Thesis (Ph. D.)--University of Missouri--Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 98-104). Also available on the Internet.

Ho Hei Ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 189-199). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Epidemiology of the Severe Acute Respiratory Syndrome (SARS) Outbreak --- p.2 / Chapter 1.2 --- The SARS Coronavirus --- p.3 / Chapter 1.2.1 --- Genome organization --- p.7 / Chapter 1.2.2 --- Structural proteins --- p.9 / Chapter 1.2.3 --- Non-structural proteins --- p.11 / Chapter 1.3 --- Introduction to SARS-CoV nsp10 Protein --- p.14 / Chapter 1.4 --- Introduction to SARS-CoV RNA-dependent RNA Polymerase (RdRp) Protein --- p.17 / Chapter 1.5 --- Objectives of the Present Study --- p.25 / Chapter Chapter 2 --- Materials and Methods / Chapter 2.1 --- Construction of Glutathione S-Transferase (GST) Fusion/Green Fluorescence Protein (GFP) N1 and C1 Fusion nsplO --- p.26 / Chapter 2.1.1 --- Primer design --- p.26 / Chapter 2.1.2 --- Gene amplification by PCR --- p.28 / Chapter 2.1.3 --- Purification of PCR product --- p.30 / Chapter 2.1.4 --- Enzyme restriction --- p.31 / Chapter 2.1.5 --- Ligation --- p.33 / Chapter 2.1.6 --- Transformation --- p.34 / Chapter 2.1.6.1 --- Preparation of competent cell DH5α --- p.34 / Chapter 2.1.7 --- Mini scale plasmid preparation --- p.36 / Chapter 2.2 --- Subcellular Localization Study --- p.39 / Chapter 2.2.1 --- Midi scale plasmid preparation --- p.39 / Chapter 2.2.2 --- Transfection of GFP recombinant plasmids --- p.41 / Chapter 2.2.2.1 --- Cell culture of Vero E6 cell line --- p.41 / Chapter 2.2.2.2 --- Lipofectamine based transfection --- p.41 / Chapter 2.2.3 --- Fluorescent microscopic visualization --- p.42 / Chapter 2.2.4 --- Western blotting for GFP fusion protein expression --- p.43 / Chapter 2.2.4.1 --- Protein extraction --- p.43 / Chapter 2.2.4.2 --- Protein quantification --- p.44 / Chapter 2.2.3.4 --- SDS-PAGE analysis --- p.45 / Chapter 2.3 --- "Expression of GFP-nsp10 in Vero E6 cells, SARS-CoV Infected Vero E6 Cells and Convalescent Patients' Serum" --- p.47 / Chapter 2.3.1 --- Cell-based immunostaining of VeroE6 cells and SARS-CoV infected Vero E6 cells --- p.47 / Chapter 2.3.1.1 --- Immobilization of Vero E6 cells and SARS-CoV infected Vero E6 cells --- p.47 / Chapter 2.3.1.2 --- Preparation of monoclonal antibodies against SARS-CoV nsp10 --- p.48 / Chapter 2.3.1.3 --- Immunostaining of SARS-CoV nsp10 in Vero E6 cells and SARS-CoV VeroE6 cells --- p.48 / Chapter 2.3.1.4 --- Fluorescent microscopic visualization --- p.49 / Chapter 2.3.2 --- Detection of SARS-CoV nsplO expression in SARS-CoV infected convalescent patients' serum --- p.50 / Chapter 2.3.2.1 --- Western blotting of SARS-CoV nsp10 by SARS-CoV infected convalescent patients' serum --- p.50 / Chapter 2.4 --- Expression of GST fusion SARS-CoV nsp10 in E.coli --- p.51 / Chapter 2.4.1 --- Preparation of competent cells --- p.51 / Chapter 2.4.2 --- Small scale expression --- p.51 / Chapter 2.4.3 --- Large scale expression of GST-nsp10 in optimized conditions --- p.54 / Chapter 2.5 --- Purification of GST fusion SARS-CoV nsp10 --- p.55 / Chapter 2.5.1 --- Glutathione Sepharose 4B affinity chromatography --- p.55 / Chapter 2.5.2 --- Superdex 75 gel filtration chromatography --- p.56 / Chapter 2.6 --- "CD Measurement, NMR and Crystallization Study of SARS-CoV nsp10" --- p.57 / Chapter 2.6.1 --- CD measurement --- p.57 / Chapter 2.6.2 --- NMR spectroscopy --- p.58 / Chapter 2.6.3 --- Crystallization of nsp10 --- p.58 / Chapter 2.7 --- "Glutathione-S-Sepharose Pull-down assay, 2D Gel Electrophoresis and Mass Spectrometry" --- p.59 / Chapter 2.7.1 --- GST pull-down assay --- p.59 / Chapter 2.7.2 --- Two-dimension gel electrophoresis --- p.59 / Chapter 2.7.2.1 --- First dimensional isoelectric focusing (IEF) --- p.59 / Chapter 2.7.2.2 --- Second dimension SDS-PAGE --- p.60 / Chapter 2.7.2.3 --- Silver staining --- p.61 / Chapter 2.7.3 --- Protein identification by mass spectrometry --- p.63 / Chapter 2.7.3.1 --- Data acquisition --- p.65 / Chapter 2.8 --- Proliferative study of SARS-CoV nsp10 in VeroE6 Cell Line and Mouse Splenocytes --- p.66 / Chapter 2.8.1 --- Assay of mitogenic activity by 3H-thymidine incorporation --- p.66 / Chapter 2.9 --- "Cloning, Expression and Purification of GST fusion SARS-CoV RNA-dependent RNA Polymerase (RdRp) Full- length Protein" --- p.67 / Chapter 2.9.1 --- Construction of GST-RdRp-full length expression plasmid --- p.67 / Chapter 2.9.2 --- Expression and purification of GST-RdRp full-length protein --- p.68 / Chapter 2.10 --- "Cloning, Expression and Purification of GST Fusion SARS-CoV RNA-dependent RNA Polymerase (RdRp) Catalytic Domain" --- p.70 / Chapter 2.10.1 --- Construction of GST-RdRp Catalytic Domain (p64) and MBP-RdRp-p64 expression plasmids --- p.70 / Chapter 2.10.2 --- Expression and purification of GST fusion catalytic domain of SARS-CoV RdRp (GST-p64) --- p.71 / Chapter 2.10.3 --- Expression and purification of MBP fusion catalytic domain of SARS-CoV RdRp --- p.72 / Chapter 2.11 --- "Cloning, Expression and Purification of the His-thioredoxin Fusion N-terminal Domain of SARS-CoV RdRp (pET32h-pl2)" --- p.74 / Chapter 2.11.1 --- Construction of His-thioredoxin fusion N-terminal domain of SARS-CoV RdRp (pET32h-pl2) expression plasmid --- p.74 / Chapter 2.11.2 --- Expression and purification of His- thioredoxin fusion N-terminal domain of SARS-CoV RdRp (pET32h-pl2) --- p.74 / Chapter 2.12 --- Interaction Study of RdRp Catalytic Domain and N-terminal Domain --- p.76 / Chapter 2.13 --- Electrophoretic Mobility Shift Assay of SARS-CoV Genomic RNA Strands with RdRp Full-length sequence --- p.76 / Chapter 2.13.1 --- Preparation of RNA transcripts --- p.76 / Chapter 2.13.2 --- EMSA --- p.77 / Chapter 2.14 --- Non-radiometric and Radiometric RdRp Assays --- p.78 / Chapter 2.14.1 --- Non-radiometric RdRp assay--luciferase coupled enzyme assay --- p.78 / Chapter 2.14.2 --- Radiometric RdRp assay ´ؤ filter-binding enzyme assay --- p.79 / Chapter 2.15 --- Western Blot Analysis for Interaction Study --- p.80 / Chapter Chapter 3 --- Results and Discussion on SARS-CoV nsplO --- p.81 / Chapter 3.1 --- "Cloning, Expression and Purification of SARS-CoV nsp10 in Prokaryotic Expression System" --- p.81 / Chapter 3.1.1 --- Cloning and expression of SARS-CoV nsp 10 --- p.81 / Chapter 3.1.2 --- Purification of GST-nsp10 by GST affinity chromatography --- p.84 / Chapter 3.1.3 --- Purification of nsp10 by size exclusion chromatography --- p.85 / Chapter 3.1.4. --- "Yield, purity and stability of SARS-CoV nsp 10" --- p.88 / Chapter 3.2 --- SARS-CoV nsp10 Sequence Alignment and Protein Structure Prediction --- p.89 / Chapter 3.2.1. --- Sequence alignment of SAR-CoV nsp10 with known viral proteins --- p.91 / Chapter 3.2.2 --- Protein structure prediction - homology modeling --- p.93 / Chapter 3.3 --- Circular Dichroism Analysis of nsp10 --- p.96 / Chapter 3.3.1 --- CD spectrum of SARS-CoV nsp10 --- p.98 / Chapter 3.3.2. --- Effect of divalent metal ions on SARS-CoV nsp10 --- p.99 / Chapter 3.4 --- Nuclear Magnetic Resonance Analysis of nsp10 --- p.101 / Chapter 3.4.1 --- Sample preparation for NMR Experiment --- p.102 / Chapter 3.4.2 --- Protein structure determination by NMR --- p.103 / Chapter 3.5 --- Crystallization of SARS-CoV nsp10 --- p.105 / Chapter 3.5.1 --- Sample preparation of nsp10 for crystallization --- p.105 / Chapter 3.5.2 --- Screening conditions for crystallization --- p.106 / Chapter 3.6 --- "Antigenic, Immunofluorescene and Subcellular Localization Studies on the SARS-CoV nsp10" --- p.110 / Chapter 3.6.1 --- Antigenic and immunofluorescene studies on the SARS-CoV nsp10 --- p.110 / Chapter 3.6.2 --- Subcellular localization of SARS-CoV nsp10 --- p.115 / Chapter 3.7 --- Proliferative Study of nsp10 --- p.120 / Chapter 3.7.1. --- Influence of proliferative effect on the host cell --- p.121 / Chapter 3.8 --- A Proteomics Strategy for Interaction Study of nsp10 --- p.124 / Chapter 3.8.1 --- 2D SDS-PAGE analysis of proteins associating with the nsp10 bait --- p.125 / Chapter 3.8.2 --- Silver staining of proteins associating with the nsp10 bait and their identification by mass spectrometry --- p.127 / Chapter 3.9 --- Discussion on SARS-CoV nsp10 --- p.129 / Chapter Chapter 4 --- Results and Discussion on SARS-CoV RdRp / Chapter 4.1 --- "Cloning, Expression and Purification of SARS-CoV RdRp Full-length, Catalytic Domain and N-terminal Domain" --- p.139 / Chapter 4.2 --- Interaction Study of RdRp Catalytic Domain and its N-terminal Domain --- p.147 / Chapter 4.3 --- Functional Analysis of RNA Binding by the SARS-CoV RdRp --- p.149 / Chapter 4.4 --- Characterization of RdRp by Non-radioactive RdRp Assay ´ؤ Luciferase-coupled Enzyme Assay --- p.152 / Chapter 4.5 --- Characterization of RdRp by Radioactive RdRp Assay ´ؤ 32P Incorporation Assay --- p.157 / Chapter 4.6 --- Discussion on SARS-CoV RdRp --- p.161 / Chapter Chapter 5 --- General Discussion / General Discussion --- p.170 / Appendix --- p.172 / References --- p.189

Chan, Wing Tung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 129-152). / Abstracts in English and Chinese. / Acknowledgements --- p.2 / Abstract --- p.3 / 摘要 --- p.5 / Table of Contents --- p.7 / List of Abbreviations and symbols --- p.13 / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Epidemics and pandemics of influenza virus --- p.17 / Chapter 1.2 --- Biology of influenza virus --- p.19 / Chapter 1.2.1 --- Types of influenza virus --- p.19 / Chapter 1.2.2 --- Viral structure and viral proteins --- p.20 / Chapter 1.2.3 --- Life cycle of influenza virus --- p.21 / Chapter 1.2.4 --- An ever-changing virus --- p.22 / Chapter 1.3 --- Pathogenesis and immunology of influenza virus --- p.24 / Chapter 1.3.1 --- Diseases and symptoms caused by influenza virus infection --- p.24 / Chapter 1.3.2 --- Production of cytokines during influenza virus infection --- p.25 / Chapter 1.3.3 --- Immune responses in the hosts --- p.27 / Chapter 1.4 --- Non-structural protein 1 (NS1) --- p.28 / Chapter 1.4.1 --- Overview of NS1 --- p.28 / Chapter 1.4.2 --- Roles of NS1 in influenza virus infection --- p.29 / Chapter 1.5 --- Aims of study --- p.33 / Chapter Chapter 2 --- Materials and Methods / Chapter 2.1 --- Materials --- p.34 / Chapter 2.1.1 --- Chemical reagents --- p.34 / Chapter 2.1.2 --- Buffers --- p.37 / Chapter 2.1.2.1 --- Preparation of buffers --- p.37 / Chapter 2.1.2.2 --- Commonly used buffers --- p.37 / Chapter 2.1.3 --- Strains and plasmids --- p.40 / Chapter 2.1.4 --- Primer list --- p.40 / Chapter 2.2 --- Methods --- p.42 / Chapter 2.2.1 --- Preparation of competent cells --- p.42 / Chapter 2.2.2 --- Molecular cloning --- p.43 / Chapter 2.2.2.1 --- Amplification of the target genes by PCR --- p.43 / Chapter 2.2.2.2 --- Agarose gel electrophoresis --- p.43 / Chapter 2.2.2.3 --- Extraction and purification of DNA from agarose gels --- p.44 / Chapter 2.2.2.4 --- Restriction digestion of DNA --- p.45 / Chapter 2.2.2.5 --- Ligation of digested insert and expression vector --- p.45 / Chapter 2.2.2.6 --- Transformation and plating out transformants --- p.46 / Chapter 2.2.2.7 --- Verification of insert by PCR --- p.46 / Chapter 2.2.2.8 --- Mini-preparation of plasmid DNA --- p.47 / Chapter 2.2.2.9 --- Confirmation of insertion in the miniprep DNA by restriction digestion --- p.48 / Chapter 2.2.2.10 --- Sequencing of the plasmid DNA --- p.48 / Chapter 2.2.3 --- Cell culture --- p.53 / Chapter 2.2.3.1 --- Cultivation of human lung epithelial NCI-H292 cells --- p.53 / Chapter 2.2.3.2 --- Transfection of cell culture --- p.53 / Chapter 2.2.4 --- Western blot analysis --- p.54 / Chapter 2.2.4.1 --- Protein extraction --- p.54 / Chapter 2.2.4.2 --- Determination of protein concentration --- p.54 / Chapter 2.2.4.3 --- Protein Blotting --- p.55 / Chapter 2.2.4.4 --- Membrane blocking and antibody incubations --- p.56 / Chapter 2.2.4.5 --- Detection of proteins --- p.57 / Chapter 2.2.5 --- Total RNA extraction --- p.58 / Chapter 2.2.5.1 --- Preparation of cell culture for total RNA extraction --- p.58 / Chapter 2.2.5.2 --- Spectrophotometric analysis of total RNA --- p.58 / Chapter 2.2.5.3 --- Agarose gel electrophoresis of total RNA --- p.59 / Chapter 2.2.6 --- DNA Microarray --- p.60 / Chapter 2.2.6.1 --- Preparation of biotin-labeled antisense cRNA --- p.60 / Chapter 2.2.6.2 --- "Hybridization, washing and scanning of DNA microarray chips" --- p.60 / Chapter 2.2.6.3 --- Data processing and analysis --- p.61 / Chapter 2.2.7 --- Quantitative real-time PCR (QRT-PCR) --- p.62 / Chapter 2.2.7.1 --- Preparation of cDNA --- p.62 / Chapter 2.2.7.2 --- Analysis of mRNA gene expression by QRT-PCR --- p.62 / Chapter Chapter 3 --- Roles of NS1A and NS1B on cellular gene expression / Chapter 3.1 --- Introduction --- p.63 / Chapter 3.2 --- Results --- p.67 / Chapter 3.2.1 --- NS1 protein expression in transfected NCI-H292 cells --- p.67 / Chapter 3.2.2 --- Purity and integrity of total RNA extracted --- p.67 / Chapter 3.2.3 --- Microarray data processing and analysis --- p.70 / Chapter 3.2.3.1 --- Genes perturbed by NS1A --- p.88 / Chapter 3.2.3.1.1 --- Effect of NS1A on antiviral gene expression --- p.91 / Chapter 3.2.3.1.2 --- Regulation of JAK-STAT pathway by NS1A --- p.92 / Chapter 3.2.3.2 --- Genes perturbed by NS1B --- p.93 / Chapter 3.2.3.2.1 --- Effects of NS1B on IFN-stimulated gene expression --- p.96 / Chapter 3.2.3.3 --- Genes perturbed by both NS1A and NS1B --- p.96 / Chapter 3.2.4 --- Verification of differentially expressed genes --- p.98 / Chapter 3.3 --- Discussion --- p.100 / Chapter 3.3.1 --- Human lung epithelial cell line as a model --- p.100 / Chapter 3.3.2 --- DNA microarray technology --- p.101 / Chapter 3.3.3 --- Different actions of NS1A and NS1B on host cell gene expression --- p.102 / Chapter 3.3.4 --- Novel roles of NSIA --- p.103 / Chapter 3.3.5 --- Novel role of NSIB --- p.107 / Chapter 3.3.6 --- Implications --- p.108 / Chapter Chapter 4 --- "Roles of NSIA, NS1B and NS1C on cytokine expression" / Chapter 4.1 --- Introduction --- p.109 / Chapter 4.2 --- Results --- p.113 / Chapter 4.2.1 --- NS1 protein expression in transfected NCI-H292 cells --- p.113 / Chapter 4.2.2 --- Purity and integrity of total RNA extracted --- p.113 / Chapter 4.2.3 --- QRT-PCR --- p.116 / Chapter 4.3 --- Discussion --- p.119 / Chapter 4.3.1 --- Human lung epithelial cell line as a model for cytokine study --- p.119 / Chapter 4.3.2 --- Implications of different cytokine patterns induced by different NS1 proteins --- p.120 / Chapter Chapter 5 --- General Discussion and Future Perspectives --- p.125 / References --- p.129

L’émergence récente de nouvelles thérapies antivirales efficaces est une avancée considérable pour lutter contre l'infection chronique par le virus de l'hépatite C (VHC). Cependant, un pic de carcinomes hépatocellulaires, représentant l'atteinte hépatique ultime liée à l'infection, est attendu dans la prochaine décennie. Approfondir les connaissances des différentes étapes du cycle viral et de l’interférence du VHC avec l'hépatocyte hôte permet de mieux comprendre la pathogénèse associée à ce virus. Les travaux présentés dans cette thèse ont eu pour objectif d'identifier le réseau de partenaires cellulaires et viraux de la protéine non-structurale NS2 du VHC et de mieux comprendre les mécanismes d'action et de régulation de cette protéine transmembranaire multi-fonctionnelle, qui est un acteur clé du clivage protéolytique de la polyprotéine virale et de la morphogénèse des virions. Dans une première partie, nous avons analysé comparativement les mécanismes moléculaires de l’activité enzymatique des protéines NS2 du VHC et de plusieurs hepacivirus non-humains, qui infectent des primates du Nouveau Monde (GBV-B) ou qui ont été récemment identifiés chez plusieurs autres espèces animales (NPHV, RHV, BHV et GHV). Des analyses phylogénétiques, des modèles structuraux tridimensionnels et des Études dans un contexte d'expression transitoire de précurseurs polypeptidiques viraux ou dans des modèles d'infection ont montré que l’activité des protéases NS2 de divers hepacivirus (1) s'exerce à la jonction NS2/NS3 sous la forme d'homodimères formant deux triades catalytiques composites ; (2) est régulée dans le contexte de la polyprotéine virale par quelques résidus de surface du domaine N-terminal de NS3 (NS3N) nécessaires à son activation ; (3) est efficace en l'absence complète de NS3N, suggérant un rôle négatif ou régulateur, plutôt qu'activateur de NS3N, contrairement au dogme en vigueur actuellement. Ces travaux soulignent l'importance fonctionnelle des mécanismes protéolytiques de NS2 conservés parmi les différents hepacivirus. Dans une deuxième partie, nous avons identifié un réseau de facteurs cellulaires et viraux interagissant avec NS2 au cours du cycle infectieux par un crible interactomique reposant sur la purification par affinité et l'analyse par spectrométrie de masse des complexes protéiques isolés de cellules hépatocytaires infectées, ainsi que par un test de complémentation enzymatique fonctionnelle. Par une approche d'ARN interférence, nous avons ensuite montré qu'un nombre limité de facteurs cellulaires interagissant avec NS2 sont impliqués dans la production et la sécrétion de particules virales infectieuses, incluant des protéines du complexe de la peptidase signal (SPCS) au sein du réticulum endoplasmique, des protéines chaperonnes (DNAJB11, HSPA5) et une protéine impliquée dans le transport intracellulaire (SURF4). Notamment, nos Études suggèrent que plusieurs membres du SPCS forment un complexe multi-protéique avec NS2, impliquant Également la glycoprotéine virale E2, qui jouerait un rôle dans une Étape précoce de l'assemblage ou lors de l’enveloppement de la particule virale. En conclusion, mes travaux de thèse ont permis d'identifier pour la première fois une série limitée de facteurs hépatocytaires interagissant spécifiquement avec la protéine NS2 du VHC au cours de l'infection et de déterminer parmi ceux-ci les facteurs essentiels la morphogenèse virale. Par ailleurs, nos résultats ont permis d’enrichir les connaissances naissantes des hepacivirus non-humains récemment identifiés et de montrer que ceux-ci partageaient avec le VHC des mécanismes clés mis en jeu au cours du cycle viral, ce qui contribue consolider leur intérêt comme modèles animaux de substitution. / The recent emergence of a panel of direct acting antivirals will certainly help combat chronic hepatitis C in the future. However, in the current context worldwide, a peak of hepatitis C virus (HCV)-induced hepatocellular carcinoma is expected in the next decade. Deepening our understanding of HCV life cycle and HCV interference with host cells may help monitor HCV-associated pathogenesis. The aim of my PhD work was to identify the network of host and viral interactors of HCV nonstructural protein 2 and to unravel the mechanisms of action and regulation of this multifunctional, transmembrane protein, which is key both for the viral polyprotein cleavage and virion morphogenesis.In the first part of the work, we comparatively characterized molecular mechanisms underlying the enzymatic activity of NS2 proteins from HCV and from various non-human hepaciviruses that infect small New World primates (GBV-B) or that were recently identified in the wild in several mammalian species (NPHV, RHV, BHV, GHV). A combination of phylogenetic analyses, tridimensional structural models, and studies relying on the transient expression of viral polypeptide precursors or on infection models showed that NS2 proteases of the various hepaciviruses (1) act as dimers with two composite active sites to ensure NS2/NS3 junction cleavage, (2) are regulated in the polyprotein backbone via a hydrophobic patch at the surface of NS3 N-terminal domain (NS3N) that is essential to activate NS2 protease, and (3) are efficient in the complete absence of NS3N, which is unprecedented and suggests that NS3N has rather a negative or regulating role on NS2 activity. These data underline the functional importance of NS2 proteolytic mechanisms that are conserved across hepaciviruses.In the second part, we identified a network of cellular factors and viral proteins that interact with NS2 in the course of HCV infection using an interactomic screen based on affinity purification and mass spectrometry analysis of protein complexes retrieved form HCV infected hepatoma cells, as well as a split-luciferase complementation assay. Next, using a gene silencing approach, we found that a limited set of NS2 interactors among these host factors were involved in HCV particle assembly and/or secretion. This includes members of the endoplasmic reticulum signal peptidase complex (SPCS), chaperone proteins (DNAJB11, HSPA5) and a factor involved in intracellular transport (SURF4). Notably, our data are in favor of the existence of a multiprotein complex involving NS2, several members of the SPCS, and the viral E2 glycoprotein, which likely plays a role in an early step of HCV particle assembly or during particle envelopment. Altogether, my PhD work allowed us to identify a limited set of hepatocyte factors interacting with HCV NS2 during infection and to pinpoint those that are essential for HCV morphogenesis. Additionally, our results contributed to the molecular characterization of the recently identified non-human hepaciviruses and revealed that these hepaciviruses share with HCV key mechanisms in the course of their infectious life cycles. This highlights the value of non-human hepaciviruses as surrogate animal models of HCV infection.

Diorhabda elongata elongata leaf beetles were released at two field locations in the upper Colorado River watershed of Texas in 2003 and 2004 for the biological control of invasive Tamarix, exotic trees deteriorating riparian ecosystems of western North America. Establishment and biological success were monitored using trees on transects from the release points. D. elongata elongata released at the Lake Thomas site in August 2003 successfully overwintered and were recovered in the spring 2004; however, beetles were not present after June 2004. The April 2004 release at Beals Creek led to establishment and survival during 2005 and 2006. Mean abundance increased from less than five insects per tree per 2 minute count in August 2004 to more than 40 insects per tree per 2 minute count in August 2006. By then the population was dispersed throughout an area of approximately 12 hectares and beetles were present on 100% of the 47 trees surveyed, 57% of which were at least 90% defoliated. To measure the impact of beetle defoliation on Tamarix, nonstructural carbohydrates (NCHOs) were measured in manipulative field cage experiments in Texas and natural experiments in Nevada. There was no significant difference in NCHOs between trees with versus trees without beetle herbivory in the cage experiment, although spring foliage regrowth was reduced by 35% in trees defoliated the previous fall. In Nevada, root crown tissue was sampled in 2005 and 2006 from trees that had experienced 0-4 years of defoliation. In 2005, NCHO concentrations differed between tree stands and ranged from 9.0 ± 0.8% (Mean ± SE) in non-defoliated trees to 3.2 ± 0.4%, 2.1 ± 0.4% and 2.3 ± 0.4% in trees defoliated for 1, 2 and 3 successive years, respectively. NCHO concentrations in 2006 were similar, ranging from 13.6 ± 0.9% in non-defoliated trees to 7.6 ± 0.8%, 2.3 ± 0.4%, 1.5 ± 0.3% and 1.7 ± 0.4% in trees defoliated for 1, 2, 3 and 4 years, respectively. The establishment, biological success and host impact of D. elongata leaf beetles suggest there is potential for biological control of Tamarix in the United States.

Diorhabda elongata elongata leaf beetles were released at two field locations in the upper Colorado River watershed of Texas in 2003 and 2004 for the biological control of invasive Tamarix, exotic trees deteriorating riparian ecosystems of western North America. Establishment and biological success were monitored using trees on transects from the release points. D. elongata elongata released at the Lake Thomas site in August 2003 successfully overwintered and were recovered in the spring 2004; however, beetles were not present after June 2004. The April 2004 release at Beals Creek led to establishment and survival during 2005 and 2006. Mean abundance increased from less than five insects per tree per 2 minute count in August 2004 to more than 40 insects per tree per 2 minute count in August 2006. By then the population was dispersed throughout an area of approximately 12 hectares and beetles were present on 100% of the 47 trees surveyed, 57% of which were at least 90% defoliated. To measure the impact of beetle defoliation on Tamarix, nonstructural carbohydrates (NCHOs) were measured in manipulative field cage experiments in Texas and natural experiments in Nevada. There was no significant difference in NCHOs between trees with versus trees without beetle herbivory in the cage experiment, although spring foliage regrowth was reduced by 35% in trees defoliated the previous fall. In Nevada, root crown tissue was sampled in 2005 and 2006 from trees that had experienced 0-4 years of defoliation. In 2005, NCHO concentrations differed between tree stands and ranged from 9.0 ± 0.8% (Mean ± SE) in non-defoliated trees to 3.2 ± 0.4%, 2.1 ± 0.4% and 2.3 ± 0.4% in trees defoliated for 1, 2 and 3 successive years, respectively. NCHO concentrations in 2006 were similar, ranging from 13.6 ± 0.9% in non-defoliated trees to 7.6 ± 0.8%, 2.3 ± 0.4%, 1.5 ± 0.3% and 1.7 ± 0.4% in trees defoliated for 1, 2, 3 and 4 years, respectively. The establishment, biological success and host impact of D. elongata leaf beetles suggest there is potential for biological control of Tamarix in the United States.

Thesis (Ph. D.)--University of Missouri--Columbia, 2001. / "August 2001." Typescript. Vita. Includes bibliographical references (leaves 172-183). Also available on the Internet.

Eastern Equine Encephalitis virus (EEEV) causes a fatal mosquito-borne virus that is vaccine preventable for horses. The conventional serological tests measure antibodies to the structural proteins of EEEV which are also found in the vaccine. This makes it difficult to differentiate infected and vaccinated animals (DIVA). Detection of antibodies to non-structural proteins (NSPs) is a theoretical strategy that would allow you to survey natural infections among vaccinated populations. This test would also allow for more accurate representations of the natural infection rate, vaccination rate, and help identify vaccine failures. The potential uses of the NSPs of Eastern Equine Encephalitis virus as diagnostic antigens were examined in this study. Each of the four NSP encoding genes of EEEV strain FL93-939 was separated into two parts, inserted into expression vector pDEST17, and expressed in Escherichia coli strain BL21-AI. Recombinant forms of the protein were used as an antigen for an indirect IgG ELISA to measure the serological response of horse sera to the NSPs. Serum samples collected from infected, vaccinated, and unvaccinated horses were tested for NSP antibodies. A decrease in the optical densities (ODs) for the vaccinated horse sera was seen when using the NSPs compared to whole EEEV antigen. However, the ODs for the vaccinated horses were lowered to the same level as those infected, leaving no quantitative difference between the two. The use of the IgGa secondary antibody decreased the ODs even more for the vaccinated samples, but it was still impossible to differentiate the infected and vaccinated sera due to the samples' ODs being below the cutoff point. The IgGa ELISA however, was the only ELISA where the infected samples were consistently above the vaccinated samples. Based on the results of the study, it was not possible to accurately differentiate between infected and vaccinated animals. Future research should be conducted in other ways to use the NSP recombinants for the DIVA strategy. This could include the use of an IgM ELISA or microsphere immunoassay (MIA), using different IgG subtypes for the assays, using epitope mapping to develop a new recombinant protein, or the development of a DIVA vaccine.

The rubella virus (RUB) capsid protein (C) is a multifunctional phosphoprotein with roles beyond encapsidation. It is able to rescue a large lethal deletion of the Q domain in the P150 replicase gene at a step in replication before detectable viral RNA synthesis, indicating a common function shared by RUB C and the Q domain. The goal of this dissertation was to use constructs containing the N-terminal 88 amino acids of RUB C, the region previously defined as the minimal region required for the rescue of Q domain mutants, to elucidate the function of RUB C in Q domain rescue and viral RNA synthesis. In the first specific aim, the rescue function of 1-88 RUB C and the importance of an arginine-rich cluster, R2, within 1-88 RUB C for rescue were confirmed. Rescue was not correlated with intracellular localization or phosphorylation status of RUB C. In the second specific aim, the involvement of RUB C in early events post-transfection with RUB RNA was analyzed. RUB C specifically protected RUB transcripts early post-transfection and protection required R2. However, it was concluded the protection observed was due to the encapsidation function of RUB C and not related to Q domain rescue. No differences in the translation of the RUB nonstructural proteins in the presence or absence of RUB C were observed. Interactions of RUB C with host cell proteins were analyzed. Although the interaction of RUB C with cellular p32 required the R2 cluster, both wild type (does not require RUB C for replication) and RQQ (requires RUB C for replication) Q domain bound p32, indicating interaction with this binding partner is not the basis of rescue. Using a human protein array phosphatidylinositol transfer protein alpha isoform (PITPα) was found to interact with RUB C but not its R2 mutant. However, co-immunoprecipitation experiments revealed that this protein binds both forms of RUB C. Although the mechanism behind the rescue of the RUB P150 Q domain by RUB C remains unknown, we propose a model that RUB C plays a role in generation of the virus replication complex in infected cells.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 5 uppsatser.