DOCSLIB.ORG

HIV-1) CD4 Receptor and Its Central Role in Promotion of HIV-1 Infection

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

MICROBIOLOGICAL REVIEWS, Mar. 1995, p. 63–93 Vol. 59, No. 1 0146-0749/95/$04.0010 Copyright q 1995, American Society for Microbiology The Human Immunodeficiency Virus Type 1 (HIV-1) CD4 Receptor and Its Central Role in Promotion of HIV-1 Infection STEPHANE BOUR,* ROMAS GELEZIUNAS,† AND MARK A. WAINBERG* McGill AIDS Centre, Lady Davis Institute-Jewish General Hospital, and Departments of Microbiology and Medicine, McGill University, Montreal, Quebec, Canada H3T 1E2 INTRODUCTION .........................................................................................................................................................63 RETROVIRAL RECEPTORS .....................................................................................................................................64 Receptors for Animal Retroviruses ........................................................................................................................64 CD4 Is the Major Receptor for HIV-1 Infection..................................................................................................65 ROLE OF THE CD4 CORECEPTOR IN T-CELL ACTIVATION........................................................................65 Structural Features of the CD4 Coreceptor..........................................................................................................65 Interactions of CD4 with Class II MHC Determinants ......................................................................................66 CD4–T-Cell Receptor Interactions during T-Cell Activation .............................................................................67 Signal Transduction by the CD4-p56lck Complex.................................................................................................67 CD4 Can Transduce Inhibitory Signals to T Cells..............................................................................................68 STRUCTURE AND MATURATION OF HIV-1 ENVELOPE GLYCOPROTEINS.............................................69 Biosynthesis of the gp160 Polyprotein Precursor.................................................................................................69 Endoproteolytic Cleavage of gp160.........................................................................................................................69 Glycosylation and Trimming...................................................................................................................................70 Oligomeric Structure of the Envelope Glycoproteins of HIV-1..........................................................................70 MOLECULAR CHARACTERIZATION OF CD4-gp120 INTERACTIONS .........................................................70 Role of Oligosaccharides in CD4-gp120 Interactions..........................................................................................70 Binding Site for gp120 on CD4...............................................................................................................................70 The MHC II- and gp120-Binding Sites on CD4 Are Distinct but Overlapping ..............................................71 Binding Site for CD4 on gp120...............................................................................................................................72 Postentry Events Involving CD4 and Viral Envelope Glycoproteins.................................................................72 BIOLOGICAL EFFECTS OF CD4-gp120 CELL SURFACE INTERACTIONS..................................................73 Triggering of T-Cell Activation...............................................................................................................................73 Inhibition of T-Cell Activation by gp120 and Induction of Apoptosis ..............................................................74 RETROVIRAL INTERFERENCE ..............................................................................................................................75 Classification of Retroviruses in Receptor Interference Groups .......................................................................75 Retroviral Interference by HIV-1............................................................................................................................76 Cytopathology Associated with Superinfection.....................................................................................................76 Downregulation of MHC Antigens as a Means of Immune Evasion ................................................................76 INTRACELLULAR INTERACTIONS BETWEEN CD4 AND HIV-1....................................................................77 HIV-1 Infection Downregulates CD4 Transcription ............................................................................................77 Formation of Intracellular Complexes between CD4 and gp160 .......................................................................77 Regulation of CD4-gp160 Complexes and CD4 Degradation by Vpu ...............................................................78 Vpu Induces Degradation of ER-Resident CD4 ...................................................................................................78 Receptor Interference by the Nef Protein..............................................................................................................80 CONCLUSION..............................................................................................................................................................82 ACKNOWLEDGMENTS .............................................................................................................................................82 REFERENCES ..............................................................................................................................................................82 INTRODUCTION the surface (SU) envelope glycoprotein of HIV-1 (gp120) ini- tiate infection and viral entry (232, 296). HIV infection com- Infection of target cells by human immunodeficiency virus monly leads to progressive loss of CD4-expressing cells, includ- type 1 (HIV-1) is dependent on surface representation of clus- ing CD41 T lymphocytes (26). This is correlated with the ter determinant 4 (CD4), which serves as a specific virus re- occurrence of opportunistic infections and development of ceptor (232, 276). High-affinity interactions between CD4 and AIDS (119). In addition to peripheral blood lymphocytes, HIV-1 targets CD41 cells in the thymus, the primary site of CD41 T-cell * Corresponding author. Mailing address for Stephane Bour: Lab- selection (40, 437), and lymph nodes, a major HIV reservoir in oratory of Molecular Microbiology, National Institute of Allergy and asymptomatic infected individuals (346). HIV can induce cy- Infectious Diseases, Bethesda, MD 20892-0460. Mailing address for topathic effects, including syncytium formation and cell death Mark A. Wainberg: Lady Davis Institute-Jewish General Hospital, 1 3755 Cote-Ste-Catherine Road, Montreal, Quebec, Canada H3T 1E2. (270). It can also persistently infect CD4 cells both in vivo Phone: (514) 340-8260. Fax: (514) 340-7537. and in cell culture (193, 363, 405), leading to immunological † Present address: Gladstone Institute of Virology and Immunology, dysregulation and a loss of immune competence in infected San Francisco, CA 94110. individuals (120). 63 64 BOUR ET AL. MICROBIOL.REV. TABLE 1. Biological characteristics of known receptors for animal retroviruses Chromosome Biochemical Structural Receptor Virusa containing receptor characteristics of Cellular function of receptor homology of name Mouse Human receptor receptor ALSV-A tv-a 101–138-aa protein LDL receptor MuLV-E Rec1 (Atrc1) 5 622-aa protein Amino acid transporter Tea, H13 MuLV-A Ram1 8 8 656-aa protein Phosphate permease GLVR-1 MuLV-P (MCFF) Rmc1 1 Sxv MuLV-X Sxv 1 Rmc1 MMTV Mtvr1 16 M813 (asian MuLV) Rec2 2 FeLV-A 70-kDa protein BLV BLVR-1 729-aa protein GALV FeLV-B GLVR-1 2 2q 629-aa protein Phosphate permease pho41 permease MuLV-XCaroli SRV-D FEV-C (RD114) BaEV-C 19q 60-kDa protein REV HTLV-I HTLV-II HTLV-R 17q 31–70-kDa proteins STLV HIV-1 HIV-2 CD4 6 12 433-aa glycoprotein T-lymphocyte coreceptor IgG superfamily SIV a Abbreviations: ASLV, avian leukosis and sarcoma virus; MMTV, mouse mammary tumor virus; FeLV, feline leukemia virus; BLV, bovine leukemia virus; SRV, simian retrovirus; FEV, feline endogenous virus; BaEV, baboon endogenous virus; REV, reticuloendotheliosis virus; STLV, simian T-cell leukemia virus; MCFF, mink cell focus-forming virus; aa, amino acid; LDL, low-density lipoprotein. This review deals with molecular mechanisms that underlie tion as a basic amino acid transporter (66, 229, 484). The perturbation of CD41 cell function and maintenance of HIV selectivity and electrochemical properties of the EcoR trans- infection; most such changes involve alterations of both expres- porter are identical to those of the previously identified y1 sion and function of the CD4 molecule. cationic L-amino acid transporter, found at the plasma mem- brane of mammalian cells (359, 496, 497). RETROVIRAL RECEPTORS A human gene homologous to EcoR (H13) has been iden- tified and mapped to chromosome 13 (514). Although H13 is Receptors for Animal Retroviruses unable to serve as a receptor for MuLV infection, it has a 87.6% amino acid homology with EcoR and shares 14 trans- Retroviral envelope proteins bind to specific receptor mol- membrane-spanning regions with its mouse homolog (514). ecules expressed
Recommended publications
  • It Takes Two to Tango

    It Takes Two to Tango

    HIGHLIGHTS IMMUNOTHERAPY It takes two to tango Much of the recent work on the development of active, specific immunotherapy of cancer has focused on the induction of CD8+ cytotoxic T-lymphocyte (CTL) responses, and several studies have shown that it is possible to stimulate tumour-specific CTLs using dendritic cells (DCs) that are loaded with tumour antigens. But CD4+ T-helper type 1 (TH1) cells are also important day of vaccination and loaded with various So, the results from this Phase I trial provide components of effective immune responses. MHC class-I- and -II-restricted peptides. convincing evidence that cryopreserved DCs In this study, Schuler–Thurner and Patients with incurable melanoma were can induce TH1 responses against tumour colleagues provide the first evidence that DCs treated with five biweekly vaccinations of antigens without significant toxicity, and it that are loaded with tumour-specific peptides DCs, followed by assessment one month also encourages further development of can rapidly induce TH1 responses in cancer after the final vaccination. DC-based vaccination technology. patients that are readily detectable ex vivo. The results showed that the vaccination Elaine Bell References and links The DCs that were used for vaccination protocol induced a rapid TH1 response in in this study were derived from blood patients, both to a control immunizing antigen ORIGINAL RESEARCH PAPER Schuler–Thurner, B. et al. Rapid induction of tumor-specific type 1 T helper cells in monocytes that were matured ex vivo using and also to defined MHC class-II-restricted metastatic melanoma patients by vaccination with mature, a defined cocktail (consisting of interleukin tumour antigens.
  • Role of IL-4 Receptor &Alpha

    Role of IL-4 Receptor &Alpha

    Role of IL-4 receptor a–positive CD41 T cells in chronic airway hyperresponsiveness Frank Kirstein, PhD, Natalie E. Nieuwenhuizen, PhD,* Jaisubash Jayakumar, PhD, William G. C. Horsnell, PhD, and Frank Brombacher, PhD Cape Town, South Africa, and Berlin, Germany Background: TH2 cells and their cytokines are associated with IL-17–producing T cells and, consequently, increased airway allergic asthma in human subjects and with mouse models of neutrophilia. allergic airway disease. IL-4 signaling through the IL-4 receptor Conclusion: IL-4–responsive T helper cells are dispensable for 1 a (IL-4Ra) chain on CD4 T cells leads to TH2 cell acute OVA-induced airway disease but crucial in maintaining differentiation in vitro, implying that IL-4Ra–responsive CD41 chronic asthmatic pathology. (J Allergy Clin Immunol T cells are critical for the induction of allergic asthma. However, 2016;137:1852-62.) mechanisms regulating acute and chronic allergen-specific T 2 H Key words: responses in vivo remain incompletely understood. TH2 cell, acute allergic airway disease, chronic asthma, Objective: This study defines the requirements for IL-4Ra– cytokine receptors, IL-4, IL-13, gene-deficient mice responsive CD41 T cells and the IL-4Ra ligands IL-4 and IL-13 in the development of allergen-specific TH2 responses during the Allergic asthma is a chronic inflammatory disease of the airways onset and chronic phase of experimental allergic airway disease. characterized by an inappropriate immune response to harmless Methods: Development of acute and chronic ovalbumin environmental antigens. T 2 cells regulate adaptive immune 1 H (OVA)–induced allergic asthma was assessed weekly in CD4 T responses to allergens, and their presence correlates with disease 2 cell–specific IL-4Ra–deficient BALB/c mice (LckcreIL-4Ra /lox) symptoms in human subjects and mice.1 IL-4 plays a crucial role and respective control mice in the presence or absence of IL-4 in the in vitro and in vivo differentiation of TH2 cells, suggesting or IL-13.
  • Dissertation Philip Böhler

    Dissertation Philip Böhler

    Three Tales of Death: New Pathways in the Induction, Inhibition and Execution of Apoptosis Inaugural-Dissertation zur Erlangung des Doktorgrades der Mathematisch-Naturwissenschaftlichen Fakultät der Heinrich-Heine-Universität Düsseldorf vorgelegt von Philip Böhler aus Bonn Düsseldorf, Juni 2019 aus dem Institut für Molekulare Medizin I der Heinrich-Heine-Universität Düsseldorf Gedruckt mit der Genehmigung der Mathematisch-Naturwissenschaftlichen Fakultät der Heinrich-Heine-Universität Düsseldorf Berichterstatter: 1. Prof. Dr. Sebastian Wesselborg 2. Prof. Dr. Henrike Heise Tag der mündlichen Prüfung: 29. Oktober 2019 “Where the first primal cell was, there was I also. Where man is, there am I. When the last life crawls under freezing stars, there will I be.” — DEATH, in: Mort, by Terry Pratchett “Right away I found out something about biology: it was very easy to find a question that was very interesting, and that nobody knew the answer to.” — Richard Feynman, in: Surely You're Joking, Mr. Feynman! Acknowledgements (Danksagung) Acknowledgements (Danksagung) Viele Menschen haben zum Gelingen meiner Forschungsarbeit und dieser Dissertation beigetragen, und nicht alle können hier namentlich erwähnt werden. Dennoch möchte ich einige besonders hervorheben. An erster Stelle möchte ich Professor Sebastian Wesselborg danken, der diese Dissertation als Erstgutachter betreut hat und der mir die Möglichkeit gab, die dazugehörigen experimentellen Arbeiten am Institut für Molekulare Medizin durchzuführen. Er und Professor Björn Stork, dem ich für die herzliche Aufnahme in seine Arbeitsgruppe danke, legten durch die richtige Mischung aus aktiver Förderung und dem Freiraum zur Umsetzung eigener wissenschaftlicher Ideen die ideale Grundlage für die Forschungsprojekte, aus denen diese Dissertation entstand. Professorin Henrike Heise, die sich freundlicherweise zur Betreuung dieser Dissertation als Zweitgutachterin bereiterklärt hat, gilt ebenfalls mein herzlicher Dank.
  • Characterization of the Matrix Proteins of the Fish Rhabdovirus, Infectious Hematopoietic Necrosis Virus

    Characterization of the Matrix Proteins of the Fish Rhabdovirus, Infectious Hematopoietic Necrosis Virus

    AN ABSTRACT OF THE THESIS OF Patricia A. Ormonde for the degree of Master of Science presented on April 14. 1995. Title: Characterization of the Matrix Proteins of the Fish Rhabdovinis, Infectious Hematopoietic Necrosis Virus. Redacted for Privacy Abstract approved: Jo-Ann C. ong Infectious hematopoietic necrosis virus (1HNV) is an important fish pathogen enzootic in salmon and trout populations of the Pacific Northwestern United States. Occasional epizootics in fish hatcheries can result in devastating losses of fish stocks. The complete nucleotide sequence of IHNV has not yet been determined. This knowledge is the first step towards understanding the roles viral proteins play in IHNV infection, and is necessary for determining the relatedness of IHNV to other rhabdoviruses. The glycoprotein, nucleocapsid and non-virion genes of IHNV have been described previously; however, at the initiation of this study, very little was known about the matrix protein genes. Rhabdoviral matrix proteins have been found to be important in viral transcription and virion assembly. This thesis describes the preliminary characterization of the M1 and M2 matrix proteins of IHNV. In addition, the trout humoral immune response to M1 and M2 proteins expressed from plasmid DNA injected into the fish was investigated. This work may prove useful in designing future vaccines against IHN. The sequences of M1 phosphoprotein and M2 matrix protein genes of IHNV were determined from both genomic and mRNA clones. Analysis of the sequences indicated that the predicted open reading frame of M1 gene encoded a 230 amino acid protein with a estimated molecular weight of 25.6 kDa. Further analysis revealed a second open reading frame encoding a 42 amino acid protein with a calculated molecular weight of 4.8 kDa.
  • List of Genes Used in Cell Type Enrichment Analysis

    List of Genes Used in Cell Type Enrichment Analysis

    List of genes used in cell type enrichment analysis Metagene Cell type Immunity ADAM28 Activated B cell Adaptive CD180 Activated B cell Adaptive CD79B Activated B cell Adaptive BLK Activated B cell Adaptive CD19 Activated B cell Adaptive MS4A1 Activated B cell Adaptive TNFRSF17 Activated B cell Adaptive IGHM Activated B cell Adaptive GNG7 Activated B cell Adaptive MICAL3 Activated B cell Adaptive SPIB Activated B cell Adaptive HLA-DOB Activated B cell Adaptive IGKC Activated B cell Adaptive PNOC Activated B cell Adaptive FCRL2 Activated B cell Adaptive BACH2 Activated B cell Adaptive CR2 Activated B cell Adaptive TCL1A Activated B cell Adaptive AKNA Activated B cell Adaptive ARHGAP25 Activated B cell Adaptive CCL21 Activated B cell Adaptive CD27 Activated B cell Adaptive CD38 Activated B cell Adaptive CLEC17A Activated B cell Adaptive CLEC9A Activated B cell Adaptive CLECL1 Activated B cell Adaptive AIM2 Activated CD4 T cell Adaptive BIRC3 Activated CD4 T cell Adaptive BRIP1 Activated CD4 T cell Adaptive CCL20 Activated CD4 T cell Adaptive CCL4 Activated CD4 T cell Adaptive CCL5 Activated CD4 T cell Adaptive CCNB1 Activated CD4 T cell Adaptive CCR7 Activated CD4 T cell Adaptive DUSP2 Activated CD4 T cell Adaptive ESCO2 Activated CD4 T cell Adaptive ETS1 Activated CD4 T cell Adaptive EXO1 Activated CD4 T cell Adaptive EXOC6 Activated CD4 T cell Adaptive IARS Activated CD4 T cell Adaptive ITK Activated CD4 T cell Adaptive KIF11 Activated CD4 T cell Adaptive KNTC1 Activated CD4 T cell Adaptive NUF2 Activated CD4 T cell Adaptive PRC1 Activated
  • Viral Strategies to Arrest Host Mrna Nuclear Export

    Viral Strategies to Arrest Host Mrna Nuclear Export

    Viruses 2013, 5, 1824-1849; doi:10.3390/v5071824 OPEN ACCESS viruses ISSN 1999-4915 www.mdpi.com/journal/viruses Review Nuclear Imprisonment: Viral Strategies to Arrest Host mRNA Nuclear Export Sharon K. Kuss *, Miguel A. Mata, Liang Zhang and Beatriz M. A. Fontoura Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; E-Mails: [email protected] (M.A.M.); [email protected] (L.Z.); [email protected] (B.M.A.F) * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +1-214-633-2001; Fax: +1-214-648-5814. Received: 10 June 2013; in revised form: 27 June 2013 / Accepted: 11 July 2013 / Published: 18 July 2013 Abstract: Viruses possess many strategies to impair host cellular responses to infection. Nuclear export of host messenger RNAs (mRNA) that encode antiviral factors is critical for antiviral protein production and control of viral infections. Several viruses have evolved sophisticated strategies to inhibit nuclear export of host mRNAs, including targeting mRNA export factors and nucleoporins to compromise their roles in nucleo-cytoplasmic trafficking of cellular mRNA. Here, we present a review of research focused on suppression of host mRNA nuclear export by viruses, including influenza A virus and vesicular stomatitis virus, and the impact of this viral suppression on host antiviral responses. Keywords: virus; influenza virus; vesicular stomatitis virus; VSV; NS1; matrix protein; nuclear export; nucleo-cytoplasmic trafficking; mRNA export; NXF1; TAP; CRM1; Rae1 1. Introduction Nucleo-cytoplasmic trafficking of proteins and RNA is critical for proper cellular functions and survival.
  • 1 ICAM3-Fc Outperforms Receptor-Specific Antibodies

    1 ICAM3-Fc Outperforms Receptor-Specific Antibodies

    Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 10 April 2019 doi:10.20944/preprints201904.0118.v1 Peer-reviewed version available at Molecules 2019, 24, 1825; doi:10.3390/molecules24091825 ICAM3-Fc outperforms receptor-specific antibodies targeted nanoparticles to dendritic cells for cross-presentation Luis J. Cruz,1* Paul J. Tacken,2 Johan S. van der Schoot,2 Felix Rueda,3 Ruurd Torensma,2 Carl G. Figdor2* 1Translational Nanobiomaterials and Imaging, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands. 2Department of Tumor Immunology, Radboud Insititute for Molecular Life Sciences, Radboud University Medical Center, Postbox 9101, 6500 HB Nijmegen, The Netherlands. 3Department of Biochemistry and Molecular Biology, University of Barcelona, Diagonal 643, 08028 Barcelona, Spain. Running title: ICAM3-Fc- versus antibody-targeted NP vaccines to human DCs Keywords: Delivery system; nanoparticle; targeting. AUTHOR INFORMATION Corresponding Author *Dr. Luis J. Cruz Translational Nanobiomaterials and Imaging, Department of Radiology, Bldg.1, C5-60. Leiden University Medical Center, Albinusdreef 2 2333 ZA Leiden, The Netherlands Tel: +31 71 5263025 Email: [email protected] *Prof. Dr. Carl G. Figdor Department of Tumor Immunology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Postbox 9101, 6500 HB Nijmegen, The Netherlands. Fax: +31-24-3540339; Tel.: +31-24-3617600; E-mail: [email protected] 1 © 2019 by the author(s). Distributed
  • Herpes Simplex Virus Type 1 Oril Is Not Required for Virus Infection In

    Herpes Simplex Virus Type 1 Oril Is Not Required for Virus Infection In

    JOURNAL OF VIROLOGY, Nov. 1987, p. 3528-3535 Vol. 61, No. 11 0022-538X/87/113528-08$02.00/0 Copyright C 1987, American Society for Microbiology Herpes Simplex Virus Type 1 oriL Is Not Required for Virus Replication or for the Establishment and Reactivation of Latent Infection in Mice MARYELLEN POLVINO-BODNAR, PAULO K. ORBERG, AND PRISCILLA A. SCHAFFER* Laboratory of Tumor Virus Genetics, Dana-Farber Cancer Institute, and Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115 Received 11 May 1987/Accepted 31 July 1987 During the course of experiments designed to isolate deletion mutants of herpes simplex virus type 1 in the gene encoding the major DNA-binding protein, ICP8, a mutant, d61, that grew efficiently in ICP8-expressing Vero cells but not in normal Vero cells was isolated (P. K. Orberg and P. A. Schaffer, J. Virol. 61:1136-1146, 1987). d61 was derived by cotransfection of ICP8-expressing Vero cells with infectious wild-type viral DNA and a plasmid, pDX, that contains an engineered 780-base-pair (bp) deletion in the ICP8 gene, as well as a spontaneous -55-bp deletion in OriL. Gel electrophoresis and Southern blot analysis indicated that d61 DNA carried both deletions present in pDX. The ability of d61 to replicate despite the deletion in OriL suggested that a functional OriL is not essential for virus replication in vitro. Because d61 harbored two mutations, a second mutant, ts+7, with a deletion in oriL-associated sequences and an intact ICP8 gene was constructed. Both d61 and ts+7 replicated efficiently in their respective permissive host cells, although their yields were slightly lower than those of control viruses with intact oriL sequences.
  • Topological Analysis of the Gp41 MPER on Lipid Bilayers Relevant to the Metastable HIV-1 Envelope Prefusion State

    Topological Analysis of the Gp41 MPER on Lipid Bilayers Relevant to the Metastable HIV-1 Envelope Prefusion State

    Topological analysis of the gp41 MPER on lipid bilayers relevant to the metastable HIV-1 envelope prefusion state Yi Wanga,b, Pavanjeet Kaurc,d, Zhen-Yu J. Sune,1, Mostafa A. Elbahnasawya,b,2, Zahra Hayatic,d, Zhi-Song Qiaoa,b,3, Nhat N. Buic, Camila Chilea,b,4, Mahmoud L. Nasre,5, Gerhard Wagnere, Jia-Huai Wanga,f, Likai Songc, Ellis L. Reinherza,b,6, and Mikyung Kima,g,6 aLaboratory of Immunobiology, Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115; bDepartment of Medicine, Harvard Medical School, Boston, MA 02115; cNational High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32306; dDepartment of Physics, Florida State University, Tallahassee, FL 32306; eDepartment of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115; fDepartment of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215; and gDepartment of Dermatology, Harvard Medical School, Boston, MA 02215 Edited by Peter Palese, Icahn School of Medicine at Mount Sinai, New York, NY, and approved September 23, 2019 (received for review July 18, 2019) The membrane proximal external region (MPER) of HIV-1 envelope immunologically vulnerable epitopes targeted by several of the most glycoprotein (gp) 41 is an attractive vaccine target for elicitation of broadly neutralizing antibodies (bNAbs) developed during the broadly neutralizing antibodies (bNAbs) by vaccination. However, course of natural HIV-1 infection (10–13). Insertion, deletion, current details regarding the quaternary structural organization of and mutations of residues in the MPER defined the functional the MPER within the native prefusion trimer [(gp120/41)3] are elu- importance of the MPER in Env incorporation, viral fusion, and sive and even contradictory, hindering rational MPER immunogen infectivity (14–16).
  • The Nef-Infectivity Enigma: Mechanisms of Enhanced Lentiviral Infection Jolien Vermeire§, Griet Vanbillemont§, Wojciech Witkowski and Bruno Verhasselt*

    The Nef-Infectivity Enigma: Mechanisms of Enhanced Lentiviral Infection Jolien Vermeire§, Griet Vanbillemont§, Wojciech Witkowski and Bruno Verhasselt*

    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by PubMed Central 474 Current HIV Research, 2011, 9, 474-489 The Nef-Infectivity Enigma: Mechanisms of Enhanced Lentiviral Infection Jolien Vermeire§, Griet Vanbillemont§, Wojciech Witkowski and Bruno Verhasselt* Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, Belgium Abstract: The Nef protein is an essential factor for lentiviral pathogenesis in humans and other simians. Despite a multitude of functions attributed to this protein, the exact role of Nef in disease progression remains unclear. One of its most intriguing functions is the ability of Nef to enhance the infectivity of viral particles. In this review we will discuss current insights in the mechanism of this well-known, yet poorly understood Nef effect. We will elaborate on effects of Nef, on both virion biogenesis and the early stage of the cellular infection, that might be involved in infectivity enhancement. In addition, we provide an overview of different HIV-1 Nef domains important for optimal infectivity and briefly discuss some possible sources of the frequent discrepancies in the field. Hereby we aim to contribute to a better understanding of this highly conserved and therapeutically attractive Nef function. Keywords: Nef, HIV, infectivity, viral replication, mutation analysis, envelope protein, cholesterol, proteasome. 1. INTRODUCTION 2. THE MULTIFACETED NEF PROTEIN Despite the globally declining number of new human As early as 1991, infections of rhesus monkeys with nef- immunodeficiency virus (HIV) infections [1] and the hopeful deleted simian immunodeficiency virus (SIV) revealed a observation that cure from HIV infection does not seem dramatic reduction of viral loads and disease progression in impossible [2], the HIV pandemic still remains a very absence of nef [6].
  • HIV-1 Rev Downregulates Tat Expression and Viral Replication Via Modulation of NAD(P)H:Quinine Oxidoreductase 1 (NQO1)

    HIV-1 Rev Downregulates Tat Expression and Viral Replication Via Modulation of NAD(P)H:Quinine Oxidoreductase 1 (NQO1)

    ARTICLE Received 25 Jul 2014 | Accepted 22 Apr 2015 | Published 10 Jun 2015 DOI: 10.1038/ncomms8244 HIV-1 Rev downregulates Tat expression and viral replication via modulation of NAD(P)H:quinine oxidoreductase 1 (NQO1) Sneh Lata1,*, Amjad Ali2,*, Vikas Sood1,2,w, Rameez Raja2 & Akhil C. Banerjea2 HIV-1 gene expression and replication largely depend on the regulatory proteins Tat and Rev, but it is unclear how the intracellular levels of these viral proteins are regulated after infection. Here we report that HIV-1 Rev causes specific degradation of cytoplasmic Tat, which results in inhibition of HIV-1 replication. The nuclear export signal (NES) region of Rev is crucial for this activity but is not involved in direct interactions with Tat. Rev reduces the levels of ubiquitinated forms of Tat, which have previously been reported to be important for its transcriptional properties. Tat is stabilized in the presence of NAD(P)H:quinine oxidoreductase 1 (NQO1), and potent degradation of Tat is induced by dicoumarol, an NQO1 inhibitor. Furthermore, Rev causes specific reduction in the levels of endogenous NQO1. Thus, we propose that Rev is able to induce degradation of Tat indirectly by downregulating NQO1 levels. Our findings have implications in HIV-1 gene expression and latency. 1 Department of Microbiology, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi 110095, India. 2 Laboratory of Virology, National Institute of Immunology, New Delhi 110067, India. * These authors contributed equally to this work. w Present address: Translational Health Science and Technology Institute, Faridabad, Haryana 121004, India. Correspondence and requests for materials should be addressed to A.C.B.
  • Single-Cell RNA Sequencing Demonstrates the Molecular and Cellular Reprogramming of Metastatic Lung Adenocarcinoma

    Single-Cell RNA Sequencing Demonstrates the Molecular and Cellular Reprogramming of Metastatic Lung Adenocarcinoma

    ARTICLE https://doi.org/10.1038/s41467-020-16164-1 OPEN Single-cell RNA sequencing demonstrates the molecular and cellular reprogramming of metastatic lung adenocarcinoma Nayoung Kim 1,2,3,13, Hong Kwan Kim4,13, Kyungjong Lee 5,13, Yourae Hong 1,6, Jong Ho Cho4, Jung Won Choi7, Jung-Il Lee7, Yeon-Lim Suh8,BoMiKu9, Hye Hyeon Eum 1,2,3, Soyean Choi 1, Yoon-La Choi6,10,11, Je-Gun Joung1, Woong-Yang Park 1,2,6, Hyun Ae Jung12, Jong-Mu Sun12, Se-Hoon Lee12, ✉ ✉ Jin Seok Ahn12, Keunchil Park12, Myung-Ju Ahn 12 & Hae-Ock Lee 1,2,3,6 1234567890():,; Advanced metastatic cancer poses utmost clinical challenges and may present molecular and cellular features distinct from an early-stage cancer. Herein, we present single-cell tran- scriptome profiling of metastatic lung adenocarcinoma, the most prevalent histological lung cancer type diagnosed at stage IV in over 40% of all cases. From 208,506 cells populating the normal tissues or early to metastatic stage cancer in 44 patients, we identify a cancer cell subtype deviating from the normal differentiation trajectory and dominating the metastatic stage. In all stages, the stromal and immune cell dynamics reveal ontological and functional changes that create a pro-tumoral and immunosuppressive microenvironment. Normal resident myeloid cell populations are gradually replaced with monocyte-derived macrophages and dendritic cells, along with T-cell exhaustion. This extensive single-cell analysis enhances our understanding of molecular and cellular dynamics in metastatic lung cancer and reveals potential diagnostic and therapeutic targets in cancer-microenvironment interactions. 1 Samsung Genome Institute, Samsung Medical Center, Seoul 06351, Korea.