DOCSLIB.ORG

Hassan Khonsari College of Health and Life Sciences

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Hassan Khonsari College of Health and Life Sciences Lentivirus-meditated frataxin gene delivery reverses genome instability in Friedreich ataxia patient and mouse model fibroblasts Thesis submitted for the degree of Doctor of Philosophy by Hassan Khonsari November 2015 College of Health and Life Sciences ABSTRACT Friedreich ataxia (FRDA) is a progressive neurodegenerative disease with primary sites of pathology in the large sensory neurons of the dorsal root ganglia (DRG) and dentate nucleus of the cerebellum. FRDA is also often accompanied by severe cardiomyopathy and diabetes mellitus. FRDA is caused by loss of frataxin (FXN) expression, which is due to GAA repeat expansion in intron 1 of the FXN gene. Frataxin is a mitochondrial protein important in iron-sulphur cluster (ISC) biogenesis and in the electron transport chain (ETC). As a consequence of impaired mitochondrial energy metabolism, FRDA cells show increased levels of and sensitivity to oxidative stress, which is known to be associated with genome instability. In this study, we investigated DNA damage/repair in relation to FXN expression via immunostaining of γ-H2AX, a nuclear protein that is recruited to DNA double strand breaks (DSBs). We found FRDA patient and YG8sR FRDA mouse model fibroblasts to have inherently elevated DNA DSBs (1.8 and 0.9 foci/nucleus) compared to normal fibroblasts (0.6 and 0.2 foci/nucleus, in each case P <0.001). By delivering the FXN gene to these cells with a lentivirus vector (LV) at a copy number of ~1/cell, FXN mRNA levels reached 48 fold (patient cells) and 42 fold (YG8sR cells) and protein levels reached 20 fold (patient cells) and 3.5 fold (YG8sR cells) that of untreated fibroblasts, without observable cytotoxicity. This resulted in a reduction in DNA DSB foci to 0.7 and 0.43 (in each case P <0.001) in human and YG8sR fibroblasts, respectively and an increase in cell survival to that found for normal fibroblasts. We next irradiated the FRDA fibroblasts (2Gy) and measured their DSB repair profiles. Both human and mouse FRDA fibroblasts were unable to repair damaged DNA. However, repair returned to near normal levels following LV FXN gene transfer. Our data suggest frataxin may be important for genome stability and cell survival by ensuring ISC for DNA damage repair enzymes or may be required directly for DNA DSB repair. I ACKNOWLEDGEMENTS First I would like to express the deepest gratitude to my first and second supervisors Dr. Michael Themis and Dr. Mark Pook for their guidance, support and encouragement throughout my PhD. I am highly grateful for this opportunity and I thank them for accepting me as their student. I would like to thank Dr. Sahar Al-Mahdawi and Dr. Matthew Themis for the training, advice and assistances they have always provided in every step of the way. I am grateful to Dr. Christopher Parris for his input in the DNA damage study and also his suggestions with the immunofluorescence assays. I would like to express my sincere thanks to Dr. Yaghoub Gozaly and Dr. Hemad Yasaei for being helpful whenever needed. I would like to thank Dr. Steve Howe (UCL, UK) for providing the vectors used in this project. It is my pleasant honour to thank Ataxia UK, FARA Australia and FARA USA for providing financial support. Finally I would like to thank my parents for been patient and supportive during these years and also I would like to thank my wife for being with me in every step of the way. II DECLARATION I hereby declare that the research presented in this thesis is my own work, except where otherwise specified, and has not been submitted for any other degree. Hassan Khonsari III TABLE OF CONTENTS ABSTRACT ____________________________________________________________________________ I ACKNOWLEDGEMENTS ________________________________________________________________ II DECLARATION _______________________________________________________________________ III TABLE OF CONTENTS _________________________________________________________________ IV LIST OF TABLES _____________________________________________________________________VIII LIST OF FIGURES _____________________________________________________________________ IX ABBREVIATIONS _____________________________________________________________________ XII 1. CHAPTER 1 - FRIEDREICH ATAXIA: LITERATURE REVIEW ______________________________________ 1 1.1 ATAXIA ____________________________________________________________________________ 2 1.2 FRIEDREICH ATAXIA __________________________________________________________________ 4 1.2.1 Clinical Features ________________________________________________________________ 4 1.2.2 Pathophysiology _________________________________________________________________ 6 1.2.3 Prevalence _____________________________________________________________________ 8 1.2.4 Friedreich ataxia gene structure ____________________________________________________ 10 1.2.5 Friedreich ataxia gene expression __________________________________________________ 12 1.2.6 Frataxin protein structure _________________________________________________________ 13 1.2.7 Cellular function of frataxin _______________________________________________________ 14 1.3 GAA REPEAT MUTATION ______________________________________________________________ 16 1.3.1 Instability of the GAA repeat: ______________________________________________________ 17 1.3.2 Somatic instability is tissue and age dependent ________________________________________ 18 1.3.3 Meiotic (intergenerational) instability of GAA repeats __________________________________ 20 1.4 MECHANISMS REDUCING FXN TRANSCRIPTION _____________________________________________ 20 1.4.1 Triplex formation _______________________________________________________________ 21 1.4.2 Sticky DNA ____________________________________________________________________ 23 1.4.3 Histone modifications ____________________________________________________________ 26 1.4.4 DNA methylation changes _________________________________________________________ 28 1.5 FRIEDREICH ATAXIA MOUSE MODELS ____________________________________________________ 29 1.5.1 Knockout mouse models __________________________________________________________ 29 1.5.2 Knockin mouse models ___________________________________________________________ 29 1.5.3 FXN YAC transgenic mouse model __________________________________________________ 30 1.5.4 Human frataxin is functional and rescues FXN knockout mouse ___________________________ 30 1.5.5 Human FXN YAC transgenic mouse containing a GAA repeat ____________________________ 32 1.6 THERAPEUTICS _____________________________________________________________________ 35 1.6.1 Antioxidants and oxidative stress ___________________________________________________ 35 1.6.2 Removal of mitochondrial iron _____________________________________________________ 35 1.6.3 Increasing frataxin levels _________________________________________________________ 36 1.6.3.1 Inhibition of triplex formation ____________________________________________________ 36 1.6.3.2 Inhibition of heterochromatin mediated silencing _____________________________________ 37 1.6.3.3 HDAC inhibitors as a therapy for FRDA ____________________________________________ 38 1.7 DEVELOPING GENE THERAPIES FOR FRDA ________________________________________________ 39 1.7.1 Retroviral and lentiviral vectors. ___________________________________________________ 41 1.7.2 Adeno-associated virus ___________________________________________________________ 42 1.7.3 Herpes simplex virus type 1 _______________________________________________________ 44 1.7.4 Nonviral-based delivery __________________________________________________________ 45 1.7.4 The challenges faced in gene therapies for FRDA ______________________________________ 46 1.8 GENE THERAPY STRATEGIES FOR MONOGENIC DISEASES ______________________________________ 47 1.9 VIRAL VECTORS FOR GENE THERAPY _____________________________________________________ 50 1.10 RETROVIRUSES ____________________________________________________________________ 52 1.10.1 Retrovirus biology ______________________________________________________________ 54 1.10.1.1 Coding sequences _____________________________________________________________ 55 IV 1.10.1.2 Non‐coding sequences _________________________________________________________ 56 1.10.2 Retrovirus Structure ____________________________________________________________ 57 1.11 LENTIVIRAL LIFE CYCLE _____________________________________________________________ 59 1.11.1 Entry and uncoating ____________________________________________________________ 61 1.11.2 Reverse transcription ___________________________________________________________ 61 1.11.3 Integration ___________________________________________________________________ 63 1.11.4 Transcription _________________________________________________________________ 64 1.11.5 Translation ___________________________________________________________________ 64 1.11.6 Virion assembly and budding _____________________________________________________ 65 1.12 LENTIVIRAL VECTORS _______________________________________________________________ 66 1.12.1 Early HIV-1 vectors ____________________________________________________________ 67 1.12.2 Expanded tropism through pseudotyping with vesicular stomatitis virus envelope-glycoprotein G (VSV-G). ___________________________________________________________________________ 68 1.12.3 First-generation HIV-1-based lentiviral vectors _______________________________________ 68 1.12.4 Second generation lentiviral vectors ________________________________________________ 70
Load more

Recommended publications
  • Assessment and Analysis of the Restriction of Retroviral Infection by the Murine APOBEC3 Protein
    Assessment and Analysis of the Restriction of Retroviral Infection by the Murine APOBEC3 Protein Halil Aydin Thesis submitted to the Faculty of Graduate and Postdoctoral Studies of the University of Ottawa in partial fulfillment of the requirements for the degree of Masters of Science Department of Biochemistry, Microbiology and Immunology Faculty of Medicine ©Halil Aydin, Ottawa, Ontario, Canada, 2011 Learning the rules is hard work and lengthy but playing the game is exciting and fun. John Polanyi Nobel Prize Winner in Chemistry ii ABSTRACT Human APOBEC3 proteins are host-encoded intrinsic restriction factors that can prevent the replication of a broad range of human and animal retroviruses such as HIV, SIV, FIV, MLVs and XMRV. The main pathway of the restriction is believed to occur as a result of the cytidine deaminase activity of these proteins that converts cytidines into uridines in single- stranded DNA retroviral replication intermediates. Uridines in these DNA intermediates disrupt the viral replication cycle and also alter retrovirus infectivity because of the C-to-T transition mutations generated as a result of the deaminase activity on the minus strand DNA. In addition, human APOBEC3 proteins also exhibit a deamination-independent pathway to restrict retroviruses that is not currently well understood. Although the restriction of retroviruses by human APOBEC3 proteins has been intensely studied in vitro, our understanding of how the murine APOBEC3 (mA3) protein restricts retroviruses and/or prevents zoonotic infections in vivo is very limited. In contrast to humans and primates that have 7 APOBEC3 genes, mice have but a single copy. My study of the function and structure of mA3 revealed that it has an inverted functional organization for cytidine deamination in comparison to the human A3G catalytic sites.
    [Show full text]
  • Endogenous Retroviruses and the Immune System
    Endogenous Retroviruses and the Immune System George Robert Young Submitted to University College London in part fulfilment of the requirements for the degree of Doctor of Philosophy 2012 Division of Infection and Immunity Division of Immunoregulation University College London National Institute for Medical Research Gower Street The Ridgeway London London WC1E 6BT NW7 1AA 2 I, George Robert Young, 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. 3 Abstract ABSTRACT 4 Initial sequencing of the human and mouse genomes revealed that substantial fractions were composed of retroelements (REs) and endogenous retroviruses (ERVs), the latter being relics of ancestral retroviral infection. Further study revealed ERVs constitute up to 10% of many mammalian genomes. Despite this abundance, comparatively little is known about their interactions, beneficial or detrimental, with the host. This thesis details two distinct sets of interactions with the immune system. Firstly, the presentation of ERV-derived peptides to developing lymphocytes was shown to exert a control on the immune response to infection with Friend Virus (FV). A self peptide encoded by an ERV negatively selected a significant fraction of polyclonal FV- specific CD4+ T cells and resulted in an impaired immune response. However, CD4+ T cell-mediated antiviral activity was fully preserved and repertoire analysis revealed a deletional bias according to peptide affinity, resulting in an effective enrichment of high-affinity CD4+ T cells. Thus, ERVs exerted a significant influence on the immune response, a mechanism that may partially contribute to the heterogeneity seen in human immune responses to retroviral infections.
    [Show full text]
  • Contents Part 1 DNA TUMOR VIRUSES
    Contents Part 1 DNA TUMOR VIRUSES Symposium Participants V Foreword xvii Viral Oncogenes H. M. Temin Synopses Transforming Genes of DNA Tumor Viruses L. V. Crawford 9 Transforming Genes of Retroviruses P.H. Duesberg 13 DNA Tumor Viruses: Early RNAs and Early Proteins Transcription of the SV40 Genome in Virus-transformed Cells and Early Lytic Infection P. K. Ghosh, M. Piatak, V. B. Reddy, J. Swinscoe, P. Lebowitz, and S. M. Weissman 31 Regulation of SV40 Gene Expression through RNA Splicing G. Khoury, J. C. Alwine, R. Dhar, P. Gruss, C-J. Lai, S. Segal, and I. Seif 41 A Third Splice Site in SV40 Early mRNA D.F. Mark and P. Berg 55 Comparison of Polyoma Virus Transcription in Productively Infected Mouse Cells and Transformed Rodent Cell Lines R. Kamen, J. Favalom, J. Parker, R. Treisman, L. Lania, M. Fried, and A. Mellor 63 Transcription of SV40 DNA in Transformed Rat Cells M. Grigoryan, P. Chumakov, and E. Lukanidin 77 Expression of Transforming Viral Genes in Semipermissive Cells Transformed by SV40 or Adenovirus Type 2 or Type 5 S. J. Flint and G. A. Beltz 89 Catalytic Properties of the SV40 Large T Antigen R. Tfian, A. Robbins, and R. Clark 103 Enzymatic Activities Associated with the SV40 Large T Antigen J.D. Griffin, G. Spangler, and D. M. Livingston 113 DNA Binding and Sedimentation Properties of SV40 T Antigens Synthesized In Vivo and In Vitro C. Prives, Y. Beck, D. Gidoni, M. Oren, and it. Shure 123 Organization of T Antigens in the Polyoma Virus Genome T. Hunter, M.
    [Show full text]
  • Presence and Expression of Friend Erythroleukemia Virus-Related Sequences in Normal and Leukemic Mouse Tissues
    Proc. Natl. Acad. Sci. USA Vol. 76, No. 9, pp. 4455-4459, September 1979 Cell Biology Presence and expression of Friend erythroleukemia virus-related sequences in normal and leukemic mouse tissues (RNA tumor viruses/Friend spleen focus-forming virus/mechanism of transformation/differentiation/gene expression) ALAN BERNSTEIN, CATHERINE GAMBLE, DONNA PENROSE, AND TAK W. MAK The Ontario Cancer Institute, and Department of Medical Biophysics, University of Toronto, 500 Sherbourne Street, Toronto, Ontario, Canada M4X 1K9 Communicated by J. Tuzo Wilson, May 22, 1979 ABSTRACT The nature and distribution of sequences re- Although the origin and nature of sarcoma virus-specific lated to the murine erythroleukemia virus, Friend spleen sequences have been well characterized, no comparable studies focus-forming virus (SFFV), have been analyzed by using a ra- have been reported on the rapidly transforming mammalian dioactive cDNA probe specific for the SFFV genome (cDNAsff). From the proportion of high molecular weight viral [32PJRNA leukemia viruses. These viruses, which include the murine which hybridized to cDNAsff, it was estimated that these se- Abelson (9) and Friend (10-12) leukemia viruses, are replica- quences represent about 50% of the SFFV genome, indicating tion-defective and hence require helper virus to produce in- a genetic complexity of about 3300 nucleotides. cDNAff hy- fectious progeny. Immunological and molecular hybridization bridized extensively (80-95%) to SFFV virion RNA and to cel- analyses of cell clones nonproductively infected with the de- lular RNA from murine and rat cells productively or nonpro- fective Friend focus- ductively infected with SFFV. Only background homology was erythroleukemia-inducing virus, spleen detected between cDNAff and viral RNA from a number of forming virus (SFFV), have indicated that the SFFV genome murine [Friend murine leukemia virus (MuLV), Moloney-MuLV, contains some, but not all, of the sequences found on its helper and Kirsten sarcoma virus] and nonmurine (Rous sarcoma virus, lymphoid leukemia virus (13, 14).
    [Show full text]
  • Envelope Gene of the Friend Spleen Focus-Forming Virus
    Proc. NatL Acad. Sci. USA Vol. 80, pp. 4718-4722, August 1983 Biochemistry Envelope gene of the Friend spleen focus-forming virus: Deletion and insertions in 3' gp70/pl5E-encoding region have resulted in unique features in the primary structure of its protein product (retrovirus/nueleotide sequence/acute erythroleukemia/polycythemia/membrane glycoprotein) LINDA WOLFF*, EDWARD SCOLNICKt, AND SANDRA RUSCETTI* *Laboratory of Genetics, National Cancer Institute, Bethesda, Maryland 20205; and tMerck Sharp & Dohme Research Laboratories, West Point, Pennsylvania 19486 Communicated by Peter K. Vogt, May 19, 1983 ABSTRACT A nucleotide sequence was determined for the with endogenous sequences like those of xenotropic and MCF envelope (env) gene of the polycythemia-inducing strain of the acute viruses (11, 12). Our more recent experiments using mono- leukemia-inducing Friend spleen focus-forming virus (SFFV) and clonal antibody and peptide mapping indicate that the domain from this the amino acid sequence of its gene product, gp52, was of gp52 encoded by the endogenously acquired genetic region deduced. All major elements of the gene were found to be related begins at the amino terminus of the protein (13). to genes of other retroviruses that code for functional glycopro- We have determined the nucleotide sequence of the env gene teins. Although the carboxyl terminus of gp52 is encoded by se- of the molecularly cloned (14) polycythemia-inducing form of quences highly related to sequences in its putative parent, eco- SFFV (designated SFFVp) in order to obtain a better under- tropic Friend murine leukemia virus, the majority of the protein the genetic basis for some of the unusual properties (69%), including the amino terminus, is encoded by dualtropic vi- standing of rus-like sequences.
    [Show full text]
  • The Coming of Age of Tumor Virology: Presidential Address1
    [CANCER RESEARCH 37, 1255-1263, May 19771 The Coming of Age of Tumor Virology: Presidential Address1 Charlotte Friend The Center for Experimental Cell Biology, The Mollie B. Roth Laboratory, Mount Sinai School of Medicine, New York, New York mary carcinoma that bears his name. Nevertheless, investi gations along these lines were not completely abandoned. In 1908, the Danish scientists Ellerman and Bang (32) re ported that leukemia in chickens was caused by a filterable agent, but their findings received little attention since leu kemia was not then considered to be a neoplastic disease. Three years later, Rous described a malignant chicken sar coma caused by a virus (96). This paper, which was to become a classic, met with such “downrightdisbelief―(97) that 55 years were to pass before the author, then well over 90, was to be awarded the Nobel Prize for his work. After spending several discouraging years in a fruitless search for similar viruses in transplantable mouse tumors, Rous gave up his study of cancer for almost 20 years. He returned to this first love in 1934, when Richard Shope (105), who had discovered a virus that induced papillomas in rabbits, of fered it to him. He could not resist the study of a virus that caused neoplastic changes in the epithelial cells of a mam malian host. From then to the end of his long and produc tive life, he continued to explore the mechanisms involved in carcinogenesis, but he never again worked on the chicken sarcoma virus that he discovered (RSV).2 Although the climate did not improve much even after Bittner (13) found the virus that causes mammary tumors in mice, a small number of men and women persisted in inves tigating the role that viruses might play in causing a cancer cell to march to a different bugle.
    [Show full text]
  • Co-Infection with the Friend Retrovirus and Mouse Scrapie Does Not Alter Prion Disease Pathogenesis in Susceptible Mice
    Co-Infection with the Friend Retrovirus and Mouse Scrapie Does Not Alter Prion Disease Pathogenesis in Susceptible Mice Pascal Leblanc1,2,3,4, Kim Hasenkrug5, Anne Ward5, Lara Myers5, Ronald J. Messer5, Sandrine Alais1,2,4, Andrew Timmes5, Sue Priola5* 1 Universite´ de Lyon, Lyon, France, 2 Laboratoire de Virologie Humaine, INSERM U758, Lyon, France, 3 Laboratoire de Biologie Mole´culaire de la Cellule, UMR5239, Lyon, France, 4 Ecole Normale Supe´rieure de Lyon, Lyon, France, 5 Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America Abstract Prion diseases are fatal, transmissible neurodegenerative diseases of the central nervous system. An abnormally protease- resistant and insoluble form (PrPSc) of the normally soluble protease-sensitive host prion protein (PrPC) is the major component of the infectious prion. During the course of prion disease, PrPSc accumulates primarily in the lymphoreticular and central nervous systems. Recent studies have shown that co-infection of prion-infected fibroblast cells with the Moloney murine leukemia virus (Mo-MuLV) strongly enhanced the release and spread of scrapie infectivity in cell culture, suggesting that retroviral coinfection might significantly influence prion spread and disease incubation times in vivo. We now show that another retrovirus, the murine leukemia virus Friend (F-MuLV), also enhanced the release and spread of scrapie infectivity in cell culture. However, peripheral co-infection of mice with both Friend virus and the mouse scrapie strain 22L did not alter scrapie disease incubation times, the levels of PrPSc in the brain or spleen, or the distribution of pathological lesions in the brain.
    [Show full text]
  • Long-Term Infection and Vertical Transmission of a Gammaretrovirus in a Foreign Host Species
    Long-Term Infection and Vertical Transmission of a Gammaretrovirus in a Foreign Host Species Toshie Sakuma, Jason M. Tonne, Jessica A. Malcolm, Tayaramma Thatava, Seiga Ohmine, Kah-Whye Peng, Yasuhiro Ikeda* Department of Molecular Medicine, Mayo Clinic, Rochester, Minnesota, United States of America Abstract Increasing evidence has indicated natural transspecies transmission of gammaretroviruses; however, viral-host interactions after initial xeno-exposure remain poorly understood. Potential association of xenotropic murine leukemia virus-related virus (XMRV) in patients with prostate cancer and chronic fatigue syndrome has attracted broad interests in this topic. Although recent studies have indicated that XMRV is unlikely a human pathogen, further understanding of XMRV xenoinfection would allow in vivo modeling of the initial steps of gammaretroviral interspecies transmission, evolution and dissemination in a new host population. In this study, we monitored the long-term consequences of XMRV infection and its possible vertical transmission in a permissive foreign host, wild-derived Mus pahari mice. One year post-infection, XMRV- infected mice showed no notable pathological changes, while proviral DNA was detected in three out of eight mice. XMRV- infected mice remained seropositive throughout the study although the levels of gp70 Env- and p30 capsid-specific antibodies gradually decreased. When vertical XMRV transmission was assessed, no viremia, humoral immune responses nor endogenization were observed in nine offspring from infected mothers, yet one offspring was found PCR-positive for XMRV- specific sequences. Amplified viral sequences from the offspring showed several mutations, including one amino acid deletion in the receptor binding domain of Env SU. Our results therefore demonstrate long-term asymptomatic infection, low incidence of vertical transmission and limited evolution of XMRV upon transspecies infection of a permissive new host, Mus pahari.
    [Show full text]
  • Mapping of a Neurovirulence Determinant Within the Envelope
    VIROLOGY 248, 199±207 (1998) ARTICLE NO. VY989258 Mapping of a Neurovirulence Determinant within the Envelope Protein of a Polytropic Murine Retrovirus: Induction of Central Nervous System Disease by Low Levels of Virus David J. Poulsen, Shelly J. Robertson, Cynthia A. Favara, John L. Portis, and Bruce W. Chesebro1 Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South 4th Street, Hamilton, Montana 59840 Received April 20, 1998; accepted May 27, 1998 Murine leukemia virus (MuLV) clone Fr98 is a recombinant polytropic virus that causes neurological disease characterized by ataxia in susceptible mouse strains. The envelope gene of Fr98 has been previously shown to encode at least two separate neurovirulence determinants. In the present study, the determinant encoded within the EcoRI/AvrII fragment of the envelope gene was further defined. In these experiments, neurovirulence was associated with a change from a serine to an arginine at position 195 and a glycine to an alanine at position 198 within the envelope protein. Neurovirulent and nonvirulent virus clones, which differed only at these two amino acid residues, showed no difference in the type or location of cells infected. Furthermore, equivalent levels of viral p30 capsid protein were detected in the brains of mice infected with either the neurovirulent or nonvirulent virus clones. These results were consistent with the interpretation that the envelope protein of the neurovirulent virus differed from that of the nonvirulent virus by having a greater toxic effect on central nervous system function. INTRODUCTION fected brain capillary endothelial cells (Park et al., 1993, 1994).
    [Show full text]
  • Neurologic Disease Induced by Polytropic Murine Retroviruses: Neurovirulence Determined by Efficiency of Spread to Microglial Cells
    JOURNAL OF VIROLOGY, July 1997, p. 5287–5294 Vol. 71, No. 7 0022-538X/97/$04.0010 Copyright © 1997, American Society for Microbiology Neurologic Disease Induced by Polytropic Murine Retroviruses: Neurovirulence Determined by Efficiency of Spread to Microglial Cells SHELLY J. ROBERTSON, KIM J. HASENKRUG, BRUCE CHESEBRO, AND JOHN L. PORTIS* Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840 Received 10 May 1996/Accepted 26 March 1997 Several murine leukemia viruses (MuLV) induce neurologic disease in susceptible mice. To identify features of central nervous system (CNS) infection that correlate with neurovirulence, we compared two neurovirulent MuLV, Fr98 and Fr98/SE, with a nonneurovirulent MuLV, Fr54. All three viruses utilize the polytropic receptor and are coisogenic, each containing a different envelope gene within a common genetic background. Both Fr98 and Fr98/SE induce a clinical neurologic disease characterized by hyperexcitability and ataxia yet differ in incubation period, 16 to 30 and 30 to 60 days, respectively. Fr54 infects the CNS but fails to induce clinical signs of neurologic disease. In this study, we compared the histopathology, regional virus distribution, and cell tropism in the brain, as well as the relative CNS viral burdens. All three viruses induced similar histopathologic effects, characterized by intense reactive astrogliosis and microglial activation associated with minimal vacuolar degeneration. The infected target cells for each virus consisted primarily of endothelial and microglial cells, with rare oligodendrocytes. Infection localized predominantly in white matter tracts of the cerebellum, internal capsule, and corpus callosum. The only feature that correlated with relative neuroviru- lence was viral burden as measured by both viral CA protein expression in cerebellar homogenates and quantification of infected cells.
    [Show full text]
  • Identification and Characterization of Two Novel Syncytin-Like Retroviral
    Identification and Characterization of Two Novel Syncytin-Like Retroviral Envelope Genes, Captured for a Possible role in the Atypical Structure of the Hyena Placenta and in the Emergence of the Non-Mammalian Mabuya Lizard Placenta a Mathis Funk To cite this version: Mathis Funk. Identification and Characterization of Two Novel Syncytin-Like Retroviral Envelope Genes, Captured for a Possible role in the Atypical Structure of the Hyena Placenta and in the Emergence of the Non-Mammalian Mabuya Lizard Placenta a. Virology. Université Paris Saclay (COmUE), 2018. English. NNT : 2018SACLS106. tel-02377630 HAL Id: tel-02377630 https://tel.archives-ouvertes.fr/tel-02377630 Submitted on 24 Nov 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Identification and characterization of 106 S two novel syncytin-like retroviral SACL envelope genes, captured for a 8 possible role in the atypical structure : 201 of the hyena placenta and in the NNT emergence of the non-mammalian Mabuya lizard placenta Thèse de doctorat de l'Université Paris-Saclay préparée à l'UMR
    [Show full text]
  • NK Cells Improve Control of Friend Virus Infection in Mice Persistently
    Francois et al. Retrovirology 2013, 10:58 http://www.retrovirology.com/content/10/1/58 RESEARCH Open Access NK cells improve control of friend virus infection in mice persistently infected with murine cytomegalovirus Sandra Francois1, Jing Peng1, Tatjana Schwarz1, Janine Duppach1, Kathrin Gibbert1, Ulf Dittmer1 and Anke RM Kraft1,2* Abstract Background: Co-infection of HIV patients with cytomegalovirus (CMV) is associated with enhanced AIDS progression and CMV end-organ diseases. On the other hand, persistent CMV infection has recently been shown to decrease tumor relapse and protect against lethal bacterial infection. The influence of persistent CMV on the outcome of an acute retroviral superinfection is still unknown. Results: Here we show that a persistent murine CMV (mCMV) infection surprisingly confers higher resistance to a primary Friend retrovirus infection (FV) of mice. Decreased FV titers and augmented FV-specific CD8 T-cell responses were found in mCMV infected mice during primary FV superinfection. NK cells produced higher amounts of IFNgamma after FV infection of persistently mCMV infected mice suggesting that these cells were involved in the ‘protective’ effect. Depletion of NK1.1+ cells or neutralization of IFNgamma during FV superinfection abrogated the mCMV-mediated effect. Conclusion: Our data demonstrate for the first time that a persistent CMV infection induces long-lasting NK cell responses that can enhance immunity to primary retroviral infections. To our knowledge, studies investigating primary HIV infection have not analyzed the role of the CMV seropositivity in these patients. Our observations suggest that NK cells in CMV seropositive individuals might contribute to the control of primary HIV infection.
    [Show full text]