DOCSLIB.ORG

Cell Entry and Exit of Porcine Endogenous Retrovirus A: Receptors and Release Inhibitor

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Cell Entry and Exit of Porcine Endogenous Retrovirus A: Receptors and Release Inhibitor Cell Entry and Exit of Porcine Endogenous Retrovirus A: Receptors and Release Inhibitor Giada Mattiuzzo Submitted to University College London For the degree of Doctor of Philosophy September 2009 Wohl Virion Centre Windeyer Building University College London 1 Declaration I, Giada Mattiuzzo, confirm that the work presented in this thesis is my own. Where information has been derived from other sources, I confirm that this has been indicated in the thesis. 2 Abstract Following the discovery that porcine endogenous retrovirus (PERV) can infect human cells, the potential risk of a zoonotic infection by PERV has been a major obstacle in the xenotransplantation field. The aim of this thesis is to gain a better understanding of PERV biology, so as to help assess and reduce the risk of PERV zoonosis. PERV subgroup A can enter human cells through two human PERV-A receptors (huPAR-1 and -2). To determine critical regions in the receptor for PERV-A infection, chimeric receptors between huPAR-2 and the non functional murine PAR (muPAR) have been analysed. A single amino acid difference (amino acid 109) was found responsible for the inability of muPAR to mediate PERV-A binding and infection. These results were then applied to the evaluation of PERV infection of non-human primates (NHP). NHP could represent an ideal animal model for assessing the risk of zoonosis following long-term exposure to porcine material. However, PERV does not infect NHP cells with the same efficiency as it does human cells. The data presented in this thesis suggests that in some NHP species the poor infectivity is due to mutation of the same critical amino acid (a.a.109) described for muPAR. However, African green monkey cells express two functional receptors and other mechanisms are likely to be responsible for the low susceptibility to PERV-A infection. Secondly, I evaluated the effect of a release inhibitor as a possible strategy to reduce PERV dissemination from pig cells. Human tetherin can inhibit retrovirus production from cells. I showed that overexpression of human and newly cloned porcine tetherin in pig cells can reduce the release of PERV. My data suggests that tetherin-expressing transgenic pigs could represent a safer donor in xenotransplantation. 3 Acknowledgments I would like to thank my supervisor Yasu Takeuchi for his guidance and patience during these four years of my PhD. He showed me novel, yet rigorous, ways to address scientific problems which I am convinced have made me a more rounded scientist. I’d like to thank Paul Kellam, my second supervisor, and members of his group. Additionally, thanks go to Mary Collins, Greg Towers, Benny Chain and the friendly people who work, or have worked, in their laboratories, too numerous to mention. During these years they provided helpful suggestions, protocols, cells and reagents. I felt privileged to work in the Wohl Virion Centre, whether headed by Robin Weiss (at the beginning) or Ari Fassati (at the end) has always been a stimulating environment to work in. Anna, Belinda, Claire, Doug, Kenneth, Khoon, Liz, Luciano, Nigel, Sham, Suzy, and Willie made the time spent in the lab a pleasant one. Special thanks go to Ed and Sean not only for the laughs we have in the lab, but also for the considered suggestions and critical reading of this thesis. These years in the Windeyer not only made me a better, more confident scientist, but also rewarded me with life-long friendships with Giovanna, Marieke, Rino, Sabrina, Torsten. Deep thanks to Massimo Pizzato. I would not be here if it was not for him. Finally, I would like to dedicate this thesis to my beloved boyfriend Ben for coping with me during the difficult times of this PhD, for his support, and for comments and suggestions during the research and writing of my thesis. 4 Table of Contents Declaration................................................................................................2 Abstract.....................................................................................................3 Acknowledgments.................... ...............................................................4 Table of Contents......................................................................................5 List of Figures............................................................................................9 List of Tables...........................................................................................11 Abbreviations...........................................................................................12 1 INTRODUCTION ........................................................................................ 16 1.1 Xenotransplantation ........................................................................ 16 1.1.1 Genetically modified pigs ................................................................ 19 1.2 Zoonosis in xenotranplantation ...................................................... 21 1.2.1 Porcine exogenous viruses ............................................................. 22 1.2.2 Porcine Herpesviruses .................................................................... 25 1.3 Retroviruses ..................................................................................... 27 1.3.1 Structure ......................................................................................... 27 1.3.2 Genomic RNA ................................................................................. 30 1.3.3 Life cycle ......................................................................................... 31 1.3.4 Retroviral pathogenesis .................................................................. 37 1.3.5 Endogenous retroviruses ................................................................ 39 1.4 Porcine endogenous retrovirus ...................................................... 43 1.4.1 Replication-competent PERVs and host range ............................... 43 1.4.2 PERV recombination ....................................................................... 44 1.4.3 Diagnostic methods for PERV detection ......................................... 45 1.4.4 Strategies to reduce the risk of PERV transmission ....................... 46 1.5 γ-RETROVIRUS RECEPTORS ......................................................... 50 1.5.1 Receptor cloning ............................................................................. 51 1.5.2 Receptor topology ........................................................................... 53 1.5.3 Physiological function ..................................................................... 54 1.5.4 Identification of sites critical for infection and binding ..................... 56 1.5.5 Receptor-mediated barriers to infection .......................................... 58 1.6 Host restriction factors .................................................................... 60 1.6.1 Early post entry restriction factors: Fv1 and TRIM protein family .... 61 1.6.2 APOBEC proteins ........................................................................... 64 1.6.3 ZAP, a zinc finger antiviral protein .................................................. 66 5 1.6.4 Tetherin ........................................................................................... 66 1.7 Aims .................................................................................................. 69 2 MATERIALS AND METHODS ................................................................... 70 2.1 Materials ........................................................................................... 70 2.2 Molecular biology methods ............................................................. 70 2.2.1 Preparation and transformation of chemically competent bacterial cells 70 2.2.2 Plasmid DNA mini preparations ...................................................... 71 2.2.3 Enzymatic reactions ........................................................................ 71 2.2.4 Agarose gel electrophoresis ........................................................... 71 2.2.5 DNA purification from agarose gel .................................................. 72 2.2.6 Genomic DNA extraction ................................................................ 72 2.2.7 RNA extraction ................................................................................ 72 2.2.8 Polymerase chain reaction (PCR) ................................................... 72 2.2.9 Reverse transcriptase (RT) reaction ............................................... 74 2.2.10 Quantitative PCR ......................................................................... 74 2.2.11 PCR-based mutagenesis ............................................................. 76 2.2.12 Construction of HA-tagged chimeric receptors ............................ 76 2.2.13 Generation of soluble myc-tagged PERV-A14/220 SU Env ........ 77 2.2.14 Receptors cloning ........................................................................ 77 2.2.15 Cloning of porcine tetherin ........................................................... 78 2.3 Cell culture methods ........................................................................ 79 2.3.1 Cell transfection .............................................................................. 79 2.3.2 Pseudotyped virus production ......................................................... 79 2.3.3 EGFP(PERV) production ................................................................ 80 2.3.4 EGFP-pseudotyped virus titration ..................................................
Load more

Recommended publications
  • Non-Primate Lentiviral Vectors and Their Applications in Gene Therapy for Ocular Disorders
    viruses Review Non-Primate Lentiviral Vectors and Their Applications in Gene Therapy for Ocular Disorders Vincenzo Cavalieri 1,2,* ID , Elena Baiamonte 3 and Melania Lo Iacono 3 1 Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze Edificio 16, 90128 Palermo, Italy 2 Advanced Technologies Network (ATeN) Center, University of Palermo, Viale delle Scienze Edificio 18, 90128 Palermo, Italy 3 Campus of Haematology Franco e Piera Cutino, Villa Sofia-Cervello Hospital, 90146 Palermo, Italy; [email protected] (E.B.); [email protected] (M.L.I.) * Correspondence: [email protected] Received: 30 April 2018; Accepted: 7 June 2018; Published: 9 June 2018 Abstract: Lentiviruses have a number of molecular features in common, starting with the ability to integrate their genetic material into the genome of non-dividing infected cells. A peculiar property of non-primate lentiviruses consists in their incapability to infect and induce diseases in humans, thus providing the main rationale for deriving biologically safe lentiviral vectors for gene therapy applications. In this review, we first give an overview of non-primate lentiviruses, highlighting their common and distinctive molecular characteristics together with key concepts in the molecular biology of lentiviruses. We next examine the bioengineering strategies leading to the conversion of lentiviruses into recombinant lentiviral vectors, discussing their potential clinical applications in ophthalmological research. Finally, we highlight the invaluable role of animal organisms, including the emerging zebrafish model, in ocular gene therapy based on non-primate lentiviral vectors and in ophthalmology research and vision science in general. Keywords: FIV; EIAV; BIV; JDV; VMV; CAEV; lentiviral vector; gene therapy; ophthalmology; zebrafish 1.
    [Show full text]
  • 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.
    [Show full text]
  • Parallels Among Positive-Strand RNA Viruses, Reverse-Transcribing Viruses and Double-Stranded RNA Viruses
    REVIEWS Parallels among positive-strand RNA viruses, reverse-transcribing viruses and double-stranded RNA viruses Paul Ahlquist Abstract | Viruses are divided into seven classes on the basis of differing strategies for storing and replicating their genomes through RNA and/or DNA intermediates. Despite major differences among these classes, recent results reveal that the non-virion, intracellular RNA- replication complexes of some positive-strand RNA viruses share parallels with the structure, assembly and function of the replicative cores of extracellular virions of reverse-transcribing viruses and double-stranded RNA viruses. Therefore, at least four of seven principal virus classes share several underlying features in genome replication and might have emerged from common ancestors. This has implications for virus function, evolution and control. Positive-strand RNA virus Despite continuing advances, established and emerging ssRNA or dsRNA. Other viruses replicate by intercon- A virus, the infectious virions of viruses remain major causes of human disease, with verting their genomes between RNA and DNA. The viri- which contain the genome in a dramatic costs in mortality, morbidity and economic ons of such reverse-transcribing viruses always initially single-stranded, messenger- terms. In addition to acute diseases, viruses cause at package the RNA forms of their genomes, and either sense RNA form. least 15–20% of human cancers1,2 and are implicated in might (for example, hepadnaviruses and foamy retro- neurological and other chronic disorders. One of many viruses) or might not (for example, orthoretroviruses) challenges in controlling viruses and virus-mediated dis- reverse-transcribe the RNA into DNA before the virion eases is that viruses show an amazing diversity in basic exits the initially infected producer cell.
    [Show full text]
  • The Expression of Human Endogenous Retroviruses Is Modulated by the Tat Protein of HIV‐1
    The Expression of Human Endogenous Retroviruses is modulated by the Tat protein of HIV‐1 by Marta Jeannette Gonzalez‐Hernandez A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Immunology) in The University of Michigan 2012 Doctoral Committee Professor David M. Markovitz, Chair Professor Gary Huffnagle Professor Michael J. Imperiale Associate Professor David J. Miller Assistant Professor Akira Ono Assistant Professor Christiane E. Wobus © Marta Jeannette Gonzalez‐Hernandez 2012 For my family and friends, the most fantastic teachers I have ever had. ii Acknowledgements First, and foremost, I would like to thank David Markovitz for his patience and his scientific and mentoring endeavor. My time in the laboratory has been an honor and a pleasure. Special thanks are also due to all the members of the Markovitz laboratory, past and present. It has been a privilege, and a lot of fun, to work near such excellent scientists and friends. You all have a special place in my heart. I would like to thank all the members of my thesis committee for all the valuable advice, help and jokes whenever needed. Our collaborators from the Bioinformatics Core, particularly James Cavalcoli, Fan Meng, Manhong Dai, Maureen Sartor and Gil Omenn gave generous support, technical expertise and scientific insight to a very important part of this project. Thank you. Thanks also go to Mariana Kaplan’s and Akira Ono’s laboratory for help with experimental designs and for being especially generous with time and reagents. iii Table of Contents Dedication ............................................................................................................................ ii Acknowledgements ............................................................................................................. iii List of Figures ...................................................................................................................
    [Show full text]
  • HIV 101: Pathogenesis and Treatment
    HIV 101: Pathogenesis and Treatment Stephen Raffanti MD MPH Professor of Medicine Vanderbilt University School of Medicine . Dr. Raffanti has no financial disclosures to make. Objectives . After this presentation the attendee should be able to: . Describe current issues in the epidemiology of the HIV epidemic. Describe the life cycle of HIV; . Describe the way that HIV interacts with its host, producing disease. Describe the principles of treatment. Describe Acute HIV infection . Describe the initial evaluation of an HIV infected patient Testing, linkage to care, effective treatment and effective PrEP could stop the epidemic today. Percentages of Diagnoses of HIV Infection among Adults and Adolescents, by Region and Population of Area of Residence, 2015—United States Note. Data include persons with a diagnosis of HIV infection regardless of stage of disease at diagnosis. Data for the year 2015 are preliminary and based on 6 months reporting delay. Data exclude persons whose county of residence is unknown. Percentages of Diagnoses of HIV Infection among Adults and Adolescents, by Population of Area of Residence and Age at Diagnosis, 2015—United States Note. Data include persons with a diagnosis of HIV infection regardless of stage of disease at diagnosis. Data for the year 2015 are preliminary and based on 6 months reporting delay. Data exclude persons whose county of residence is unknown. Diagnoses of HIV Infection among Men Who Have Sex with Men, by Age Group, 2010–2014—United States and 6 Dependent Areas Note. Data include persons with a diagnosis of HIV infection regardless of stage of disease at diagnosis. All displayed data have been statistically adjusted to account for reporting delays and missing transmission category, but not for incomplete reporting.
    [Show full text]
  • VMC 321: Systematic Veterinary Virology Retroviridae Retro: from Latin Retro,"Backwards”
    VMC 321: Systematic Veterinary Virology Retroviridae Retro: from Latin retro,"backwards” - refers to the activity of reverse RETROVIRIDAE transcriptase and the transfer of genetic information from RNA to DNA. Retroviruses Viral RNA Viral DNA Viral mRNA, genome (integrated into host genome) Reverse (retro) transfer of genetic information Usually, well adapted to their hosts Endogenous retroviruses • RNA viruses • single stranded, positive sense, enveloped, icosahedral. • Distinguished from all other RNA viruses by presence of an unusual enzyme, reverse transcriptase. Retroviruses • Retro = reversal • RNA is serving as a template for DNA synthesis. • One genera of veterinary interest • Alpharetrovirus • • Family - Retroviridae • Subfamily - Orthoretrovirinae [Ortho: from Greek orthos"straight" • Genus -. Alpharetrovirus • Genus - Betaretrovirus Family- • Genus - Gammaretrovirus • Genus - Deltaretrovirus Retroviridae • Genus - Lentivirus [ Lenti: from Latin lentus, "slow“ ]. • Genus - Epsilonretrovirus • Subfamily - Spumaretrovirinae • Genus - Spumavirus Retroviridae • Subfamily • Orthoretrovirinae • Genus • Alpharetrovirus Alpharetrovirus • Species • Avian leukosis virus(ALV) • Rous sarcoma virus (RSV) • Avian myeloblastosis virus (AMV) • Fujinami sarcoma virus (FuSV) • ALVs have been divided into 10 envelope subgroups - A , B, C, D, E, F, G, H, I & J based on • host range Avian • receptor interference patterns • neutralization by antibodies leukosis- • subgroup A to E viruses have been divided into two groups sarcoma • Noncytopathic (A, C, and E) • Cytopathic (B and D) virus (ALV) • Cytopathic ALVs can cause a transient cytotoxicity in 30- 40% of the infected cells 1. The viral envelope formed from host cell membrane; contains 72 spiked knobs. 2. These consist of a transmembrane protein TM (gp 41), which is linked to surface protein SU (gp 120) that binds to a cell receptor during infection. 3. The virion has cone-shaped, icosahedral core, Structure containing the major capsid protein 4.
    [Show full text]
  • Theory of an Immune System Retrovirus
    Proc. Nati. Acad. Sci. USA Vol. 83, pp. 9159-9163, December 1986 Medical Sciences Theory of an immune system retrovirus (human immunodeficiency virus/acquired immune deficiency syndrome) LEON N COOPER Physics Department and Center for Neural Science, Brown University, Providence, RI 02912 Contributed by Leon N Cooper, July 23, 1986 ABSTRACT Human immunodeficiency virus (HIV; for- initiates clonal expansion, sustained by interleukin 2 and y merly known as human T-cell lymphotropic virus type interferon. Ill/lymphadenopathy-associated virus, HTLV-Ill/LAV), the I first give a brief sketch of these events in a linked- retrovirus that infects T4-positive (helper) T cells of the interaction model in which it is assumed that antigen-specific immune system, has been implicated as the agent responsible T cells must interact with the B-cell-processed virus to for the acquired immune deficiency syndrome. In this paper, initiate clonal expansion (2). I then assume that virus-specific I contrast the growth of a "normal" virus with what I call an antibody is the major component ofimmune system response immune system retrovirus: a retrovirus that attacks the T4- that limits virus spread. As will be seen, the details of these positive T cells of the immune system. I show that remarkable assumptions do not affect the qualitative features of my interactions with other infections as well as strong virus conclusions. concentration dependence are general properties of immune Linked-Interaction Model for Clonal Expansion of Lympho- system retroviruses. Some of the consequences of these ideas cytes. Let X be the concentration of normal infecting virus are compared with observations.
    [Show full text]
  • ICTV Virus Taxonomy Profile: Parvoviridae
    ICTV VIRUS TAXONOMY PROFILES Cotmore et al., Journal of General Virology 2019;100:367–368 DOI 10.1099/jgv.0.001212 ICTV ICTV Virus Taxonomy Profile: Parvoviridae Susan F. Cotmore,1,* Mavis Agbandje-McKenna,2 Marta Canuti,3 John A. Chiorini,4 Anna-Maria Eis-Hubinger,5 Joseph Hughes,6 Mario Mietzsch,2 Sejal Modha,6 Mylene Ogliastro,7 Judit J. Penzes, 2 David J. Pintel,8 Jianming Qiu,9 Maria Soderlund-Venermo,10 Peter Tattersall,1,11 Peter Tijssen12 and ICTV Report Consortium Abstract Members of the family Parvoviridae are small, resilient, non-enveloped viruses with linear, single-stranded DNA genomes of 4–6 kb. Viruses in two subfamilies, the Parvovirinae and Densovirinae, are distinguished primarily by their respective ability to infect vertebrates (including humans) versus invertebrates. Being genetically limited, most parvoviruses require actively dividing host cells and are host and/or tissue specific. Some cause diseases, which range from subclinical to lethal. A few require co-infection with helper viruses from other families. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the Parvoviridae, which is available at www.ictv.global/report/parvoviridae. Table 1. Characteristics of the family Parvoviridae Typical member: human parvovirus B19-J35 G1 (AY386330), species Primate erythroparvovirus 1, genus Erythroparvovirus, subfamily Parvovirinae Virion Small, non-enveloped, T=1 icosahedra, 23–28 nm in diameter Genome Linear, single-stranded DNA of 4–6 kb with short terminal hairpins Replication Rolling hairpin replication, a linear adaptation of rolling circle replication. Dynamic hairpin telomeres prime complementary strand and duplex strand-displacement synthesis; high mutation and recombination rates Translation Capped mRNAs; co-linear ORFs accessed by alternative splicing, non-consensus initiation or leaky scanning Host range Parvovirinae: mammals, birds, reptiles.
    [Show full text]
  • Discovery of HTLV-1, the First Human Retrovirus, Its Unique Regulatory Mechanisms, and Insights Into Pathogenesis
    Oncogene (2005) 24, 5931–5937 & 2005 Nature Publishing Group All rights reserved 0950-9232/05 $30.00 www.nature.com/onc Discovery of HTLV-1, the first human retrovirus, its unique regulatory mechanisms, and insights into pathogenesis Mitsuaki Yoshida*,1 1Banyu Tsukuba Research Institute, Banyu Pharmaceutical Co., Ltd., 3 Ohkubo, Tsukuba, Ibaraki 300-2611, Japan I briefly review the discovery and characterization of the In Japan something was there, but it was not clear first human retrovirus, human T-cell leukemia virus type 1, focusing on contributions from Japanese researchers. Discovery of ATL The unique regulatory mechanisms for the viral regulation The first key event for human retrovirus was the with Tax and Rex, etiology of ATL and possible discovery of adult T-cell leukemia (ATL) by Kiyoshi leukemogenic mechanism with Tax are also discussed Takatsuki and his colleagues in Japan in 1976 (Uchi- briefly. et al Oncogene (2005) 24, 5931–5937. doi:10.1038/sj.onc.1208981 yama ., 1977). The reports from his laboratory described unique characteristics of the leukemia such as Keywords: HTLV-1; transcription; tumor-suppressor unusual morphology of leukemic cells with lobulated genes; cell cycle; epidemiology nuclei and surface phenotypes. The most striking feature of the disease was the Kyushu (West part of Japan) origin of most of the patients who were identified in Kyoto where Takatsuki’s group performed their research. Takatsuki’s findings were later confirmed by extensive epidemiology and a clear clustering of Introduction ATL cases in the Kyushu area strongly suggested a unique etiology (Hinuma et al., 1981a). At the time, When virologists and oncologists are challenged to this novel discovery elicited enormous attention from identify human tumor viruses, they dream of the physicians, virologists, epidemiologists and oncologists, contribution of such viruses towards understanding but still there was no clue as to how to search for an cancers and answering questions such as how and why etiology.
    [Show full text]
  • Diversity and Evolution of Viral Pathogen Community in Cave Nectar Bats (Eonycteris Spelaea)
    viruses Article Diversity and Evolution of Viral Pathogen Community in Cave Nectar Bats (Eonycteris spelaea) Ian H Mendenhall 1,* , Dolyce Low Hong Wen 1,2, Jayanthi Jayakumar 1, Vithiagaran Gunalan 3, Linfa Wang 1 , Sebastian Mauer-Stroh 3,4 , Yvonne C.F. Su 1 and Gavin J.D. Smith 1,5,6 1 Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore 169857, Singapore; [email protected] (D.L.H.W.); [email protected] (J.J.); [email protected] (L.W.); [email protected] (Y.C.F.S.) [email protected] (G.J.D.S.) 2 NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 119077, Singapore 3 Bioinformatics Institute, Agency for Science, Technology and Research, Singapore 138671, Singapore; [email protected] (V.G.); [email protected] (S.M.-S.) 4 Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore 5 SingHealth Duke-NUS Global Health Institute, SingHealth Duke-NUS Academic Medical Centre, Singapore 168753, Singapore 6 Duke Global Health Institute, Duke University, Durham, NC 27710, USA * Correspondence: [email protected] Received: 30 January 2019; Accepted: 7 March 2019; Published: 12 March 2019 Abstract: Bats are unique mammals, exhibit distinctive life history traits and have unique immunological approaches to suppression of viral diseases upon infection. High-throughput next-generation sequencing has been used in characterizing the virome of different bat species. The cave nectar bat, Eonycteris spelaea, has a broad geographical range across Southeast Asia, India and southern China, however, little is known about their involvement in virus transmission.
    [Show full text]
  • Diversity and Evolution of Novel Invertebrate DNA Viruses Revealed by Meta-Transcriptomics
    viruses Article Diversity and Evolution of Novel Invertebrate DNA Viruses Revealed by Meta-Transcriptomics Ashleigh F. Porter 1, Mang Shi 1, John-Sebastian Eden 1,2 , Yong-Zhen Zhang 3,4 and Edward C. Holmes 1,3,* 1 Marie Bashir Institute for Infectious Diseases and Biosecurity, Charles Perkins Centre, School of Life & Environmental Sciences and Sydney Medical School, The University of Sydney, Sydney, NSW 2006, Australia; [email protected] (A.F.P.); [email protected] (M.S.); [email protected] (J.-S.E.) 2 Centre for Virus Research, Westmead Institute for Medical Research, Westmead, NSW 2145, Australia 3 Shanghai Public Health Clinical Center and School of Public Health, Fudan University, Shanghai 201500, China; [email protected] 4 Department of Zoonosis, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing 102206, China * Correspondence: [email protected]; Tel.: +61-2-9351-5591 Received: 17 October 2019; Accepted: 23 November 2019; Published: 25 November 2019 Abstract: DNA viruses comprise a wide array of genome structures and infect diverse host species. To date, most studies of DNA viruses have focused on those with the strongest disease associations. Accordingly, there has been a marked lack of sampling of DNA viruses from invertebrates. Bulk RNA sequencing has resulted in the discovery of a myriad of novel RNA viruses, and herein we used this methodology to identify actively transcribing DNA viruses in meta-transcriptomic libraries of diverse invertebrate species. Our analysis revealed high levels of phylogenetic diversity in DNA viruses, including 13 species from the Parvoviridae, Circoviridae, and Genomoviridae families of single-stranded DNA virus families, and six double-stranded DNA virus species from the Nudiviridae, Polyomaviridae, and Herpesviridae, for which few invertebrate viruses have been identified to date.
    [Show full text]
  • Chronic Viral Infections Vs. Our Immune System: Revisiting Our View of Viruses As Pathogens
    Chronic Viral Infections vs. Our Immune System: Revisiting our view of viruses as pathogens Tiffany A. Reese Assistant Professor Departments of Immunology and Microbiology Challenge your idea of classic viral infection and disease • Define the microbiome and the virome • Brief background on persistent viruses • Illustrate how viruses change disease susceptibility – mutualistic symbiosis – gene + virus = disease phenotype – virome in immune responses Bacteria-centric view of the microbiome The microbiome defined Definition of microbiome – Merriam-Webster 1 :a community of microorganisms (such as bacteria, fungi, and viruses) that inhabit a particular environment and especially the collection of microorganisms living in or on the human body 2 :the collective genomes of microorganisms inhabiting a particular environment and especially the human body Virome Ø Viral component of the microbiome Ø Includes both commensal and pathogenic viruses Ø Viruses that infect host cells Ø Virus-derived elements in host chromosomes Ø Viruses that infect other organisms in the body e.g. phage/bacteria Viruses are everywhere! • “intracellular parasites with nucleic acids that are capable of directing their own replication and are not cells” – Roossinck, Nature Reviews Microbiology 2011. • Viruses infect all living things. • We are constantly eating and breathing viruses from our environment • Only a small subset of viruses cause disease. • We even carry viral genomes as part of our own genetic material! Diverse viruses all over the body Adenoviridae Picornaviridae
    [Show full text]