DOCSLIB.ORG

Molecular Classification of a Vector and Roles of Bacterial Surface Proteins in Pathogenesis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Molecular Classification of a Vector and Roles of Bacterial Surface Proteins in Pathogenesis Neorickettsia spp.: Molecular Classification of a Vector and Roles of Bacterial Surface Proteins in Pathogenesis Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Kathryn Elizabeth Gibson, D.V.M. Graduate Program in Veterinary Biosciences The Ohio State University 2011 Dissertation Committee Yasuko Rikihisa, Advisor Prosper Boyaka Steven Krakowka Michael Oglesbee 1 Copyright by Kathryn Gibson 2011 2 Abstract Neorickettsia spp. are Gram-negative, obligate intracellular bacteria of the family Anaplasmataceae. Given their prevalence throughout the world, their propensity to cause human disease and deadly animal diseases, and the continuing discovery of new Neorickettsia spp., they are significant pathogens requiring better comprehension. The overall objective of this dissertation is to determine the host-bacterium relationships of Neorickettsia. Chapter 1 details background on Neorickettsia spp., with emphasis on Neorickettsia risticii and Neorickettsia sennetsu. The objective of Chapter 2 was to demonstrate the lineage of all N. risticii-infected trematode life stages. The study established the molecular identification of the N. risticii adult trematode host and its immature life stages, demonstrating as hypothesized that all life stages harboring N. risticii belong to the same clade. The objective of Chapter 3 was to determine the major surface proteins of N. sennetsu involved in host-pathogen interaction and to determine the roles of the major surface proteins. Four proteins: the 51-kDa antigen (P51), Neorickettsia surface proteins 2 (Nsp2) and 3 (Nsp3), and heat-shock protein 60 (GroEL), were found to have the highest surface expression. It was hypothesized that the two major β-barrel proteins, P51 and Nsp3 function as porins. The outer membrane fraction of N. sennetsu, as well as native P51 and Nsp3 were incorporated into proteoliposomes and tested by porin-swelling assays, and it was confirmed that P51 is a large porin. The ii objective of Chapter 4 was to determine levels of variation within predicted surface- exposed proteins of N. risticii, with the hypothesis being that geographic and temporal variation would occur among strains of N. risticii. Variation in P51 demonstrated geographic separation of N. risticii strains. Nsp2, Nsp3, and strain-specific antigen 3 (Ssa3) demonstrated temporal variation. Variety within the β-barrel proteins P51, Nsp2, and Nsp3 occurred mainly within regions predicted as external loops. Ssa3 variation mainly occurred in an N-terminal localized repeat region and consisted of changes in the number of 52-aa repeats. The objective of Chapter 5 was to determine causes of cytokine and chemokine induction in N. sennetsu infection, thus potential reasons for disease symptoms. The studies in this chapter first validated the mouse model of Sennetsu neorickettsiosis in immunocompetent BALB/c mice and then demonstrated cytokine and chemokine production by quantitative reverse-transcriptase polymerase chain reaction within spleens of infected mice during disease. Cytokine and chemokine production in the whole mouse was replicated in vitro within splenocyte and bone marrow-derived macrophage (BMDM) cultures, with significant induction of IL-1β, CXCL2, and IL-12A (p35) mRNAs occurring within whole bacteria and the Sarkosyl-purified bacterial outer membrane fraction of N. sennetsu. It was hypothesized that P51 is a major cause of cytokine induction, is recognized by Toll-like receptor 2, and that cytokine/chemokine induction is MyD88 dependent. Preliminary studies showed that cytokine/chemokine levels were reduced in MyD88-knockout mouse BMDMs and TLR2-knockout mouse splenocytes incubated with whole bacteria and in TLR2-knockout mouse BMDMs incubated with whole bacteria and bacterial outer membrane fraction. In conclusion, iii these studies demonstrated important host-pathogen relationships during Neorickettsial infection and disease useful for further understanding of these bacteria. iv Dedication Dedicated to my family, both human and animal v Acknowledgement I would foremost like to thank my advisor, Dr. Yasuko Rikihisa for her guidance, assistance, wisdom, patience, and resources. I would like to thank the members of my dissertation committee, Dr. Proper Boyaka, Dr. Steven Krakowka, and Dr. Michael Oglesbee for their valuable input and advice. I would like to thank all the members past and present of the Rikihisa laboratory, including Dr. Jason Mott, Dr. Mingqun Lin, Dr. Yumi Kumagai, Dr. Junji Matsuo, Dr. Rahman Akhlakur, Dr. Hua Niu, Dr. Tzung-Huei Lai, and Dr. Yan Ge, for their technical advice and assistance. I would like to thank future veterinarians Susanne Moesta and Gabrielle Pastenkos for their hard work and dedication during their summer research programs in the Rikihisa Laboratory. I would like to thank the members of the Mass Spectrometry and Proteomics Facility, including Dr. Karen Green-Church for their assistance. I appreciate Dr. Hiroshi Nikaido at the University of California, Berkeley for his valuable advice. I also would like to acknowledge The Ohio State University College of Veterinary Medicine and Department of Veterinary Biosciences. These works were funded by grant R01AI30010 and T32 RR0070703 from the National Institutes of Health. vi Vita June 1996 ……………………………… Granville High School May 2000 ……………………………… B.A. Biology and Music, Minor in Chemistry, Salem College 2001-2003 ……………………………… Graduate research associate, Department of Veterinary Biosciences, The Ohio State University August 2003 ……………………………… M.S. Veterinary Biosciences, The Ohio State University 2003-2007 ……………………………… D.V.M., The Ohio State University 2007-2008 ……………………………… Graduate research associate, Department of Veterinary Biosciences, The Ohio State University 2008-2010 ……………………………… Post-doctoral fellow, Department of Veterinary Biosciences, The Ohio State University 2010-Present ……………………………… Graduate research associate, Department of Veterinary Biosciences, The Ohio State University vii Publications Gibson, K., Y. Rikihisa, C. Zhang, and C. Martin (2005). “Neorickettsia risticii is vertically transmitted in the trematode Acanthatrium oregonense and horizontally transmitted to bats.” Environ Microbiol 7: 203-212. Gibson, K. and Y. Rikihisa (2008). “Molecular link of different stages of the trematode host of Neorickettsia risticii to Acanthatrium oregonense.” Environ Microbiol 10: 2064- 2073. Lin, M., C. Zhang, K. Gibson, and Y. Rikihisa (2009). “Analysis of complete genome sequence of Neorickettsia risticii: Causative agent of Potomac horse fever.” Nucleic Acids Res 37(18): 6076-6091. Gibson, K., Y. Kumagai, and Y. Rikihisa (2010). “Proteomic analysis of Neorickettsia sennetsu surface-exposed proteins and porin activity of the major surface protein P51.” J Bacteriol 192(22): 5898-5905. Fields of Study Major Field: Veterinary Biosciences viii Table of Contents Title Page ..……………………………………………………………………….………. i Abstract ……………………………….………………………………………….……… ii Dedication ………………………….……………………………………………………. v Acknowledgement .………………..………….………………………………………… vi Vita …………………………………………..………………………………………… vii List of Tables …………………………………………………………………….….…... x List of Figures ……………………………………………………………………….…. xii List of Symbols and Abbreviations …………………………………………………….. xv Chapter 1: Introduction ………………………………………………………………….. 1 Chapter 2: Molecular Identification of the Trematode Host of Neorickettsia risticii by 18S rRNA ……………………………………………………………………………… 14 Chapter 3: Identification of Neorickettsia sennetsu Surface-Exposed Proteins and Characterization of P51 as a Porin ……………………………………….…………….. 41 Chapter 4: Identification of Geographical and Temporal Variation within N. risticii Surface-Exposed Proteins and Their Antigenicity within Naturally-Infected Horses …. 80 Chapter 5: Cytokine Induction by N. sennetsu Outer Membrane Proteins ……….…... 110 References …………………………………………………………………………….. 157 Appendix A …………………………………………………………………………… 179 ix List of Tables Table 1. Trematode 18S rRNA sequence sample information ………………………… 24 Table 2. 18S rRNA Region 3 (767 bp) percent sequence identity for all trematode samples …………………………………………………………………………………. 25 Table 3. 18S rRNA Region 1 percent sequence identity for N. risticii-positive trematodes ……………………………………………………………………………… 26 Table 4. 18S rRNA Region 2 percent sequence identity for N. risticii-positive trematodes ……………………………………………………………………………… 26 Table 5. 18S rRNA Region 4 percent sequence identity for N. risticii-positive trematodes ……………………………………………………………………………… 26 Table 6. NCBI BLAST search results for trematode 18S rRNA sequences …………… 33 Table 7. Streptavidin affinity-purified and proteomics-identified proteins for N. sennetsu Miyayama ……………………………………………………………………………… 54 Table 8. Amino acid differences among predicted P51 transmembrane domains …….. 65 Table 9. Primers utilized for Neorickettsia PCR amplification ………………………... 83 Table 10. Sequences amplified for Neorickettsia ……………………………………… 85 Table 11. Proteomics-identified proteins for two N. risticii strains ……………………. 89 Table 12. PHF-positive sera from naturally-infected horses and negative sera ……….. 92 Table 13. Primer pairs for RT-PCR, qPCR, and qRT-PCR …………………………... 122 x Table 14. Expression analysis of N. sennetsu surface proteins in four and eight-week-old BALB/c mouse spleens ……………………………………………………………….. 132 Table 15. Means for qRT-PCR results for cytokine induction studies in spleens in the BALB/c mouse model of disease ……………………………………………………..
Load more

Recommended publications
  • Interactions De La Protéine Nsp1 Du Virus Chikungunya Avec Les Membranes De L’Hôte Et Conséquences Fonctionnelles William Bakhache
    Interactions de la protéine nsP1 du virus Chikungunya avec les membranes de l’hôte et conséquences fonctionnelles William Bakhache To cite this version: William Bakhache. Interactions de la protéine nsP1 du virus Chikungunya avec les membranes de l’hôte et conséquences fonctionnelles. Médecine humaine et pathologie. Université Montpellier, 2020. Français. NNT : 2020MONTT008. tel-03132645 HAL Id: tel-03132645 https://tel.archives-ouvertes.fr/tel-03132645 Submitted on 5 Feb 2021 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. THÈSE POUR OBTENIR LE GRADE DE DOCTEUR DE L’UNIVERSITÉ DE M ONTPELLIER En Biologie Santé École Doctorale Sciences Chimiques et Biologiques pour la Santé UMR 9004 - Institut de Recherche en Infectiologie de Montpellier Interactions de la protéine nsP1 du virus Chikungunya avec les membranes de l’hôte et conséquences fonctionnelles Présentée par William Bakhache Le 27 Mars 2020 Sous la direction de Laurence Briant Devant le jury composé de Jean-Luc Battini, Directeur de Recherche, IRIM, Montpellier Président de jury Ali Amara, Directeur de recherche, U944 INSERM, Paris Rapporteur Juan Reguera, Chargé de recherche, AFMB, Marseille Rapporteur Raphaël Gaudin, Chargé de recherche, IRIM, Montpellier Examinateur Yves Rouillé, Directeur de Recherche, CIIL, Lille Examinateur Bruno Coutard, Professeur des universités, UVE, Marseille Co-encadrant de thèse Laurence Briant, Directeur de recherche, IRIM, Montpellier Directeur de thèse 1 Acknowledgments I want to start by thanking the members of my thesis jury.
    [Show full text]
  • Abstract Betaproteobacteria Alphaproteobacteria
    Abstract N-210 Contact Information The majority of the soil’s biosphere containins biodiveristy that remains yet to be discovered. The occurrence of novel bacterial phyla in soil, as well as the phylogenetic diversity within bacterial phyla with few cultured representatives (e.g. Acidobacteria, Anne Spain Dr. Mostafa S.Elshahed Verrucomicrobia, and Gemmatimonadetes) have been previously well documented. However, few studies have focused on the Composition, Diversity, and Novelty within Soil Proteobacteria Department of Botany and Microbiology Department of Microbiology and Molecular Genetics novel phylogenetic diversity within phyla containing numerous cultured representatives. Here, we present a detailed University of Oklahoma Oklahoma State University phylogenetic analysis of the Proteobacteria-affiliated clones identified in a 13,001 nearly full-length 16S rRNA gene clones 770 Van Vleet Oval 307 LSE derived from Oklahoma tall grass prairie soil. Proteobacteria was the most abundant phylum in the community, and comprised Norman, OK 73019 Stillwater, OK 74078 25% of total clones. The most abundant and diverse class within the Proteobacteria was Alphaproteobacteria, which comprised 405 325 5255 405 744 6790 39% of Proteobacteria clones, followed by the Deltaproteobacteria, Betaproteobacteria, and Gammaproteobacteria, which made Anne M. Spain (1), Lee R. Krumholz (1), Mostafa S. Elshahed (2) up 37, 16, and 8% of Proteobacteria clones, respectively. Members of the Epsilonproteobacteria were not detected in the dataset. [email protected] [email protected] Detailed phylogenetic analysis indicated that 14% of the Proteobacteria clones belonged to 15 novel orders and 50% belonged (1) Dept. of Botany and Microbiology, University of Oklahoma, Norman, OK to orders with no described cultivated representatives or were unclassified.
    [Show full text]
  • 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.
    [Show full text]
  • Emerging Roles for Lipid Droplets in Immunity and Host-Pathogen Interactions
    CB28CH16-Valdivia ARI 5 September 2012 17:10 Emerging Roles for Lipid Droplets in Immunity and Host-Pathogen Interactions Hector Alex Saka and Raphael Valdivia Department of Molecular Genetics and Microbiology and Center for Microbial Pathogenesis, Duke University Medical Center, Durham, North Carolina 27710; email: [email protected] Annu. Rev. Cell Dev. Biol. 2012. 28:411–37 Keywords First published online as a Review in Advance on eicosanoids, interferon, autophagy May 11, 2012 The Annual Review of Cell and Developmental Abstract Biology is online at cellbio.annualreviews.org Lipid droplets (LDs) are neutral lipid storage organelles ubiquitous to Access provided by Duke University on 10/14/19. For personal use only. This article’s doi: eukaryotic cells. It is increasingly recognized that LDs interact exten- 10.1146/annurev-cellbio-092910-153958 sively with other organelles and that they perform functions beyond Annu. Rev. Cell Dev. Biol. 2012.28:411-437. Downloaded from www.annualreviews.org Copyright c 2012 by Annual Reviews. passive lipid storage and lipid homeostasis. One emerging function for All rights reserved LDs is the coordination of immune responses, as these organelles par- 1081-0706/12/1110-0411$20.00 ticipate in the generation of prostaglandins and leukotrienes, which are important inflammation mediators. Similarly, LDs are also beginning to be recognized as playing a role in interferon responses and in antigen cross presentation. Not surprisingly, there is emerging evidence that many pathogens, including hepatitis C and Dengue viruses, Chlamydia, and Mycobacterium, target LDs during infection either for nutritional purposes or as part of an anti-immunity strategy.
    [Show full text]
  • Evolutionary Origin of Insect–Wolbachia Nutritional Mutualism
    Evolutionary origin of insect–Wolbachia nutritional mutualism Naruo Nikoha,1, Takahiro Hosokawab,1, Minoru Moriyamab,1, Kenshiro Oshimac, Masahira Hattoric, and Takema Fukatsub,2 aDepartment of Liberal Arts, The Open University of Japan, Chiba 261-8586, Japan; bBioproduction Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8566, Japan; and cCenter for Omics and Bioinformatics, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa 277-8561, Japan Edited by Nancy A. Moran, University of Texas at Austin, Austin, TX, and approved June 3, 2014 (received for review May 20, 2014) Obligate insect–bacterium nutritional mutualism is among the insects, generally conferring negative fitness consequences to most sophisticated forms of symbiosis, wherein the host and the their hosts and often causing hosts’ reproductive aberrations to symbiont are integrated into a coherent biological entity and un- enhance their own transmission in a selfish manner (7, 8). Re- able to survive without the partnership. Originally, however, such cently, however, a Wolbachia strain associated with the bedbug obligate symbiotic bacteria must have been derived from free-living Cimex lectularius,designatedaswCle, was shown to be es- bacteria. How highly specialized obligate mutualisms have arisen sential for normal growth and reproduction of the blood- from less specialized associations is of interest. Here we address this sucking insect host via provisioning of B vitamins (9). Hence, it –Wolbachia evolutionary
    [Show full text]
  • Ehrlichiosis and Anaplasmosis Are Tick-Borne Diseases Caused by Obligate Anaplasmosis: Intracellular Bacteria in the Genera Ehrlichia and Anaplasma
    Ehrlichiosis and Importance Ehrlichiosis and anaplasmosis are tick-borne diseases caused by obligate Anaplasmosis: intracellular bacteria in the genera Ehrlichia and Anaplasma. These organisms are widespread in nature; the reservoir hosts include numerous wild animals, as well as Zoonotic Species some domesticated species. For many years, Ehrlichia and Anaplasma species have been known to cause illness in pets and livestock. The consequences of exposure vary Canine Monocytic Ehrlichiosis, from asymptomatic infections to severe, potentially fatal illness. Some organisms Canine Hemorrhagic Fever, have also been recognized as human pathogens since the 1980s and 1990s. Tropical Canine Pancytopenia, Etiology Tracker Dog Disease, Ehrlichiosis and anaplasmosis are caused by members of the genera Ehrlichia Canine Tick Typhus, and Anaplasma, respectively. Both genera contain small, pleomorphic, Gram negative, Nairobi Bleeding Disorder, obligate intracellular organisms, and belong to the family Anaplasmataceae, order Canine Granulocytic Ehrlichiosis, Rickettsiales. They are classified as α-proteobacteria. A number of Ehrlichia and Canine Granulocytic Anaplasmosis, Anaplasma species affect animals. A limited number of these organisms have also Equine Granulocytic Ehrlichiosis, been identified in people. Equine Granulocytic Anaplasmosis, Recent changes in taxonomy can make the nomenclature of the Anaplasmataceae Tick-borne Fever, and their diseases somewhat confusing. At one time, ehrlichiosis was a group of Pasture Fever, diseases caused by organisms that mostly replicated in membrane-bound cytoplasmic Human Monocytic Ehrlichiosis, vacuoles of leukocytes, and belonged to the genus Ehrlichia, tribe Ehrlichieae and Human Granulocytic Anaplasmosis, family Rickettsiaceae. The names of the diseases were often based on the host Human Granulocytic Ehrlichiosis, species, together with type of leukocyte most often infected.
    [Show full text]
  • A SARS-Cov-2-Human Protein-Protein Interaction Map Reveals Drug Targets and Potential Drug-Repurposing
    A SARS-CoV-2-Human Protein-Protein Interaction Map Reveals Drug Targets and Potential Drug-Repurposing Supplementary Information Supplementary Discussion All SARS-CoV-2 protein and gene functions described in the subnetwork appendices, including the text below and the text found in the individual bait subnetworks, are based on the functions of homologous genes from other coronavirus species. These are mainly from SARS-CoV and MERS-CoV, but when available and applicable other related viruses were used to provide insight into function. The SARS-CoV-2 proteins and genes listed here were designed and researched based on the gene alignments provided by Chan et. al. 1 2020 .​ Though we are reasonably sure the genes here are well annotated, we want to note that not every ​ protein has been verified to be expressed or functional during SARS-CoV-2 infections, either in vitro or in vivo. ​ ​ In an effort to be as comprehensive and transparent as possible, we are reporting the sub-networks of these functionally unverified proteins along with the other SARS-CoV-2 proteins. In such cases, we have made notes within the text below, and on the corresponding subnetwork figures, and would advise that more caution be taken when examining these proteins and their molecular interactions. Due to practical limits in our sample preparation and data collection process, we were unable to generate data for proteins corresponding to Nsp3, Orf7b, and Nsp16. Therefore these three genes have been left out of the following literature review of the SARS-CoV-2 proteins and the protein-protein interactions (PPIs) identified in this study.
    [Show full text]
  • Thiopurines Activate an Antiviral Unfolded Protein Response That
    bioRxiv preprint doi: https://doi.org/10.1101/2020.09.30.319863; this version posted October 1, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Thiopurines activate an antiviral unfolded protein response that blocks viral glycoprotein 2 accumulation in cell culture infection model 3 Patrick Slaine1, Mariel Kleer 2, Brett Duguay 1, Eric S. Pringle 1, Eileigh Kadijk 1, Shan Ying 1, 4 Aruna D. Balgi 3, Michel Roberge 3, Craig McCormick 1, #, Denys A. Khaperskyy 1, # 5 6 1Department of Microbiology & Immunology, Dalhousie University, 5850 College Street, Halifax 7 NS, Canada B3H 4R2 8 2Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, 3330 9 Hospital Drive NW, Calgary AB, Canada T2N 4N1 10 3Department of Biochemistry and Molecular Biology, 2350 Health Sciences Mall, University of 11 British Columbia, Vancouver BC, Canada V6T 1Z3 12 13 14 #Co-corresponding authors: C.M., [email protected], D.A.K., [email protected] 15 16 17 Running Title: Drug-induced antiviral unfolded protein response 18 Keywords: virus, influenza, coronavirus, SARS-CoV-2, thiopurine, 6-thioguanine, 6- 19 thioguanosine, unfolded protein response, hemagglutinin, neuraminidase, glycosylation, host- 20 targeted antiviral 21 22 23 ABSTRACT 24 Enveloped viruses, including influenza A viruses (IAVs) and coronaviruses (CoVs), utilize the 25 host cell secretory pathway to synthesize viral glycoproteins and direct them to sites of assembly. 26 Using an image-based high-content screen, we identified two thiopurines, 6-thioguanine (6-TG) 27 and 6-thioguanosine (6-TGo), that selectively disrupted the processing and accumulation of IAV 28 glycoproteins hemagglutinin (HA) and neuraminidase (NA).
    [Show full text]
  • Ultrastructure and Localization of Neorickettsia in Adult Digenean
    Washington University School of Medicine Digital Commons@Becker Open Access Publications 2017 Ultrastructure and localization of Neorickettsia in adult digenean trematodes provides novel insights into helminth-endobacteria interaction Kerstin Fischer Washington University School of Medicine in St. Louis Vasyl V. Tkach University of North Dakota Kurt C. Curtis Washington University School of Medicine in St. Louis Peter U. Fischer Washington University School of Medicine in St. Louis Follow this and additional works at: https://digitalcommons.wustl.edu/open_access_pubs Recommended Citation Fischer, Kerstin; Tkach, Vasyl V.; Curtis, Kurt C.; and Fischer, Peter U., ,"Ultrastructure and localization of Neorickettsia in adult digenean trematodes provides novel insights into helminth-endobacteria interaction." Parasites & Vectors.10,. 177. (2017). https://digitalcommons.wustl.edu/open_access_pubs/5789 This Open Access Publication is brought to you for free and open access by Digital Commons@Becker. It has been accepted for inclusion in Open Access Publications by an authorized administrator of Digital Commons@Becker. For more information, please contact [email protected]. Fischer et al. Parasites & Vectors (2017) 10:177 DOI 10.1186/s13071-017-2123-7 RESEARCH Open Access Ultrastructure and localization of Neorickettsia in adult digenean trematodes provides novel insights into helminth- endobacteria interaction Kerstin Fischer1, Vasyl V. Tkach2, Kurt C. Curtis1 and Peter U. Fischer1* Abstract Background: Neorickettsia are a group of intracellular α proteobacteria transmitted by digeneans (Platyhelminthes, Trematoda). These endobacteria can also infect vertebrate hosts of the helminths and cause serious diseases in animals and humans. Neorickettsia have been isolated from infected animals and maintained in cell cultures, and their morphology in mammalian cells has been described.
    [Show full text]
  • Membrane Integration of an Essential Β-Barrel Protein Prerequires Burial of an Extracellular Loop
    Membrane integration of an essential β-barrel protein prerequires burial of an extracellular loop Joseph S. Wzoreka, James Leea,b, David Tomaseka,b, Christine L. Hagana, and Daniel E. Kahnea,b,c,1 aDepartment of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138; bDepartment of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138; and cDepartment of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115 Edited by Robert T. Sauer, Massachusetts Institute of Technology, Cambridge, MA, and approved February 1, 2017 (received for review October 5, 2016) The Bam complex assembles β-barrel proteins into the outer mem- these studies have emphasized how the machine might alter the brane (OM) of Gram-negative bacteria. These proteins comprise membrane structure or how its components might sequentially cylindrical β-sheets with long extracellular loops and create pores bind and thereby guide substrates into the membrane. However, to allow passage of nutrients and waste products across the mem- much less has been done to understand how structure emerges brane. Despite their functional importance, several questions re- within a substrate during assembly by these machines. Here, we main about how these proteins are assembled into the OM after have taken the approach of characterizing the nascent structure their synthesis in the cytoplasm and secretion across the inner of a substrate as it interacts with the machine to identify the membrane. To understand this process better, we studied the as- features of the substrate required to permit its proper membrane sembly of an essential β-barrel substrate for the Bam complex, integration.
    [Show full text]
  • Kunjin Virus Replicon Vectors for Human Immunodeficiency Virus Vaccine Development† Tracey J
    JOURNAL OF VIROLOGY, July 2003, p. 7796–7803 Vol. 77, No. 14 0022-538X/03/$08.00ϩ0 DOI: 10.1128/JVI.77.14.7796–7803.2003 Copyright © 2003, American Society for Microbiology. All Rights Reserved. Kunjin Virus Replicon Vectors for Human Immunodeficiency Virus Vaccine Development† Tracey J. Harvey,1,2 Itaru Anraku,1,2,3 Richard Linedale,1,2 David Harrich,1 Jason Mackenzie,1,2 Andreas Suhrbier,3 and Alexander A. Khromykh1,2* Downloaded from Sir Albert Sakzewski Virus Research Centre, Royal Children’s Hospital,1 Clinical Medical Virology Centre,2 and The Australian Centre for International and Tropical Health and Nutrition, Queensland Institute of Medical Research,3 University of Queensland, Brisbane, Queensland, Australia Received 2 December 2002/Accepted 29 April 2003 We have previously demonstrated the ability of the vaccine vectors based on replicon RNA of the Australian flavivirus Kunjin (KUN) to induce protective antiviral and anticancer CD8؉ T-cell responses using murine polyepitope as a model immunogen (I. Anraku, T. J. Harvey, R. Linedale, J. Gardner, D. Harrich, A. Suhrbier, http://jvi.asm.org/ and A. A. Khromykh, J. Virol. 76:3791-3799, 2002). Here we showed that immunization of BALB/c mice with KUN replicons encoding HIV-1 Gag antigen resulted in induction of both Gag-specific antibody and protective Gag-specific CD8؉ T-cell responses. Two immunizations with KUNgag replicons in the form of virus-like particles (VLPs) induced anti-Gag antibodies with titers of >1:10,000. Immunization with KUNgag replicons delivered as plasmid DNA, naked RNA, or VLPs induced potent Gag-specific CD8؉ T-cell responses, with one -immunization of KUNgag VLPs inducing 4.5-fold-more CD8؉ T cells than the number induced after immu nization with recombinant vaccinia virus carrying the gag gene (rVVgag).
    [Show full text]
  • In Vitro Evolution of High-Titer, Virus-Like Vesicles Containing a Single Structural Protein
    In vitro evolution of high-titer, virus-like vesicles containing a single structural protein Nina F. Rosea, Linda Buonocorea, John B. Schella, Anasuya Chattopadhyaya, Kapil Bahla, Xinran Liub, and John K. Rosea,1 aDepartment of Pathology, Yale University School of Medicine, New Haven, CT 06510; and bCenter for Cellular and Molecular Imaging, Yale University School of Medicine, New Haven, CT 06510 Edited* by Robert A. Lamb, Northwestern University, Evanston, IL, and approved October 22, 2014 (received for review August 6, 2014) Self-propagating, infectious, virus-like vesicles (VLVs) are gener- RNA. These proteins form a complex that directs replication of ated when an alphavirus RNA replicon expresses the vesicular the genomic RNA to form antigenomic RNA, which is then stomatitis virus glycoprotein (VSV G) as the only structural protein. copied to form full-length positive strand RNA and a subgenomic The mechanism that generates these VLVs lacking a capsid protein mRNA that encodes the structural proteins. The capsid protein has remained a mystery for over 20 years. We present evidence encases the genomic RNA in the cytoplasm and then buds from that VLVs arise from membrane-enveloped RNA replication facto- the cell surface in a membrane containing the SFV glycoproteins. ries (spherules) containing VSV G protein that are largely trapped Alphavirus RNA replication occurs inside light-bulb shaped, on the cell surface. After extensive passaging, VLVs evolve to membrane-bound compartments called spherules that initially grow to high titers through acquisition of multiple point muta- form on the cell surface and are then endocytosed to form cyto- tions in their nonstructural replicase proteins.
    [Show full text]