled to the cell surface for incorporation into virus assembly sites. This study implicates a novel intracellular compartment, marked by host-cell Rab14 GTPases, for the sequestration of Env. Therapeutic approaches aimed at mobilizing this intracellular pool of Env could lead to stronger immune control of HIV-1 infection via antibody-dependent cell-mediated cytotoxicity.
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Affiliation(s)
- Huxley K. Hoffman
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Rebekah S. Aguilar
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Austin R. Clark
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Nicholas S. Groves
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Nairi Pezeshkian
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Merissa M. Bruns
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Schuyler B. van Engelenburg
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
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5
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Espinar-Buitrago M, Muñoz-Fernández MA. New Approaches to Dendritic Cell-Based Therapeutic Vaccines Against HIV-1 Infection. Front Immunol 2022; 12:719664. [PMID: 35058917 PMCID: PMC8763680 DOI: 10.3389/fimmu.2021.719664] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 12/07/2021] [Indexed: 11/13/2022] Open
Abstract
Due to the success of combined antiretroviral therapy (cART) in recent years, the pathological outcome of Human Immunodeficiency Virus type 1 (HIV-1) infection has improved substantially, achieving undetectable viral loads in most cases. Nevertheless, the presence of a viral reservoir formed by latently infected cells results in patients having to maintain treatment for life. In the absence of effective eradication strategies against HIV-1, research efforts are focused on obtaining a cure. One of these approaches is the creation of therapeutic vaccines. In this sense, the most promising one up to now is based on the establishing of the immunological synapse between dendritic cells (DCs) and T lymphocytes (TL). DCs are one of the first cells of the immune system to encounter HIV-1 by acting as antigen presenting cells, bringing about the interaction between innate and adaptive immune responses mediated by TL. Furthermore, TL are the end effector, and their response capacity is essential in the adaptive elimination of cells infected by pathogens. In this review, we summarize the knowledge of the interaction between DCs with TL, as well as the characterization of the specific T-cell response against HIV-1 infection. The use of nanotechnology in the design and improvement of vaccines based on DCs has been researched and presented here with a special emphasis.
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Affiliation(s)
- Marisierra Espinar-Buitrago
- Section Head Immunology, Laboratorio InmunoBiología Molecular, Hospital General Universitario Gregorio Marañón (HGUGM), Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - Ma Angeles Muñoz-Fernández
- Section Head Immunology, Laboratorio InmunoBiología Molecular, Hospital General Universitario Gregorio Marañón (HGUGM), Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.,Spanish Human Immunodeficiency Virus- Hospital Gregorio Marañón (HIV-HGM) BioBank, Madrid, Spain.,Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
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6
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Engels R, Falk L, Albanese M, Keppler OT, Sewald X. LFA1 and ICAM1 are critical for fusion and spread of murine leukemia virus in vivo. Cell Rep 2022; 38:110279. [PMID: 35045303 DOI: 10.1016/j.celrep.2021.110279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 10/18/2021] [Accepted: 12/23/2021] [Indexed: 11/25/2022] Open
Abstract
Murine leukemia virus (MLV)-presenting cells form stable intercellular contacts with target cells during infection of lymphoid tissue, indicating a role of cell-cell contacts in retrovirus dissemination. Whether host cell adhesion proteins are required for retrovirus spread in vivo remains unknown. Here, we demonstrate that the lymphocyte-function-associated-antigen-1 (LFA1) and its ligand intercellular-adhesion-molecule-1 (ICAM1) are important for cell-contact-dependent transmission of MLV between leukocytes. Infection experiments in LFA1- and ICAM1-deficient mice demonstrate a defect in MLV spread within lymph nodes. Co-culture of primary leukocytes reveals a specific requirement for ICAM1 on donor cells and LFA1 on target cells for cell-contact-dependent spread through trans- and cis-infection. Importantly, adoptive transfer experiments combined with a newly established MLV-fusion assay confirm that the directed LFA1-ICAM1 interaction is important for retrovirus fusion and transmission in vivo. Taken together, our data provide insights on how retroviruses exploit host proteins and the biology of cell-cell interactions for dissemination.
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Affiliation(s)
- Rebecca Engels
- LMU München, Max von Pettenkofer Institute & Gene Center, Virology, National Reference Center for Retroviruses, Munich, Germany
| | - Lisa Falk
- LMU München, Max von Pettenkofer Institute & Gene Center, Virology, National Reference Center for Retroviruses, Munich, Germany
| | - Manuel Albanese
- LMU München, Max von Pettenkofer Institute & Gene Center, Virology, National Reference Center for Retroviruses, Munich, Germany
| | - Oliver T Keppler
- LMU München, Max von Pettenkofer Institute & Gene Center, Virology, National Reference Center for Retroviruses, Munich, Germany
| | - Xaver Sewald
- LMU München, Max von Pettenkofer Institute & Gene Center, Virology, National Reference Center for Retroviruses, Munich, Germany.
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7
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Tang Y, Woodward BO, Pastor L, George AM, Petrechko O, Nouvet FJ, Haas DW, Jiang G, Hildreth JEK. Endogenous Retroviral Envelope Syncytin Induces HIV-1 Spreading and Establishes HIV Reservoirs in Placenta. Cell Rep 2021; 30:4528-4539.e4. [PMID: 32234485 DOI: 10.1016/j.celrep.2020.03.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 01/16/2020] [Accepted: 03/05/2020] [Indexed: 02/08/2023] Open
Abstract
Radical cure of HIV-1 (HIV) is hampered by the establishment of HIV reservoirs and persistent infection in deep tissues despite suppressive antiretroviral therapy (ART). Here, we show that among HIV-positive women receiving suppressive ART, cells from placental tissues including trophoblasts contain HIV RNA and DNA. These viruses can be reactivated by latency reversal agents. We find that syncytin, the envelope glycoprotein of human endogenous retrovirus family W1 expressed on placental trophoblasts, triggers cell fusion with HIV-infected T cells. This results in cell-to-cell spread of HIV to placental trophoblasts. Such cell-to-cell spread of HIV is less sensitive to ART than free virus. Replication in syncytin-expressing cells can also produce syncytin-pseudotyped HIV, further expanding its ability to infect non-CD4 cells. These previously unrecognized mechanisms of HIV entry enable the virus to bypass receptor restriction to infect host barrier cells, thereby facilitating viral transmission and persistent infection in deep tissues.
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Affiliation(s)
- Yuyang Tang
- University of North Carolina at Chapel Hill, HIV Cure Center and Institute of Global Health & Infectious Diseases, Chapel Hill, NC 27599, USA; Department of Medical Microbiology and Immunology, University of California, Davis, Davis, CA 95616, USA
| | - Beverly O Woodward
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
| | - Lorena Pastor
- Department of Medical Microbiology and Immunology, University of California, Davis, Davis, CA 95616, USA
| | - Alvin M George
- Department of Internal Medicine, Meharry Medical College, Nashville, TN 37208, USA
| | - Oksana Petrechko
- Department of Medical Microbiology and Immunology, University of California, Davis, Davis, CA 95616, USA
| | - Franklin J Nouvet
- Department of Internal Medicine, Meharry Medical College, Nashville, TN 37208, USA
| | - David W Haas
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University School of Medicine, Nashville, TN 37240, USA; Department of Internal Medicine, Meharry Medical College, Nashville, TN 37208, USA
| | - Guochun Jiang
- University of North Carolina at Chapel Hill, HIV Cure Center and Institute of Global Health & Infectious Diseases, Chapel Hill, NC 27599, USA; Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - James E K Hildreth
- Department of Medical Microbiology and Immunology, University of California, Davis, Davis, CA 95616, USA; Department of Internal Medicine, Meharry Medical College, Nashville, TN 37208, USA.
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8
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Koh WH, Lopez P, Ajibola O, Parvarchian R, Mohammad U, Hnatiuk R, Kindrachuk J, Murooka TT. HIV-Captured DCs Regulate T Cell Migration and Cell-Cell Contact Dynamics to Enhance Viral Spread. iScience 2020; 23:101427. [PMID: 32798973 PMCID: PMC7452485 DOI: 10.1016/j.isci.2020.101427] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/24/2020] [Accepted: 07/30/2020] [Indexed: 02/07/2023] Open
Abstract
Trafficking of cell-associated HIV-1 from the genital mucosa to lymphoid organs represents a critical first step toward systemic infection. Mature DCs capture and transmit HIV-1 to T cells, but insights into DC-to-T cell viral spread dynamics within a 3-dimensional environment is lacking. Using live-cell imaging, we show that mature DCs rapidly compartmentalize HIV-1 within surface-accessible invaginations near the uropod. HIV-1 capture did not interfere with DC migration toward lymph node homing chemo-attractants and their ability to enter lymphatic vessels. However, HIV-captured DCs engaged in prolonged contacts with autologous CD4+ T cells, which led to high T cell infection. Interestingly, we show that surface bound, virion-associated Env induced signal transduction in motile T cells that facilitated prolonged DC:T cell interactions, partially through high-affinity LFA-1 expression. Together, we describe a mechanism by which surface bound HIV-1 particles function as signaling receptors that regulate T cell motility, cell-cell contact dynamics, and productive infection. Mature DCs compartmentalize HIV particles near the uropodia via Siglec-1 receptor HIV-captured DCs respond to lymph node-homing chemokines and access lymphatics Prolonged contacts between HIV-captured DCs and CD4 T cells facilitate virus transfer Surface-accessible HIV particles can induce T cell signaling via Env:CD4 engagement
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Affiliation(s)
- Wan Hon Koh
- University of Manitoba, Rady Faculty of Health Sciences, Department of Immunology, Winnipeg, MB, Canada
| | - Paul Lopez
- University of Manitoba, Rady Faculty of Health Sciences, Department of Immunology, Winnipeg, MB, Canada
| | - Oluwaseun Ajibola
- University of Manitoba, Rady Faculty of Health Sciences, Department of Immunology, Winnipeg, MB, Canada
| | - Roshan Parvarchian
- University of Manitoba, Rady Faculty of Health Sciences, Department of Immunology, Winnipeg, MB, Canada
| | - Umar Mohammad
- University of Manitoba, Rady Faculty of Health Sciences, Department of Immunology, Winnipeg, MB, Canada
| | - Ryan Hnatiuk
- University of Manitoba, Rady Faculty of Health Sciences, Department of Immunology, Winnipeg, MB, Canada
| | - Jason Kindrachuk
- University of Manitoba, Rady Faculty of Health Sciences, Department of Medical Microbiology and Infectious Diseases, Winnipeg, Canada
| | - Thomas T Murooka
- University of Manitoba, Rady Faculty of Health Sciences, Department of Immunology, Winnipeg, MB, Canada; University of Manitoba, Rady Faculty of Health Sciences, Department of Medical Microbiology and Infectious Diseases, Winnipeg, Canada.
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9
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Okutomi T, Minakawa S, Hirota R, Katagiri K, Morikawa Y. HIV Reactivation in Latently Infected Cells With Virological Synapse-Like Cell Contact. Viruses 2020; 12:v12040417. [PMID: 32276457 PMCID: PMC7232209 DOI: 10.3390/v12040417] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/05/2020] [Accepted: 04/06/2020] [Indexed: 12/13/2022] Open
Abstract
HIV reactivation from latency is induced by cytokines but also by cell contact with other cells. To better understand this, J1.1 cells, a latent HIV-1-infected Jurkat derivative, were cocultured with its parental Jurkat. J1.1 cells became p17MA-positive and produced a high level of HIV p24CA antigen, only when they were cocultured with stimulated Jurkat with cell-to-cell contact. In contrast, very little p24CA was produced when they were cocultured without cell contact. Similar results were obtained when latent ACH-2 and its parental A3.01 cells were cocultured. Confocal microscopy revealed that not only HIV-1 p17MA and gp120Env but also LFA-1, CD81, CD59, and TCR CD3 accumulated at the cell contact site, suggesting formation of the virological synapse-like structure. LFA-1–ICAM-1 interaction was involved in the cell-to-cell contact. When J1.1 was cocultured with TCR-deficient Jurkat, the p17MA-positive rate was significantly lower, although the cell-to-cell contact was not impaired. Quantitative proteomics identified 54 membrane molecules, one of which was MHC class I, that accumulated at the cell contact site. Reactivation from latency was also influenced by the presence of stromal cells. Our study indicated that latent HIV-1 in J1.1/ACH-2 cells was efficiently reactivated by cell-to-cell contact with stimulated parental cells, accompanying the virological synapse-like structure.
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Affiliation(s)
- Toshiki Okutomi
- Graduate School of Infection Control Sciences, Kitasato University, Shirokane 5-9-1, Minato-ku, Tokyo 108-8641, Japan; (T.O.); (S.M.); (R.H.)
| | - Satoko Minakawa
- Graduate School of Infection Control Sciences, Kitasato University, Shirokane 5-9-1, Minato-ku, Tokyo 108-8641, Japan; (T.O.); (S.M.); (R.H.)
| | - Riku Hirota
- Graduate School of Infection Control Sciences, Kitasato University, Shirokane 5-9-1, Minato-ku, Tokyo 108-8641, Japan; (T.O.); (S.M.); (R.H.)
| | - Koko Katagiri
- Department of Biosciences, School of Science, Kitasato University, Kitasato 1-15-1, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan;
| | - Yuko Morikawa
- Graduate School of Infection Control Sciences, Kitasato University, Shirokane 5-9-1, Minato-ku, Tokyo 108-8641, Japan; (T.O.); (S.M.); (R.H.)
- Correspondence: ; Tel.: +81-3-5791-6129
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10
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HIV Infection Stabilizes Macrophage-T Cell Interactions To Promote Cell-Cell HIV Spread. J Virol 2019; 93:JVI.00805-19. [PMID: 31270227 DOI: 10.1128/jvi.00805-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 06/25/2019] [Indexed: 02/06/2023] Open
Abstract
Macrophages are susceptible to HIV infection and play an important role in viral dissemination through cell-cell contacts with T cells. However, our current understanding of macrophage-to-T cell HIV transmission is derived from studies that do not consider the robust migration and cell-cell interaction dynamics between these cells. Here, we performed live-cell imaging studies in 3-dimensional (3D) collagen that allowed CD4+ T cells to migrate and to locate and engage HIV-infected macrophages, modeling the dynamic aspects of the in situ environment in which these contacts frequently occur. We show that HIV+ macrophages form stable contacts with CD4+ T cells that are facilitated by both gp120-CD4 and LFA-1-ICAM-1 interactions and that prolonged contacts are a prerequisite for efficient viral spread. LFA-1-ICAM-1 adhesive contacts function to restrain highly motile T cells, since their blockade substantially destabilized macrophage-T cell contacts, resulting in abnormal tethering events that reduced cell-cell viral spread. HIV-infected macrophages displayed strikingly elongated podosomal extensions that were dependent on Nef expression but were dispensable for stable cell-cell contact formation. Finally, we observed persistent T cell infection in dynamic monocyte-derived macrophage (MDM)-T cell cocultures in the presence of single high antiretroviral drug concentrations but achieved complete inhibition with combination therapy. Together, our data implicate macrophages as drivers of T cell infection by altering physiological MDM-T cell contact dynamics to access and restrain large numbers of susceptible, motile T cells within lymphoid tissues.IMPORTANCE Once HIV enters the lymphoid organs, exponential viral replication in T cells ensues. Given the densely packed nature of these tissues, where infected and uninfected cells are in nearly constant contact with one another, efficient HIV spread is thought to occur through cell-cell contacts in vivo However, this has not been formally demonstrated. In this study, we performed live-cell imaging studies within a 3-dimensional space to recapitulate the dynamic aspects of the lymphoid microenvironment and asked whether HIV can alter the morphology, migration capacity, and cell-cell contact behaviors between macrophages and T cells. We show that HIV-infected macrophages can engage T cells in stable contacts through binding of virus- and host-derived adhesive molecules and that stable macrophage-T cell contacts were required for high viral spread. Thus, HIV alters physiological macrophage-T cell interactions in order to access and restrain large numbers of susceptible, motile T cells, thereby playing an important role in HIV progression.
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11
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Bayliss RJ, Piguet V. Masters of manipulation: Viral modulation of the immunological synapse. Cell Microbiol 2018; 20:e12944. [PMID: 30123959 PMCID: PMC6492149 DOI: 10.1111/cmi.12944] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/01/2018] [Accepted: 08/14/2018] [Indexed: 02/06/2023]
Abstract
In order to thrive, viruses have evolved to manipulate host cell machinery for their own benefit. One major obstacle faced by pathogens is the immunological synapse. To enable efficient replication and latency in immune cells, viruses have developed a range of strategies to manipulate cellular processes involved in immunological synapse formation to evade immune detection and control T-cell activation. In vitro, viruses such as human immunodeficiency virus 1 and human T-lymphotropic virus type 1 utilise structures known as virological synapses to aid transmission of viral particles from cell to cell in a process termed trans-infection. The formation of the virological synapse provides a gateway for virus to be transferred between cells avoiding the extracellular space, preventing antibody neutralisation or recognition by complement. This review looks at how viruses are able to subvert intracellular signalling to modulate immune function to their advantage and explores the role synapse formation has in viral persistence and cell-to-cell transmission.
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Affiliation(s)
- Rebecca J. Bayliss
- Division of Infection and Immunity, School of MedicineCardiff UniversityCardiffUK
| | - Vincent Piguet
- Division of Infection and Immunity, School of MedicineCardiff UniversityCardiffUK
- Division of Dermatology, Department of MedicineUniversity of TorontoTorontoOntarioCanada
- Division of DermatologyWomen's College HospitalTorontoOntarioCanada
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12
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Dufloo J, Bruel T, Schwartz O. HIV-1 cell-to-cell transmission and broadly neutralizing antibodies. Retrovirology 2018; 15:51. [PMID: 30055632 PMCID: PMC6064125 DOI: 10.1186/s12977-018-0434-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 07/23/2018] [Indexed: 12/19/2022] Open
Abstract
HIV-1 spreads through contacts between infected and target cells. Polarized viral budding at the contact site forms the virological synapse. Additional cellular processes, such as nanotubes, filopodia, virus accumulation in endocytic or phagocytic compartments promote efficient viral propagation. Cell-to-cell transmission allows immune evasion and likely contributes to HIV-1 spread in vivo. Anti-HIV-1 broadly neutralizing antibodies (bNAbs) defeat the majority of circulating viral strains by binding to the viral envelope glycoprotein (Env). Several bNAbs have entered clinical evaluation during the last years. It is thus important to understand their mechanism of action and to determine how they interact with infected cells. In experimental models, HIV-1 cell-to-cell transmission is sensitive to neutralization, but the effect of antibodies is often less marked than during cell-free infection. This may be due to differences in the conformation or accessibility of Env at the surface of virions and cells. In this review, we summarize the current knowledge on HIV-1 cell-to-cell transmission and discuss the role of bNAbs during this process.
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Affiliation(s)
- Jérémy Dufloo
- Virus and Immunity Unit, Department of Virology, Institut Pasteur, Paris, France.,CNRS-UMR3569, Paris, France
| | - Timothée Bruel
- Virus and Immunity Unit, Department of Virology, Institut Pasteur, Paris, France.,CNRS-UMR3569, Paris, France.,Vaccine Research Institute, Créteil, France
| | - Olivier Schwartz
- Virus and Immunity Unit, Department of Virology, Institut Pasteur, Paris, France. .,CNRS-UMR3569, Paris, France. .,Vaccine Research Institute, Créteil, France.
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13
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Cyrklaff M, Frischknecht F, Kudryashev M. Functional insights into pathogen biology from 3D electron microscopy. FEMS Microbiol Rev 2018; 41:828-853. [PMID: 28962014 DOI: 10.1093/femsre/fux041] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 07/25/2017] [Indexed: 01/10/2023] Open
Abstract
In recent years, novel imaging approaches revolutionised our understanding of the cellular and molecular biology of microorganisms. These include advances in fluorescent probes, dynamic live cell imaging, superresolution light and electron microscopy. Currently, a major transition in the experimental approach shifts electron microscopy studies from a complementary technique to a method of choice for structural and functional analysis. Here we review functional insights into the molecular architecture of viruses, bacteria and parasites as well as interactions with their respective host cells gained from studies using cryogenic electron tomography and related methodologies.
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Affiliation(s)
- Marek Cyrklaff
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Mikhail Kudryashev
- Max Planck Institute of Biophysics, Max-von-Laue Strasse 3, 60438 Frankfurt, Germany.,Buchmann Institute for Molecular Life Sciences, Goethe University of Frankfurt, Max-von-Laue Strasse 17, 60438 Frankfurt, Germany
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14
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Abstract
While HIV-1 infection of target cells with cell-free viral particles has been largely documented, intercellular transmission through direct cell-to-cell contact may be a predominant mode of propagation in host. To spread, HIV-1 infects cells of the immune system and takes advantage of their specific particularities and functions. Subversion of intercellular communication allows to improve HIV-1 replication through a multiplicity of intercellular structures and membrane protrusions, like tunneling nanotubes, filopodia, or lamellipodia-like structures involved in the formation of the virological synapse. Other features of immune cells, like the immunological synapse or the phagocytosis of infected cells are hijacked by HIV-1 and used as gateways to infect target cells. Finally, HIV-1 reuses its fusogenic capacity to provoke fusion between infected donor cells and target cells, and to form infected syncytia with high capacity of viral production and improved capacities of motility or survival. All these modes of cell-to-cell transfer are now considered as viral mechanisms to escape immune system and antiretroviral therapies, and could be involved in the establishment of persistent virus reservoirs in different host tissues.
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Affiliation(s)
- Lucie Bracq
- Inserm U1016, Institut Cochin, Paris, France.,CNRS, UMR8104, Paris, France.,Université Paris-Descartes, Sorbonne Paris-Cité, Paris, France.,International Associated Laboratory (LIA VirHost), Institut Pasteur Shanghai-Chinese Academy of Sciences, Shanghai, China.,International Associated Laboratory (LIA VirHost), CNRS, Université Paris-Descartes, Institut Pasteur, Paris, France
| | - Maorong Xie
- Inserm U1016, Institut Cochin, Paris, France.,CNRS, UMR8104, Paris, France.,Université Paris-Descartes, Sorbonne Paris-Cité, Paris, France.,International Associated Laboratory (LIA VirHost), CNRS, Université Paris-Descartes, Institut Pasteur, Paris, France
| | - Serge Benichou
- Inserm U1016, Institut Cochin, Paris, France.,CNRS, UMR8104, Paris, France.,Université Paris-Descartes, Sorbonne Paris-Cité, Paris, France.,International Associated Laboratory (LIA VirHost), Institut Pasteur Shanghai-Chinese Academy of Sciences, Shanghai, China.,International Associated Laboratory (LIA VirHost), CNRS, Université Paris-Descartes, Institut Pasteur, Paris, France
| | - Jérôme Bouchet
- Inserm U1016, Institut Cochin, Paris, France.,CNRS, UMR8104, Paris, France.,Université Paris-Descartes, Sorbonne Paris-Cité, Paris, France.,International Associated Laboratory (LIA VirHost), CNRS, Université Paris-Descartes, Institut Pasteur, Paris, France
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15
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Grosche L, Kummer M, Steinkasserer A. What Goes Around, Comes Around - HSV-1 Replication in Monocyte-Derived Dendritic Cells. Front Microbiol 2017; 8:2149. [PMID: 29163433 PMCID: PMC5674004 DOI: 10.3389/fmicb.2017.02149] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 10/20/2017] [Indexed: 01/12/2023] Open
Abstract
HSV-1 is a very successful human pathogen, known for its high sero-prevalence and the ability to infect a wide range of different cell types, including dendritic cells (DCs). As very potent antigen-presenting cells DCs play an important role in the induction of antiviral immune responses and therefore represent a strategic target for viral-mediated immune escape mechanisms. It is known that HSV-1 completes its gene expression profile in immature as well as in mature DCs, while lytic infection is only found in immature DCs (iDCs). Notably, HSV-1 infected mature DCs (mDCs) fail to release infectious progeny virions into the supernatant. Apart from HSV-1 dissemination via extracellular routes cell-to-cell spread counteracts a yet unknown mechanism by which the virus is trapped in mDCs and not released into the supernatant. The dissemination in a cell-cell contact-dependent manner enables HSV-1 to infect bystander cells without the exposure toward the extracellular environment. This supports the virus to successfully infect the host and establish latency. In this review the mechanism of HSV-1 replication in iDCs and mDCs and its immunological as well as virological implications, will be discussed.
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Affiliation(s)
- Linda Grosche
- Department of Immune Modulation, University Hospital Erlangen, Erlangen, Germany
| | - Mirko Kummer
- Department of Immune Modulation, University Hospital Erlangen, Erlangen, Germany
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16
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HIV Envelope gp120 Alters T Cell Receptor Mobilization in the Immunological Synapse of Uninfected CD4 T Cells and Augments T Cell Activation. J Virol 2016; 90:10513-10526. [PMID: 27630246 DOI: 10.1128/jvi.01532-16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 09/07/2016] [Indexed: 01/21/2023] Open
Abstract
HIV is transmitted most efficiently from cell to cell, and productive infection occurs mainly in activated CD4 T cells. It is postulated that HIV exploits immunological synapses formed between CD4 T cells and antigen-presenting cells to facilitate the targeting and infection of activated CD4 T cells. This study sought to evaluate how the presence of the HIV envelope (Env) in the CD4 T cell immunological synapse affects synapse formation and intracellular signaling to impact the downstream T cell activation events. CD4 T cells were applied to supported lipid bilayers that were reconstituted with HIV Env gp120, anti-T cell receptor (anti-TCR) monoclonal antibody, and ICAM-1 to represent the surface of HIV Env-bearing antigen-presenting cells. The results showed that the HIV Env did not disrupt immunological synapse formation. Instead, the HIV Env accumulated with TCR at the center of the synapse, altered the kinetics of TCR recruitment to the synapse and affected synapse morphology over time. The HIV Env also prolonged Lck phosphorylation at the synapse and enhanced TCR-induced CD69 upregulation, interleukin-2 secretion, and proliferation to promote virus infection. These results suggest that HIV uses the immunological synapse as a conduit not only for selective virus transmission to activated CD4 T cells but also for boosting the T cell activation state, thereby increasing its likelihood of undergoing productive replication in targeted CD4 T cells. IMPORTANCE There are about two million new HIV infections every year. A better understanding of how HIV is transmitted to susceptible cells is critical to devise effective strategies to prevent HIV infection. Activated CD4 T cells are preferentially infected by HIV, although how this is accomplished is not fully understood. This study examined whether HIV co-opts the normal T cell activation process through the so-called immunological synapse. We found that the HIV envelope is recruited to the center of the immunological synapse together with the T cell receptor and enhances the T cell receptor-induced activation of CD4 T cells. Heightened cellular activation promotes the capacity of CD4 T cells to support productive HIV replication. This study provides evidence of the exploitation of the normal immunological synapse and T cell activation process by HIV to boost the activation state of targeted CD4 T cells and promote the infection of these cells.
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17
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Dirk BS, Van Nynatten LR, Dikeakos JD. Where in the Cell Are You? Probing HIV-1 Host Interactions through Advanced Imaging Techniques. Viruses 2016; 8:v8100288. [PMID: 27775563 PMCID: PMC5086620 DOI: 10.3390/v8100288] [Citation(s) in RCA: 8] [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: 08/26/2016] [Revised: 10/06/2016] [Accepted: 10/10/2016] [Indexed: 12/19/2022] Open
Abstract
Viruses must continuously evolve to hijack the host cell machinery in order to successfully replicate and orchestrate key interactions that support their persistence. The type-1 human immunodeficiency virus (HIV-1) is a prime example of viral persistence within the host, having plagued the human population for decades. In recent years, advances in cellular imaging and molecular biology have aided the elucidation of key steps mediating the HIV-1 lifecycle and viral pathogenesis. Super-resolution imaging techniques such as stimulated emission depletion (STED) and photoactivation and localization microscopy (PALM) have been instrumental in studying viral assembly and release through both cell-cell transmission and cell-free viral transmission. Moreover, powerful methods such as Forster resonance energy transfer (FRET) and bimolecular fluorescence complementation (BiFC) have shed light on the protein-protein interactions HIV-1 engages within the host to hijack the cellular machinery. Specific advancements in live cell imaging in combination with the use of multicolor viral particles have become indispensable to unravelling the dynamic nature of these virus-host interactions. In the current review, we outline novel imaging methods that have been used to study the HIV-1 lifecycle and highlight advancements in the cell culture models developed to enhance our understanding of the HIV-1 lifecycle.
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Affiliation(s)
- Brennan S Dirk
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A 5C1, Canada.
| | - Logan R Van Nynatten
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A 5C1, Canada.
| | - Jimmy D Dikeakos
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A 5C1, Canada.
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18
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Abstract
The way in which a viral infection spreads within a host is a complex process that is not well understood. Different viruses, such as human immunodeficiency virus type 1 and hepatitis C virus, have evolved different strategies, including direct cell-to-cell transmission and cell-free transmission, to spread within a host. To what extent these two modes of transmission are exploited in vivo is still unknown. Mathematical modeling has been an essential tool to get a better systematic and quantitative understanding of viral processes that are difficult to discern through strictly experimental approaches. In this review, we discuss recent attempts that combine experimental data and mathematical modeling in order to determine and quantify viral transmission modes. We also discuss the current challenges for a systems-level understanding of viral spread, and we highlight the promises and challenges that novel experimental techniques and data will bring to the field.
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Affiliation(s)
- Frederik Graw
- Center for Modelling and Simulation in the Biosciences, BioQuant Center, Heidelberg University, 69120 Heidelberg, Germany
| | - Alan S Perelson
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545;
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19
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Dustin ML, Choudhuri K. Signaling and Polarized Communication Across the T Cell Immunological Synapse. Annu Rev Cell Dev Biol 2016; 32:303-325. [PMID: 27501450 DOI: 10.1146/annurev-cellbio-100814-125330] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
T cells express a somatically recombined antigen receptor (αβTCR) that is calibrated during development to respond to changes in peptides displayed by major histocompatibility complex proteins (pMHC) on the surface of antigen-presenting cells (APC). A key characteristic of pMHC for adaptive immunity is the ability to sample internal states of cells and tissues to sensitively detect changes associated with infection, cell derangement, or tissue injury. Physical T cell-APC contact sets up an axis for polarization of TCR, adhesion molecules, kinases, cytoskeletal elements, and organelles inherent in this mode of juxtacrine signaling. The discovery of further lateral organization of the TCR and adhesion molecules into radially symmetric compartments, the immunological synapse, revealed an intersecting plane of symmetry and potential for regulated symmetry breaking to control duration of T cell-APC interactions. In addition to organizing signaling machinery, the immunological synapse directs the polarized transport and secretion of cytokines and cytolytic agents across the synaptic cleft and is a site for the generation and exocytic release of bioactive microvesicles that can functionally affect recipient APC and other cells in the environment. This machinery is coopted by retroviruses, and human immune deficiency virus-1 may even use antigen-specific synapses for infection of healthy T cells. Here, we discuss recent advances in the molecular and cell biological mechanisms of immunological synapse assembly and signaling and its role in intercellular communication across the synaptic cleft.
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Affiliation(s)
- Michael L Dustin
- Kennedy Institute of Rheumatology, Nuffield Department of Orthopedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford OX3 7FY, United Kingdom;
| | - Kaushik Choudhuri
- Department of Microbiology & Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109-5620;
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20
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Hanne J, Zila V, Heilemann M, Müller B, Kräusslich HG. Super-resolved insights into human immunodeficiency virus biology. FEBS Lett 2016; 590:1858-76. [PMID: 27117435 DOI: 10.1002/1873-3468.12186] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 04/13/2016] [Accepted: 04/21/2016] [Indexed: 11/06/2022]
Abstract
The recent development of fluorescence microscopy approaches overcoming the diffraction limit of light microscopy opened possibilities for studying small-scale cellular processes. The spatial resolution achieved by these novel techniques, together with the possibility to perform live-cell and multicolor imaging, make them ideally suited for visualization of native viruses and subviral structures within the complex environment of a host cell or organ, thus providing fundamentally new possibilities for investigating virus-cell interactions. Here, we review the use of super-resolution microscopy approaches to study virus-cell interactions, and discuss recent insights into human immunodeficiency virus biology obtained by exploiting these novel techniques.
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Affiliation(s)
- Janina Hanne
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Germany.,Optical Nanoscopy Division, German Cancer Research Center, Heidelberg, Germany
| | - Vojtech Zila
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Germany
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Germany
| | - Barbara Müller
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Germany
| | - Hans-Georg Kräusslich
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Germany
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21
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Durham ND, Chen BK. Measuring T Cell-to-T Cell HIV-1 Transfer, Viral Fusion, and Infection Using Flow Cytometry. Methods Mol Biol 2016; 1354:21-38. [PMID: 26714702 DOI: 10.1007/978-1-4939-3046-3_2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Direct T cell-to-T cell HIV-1 infection is a distinct mode of HIV-1 infection that requires physical contact between an HIV-1-infected "donor" cell and an uninfected, CD4-expressing "target" cell. In vitro studies indicate that HIV-1 cell-to-cell infection is much more efficient than infection by cell-free viral particles; however, the exact mechanisms of the enhanced efficiency of this infection pathway are still unclear. Several assays have been developed to study the mechanism of direct cell-to-cell HIV-1 transmission and to assess sensitivity to neutralizing antibodies and pharmacologic inhibitors. These assays are based on the coculture of donor and target cells. Here, we describe methods that utilize flow cytometry, which can discriminate donor and target cells and can assess different stages of entry and infection following cell-to-cell contact. HIV Gag-iGFP, a clone that makes fluorescent virus particles, can be used to measure cell-to-cell transfer of virus particles. HIV NL-GI, a clone that expresses GFP as an early gene, facilitates the measure of productive infection after cell-to-cell contact. Lastly, a variation of the β-lactamase (BlaM)-Vpr fusion assay can be used to measure the viral membrane fusion process after coculture of donor and target cells in a manner that is independent of cell-cell fusion. These assays can be performed in the presence of neutralizing antibodies/inhibitors to determine the 50 % inhibitory concentration (IC50) required to block infection specifically in the target cells.
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Affiliation(s)
- Natasha D Durham
- Division of Infectious Diseases, Department of Medicine, Immunology Institute, Icahn School of Medicine at Mt. Sinai, One Gustave Levy Place, Box 1090, New York, NY, 10029, USA
| | - Benjamin K Chen
- Division of Infectious Diseases, Department of Medicine, Immunology Institute, Icahn School of Medicine at Mt. Sinai, One Gustave Levy Place, Box 1090, New York, NY, 10029, USA.
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22
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Reh L, Magnus C, Schanz M, Weber J, Uhr T, Rusert P, Trkola A. Capacity of Broadly Neutralizing Antibodies to Inhibit HIV-1 Cell-Cell Transmission Is Strain- and Epitope-Dependent. PLoS Pathog 2015; 11:e1004966. [PMID: 26158270 PMCID: PMC4497647 DOI: 10.1371/journal.ppat.1004966] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 05/21/2015] [Indexed: 12/11/2022] Open
Abstract
An increasing number of broadly neutralizing antibodies (bnAbs) are considered leads for HIV-1 vaccine development and novel therapeutics. Here, we systematically explored the capacity of bnAbs to neutralize HIV-1 prior to and post-CD4 engagement and to block HIV-1 cell-cell transmission. Cell-cell spread is known to promote a highly efficient infection with HIV-1 which can inflict dramatic losses in neutralization potency compared to free virus infection. Selection of bnAbs that are capable of suppressing HIV irrespective of the transmission mode therefore needs to be considered to ascertain their in vivo activity in therapeutic use and vaccines. Employing assay systems that allow for unambiguous discrimination between free virus and cell-cell transmission to T cells, we probed a panel of 16 bnAbs for their activity against 11 viruses from subtypes A, B and C during both transmission modes. Over a wide range of bnAb-virus combinations tested, inhibitory activity against HIV-1 cell-cell transmission was strongly decreased compared to free virus transmission. Activity loss varied considerably between virus strains and was inversely associated with neutralization of free virus spread for V1V2- and V3-directed bnAbs. In rare bnAb-virus combinations, inhibition for both transmission modes was comparable but no bnAb potently blocked cell-cell transmission across all probed virus strains. Mathematical analysis indicated an increased probability of bnAb resistance mutations to arise in cell-cell rather than free virus spread, further highlighting the need to block this pathway. Importantly, the capacity to efficiently neutralize prior to CD4 engagement correlated with the inhibition efficacy against free virus but not cell-cell transmitted virus. Pre-CD4 attachment activity proved strongest amongst CD4bs bnAbs and varied substantially for V3 and V1V2 loop bnAbs in a strain-dependent manner. In summary, bnAb activity against divergent viruses varied depending on the transmission mode and differed depending on the window of action during the entry process, underscoring that powerful combinations of bnAbs are needed for in vivo application. When selecting broadly neutralizing antibodies (bnAbs) for clinical application, potency and breadth against free viruses are vital, but additional features may be needed to ensure in vivo efficacy. Considering that HIV-1 can utilize free virus and cell-cell transmission to infect, the efficacy of neutralizing antibodies in vivo may depend on their ability to block both pathways. While breadth and potency of bnAbs against free viruses have been intensely studied, their precise activity during cell-cell spread remains uncertain. Our analysis of the cell-cell neutralization capacity of a large selection of bnAbs against a spectrum of HIV-1 strains revealed that while bnAbs showed an overall decreased activity during cell-cell transmission, losses varied substantially depending on bnAb and virus strain probed. Although bnAbs occasionally retained activity during cell-cell transmission for individual viruses, this ability was rare and generally not associated with a high potency against free virus spread. Notably, neutralization of free virus but not cell-cell transmission was linked with the activity of bnAbs to inhibit prior to CD4 engagement, highlighting the functional differences of the processes. Since no single bnAb combines the entire range of mechanistic features anticipated to support in vivo efficacy, our study adds further evidence that combinations of bnAbs need to be considered for human application.
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Affiliation(s)
- Lucia Reh
- Institute of Medical Virology, University of Zürich, Zürich, Switzerland
| | - Carsten Magnus
- Institute of Medical Virology, University of Zürich, Zürich, Switzerland
| | - Merle Schanz
- Institute of Medical Virology, University of Zürich, Zürich, Switzerland
| | - Jacqueline Weber
- Institute of Medical Virology, University of Zürich, Zürich, Switzerland
| | - Therese Uhr
- Institute of Medical Virology, University of Zürich, Zürich, Switzerland
| | - Peter Rusert
- Institute of Medical Virology, University of Zürich, Zürich, Switzerland
| | - Alexandra Trkola
- Institute of Medical Virology, University of Zürich, Zürich, Switzerland
- * E-mail:
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23
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Vpu is the main determinant for tetraspanin downregulation in HIV-1-infected cells. J Virol 2015; 89:3247-55. [PMID: 25568205 DOI: 10.1128/jvi.03719-14] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
UNLABELLED Tetraspanins constitute a family of cellular proteins that organize various membrane-based processes. Several members of this family, including CD81, are actively recruited by HIV-1 Gag to viral assembly and release sites. Despite their enrichment at viral exit sites, the overall levels of tetraspanins are decreased in HIV-1-infected cells. Here, we identify Vpu as the main viral determinant for tetraspanin downregulation. We also show that reduction of CD81 levels by Vpu is not a by-product of CD4 or BST-2/tetherin elimination from the surfaces of infected cells and likely occurs through an interaction between Vpu and CD81. Finally, we document that Vpu-mediated downregulation of CD81 from the surfaces of infected T cells can contribute to preserving the infectiousness of viral particles, thus revealing a novel Vpu function that promotes virus propagation by modulating the host cell environment. IMPORTANCE The HIV-1 accessory protein Vpu has previously been shown to downregulate various host cell factors, thus helping the virus to overcome restriction barriers, evade immune attack, and maintain the infectivity of viral particles. Our study identifies tetraspanins as an additional group of host factors whose expression at the surfaces of infected cells is lowered by Vpu. While the downregulation of these integral membrane proteins, including CD81 and CD82, likely affects more than one function of HIV-1-infected cells, we document that Vpu-mediated lowering of CD81 levels in viral particles can be critical to maintaining their infectiousness.
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24
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Yu X, Xu F, Ramirez NGP, Kijewski SDG, Akiyama H, Gummuluru S, Reinhard BM. Dressing up Nanoparticles: A Membrane Wrap to Induce Formation of the Virological Synapse. ACS NANO 2015; 9:4182-92. [PMID: 25853367 PMCID: PMC4423798 DOI: 10.1021/acsnano.5b00415] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Next-generation nanoparticle-based drug delivery systems require the ability to target specific organelles or subcellular regions in selected target cells. Human immunodeficiency virus type I (HIV-1) particles are evolutionarily optimized nanocarriers that have evolved to avoid intracellular degradation and achieve enrichment at the synapse between mature dendritic cells (mDCs) and T cells by subverting cellular trafficking mechanisms. This study demonstrates that integration of the glycosphingolipid, GM3, in a membrane around a solid nanoparticle (NP) core is sufficient to recapitulate key aspects of the virus particle trafficking in mDCs. GM3-presenting artificial virus NPs (GM3-AVNs) accumulate in CD169(+) and CD81(+) nonlysosomal compartments in an actin-dependent process that mimics the sequestration of HIV-1. Live-cell optical tracking studies reveal a preferential recruitment and arrest of surface scanning CD4(+) T cells in direct vicinity to the AVN-enriched compartments. The formed mDC-T cell conjugates exhibit strong morphological similarities between the GM3-AVN-containing mDC-T cell synapse and the HIV-1 virological synapse, indicating that GM3-CD169 interactions alone are sufficient for establishing the mDC-T cell virological synapse. These results emphasize the potential of the GM3-AVN approach for providing therapeutic access to a key step of the host immune response--formation of the synaptic junction between an antigen-presenting cell (mDC) and T cells--for modulating and controlling immune responses.
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Affiliation(s)
- Xinwei Yu
- Department of Chemistry and The Photonics Center, Boston University, Boston, MA 02215, United States
| | - Fangda Xu
- Department of Chemistry and The Photonics Center, Boston University, Boston, MA 02215, United States
| | | | - Suzanne D. G. Kijewski
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, United States
| | - Hisashi Akiyama
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, United States
| | - Suryaram Gummuluru
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, United States
| | - Björn M. Reinhard
- Department of Chemistry and The Photonics Center, Boston University, Boston, MA 02215, United States
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25
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Abstract
UNLABELLED Rapid HIV-1 spread between CD4 T lymphocytes occurs at retrovirus-induced immune cell contacts called virological synapses (VS). VS are associated with striking T cell polarization and localized virus budding at the site of contact that facilitates cell-cell spread. In addition to this, spatial clustering of organelles, including mitochondria, to the contact zone has been previously shown. However, whether cell-cell contact specifically induces dynamic T cell remodeling during VS formation and what regulates this process remain unclear. Here, we report that contact between an HIV-1-infected T cell and an uninfected target T cell specifically triggers polarization of mitochondria concomitant with recruitment of the major HIV-1 structural protein Gag to the site of cell-cell contact. Using fixed and live-cell imaging, we show that mitochondrial and Gag polarization in HIV-1-infected T cells occurs within minutes of contact with target T cells, requires the formation of stable cell-cell contacts, and is an active, calcium-dependent process. We also find that perturbation of mitochondrial polarization impairs cell-cell spread of HIV-1 at the VS. Taken together, these data suggest that HIV-1-infected T cells are able to sense and respond to contact with susceptible target cells and undergo dynamic cytoplasmic remodeling to create a synaptic environment that supports efficient HIV-1 VS formation between CD4 T lymphocytes. IMPORTANCE HIV-1 remains one of the major global health challenges of modern times. The capacity of HIV-1 to cause disease depends on the virus's ability to spread between immune cells, most notably CD4 T lymphocytes. Cell-cell transmission is the most efficient way of HIV-1 spread and occurs at the virological synapse (VS). The VS forms at the site of contact between an infected cell and an uninfected cell and is characterized by polarized assembly and budding of virions and clustering of cellular organelles, including mitochondria. Here, we show that cell-cell contact induces rapid recruitment of mitochondria to the contact site and that this supports efficient VS formation and consequently cell-cell spread. Additionally, we observed that cell-cell contact induces a mitochondrion-dependent increase in intracellular calcium, indicative of cellular signaling. Taken together, our data suggest that VS formation is a regulated process and thus a potential target to block HIV-1 cell-cell spread.
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Do T, Murphy G, Earl LA, Del Prete GQ, Grandinetti G, Li GH, Estes JD, Rao P, Trubey CM, Thomas J, Spector J, Bliss D, Nath A, Lifson JD, Subramaniam S. Three-dimensional imaging of HIV-1 virological synapses reveals membrane architectures involved in virus transmission. J Virol 2014; 88:10327-39. [PMID: 24965444 PMCID: PMC4178837 DOI: 10.1128/jvi.00788-14] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 06/12/2014] [Indexed: 01/25/2023] Open
Abstract
UNLABELLED HIV transmission efficiency is greatly increased when viruses are transmitted at virological synapses formed between infected and uninfected cells. We have previously shown that virological synapses formed between HIV-pulsed mature dendritic cells (DCs) and uninfected T cells contain interdigitated membrane surfaces, with T cell filopodia extending toward virions sequestered deep inside invaginations formed on the DC membrane. To explore membrane structural changes relevant to HIV transmission across other types of intercellular conjugates, we used a combination of light and focused ion beam scanning electron microscopy (FIB-SEM) to determine the three-dimensional (3D) architectures of contact regions between HIV-1-infected CD4(+) T cells and either uninfected human CD4(+) T cells or human fetal astrocytes. We present evidence that in each case, membrane extensions that originate from the uninfected cells, either as membrane sheets or filopodial bridges, are present and may be involved in HIV transmission from infected to uninfected cells. We show that individual virions are distributed along the length of astrocyte filopodia, suggesting that virus transfer to the astrocytes is mediated, at least in part, by processes originating from the astrocyte itself. Mechanisms that selectively disrupt the polarization and formation of such membrane extensions could thus represent a possible target for reducing viral spread. IMPORTANCE Our findings lead to new insights into unique aspects of HIV transmission in the brain and at T cell-T cell synapses, which are thought to be a predominant mode of rapid HIV transmission early in the infection process.
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Affiliation(s)
- Thao Do
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Gavin Murphy
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Lesley A Earl
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Gregory Q Del Prete
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, Frederick, Maryland, USA
| | - Giovanna Grandinetti
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Guan-Han Li
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Jacob D Estes
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, Frederick, Maryland, USA
| | - Prashant Rao
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Charles M Trubey
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, Frederick, Maryland, USA
| | - James Thomas
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, Frederick, Maryland, USA
| | - Jeffrey Spector
- National Institute of Standards and Technology, Gaithersburg, Maryland, USA
| | - Donald Bliss
- National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Avindra Nath
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Jeffrey D Lifson
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, Frederick, Maryland, USA
| | - Sriram Subramaniam
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
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Su B, Moog C. Which Antibody Functions are Important for an HIV Vaccine? Front Immunol 2014; 5:289. [PMID: 24995008 PMCID: PMC4062070 DOI: 10.3389/fimmu.2014.00289] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 06/03/2014] [Indexed: 01/18/2023] Open
Abstract
HIV antibody (Ab) functions capable of preventing mucosal cell-free or cell-to-cell HIV transmission are critical for the development of effective prophylactic and therapeutic vaccines. In addition to CD4(+) T cells, other potential HIV-target cell types including antigen-presenting cells (APCs) (dendritic cells, macrophages) residing at mucosal sites are infected. Moreover, the interactions between APCs and HIV lead to HIV cell-to-cell transmission. Recently discovered broadly neutralizing antibodies (NAbs) are able to neutralize a broad spectrum of HIV strains, inhibit cell-to-cell transfer, and efficiently protect from infection in the experimentally challenged macaque model. However, the 31% protection observed in the RV144 vaccine trial in the absence of detectable NAbs in blood samples pointed to the possible role of additional Ab inhibitory functions. Increasing evidence suggests that IgG Fcγ receptor (FcγR)-mediated inhibition of Abs present at the mucosal site may play a role in protection against HIV mucosal transmission. Moreover, mucosal IgA Abs may be determinant in protection against HIV sexual transmission. Therefore, defining Ab inhibitory functions that could lead to protection is critical for further HIV vaccine design. Here, we review different inhibitory properties of HIV-specific Abs and discuss their potential role in protection against HIV sexual transmission.
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Affiliation(s)
- Bin Su
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg , Strasbourg , France
| | - Christiane Moog
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg , Strasbourg , France
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Ezrin is a component of the HIV-1 virological presynapse and contributes to the inhibition of cell-cell fusion. J Virol 2014; 88:7645-58. [PMID: 24760896 DOI: 10.1128/jvi.00550-14] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED During cell-to-cell transmission of HIV-1, viral and cellular proteins transiently accumulate at the contact zone between infected (producer) and uninfected (target) cells, forming the virological synapse. Rearrangements of the cytoskeleton in producer and target cells are required for proper targeting of viral and cellular components during synapse formation, yet little is known about how these processes are regulated, particularly within the producer cell. Since ezrin-radixin-moesin (ERM) proteins connect F-actin with integral and peripheral membrane proteins, are incorporated into virions, and interact with cellular components of the virological presynapse, we hypothesized that they play roles during the late stage of HIV-1 replication. Here we document that phosphorylated (i.e., active) ezrin specifically accumulates at the HIV-1 presynapse in T cell lines and primary CD4(+) lymphocytes. To investigate whether ezrin supports virus transmission, we sought to ablate ezrin expression in producer cells. While cells did not tolerate a complete knockdown of ezrin, even a modest reduction of ezrin expression (~50%) in HIV-1-producing cells led to the release of particles with impaired infectivity. Further, when cocultured with uninfected target cells, ezrin-knockdown producer cells displayed reduced accumulation of the tetraspanin CD81 at the synapse and fused more readily with target cells, thus forming syncytia. Such an outcome likely is not optimal for virus dissemination, as evidenced by the fact that, in vivo, only relatively few infected cells form syncytia. Thus, ezrin likely helps secure efficient virus spread not only by enhancing virion infectivity but also by preventing excessive membrane fusion at the virological synapse. IMPORTANCE While viruses, in principal, can propagate through successions of syncytia, HIV-1-infected cells in the majority of cases do not fuse with potential target cells during viral transmission. This mode of spread is coresponsible for key features of HIV-1 pathogenesis, including killing of bystander cells and establishment of latently infected T lymphocytes. Here we identify the ERM protein family member ezrin as a cellular factor that contributes to the inhibition of cell-cell fusion and thus to suppressing excessive syncytium formation. Our analyses further suggest that ezrin, which connects integral membrane proteins with actin, functions in concert with CD81, a member of the tetraspanin family of proteins. Additional evidence, documented here and elsewhere, suggests that ezrin and CD81 cooperate to prevent cytoskeleton rearrangements that need to take place during the fusion of cellular membranes.
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Dendritic cell-lymphocyte cross talk downregulates host restriction factor SAMHD1 and stimulates HIV-1 replication in dendritic cells. J Virol 2014; 88:5109-21. [PMID: 24574390 DOI: 10.1128/jvi.03057-13] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
UNLABELLED Human immunodeficiency virus type 1 (HIV-1) replication in dendritic cells (DCs) is restricted by SAMHD1. This factor is counteracted by the viral protein Vpx; Vpx is found in HIV-2 and simian immunodeficiency virus (SIV) from sooty mangabeys (SIVsm) or from macaques (SIVmac) but is absent from HIV-1. We previously observed that HIV-1 replication in immature DCs is stimulated by cocultivation with primary T and B lymphocytes, suggesting that HIV-1 restriction in DCs may be overcome under coculture conditions. Here, we aimed to decipher the mechanism of SAMHD1-mediated restriction in DC-lymphocyte coculture. We found that coculture with lymphocytes downregulated SAMHD1 expression and was associated with increased HIV-1 replication in DCs. Moreover, in infected DC-T lymphocyte cocultures, DCs acquired maturation status and secreted type 1 interferon (alpha interferon [IFN-α]). The blockade of DC-lymphocyte cross talk by anti-ICAM-1 antibody markedly inhibited the stimulation of HIV-1 replication and prevented the downregulation of SAMHD1 expression in cocultured DCs. These results demonstrate that, in contrast to purified DCs, cross talk with lymphocytes downregulates SAMHD1 expression in DCs, triggering HIV-1 replication and an antiviral immune response. Therefore, HIV-1 replication and immune sensing by DCs should be investigated in more physiologically relevant models of DC/lymphocyte coculture. IMPORTANCE SAMHD1 restricts HIV-1 replication in dendritic cells (DCs). Here, we demonstrate that, in a coculture model of DCs and lymphocytes mimicking early mucosal HIV-1 infection, stimulation of HIV-1 replication in DCs is associated with downregulation of SAMHD1 expression and activation of innate immune sensing by DCs. We propose that DC-lymphocyte cross talk occurring in vivo modulates host restriction factor SAMHD1, promoting HIV-1 replication in cellular reservoirs and stimulating immune sensing.
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30
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Kulpa DA, Brehm JH, Fromentin R, Cooper A, Cooper C, Ahlers J, Chomont N, Sékaly RP. The immunological synapse: the gateway to the HIV reservoir. Immunol Rev 2014; 254:305-25. [PMID: 23772628 PMCID: PMC3707302 DOI: 10.1111/imr.12080] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A major challenge in the development of a cure for human immunodeficiency virus (HIV) has been the incomplete understanding of the basic mechanisms underlying HIV persistence during antiretroviral therapy. It is now realized that the establishment of a latently infected reservoir refractory to immune system recognition has thus far hindered eradication efforts. Recent investigation into the innate immune response has shed light on signaling pathways downstream of the immunological synapse critical for T-cell activation and establishment of T-cell memory. This has led to the understanding that the cell-to-cell contacts observed in an immunological synapse that involve the CD4+ T cell and antigen-presenting cell or T-cell–T-cell interactions enhance efficient viral spread and facilitate the induction and maintenance of latency in HIV-infected memory T cells. This review focuses on recent work characterizing the immunological synapse and the signaling pathways involved in T-cell activation and gene regulation in the context of HIV persistence.
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Affiliation(s)
- Deanna A Kulpa
- Division of Infectious Diseases, Vaccine and Gene Therapy Institute-Florida (VGTI-FL), Port Saint Lucie, FL 34987, USA
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31
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High-multiplicity HIV-1 infection and neutralizing antibody evasion mediated by the macrophage-T cell virological synapse. J Virol 2013; 88:2025-34. [PMID: 24307588 DOI: 10.1128/jvi.03245-13] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Macrophage infection is considered to play an important role in HIV-1 pathogenesis and persistence. Using a primary cell-based coculture model, we show that monocyte-derived macrophages (MDM) efficiently transmit a high-multiplicity HIV-1 infection to autologous CD4(+) T cells through a viral envelope glycoprotein (Env) receptor- and actin-dependent virological synapse (VS), facilitated by interactions between ICAM-1 and LFA-1. Virological synapse (VS)-mediated transmission by MDM results in high levels of T cell HIV-1 integration and is 1 to 2 orders of magnitude more efficient than cell-free infection. This mode of cell-to-cell transmission is broadly susceptible to the activity of CD4 binding site (CD4bs) and glycan or glycopeptide epitope-specific broadly neutralizing monoclonal antibodies (bNMAbs) but shows resistance to bNMAbs targeting the Env gp41 subunit membrane-proximal external region (MPER). These data define for the first time the structure and function of the macrophage-to-T cell VS and have important implications for bNMAb activity in HIV-1 prophylaxis and therapy. IMPORTANCE The ability of HIV-1 to move directly between contacting immune cells allows efficient viral dissemination with the potential to evade antibody attack. Here, we show that HIV-1 spreads from infected macrophages to T cells via a structure called a virological synapse that maintains extended contact between the two cell types, allowing transfer of multiple infectious events to the T cell. This process allows the virus to avoid neutralization by a class of antibody targeting the gp41 subunit of the envelope glycoproteins. These results have implications for viral spread in vivo and the specificities of neutralizing antibody elicited by antibody-based vaccines.
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32
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Schiffner T, Sattentau QJ, Duncan CJA. Cell-to-cell spread of HIV-1 and evasion of neutralizing antibodies. Vaccine 2013; 31:5789-97. [PMID: 24140477 DOI: 10.1016/j.vaccine.2013.10.020] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 09/29/2013] [Accepted: 10/04/2013] [Indexed: 01/13/2023]
Abstract
Cell-to-cell spread of human immunodeficiency virus (HIV-1) between immune cells was first observed over 20 years ago. During this time, the question of whether this infection route favours viral evasion of neutralizing antibodies (NAbs) targeting the virus envelope glycoprotein (Env) has been repeatedly investigated, but with conflicting results. A clearer picture has formed in the last few years as more broadly neutralizing antibodies have been isolated and we gain further insight into the mechanisms of HIV-1 transmission at virological and infectious synapses. Nevertheless consensus is still lacking, a situation which may be at least partly explained by variability in the experimental approaches used to study the activity of NAbs in the cell-to-cell context. In this review we focus on the most critical question concerning the activity of NAbs against cell-to-cell transmission: is NAb inhibition of cell-to-cell HIV-1 quantitatively or qualitatively different from cell-free infection? Overall, data consistently show that NAbs are capable of blocking HIV-1 infection at synapses, supporting the concept that cell-to-cell infection occurs through directed transfer of virions accessible to the external environment. However, more recent findings suggest that higher concentrations of certain NAbs might be needed to inhibit synaptic infection, with important potential implications for prophylactic vaccine development. We discuss several mechanistic explanations for this relative and selective loss of activity, and highlight gaps in knowledge that are still to be explored.
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Affiliation(s)
- Torben Schiffner
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom
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33
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Russell RA, Martin N, Mitar I, Jones E, Sattentau QJ. Multiple proviral integration events after virological synapse-mediated HIV-1 spread. Virology 2013; 443:143-9. [DOI: 10.1016/j.virol.2013.05.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 03/21/2013] [Accepted: 05/03/2013] [Indexed: 11/25/2022]
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34
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Earl LA, Lifson JD, Subramaniam S. Catching HIV 'in the act' with 3D electron microscopy. Trends Microbiol 2013; 21:397-404. [PMID: 23850373 PMCID: PMC3773172 DOI: 10.1016/j.tim.2013.06.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 06/12/2013] [Accepted: 06/13/2013] [Indexed: 11/25/2022]
Abstract
The development of a safe, effective vaccine to prevent HIV infection is a key step for controlling the disease on a global scale. However, many aspects of HIV biology make vaccine design problematic, including the sequence diversity and structural variability of the surface envelope glycoproteins and the poor accessibility of neutralization-sensitive epitopes on the virus. In this review, we discuss recent progress in understanding HIV in a structural context using emerging tools in 3D electron microscopy, and outline how some of these advances could be important for a better understanding of mechanisms of viral entry and for vaccine design.
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Affiliation(s)
- Lesley A Earl
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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35
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Müller B, Heilemann M. Shedding new light on viruses: super-resolution microscopy for studying human immunodeficiency virus. Trends Microbiol 2013; 21:522-33. [PMID: 23916730 DOI: 10.1016/j.tim.2013.06.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 06/20/2013] [Accepted: 06/27/2013] [Indexed: 01/09/2023]
Abstract
For more than 70 years electron microscopy (EM) techniques have played an important role in investigating structures of enveloped viruses. By contrast, use of fluorescence microscopy (FM) methods for this purpose was limited by the fact that the size of virus particles is generally around or below the diffraction limit of light microscopy. Various super-resolution (SR) fluorescence imaging techniques developed over the past two decades bypass the diffraction limit of light microscopy, allowing visualization of subviral details and bridging the gap between conventional FM and EM methods. We summarize here findings on human immunodeficiency virus (HIV-1) obtained using SR-FM techniques. Although the number of published studies is currently limited and some of the pioneering analyses also covered methodological or descriptive aspects, recent publications clearly indicate the potential to approach open questions in HIV-1 replication from a new angle.
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Affiliation(s)
- Barbara Müller
- Department of Infectious Diseases, Virology, University of Heidelberg, Germany.
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36
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Sundquist WI, Kräusslich HG. HIV-1 assembly, budding, and maturation. Cold Spring Harb Perspect Med 2013; 2:a006924. [PMID: 22762019 DOI: 10.1101/cshperspect.a006924] [Citation(s) in RCA: 517] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A defining property of retroviruses is their ability to assemble into particles that can leave producer cells and spread infection to susceptible cells and hosts. Virion morphogenesis can be divided into three stages: assembly, wherein the virion is created and essential components are packaged; budding, wherein the virion crosses the plasma membrane and obtains its lipid envelope; and maturation, wherein the virion changes structure and becomes infectious. All of these stages are coordinated by the Gag polyprotein and its proteolytic maturation products, which function as the major structural proteins of the virus. Here, we review our current understanding of the mechanisms of HIV-1 assembly, budding, and maturation, starting with a general overview and then providing detailed descriptions of each of the different stages of virion morphogenesis.
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Affiliation(s)
- Wesley I Sundquist
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, USA.
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37
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Latent HIV-1 can be reactivated by cellular superinfection in a Tat-dependent manner, which can lead to the emergence of multidrug-resistant recombinant viruses. J Virol 2013; 87:9620-32. [PMID: 23804632 DOI: 10.1128/jvi.01165-13] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The HIV-1 latent reservoir represents an important source of genetic diversity that could contribute to viral evolution and multidrug resistance following latent virus reactivation. This could occur by superinfection of a latently infected cell. We asked whether latent viruses might be reactivated when their host cells are superinfected, and if so, whether they could contribute to the generation of recombinant viruses. Using populations of latently infected Jurkat cells, we found that latent viruses were efficiently reactivated upon superinfection. Pathways leading to latent virus reactivation via superinfection might include gp120-CD4/CXCR4-induced signaling, modulation of the cellular environment by Nef, and/or the activity of Tat produced upon superinfection. Using a range of antiviral compounds and genetic approaches, we show that gp120 and Nef are not required for latent virus reactivation by superinfection, but this process depends on production of functional Tat by the superinfecting virus. In a primary cell model of latency in unstimulated CD4 T cells, superinfection also led to latent virus reactivation. Drug-resistant latent viruses were also reactivated following superinfection in Jurkat cells and were able to undergo recombination with the superinfecting virus. Under drug-selective pressure, this generated multidrug-resistant recombinants that were identified by unique restriction digestion band patterns and by population-level sequencing. During conditions of poor drug adherence, treatment interruption or treatment failure, or in drug-impermeable sanctuary sites, reactivation of latent viruses by superinfection or other means could provide for the emergence or spread of replicatively fit viruses in the face of strong selective pressures.
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38
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Productive entry of HIV-1 during cell-to-cell transmission via dynamin-dependent endocytosis. J Virol 2013; 87:8110-23. [PMID: 23678185 DOI: 10.1128/jvi.00815-13] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV-1 can be transmitted as cell-free virus or via cell-to-cell contacts. Cell-to-cell transmission between CD4(+) T cells is the more efficient mode of transmission and is predominant in lymphoid tissue, where the majority of virus resides. Yet the cellular mechanisms underlying productive cell-to-cell transmission in uninfected target cells are unclear. Although it has been demonstrated that target cells can take up virus via endocytosis, definitive links between this process and productive infection remain undefined, and this route of transmission has been proposed to be nonproductive. Here, we report that productive cell-to-cell transmission can occur via endocytosis in a dynamin-dependent manner and is sensitive to clathrin-associated antagonists. These data were obtained in a number of CD4(+) T-cell lines and in primary CD4(+) T cells, using both CXCR4- and CCR5-tropic virus. However, we also found that HIV-1 demonstrated flexibility in its use of such endocytic pathways as certain allogeneic transmissions were seen to occur in a dynamin-dependent manner but were insensitive to clathrin-associated antagonists. Also, depleting cells of the clathrin accessory protein AP180 led to a viral uptake defect associated with enhanced infection. Collectively, these data demonstrate that endosomal uptake of HIV-1 during cell-to-cell transmission leads to productive infection, but they are also indicative of a flexible model of viral entry during cell-to-cell transmission, in which the virus can alter its entry route according to the pressures that it encounters.
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39
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Wilen CB, Tilton JC, Doms RW. HIV: cell binding and entry. Cold Spring Harb Perspect Med 2012; 2:cshperspect.a006866. [PMID: 22908191 DOI: 10.1101/cshperspect.a006866] [Citation(s) in RCA: 393] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The first step of the human immunodeficiency virus (HIV) replication cycle-binding and entry into the host cell-plays a major role in determining viral tropism and the ability of HIV to degrade the human immune system. HIV uses a complex series of steps to deliver its genome into the host cell cytoplasm while simultaneously evading the host immune response. To infect cells, the HIV protein envelope (Env) binds to the primary cellular receptor CD4 and then to a cellular coreceptor. This sequential binding triggers fusion of the viral and host cell membranes, initiating infection. Revealing the mechanism of HIV entry has profound implications for viral tropism, transmission, pathogenesis, and therapeutic intervention. Here, we provide an overview into the mechanism of HIV entry, provide historical context to key discoveries, discuss recent advances, and speculate on future directions in the field.
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Affiliation(s)
- Craig B Wilen
- Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104, USA
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40
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Nzounza P, Chazal M, Guedj C, Schmitt A, Massé JM, Randriamampita C, Pique C, Ramirez BC. The scaffolding protein Dlg1 is a negative regulator of cell-free virus infectivity but not of cell-to-cell HIV-1 transmission in T cells. PLoS One 2012; 7:e30130. [PMID: 22272285 PMCID: PMC3260186 DOI: 10.1371/journal.pone.0030130] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 12/13/2011] [Indexed: 12/28/2022] Open
Abstract
Background Cell-to-cell virus transmission of Human immunodeficiency virus type-1 (HIV-1) is predominantly mediated by cellular structures such as the virological synapse (VS). The VS formed between an HIV-1-infected T cell and a target T cell shares features with the immunological synapse (IS). We have previously identified the human homologue of the Drosophila Discs Large (Dlg1) protein as a new cellular partner for the HIV-1 Gag protein and a negative regulator of HIV-1 infectivity. Dlg1, a scaffolding protein plays a key role in clustering protein complexes in the plasma membrane at cellular contacts. It is implicated in IS formation and T cell signaling, but its role in HIV-1 cell-to-cell transmission was not studied before. Methodology/Principal Findings Kinetics of HIV-1 infection in Dlg1-depleted Jurkat T cells show that Dlg1 modulates the replication of HIV-1. Single-cycle infectivity tests show that this modulation does not take place during early steps of the HIV-1 life cycle. Immunofluorescence studies of Dlg1-depleted Jurkat T cells show that while Dlg1 depletion affects IS formation, it does not affect HIV-1-induced VS formation. Co-culture assays and quantitative cell-to-cell HIV-1 transfer analyses show that Dlg1 depletion does not modify transfer of HIV-1 material from infected to target T cells, or HIV-1 transmission leading to productive infection via cell contact. Dlg1 depletion results in increased virus yield and infectivity of the viral particles produced. Particles with increased infectivity present an increase in their cholesterol content and during the first hours of T cell infection these particles induce higher accumulation of total HIV-1 DNA. Conclusion Despite its role in the IS formation, Dlg1 does not affect the VS and cell-to-cell spread of HIV-1, but plays a role in HIV-1 cell-free virus transmission. We propose that the effect of Dlg1 on HIV-1 infectivity is at the stage of virus entry.
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Affiliation(s)
- Patrycja Nzounza
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Maxime Chazal
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Chloé Guedj
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Alain Schmitt
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Jean-Marc Massé
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Clotilde Randriamampita
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Claudine Pique
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Bertha Cecilia Ramirez
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- * E-mail:
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Cellular and viral mechanisms of HIV-1 transmission mediated by dendritic cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 762:109-30. [PMID: 22975873 DOI: 10.1007/978-1-4614-4433-6_4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Dendritic cells (DCs) play a key role in the initial infection and cell-to-cell transmission events that occur upon HIV-1 infection. DCs interact closely with CD4(+) T cells, the main target of HIV-1 replication. HIV-1 challenged DCs and target CD4(+) T cells form a virological synapse that allows highly efficient transmission of HIV-1 to the target CD4(+) T cells, in the absence of productive HIV-1 replication in the DCs. Immature and subsets of mature DCs show distinct patterns of HIV-1 replication and cell-to-cell transmission, depending upon the maturation stimulus that is used. The cellular and viral mechanisms that promote formation of the virological synapse have been the subject of intense study and the most recent progress is discussed here. Characterizing the cellular and viral factors that affect DC-mediated cell-to-cell transmission of HIV-1 to CD4(+) T cells is vitally important to understanding, and potentially blocking, the initial dissemination of HIV-1 in vivo.
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Lehmann M, Nikolic DS, Piguet V. How HIV-1 takes advantage of the cytoskeleton during replication and cell-to-cell transmission. Viruses 2011; 3:1757-76. [PMID: 21994805 PMCID: PMC3187690 DOI: 10.3390/v3091757] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 08/26/2011] [Accepted: 08/30/2011] [Indexed: 12/29/2022] Open
Abstract
Human immunodeficiency virus 1 (HIV-1) infects T cells, macrophages and dendritic cells and can manipulate their cytoskeleton structures at multiple steps during its replication cycle. Based on pharmacological and genetic targeting of cytoskeleton modulators, new imaging approaches and primary cell culture models, important roles for actin and microtubules during entry and cell-to-cell transfer have been established. Virological synapses and actin-containing membrane extensions can mediate HIV-1 transfer from dendritic cells or macrophage cells to T cells and between T cells. We will review the role of the cytoskeleton in HIV-1 entry, cellular trafficking and cell-to-cell transfer between primary cells.
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Affiliation(s)
- Martin Lehmann
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, Geneva 1211, Switzerland; E-Mails: (M.L.); (D.S.N)
- Department of Dermatology and Venereology, University Hospital and Medical School of Geneva, Geneva 1211, Switzerland
| | - Damjan S. Nikolic
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, Geneva 1211, Switzerland; E-Mails: (M.L.); (D.S.N)
- Department of Dermatology and Venereology, University Hospital and Medical School of Geneva, Geneva 1211, Switzerland
| | - Vincent Piguet
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, Geneva 1211, Switzerland; E-Mails: (M.L.); (D.S.N)
- Department of Dermatology and Venereology, University Hospital and Medical School of Geneva, Geneva 1211, Switzerland
- Department of Dermatology and Wound Healing, Cardiff University School of Medicine and University Hospital of Wales, Cardiff, Wales, CF144XN, UK
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +44-(0)-29-20-744721; Fax: +44-(0)-29-20-744312
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43
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Abstract
Macrophages have been postulated to play an important role in the pathogenesis of HIV-1 infection. Their ability to cross the blood-brain barrier and their resistance to virus-induced cytopathic effects allows them to serve as reservoirs for long-term infection. Thus, exploring the mechanisms of virus transmission from macrophages to target cells such as other macrophages or T lymphocytes is central to our understanding of HIV-1 pathogenesis and progression to AIDS, and is vital to the development of vaccines and novel antiretroviral therapies. This review provides an overview of the current understanding of cell-cell transmission in macrophages.
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