Genetic Variation and Function of the HIV-1 Tat Protein
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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)
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. -
Patent Document US 06872395
I 1111111111111111 11111 111111111111111 1111111111 1111111111 lll111111111111111 US006872395B2 (12) United States Patent (10) Patent No.: US 6,872,395 B2 Kawaoka (45) Date of Patent: Mar.29,2005 (54) VIRUSES COMPRISING MUTANT ION Mena, I., et al., "Rescue of a Synthetic Choramphenicol CHANNEL PROTEIN Acetyltransferase RNA into influenza Virus-Like Particles obtained from recombinant plasmids", J. of Virology, vol. (75) Inventor: Yoshihiro Kawaoka, Madison, WI 70, No. 8, XP002150091, 5016-5024, (Aug. 1996). (US) Neumann, G., et al., "Generation of influenza A Viruses entirely from cloned cDNAs", Proc. of the Nat'l Aca. of (73) Assignee: Wisconsin Alumni Research Sciences, USA, vol. 96, XP002150093, 9345-9350, (Aug. Foundation, Madison, WI (US) 1999). ( *) Notice: Subject to any disclaimer, the term of this Neumann, G., et al., "Plasmid-Driven Formation of Influ patent is extended or adjusted under 35 enza Virus-Like Particles", J. of Virology, vol. 74, No. 1, U.S.C. 154(b) by O days. XP002150094, 547-551, (Jan. 2000). Neumann, G., et al., "RNA Polymerase I-Mediated Expres sion of Influenza Viral RNA Molecules", Virology, vol. 202, (21) Appl. No.: 09/834,095 No. 1, XP000952667, 477-479, (Jul. 1994). (22) Filed: Apr. 12, 2001 Neirynck, S., et al., "A universal influenza A vaccine based on the extracellular domain of the M2 protein", Nature (65) Prior Publication Data Medicine, 5 (10), pp. 1157-1163, (Oct. 1999). US 2003/0194694 Al Oct. 16, 2003 Piller, S. C., et al., "Vpr protein of human immunodeficiency virus type 1 forms cation-selective channels in planar lipid Related U.S. Application Data bilayers", PNAS, 93, pp. -
Opportunistic Intruders: How Viruses Orchestrate ER Functions to Infect Cells
REVIEWS Opportunistic intruders: how viruses orchestrate ER functions to infect cells Madhu Sudhan Ravindran*, Parikshit Bagchi*, Corey Nathaniel Cunningham and Billy Tsai Abstract | Viruses subvert the functions of their host cells to replicate and form new viral progeny. The endoplasmic reticulum (ER) has been identified as a central organelle that governs the intracellular interplay between viruses and hosts. In this Review, we analyse how viruses from vastly different families converge on this unique intracellular organelle during infection, co‑opting some of the endogenous functions of the ER to promote distinct steps of the viral life cycle from entry and replication to assembly and egress. The ER can act as the common denominator during infection for diverse virus families, thereby providing a shared principle that underlies the apparent complexity of relationships between viruses and host cells. As a plethora of information illuminating the molecular and cellular basis of virus–ER interactions has become available, these insights may lead to the development of crucial therapeutic agents. Morphogenesis Viruses have evolved sophisticated strategies to establish The ER is a membranous system consisting of the The process by which a virus infection. Some viruses bind to cellular receptors and outer nuclear envelope that is contiguous with an intri‑ particle changes its shape and initiate entry, whereas others hijack cellular factors that cate network of tubules and sheets1, which are shaped by structure. disassemble the virus particle to facilitate entry. After resident factors in the ER2–4. The morphology of the ER SEC61 translocation delivering the viral genetic material into the host cell and is highly dynamic and experiences constant structural channel the translation of the viral genes, the resulting proteins rearrangements, enabling the ER to carry out a myriad An endoplasmic reticulum either become part of a new virus particle (or particles) of functions5. -
Producing Vaccines Against Enveloped Viruses in Plants: Making the Impossible, Difficult
Review Producing Vaccines against Enveloped Viruses in Plants: Making the Impossible, Difficult Hadrien Peyret , John F. C. Steele † , Jae-Wan Jung, Eva C. Thuenemann , Yulia Meshcheriakova and George P. Lomonossoff * Department of Biochemistry and Metabolism, John Innes Centre, Norwich NR4 7UH, UK; [email protected] (H.P.); [email protected] (J.F.C.S.); [email protected] (J.-W.J.); [email protected] (E.C.T.); [email protected] (Y.M.) * Correspondence: [email protected] † Current address: Piramal Healthcare UK Ltd., Piramal Pharma Solutions, Northumberland NE61 3YA, UK. Abstract: The past 30 years have seen the growth of plant molecular farming as an approach to the production of recombinant proteins for pharmaceutical and biotechnological uses. Much of this effort has focused on producing vaccine candidates against viral diseases, including those caused by enveloped viruses. These represent a particular challenge given the difficulties associated with expressing and purifying membrane-bound proteins and achieving correct assembly. Despite this, there have been notable successes both from a biochemical and a clinical perspective, with a number of clinical trials showing great promise. This review will explore the history and current status of plant-produced vaccine candidates against enveloped viruses to date, with a particular focus on virus-like particles (VLPs), which mimic authentic virus structures but do not contain infectious genetic material. Citation: Peyret, H.; Steele, J.F.C.; Jung, J.-W.; Thuenemann, E.C.; Keywords: alphavirus; Bunyavirales; coronavirus; Flaviviridae; hepatitis B virus; human immunode- Meshcheriakova, Y.; Lomonossoff, ficiency virus; Influenza virus; newcastle disease virus; plant molecular farming; plant-produced G.P. -
Filoviral Immune Evasion Mechanisms
Viruses 2011, 3, 1634-1649; doi:10.3390/v3091634 OPEN ACCESS viruses ISSN 1999-4915 www.mdpi.com/journal/viruses Review Filoviral Immune Evasion Mechanisms Parameshwaran Ramanan 1,3, Reed S. Shabman 2, Craig S. Brown 1,4, Gaya K. Amarasinghe 1,*, Christopher F. Basler 2,* and Daisy W. Leung 1,* 1 Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA 2 Department of Microbiology, Mount Sinai School of Medicine, New York, NY 10029, USA 3 Biochemistry Graduate Program, Iowa State University, Ames, IA 50011, USA 4 Biochemistry Undergraduate Program, Iowa State University, Ames, IA 50011, USA * Authors to whom correspondence should be addressed; [email protected] (G.K.A); [email protected] (C.F.B); [email protected] (D.W.L.). Received: 11 August 2011 / Accepted: 15 August 2011 / Published: 7 September 2011 Abstract: The Filoviridae family of viruses, which includes the genera Ebolavirus (EBOV) and Marburgvirus (MARV), causes severe and often times lethal hemorrhagic fever in humans. Filoviral infections are associated with ineffective innate antiviral responses as a result of virally encoded immune antagonists, which render the host incapable of mounting effective innate or adaptive immune responses. The Type I interferon (IFN) response is critical for establishing an antiviral state in the host cell and subsequent activation of the adaptive immune responses. Several filoviral encoded components target Type I IFN responses, and this innate immune suppression is important for viral replication and pathogenesis. For example, EBOV VP35 inhibits the phosphorylation of IRF-3/7 by the TBK-1/IKKε kinases in addition to sequestering viral RNA from detection by RIG-I like receptors. -
A Novel Ebola Virus VP40 Matrix Protein-Based Screening for Identification of Novel Candidate Medical Countermeasures
viruses Communication A Novel Ebola Virus VP40 Matrix Protein-Based Screening for Identification of Novel Candidate Medical Countermeasures Ryan P. Bennett 1,† , Courtney L. Finch 2,† , Elena N. Postnikova 2 , Ryan A. Stewart 1, Yingyun Cai 2 , Shuiqing Yu 2 , Janie Liang 2, Julie Dyall 2 , Jason D. Salter 1 , Harold C. Smith 1,* and Jens H. Kuhn 2,* 1 OyaGen, Inc., 77 Ridgeland Road, Rochester, NY 14623, USA; [email protected] (R.P.B.); [email protected] (R.A.S.); [email protected] (J.D.S.) 2 NIH/NIAID/DCR/Integrated Research Facility at Fort Detrick (IRF-Frederick), Frederick, MD 21702, USA; courtney.fi[email protected] (C.L.F.); [email protected] (E.N.P.); [email protected] (Y.C.); [email protected] (S.Y.); [email protected] (J.L.); [email protected] (J.D.) * Correspondence: [email protected] (H.C.S.); [email protected] (J.H.K.); Tel.: +1-585-697-4351 (H.C.S.); +1-301-631-7245 (J.H.K.) † These authors contributed equally to this work. Abstract: Filoviruses, such as Ebola virus and Marburg virus, are of significant human health concern. From 2013 to 2016, Ebola virus caused 11,323 fatalities in Western Africa. Since 2018, two Ebola virus disease outbreaks in the Democratic Republic of the Congo resulted in 2354 fatalities. Although there is progress in medical countermeasure (MCM) development (in particular, vaccines and antibody- based therapeutics), the need for efficacious small-molecule therapeutics remains unmet. Here we describe a novel high-throughput screening assay to identify inhibitors of Ebola virus VP40 matrix protein association with viral particle assembly sites on the interior of the host cell plasma membrane. -
Inhibition of Tat-Mediated Transactivation and HIV Replication with Tat Mutant and Repressor Domain Fusion Proteins
Gene Therapy (1998) 5, 946–954 1998 Stockton Press All rights reserved 0969-7128/98 $12.00 http://www.stockton-press.co.uk/gt Inhibition of Tat-mediated transactivation and HIV replication with Tat mutant and repressor domain fusion proteins C Fraisier1,2, DA Abraham1, M van Oijen1, V Cunliffe3, A Irvine3, R Craig3 and EA Dzierzak1,2 1National Institute for Medical Research, Division of Eukaryotic Molecular Genetics, London, UK; 2Erasmus University Rotterdam, Department of Cell Biology and Genetics, Rotterdam, The Netherlands; and 3Therexsys Ltd, The Science Park, University of Keele, Keele, UK Strategies to inhibit the spread of HIV infection consist of moter. This fusion mutant was also examined for its a number of specific molecular approaches. Since viral capacity to block both Tat-mediated transactivation and production is dependent upon Tat-mediated transactivation HIV replication. We show that three mutants Tat⌬53, of the HIV promoter through the Tat activating region Tat⌬58 and Tat⌬53/Eng result in a transdominant pheno- (TAR), tat antisense RNA, anti-tat ribozymes, TAR decoys type inhibiting wild-type Tat-mediated transactivation, and and dominant negative Tat mutant proteins have been sug- that the inhibiting potential is increased by the presence of gested as therapeutic inhibitors. We produced and tested the entire basic domain or the fusion of a repressor several Tat mutant proteins, including a newly generated domain. However, only the transdominant mutants Tat⌬58 form Tat⌬58, for the ability to inhibit Tat-mediated trans- and Tat⌬53/Eng significantly inhibit HIV-1 replication after activation and HIV production. In addition, we generated a infection of transfected T cell lines. -
The Hepatitis C Virus P7 Protein Forms an Ion Channel That Is Inhibited by Long-Alkyl-Chain Iminosugar Derivatives
The hepatitis C virus p7 protein forms an ion channel that is inhibited by long-alkyl-chain iminosugar derivatives Davor Pavlovic´*, David C. A. Neville*, Olivier Argaud*, Baruch Blumberg†, Raymond A. Dwek*, Wolfgang B. Fischer*, and Nicole Zitzmann*‡ *Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom; and †Fox Chase Cancer Center, Philadelphia, PA 19111 Contributed by Baruch Blumberg, March 17, 2003 We show that hepatitis C virus (HCV) p7 protein forms ion channels data have been obtained by introducing mutations into an in black lipid membranes. HCV p7 ion channels are inhibited by infectious cDNA clone of BVDV. An in-frame deletion of the long-alkyl-chain iminosugar derivatives, which have antiviral ac- entire p7 does not affect RNA replication but leads to the tivity against the HCV surrogate bovine viral diarrhea virus. HCV p7 production of noninfectious virions. However, infective viral presents a potential target for antiviral therapy. particles can be generated by complementing p7 in trans (9), which suggests that the pestivirus p7 is essential for the epatitis C virus (HCV) is the major cause of chronic production of infective progeny virus. Interestingly, noninfec- Hhepatitis with a significant risk of end-stage liver cirrhosis tive BVDV particles also are created by treatment with and hepatocellular carcinoma (1). HCV belongs to the family long-alkyl-chain iminosugar derivatives (3). Flaviviridae, which consists of three genera: flaviviruses, pesti- Recently, HCV p7 has been shown to be a polytopic mem- viruses, and hepaciviruses. In the absence of both a suitable small brane protein that crosses the membrane twice and has its N and animal model and a reliable in vitro infectivity assay for HCV, C termini oriented toward the extracellular environment (10). -
Feline Origin of Rotavirus Strain, Tunisia
Article DOI: http://dx.doi.org/10.3201/eid1904.121383 Feline Origin of Rotavirus Strain, Tunisia Technical Appendix Table 1. Primers used for amplification and sequencing of the whole genome of group A rotavirus strain RVA/human-wt/TUN/17237/2008/G6P[9] from Tunisia, 2008 Gene Primer name Primer sequence VP1 Gen_VP1Fb 5 -GGC TAT TAA AGC TRT ACA ATG GGG AAG -3 Gen_VP1Rb 5 -GGT CAC ATC TAA GCG YTC TAA TCT TG -3 MG6_VP1_447F 5 -TGC AGT TAT GTT CTG GTT GG -3 Hosokawa_VP1_2587R 5 -ACG CTG ATA TTT GCG CAC -3 LAP_VP1_1200F 5 -GCT GTC AAT GTC ATC AGC -3 Gen_VP1_2417R 5 -GCT ATY TCA TCA GCT ATT CCY G -3 30-96_VP1_3163F 5 -GGA TCA TGG ATA AGC TTG TTC TG -3 26097_VP1_269R 5 -GCG TTA TAC TTA TCA TAC GAA TAC G -3 VP2 Gen_VP2Fc 5 -GGC TAT TAA AGG YTC AAT GGC GTA CAG -3 Gen_VP2Rbc 5 -GTC ATA TCT CCA CAR TGG GGT TGG -3 26097_VP2_458F 5 -AGT TGC GTA ATA GAT GGT ATT GG -3 B1711_VP2_2112R 5 -GCA ATT TTA TCT GAG GCA CG -3 NCDV_VP2_1868F 5 -AGG ATT AAT GAT GCA GTG GC -3 LAP_VP2_2543F 5 -GAC ATC AAA TCT TAC CTT CAC TG -3 260-97_VP2_345R 5 -GAC TCT TTT GGT TCG AAA GTA GG -3 FR5_VP2_23F 5 -TAC AGG AAA CGT GGA GCG -3 260-97_VP2_744R 5 -GTACTCTTTGTCTCATTTCCGC -3 Gen_VP2_2739Ra 5 -TAC AAC TCG TTC ATG ATG CG -3 VP3 Gen_VP3_24F 5 -TGY GTT TTA CCT CTG ATG GTG-3 Gen_VP3_2584R 5 -TGA CYA GTG TGT TAA GTT TYT AGC-3 NCDV_VP3_2026R 5 -CAT GCG TAA ATC AAC TCT ATC GG -3 MG6_VP3_488F 5 -GCA GCT ACA GAT GATGAT GC -3 B10925_VP3_2416F 5 -ACA ATC GAG AAT GTT CAT CCC -3 TUN1_VP3_167R 5 -TTT CTA CTG CAG CTA TGC CAG-3 VP4 LAP_VP4_788F 5 -CCT TGT GGA AAG AAA TGC-3 VP4_2348-2368Re 5 -
Gyrolab® P24 Kit for Lentivirus Titer Determination
Gyrolab® p24 Kit For lentivirus titer determination Product Information Sheet D0034387/A Benefits of performing lentivirus titer determinations with Gyrolab p24 Kit: • Accelerate lentivirus bioprocess workflows and reduce time to market – Fast results for data driven decisions – 96 data points in 80 minutes – Automated analyses – less manual operations – High throughput – up to 960 data points in one working day • Generate high data quality from small sample volumes – 10 x less sample required compared to ELISA – Broad dynamic range and low matrix interference reduces the need for dilutions Introduction Lentiviral vectors based on HIV-1 and EIA viruses are commonly Gyrolab Systems have become proven and established used as vehicles to transfer therapeutic genes. Improvements analytical tools for bioprocess development and in vector design that increase biosafety and transgene manufacturing. Features that increase the productivity in expression have led to the approval of lentiviral vectors for bioprocess workflows include automated analysis, broad use in clinical studies as well as the commercial approval of analytical range, high quality results, and software designed new therapies. Lentiviral vectors can be used ex vivo, for for 21 CFR part 11 compliance. example in the preparation of CAR T cells for the treatment To meet the need to determine lentivirus titers, Gyros Protein of acute lymphoblastic leukemia, and in direct in vivo use, Technologies has developed Gyrolab p24 Kit. Gyrolab p24 for example in the treatment of Parkinson’s disease and rare Kit is ready to use and works over a broad analytical range. retinal diseases. Use of Gyrolab Systems in combination with ready to use kits Manufacturing lentiviral vectors involves cell culture, often promises to accelerate bioprocesses involving viral vector based on HEK 293 cell lines. -
Lentivirus and Lentiviral Vectors Fact Sheet
Lentivirus and Lentiviral Vectors Family: Retroviridae Genus: Lentivirus Enveloped Size: ~ 80 - 120 nm in diameter Genome: Two copies of positive-sense ssRNA inside a conical capsid Risk Group: 2 Lentivirus Characteristics Lentivirus (lente-, latin for “slow”) is a group of retroviruses characterized for a long incubation period. They are classified into five serogroups according to the vertebrate hosts they infect: bovine, equine, feline, ovine/caprine and primate. Some examples of lentiviruses are Human (HIV), Simian (SIV) and Feline (FIV) Immunodeficiency Viruses. Lentiviruses can deliver large amounts of genetic information into the DNA of host cells and can integrate in both dividing and non- dividing cells. The viral genome is passed onto daughter cells during division, making it one of the most efficient gene delivery vectors. Most lentiviral vectors are based on the Human Immunodeficiency Virus (HIV), which will be used as a model of lentiviral vector in this fact sheet. Structure of the HIV Virus The structure of HIV is different from that of other retroviruses. HIV is roughly spherical with a diameter of ~120 nm. HIV is composed of two copies of positive ssRNA that code for nine genes enclosed by a conical capsid containing 2,000 copies of the p24 protein. The ssRNA is tightly bound to nucleocapsid proteins, p7, and enzymes needed for the development of the virion: reverse transcriptase (RT), proteases (PR), ribonuclease and integrase (IN). A matrix composed of p17 surrounds the capsid ensuring the integrity of the virion. This, in turn, is surrounded by an envelope composed of two layers of phospholipids taken from the membrane of a human cell when a newly formed virus particle buds from the cell.