Organisms Commons^™

Chlorovirus Pbcv-1 Encodes An Active Copper-Zinc Superoxide Dismutase, Ming Kang, Garry A. Duncan, Charles Kuszynski, George Oyler, Jiayin Zheng, Donald F. Becker, James L. Van Etten

James Van Etten Publications

Superoxide dismutases (SODs) are metalloproteins that protect organisms from toxic reactive oxygen species by catalyzing the conversion of superoxide anion to hydrogen peroxide and molecular oxygen. Chlorovirus PBCV-1 encodes a 187-amino-acid protein that resembles a Cu-Zn SOD with all of the conserved amino acid residues for binding copper and zinc (named cvSOD). cvSOD has an internal Met that results in a 165-amino-acid protein (named tcvSOD). Both cvSOD and tcvSOD recombinant proteins inhibited nitroblue tetrazolium reduction of superoxide anion generated in a xanthine-xanthine oxidase system in solution. tcvSOD was chosen for further characterization because it was easier to produce. Recombinant tcvSOD …

Expression Of Chlorovirus Mt325 Aquaglyceroporin (Aqpv1) In Tobacco And Its Role In Mitigating Drought Stress, Saadia Bihmidine, Mingxia Cao, Ming Kang, Tala Awada, James L. Van Etten, David Dunigan, Thomas E. Clemente

James Van Etten Publications

Main conclusions A Chlorovirus aquaglyceroporin expressed in tobacco is localized to the plastid and plasma membranes. Transgenic events display improved response to water deficit. Necrosis in adult stage plants is observed.

Aquaglyceroporins are a subclass of the water channel aquaporin proteins (AQPs) that transport glycerol along with other small molecules transcellular in addition to water. In the studies communicated herein, we analyzed the expression of the aquaglyceroporin gene designated, aqpv1, from Chlorovirus MT325, in tobacco (Nicotiana tabacum), along with phenotypic changes induced by aqpv1 expression in planta. Interestingly, aqpv1 expression under control of either a constitutive or …

Characterizing The Response Of Multidrug-Resistant Klebsiella Pneumoniae Species To The Application Of A Phage Cocktail, Steven Liu

Symposium

Project Summary: The application of bacteriophages to treat bacterial infections is known as phage therapy, which takes advantage of bacteriophage’s natural ability to infect and lyse bacterial hosts. Phages have been shaped by billions of years of evolution to be highly specialized deliverers of bactericidal agents to the cytoplasm of their target bacteria. Ever since discovery of bacteriophages in 1915, phage therapy was recognized as a potentially powerful tool for eliminating bacterial infections. The effectiveness of phage therapy can be increased by creating a mixture of multiple phages to target a wider variety of bacterial strains. Furthermore, phage therapy has …

Time-Varying, Serotype-Specific Force Of Infection Of Dengue Virus, Kanya C. Long, Robert C. Reiner, Steven T. Stoddard, Brett M. Froshey, Aaron A. King, Alicia M. Ellis, Alun L. Lloyd, Claudio Rocha, Stalin Vilcarromero, Helvio Astete, Isabel Bazan, Audrey Lenhart, Gonzalo M. Vazquez-Prokopec, Valerie A. Paz-Soldan, Phlip J. Mccall, Uriel Kitron, John P. Elder, Eric S. Halsey, Amy C. Morrison, Tadeusz J. Kochel, Thomas W. Scott

Faculty Publications

Infectious disease models play a key role in public health planning. These models rely on accurate estimates of key transmission parameters such as the force of infection (FoI), which is the percapita risk of a susceptible person being infected. The FoI captures the fundamental dynamics of transmission and is crucial for gauging control efforts, such as identifying vaccination targets. Dengue virus (DENV) is a mosquito-borne, multiserotype pathogen that currently infects ∼390 million people a year. Existing estimates of the DENV FoI are inaccurate because they rely on the unrealistic assumption that risk is constant over time. Dengue models are thus …

The Boiling Springs Lake Metavirome: Charting The Viral Sequence-Space Of An Extreme Environment Microbial Ecosystem, Geoffrey Scott Diemer

Dissertations and Theses

Viruses are the most abundant organisms on Earth, yet their collective evolutionary history, biodiversity and functional capacity is not well understood. Viral metagenomics offers a potential means of establishing a more comprehensive view of virus diversity and evolution, as vast amounts of new sequence data becomes available for comparative analysis.
Metagenomic DNA from virus-sized particles (smaller than 0.2 microns in diameter) was isolated from approximately 20 liters of sediment obtained from Boiling Springs Lake (BSL) and sequenced. BSL is a large, acidic hot-spring (with a pH of 2.2, and temperatures ranging from 50°C to 96°C) located in Lassen Volcanic National …

Viruses As Nanoparticles: Structure Versus Collective Dynamics, S. Sirotkin, A. Mermet, M. Bergoin, V. Ward, James L. Van Etten

James Van Etten Publications

In order to test the application of the “nanoparticle” concept to viruses in terms of low-frequency dynamics, large viruses (140–190 nm) were compared to similar-sized polymer colloids using ultra-small-angle x-ray scattering and very-low-frequency Raman or Brillouin scattering. While both viruses and polymer colloids show comparable highly defined morphologies, with comparable abilities of forming self-assembled structures, their respective abilities to confine detectable acoustic vibrations, as expected for such monodisperse systems, differed. Possible reasons for these different behaviors are discussed.

Viruses Infecting Marine Picoplancton Encode Functional Potassium Ion Channels, Fenja Siotto, Corinna Martin, Oliver Rauh, James L. Van Etten, Indra Schroeder, Anna Moroni, Gerhard Thiel

James Van Etten Publications

Phycodnaviruses are dsDNA viruses, which infect algae. Their large genomes encode many gene products, like small K+ channels, with homologs in prokaryotes and eukaryotes. Screening for K+ channels revealed their abundance in viruses from fresh-water habitats. Recent sequencing of viruses from marine algae or from salt water in Antarctica revealed sequences with the predicted characteristics of K+ channels but with some unexpected features. Two genes encode either 78 or 79 amino acid proteins, which are the smallest known K+ channels. Also of interest is an unusual sequence in the canonical α-helixes in K+ channels. Structural prediction algorithms indicate that the …

Nanoparticle Encapsidation Of Flock House Virus By Auto Assembly Of Tobacco Mosaic Virus Coat Protein, Payal D. Maharaj, Jyothi K. Mallajosyula, Gloria Lee, Phillip Thi, Yiyang Zhou, Christopher M. Kearney, Alison A. Mccormick

Faculty Publications & Research of the TUC College of Pharmacy

Tobacco Mosaic virus (TMV) coat protein is well known for its ability to self-assemble into supramolecular nanoparticles, either as protein discs or as rods originating from the ~300 bp genomic RNA origin-of-assembly (OA). We have utilized TMV self-assembly characteristics to create a novel Flock House virus (FHV) RNA nanoparticle. FHV encodes a viral polymerase supporting autonomous replication of the FHV genome, which makes it an attractive candidate for viral transgene expression studies and targeted RNA delivery into host cells. However, FHV viral genome size is strictly limited by native FHV capsid. To determine if this packaging restriction could be eliminated, …

Integrating Phage Therapy Into Western Medicine, Jacob B. Jaminet

Undergraduate Research Posters

The World Health Organization has described the rise of antibiotic use as a “global heath security emergency” (who.int). With the growing concern about antibiotic resistant bacteria, there has been an increased interest in bacteriophages. Bacteriophages are high-specific viruses that only infect bacteria. The use of bacteriophages medicinally to treat bacteria is called phage therapy. Research in phage therapy gained momentum until the introduction of antibiotics. While the USA and other Western countries accepted antibiotics, the Soviet Union and their satellite nations still continued to research phages. Since the funding for research was supplied by the Soviet military, the results of …

Development And Characterization Of A Recombinant Vesicular Stomatitis Virus (Rvsv) For The Treatment Of Glioblastoma, Erika A. Dillard

Theses and Dissertations (ETD)

Background: Over the past 30 years, little has changed in the treatment modalities and prognosis of patients suffering from Glioblastoma multiforme (GBM), the most common and by far the most devastating adult primary malignant brain tumor. Conventional therapies provide only a marginal increase in survival of GBM patients, post-diagnosis. Therefore, more novel means of treating GBM are needed to increase long-term survival and quality of life for those affected. Replication competent oncolytic viruses (OVs) have recently emerged as a possible option for treatment of high-grade gliomas. Particularly, recombinant vesicular stomatitis virus (rVSV), an enveloped, negative strand RNA virus, has shown …

A Box Of Paradoxes: The Fascinating World Of Viruses, Boriana Marintcheva

Bridgewater Review

No abstract provided.

The Epidemiology Of Human Herpesvirus-8: Transmission Of Infection To Children In Zambian Households, Kay L. Crabtree

School of Biological Sciences: Dissertations, Theses, and Student Research

Human Herpes virus-8 (HHV-8) is the known etiologic agent for several malignant pathologies, including Kaposi’s sarcoma (KS), the most common tumor in children in sub-Saharan Africa. Saliva is implicated as the culprit of transmission; however there is a paucity of information regarding transmission to young children. In this study, we investigated the hypothesis that household behaviors exposing the susceptible child to saliva increase the risk of transmission of HHV-8 to that child.

To test our hypothesis a large prospective cohort study in Lusaka, Zambia, enrolling 464 young children and their households, was followed for 48 months. Socio-demographics, health histories, feeding …

An In-Depth Look At Recent Influenza Seasons And Vaccine Effectiveness, Ariana Ricci

Honors Projects in Science and Technology

This paper aims to present an in-depth exploration of immunology, the influenza virus, vaccination, and vaccination’s effectiveness with respect to influenza. It also delves into the possible causes behind the large increase in early childhood deaths during the 2003-2004 influenza season, which was a turning point in terms of influenza incident reporting. Finally, data analysis on the relationship between childhood flu vaccine coverage and childhood outpatient ILI (influenza-like illness) visits by region is presented as a measurement of vaccine effectiveness and identifier of trends. Although this relationship was not statistically significant (alpha=0.05) regionally, this simply points to alternate factors that …

The Voltage-Sensing Domain Of A Phosphatase Gates The Pore Of A Potassium Channel, Cristina Arrigoni, Indra Schroeder, Giulia Romani, James L. Van Etten, Gerhard Thiel, Anna Moroni

James Van Etten Publications

The modular architecture of voltage-gated K⁺ (Kv) channels suggests that they resulted from the fusion of a voltage-sensing domain (VSD) to a pore module. Here, we show that the VSD of Ciona intestinalis phosphatase (Ci-VSP) fused to the viral channel Kcv creates Kv_Synth1, a functional voltage-gated, outwardly rectifying K⁺ channel. Kv_Synth1 displays the summed features of its individual components: pore properties of Kcv (selectivity and filter gating) and voltage dependence of Ci-VSP (V1/2 = +56 mV; z of approx. 1), including the depolarizationinduced mode shift. The degree of outward rectification of the channel is critically …

A Virus-Encoded Potassium Ion Channel Is A Structural Protein In The Chlorovirus Paramecium Bursaria Chlorella Virus 1 Virion, Giulia Romani, Adrianna Piotrowski, Stefan Hillmer, James Gurnon, James L. Van Etten, Anna Moroni, Gerhard Thiel, Brigitte Hertel

James Van Etten Publications

Most chloroviruses encode small K+ channels, which are functional in electrophysiological assays. The experimental finding that initial steps in viral infection exhibit the same sensitivity to channel inhibitors as the viral K+ channels has led to the hypothesis that the channels are structural proteins located in the internal membrane of the virus particles. This hypothesis was questioned recently because proteomic studies failed to detect the channel protein in virions of the prototype chlorovirus Paramecium bursaria chlorella virus 1 (PBCV-1). Here, we used a mAb raised against the functional K+ channel from chlorovirus MA-1D to search for the viral K+ channel …

A Virus-Encoded Potassium Ion Channel Is A Structural Protein In The Chlorovirus Paramecium Bursaria Chlorella Virus 1 Virion, Giulia Romani, Adrianna Piotrowski, Stefan Hillmer, James Gurnon, James L. Van Etten, Anna Morani, Gerhard Thiel, Brigitte Hertel

James Van Etten Publications

Most chloroviruses encode small K+ channels, which are functional in electrophysiological assays. The experimental finding that initial steps in viral infection exhibit the same sensitivity to channel inhibitors as the viral K+ channels has led to the hypothesis that the channels are structural proteins located in the internal membrane of the virus particles. This hypothesis was questioned recently because proteomic studies failed to detect the channel protein in virions of the prototype chlorovirus Paramecium bursaria chlorella virus 1 (PBCV-1). Here, we used a mAb raised against the functional K+ channel from chlorovirus MA-1D to search for the viral K+ channel …

Potassium Ion Channels: Could They Have Evolved From Viruses?1[W], Gerhard Thiel, Anna Moroni, Guillaume Blanc, James L. Van Etten

James Van Etten Publications

Cells communicate among themselves by electrical activity. Sophisticated membrane-embedded proteins, called ion channels, catalyze rapid, selective, and regulated ion fluxes across membranes (Hille, 2001). The resulting membrane currents are responsible for neuronal activity and the systemic propagation of electrical signals in animals. The activity of some channels is important for muscle movement in animals or growth in plants; other channels sense the concentration of physiological signals and modulate key processes in all kinds of eukaryotic cells. Among the many diverse ion channels in higher organisms, K+ channels are among the most important. One feature of K+ channels is that they …

Comparative Study Of Influenza Virus Replication In Mdck Cells And In Primary Cells Derived From Adenoids And Airway Epithelium, Natalia A. Ilyushina, Mine R. Ikizler, Yoshihiro Kawaoka, Larisa G. Rudenko

Dartmouth Scholarship

Although clinical trials with human subjects are essential for determination of safety, infectivity, and immunogenicity, it is de- sirable to know in advance the infectiousness of potential candidate live attenuated influenza vaccine strains for human use. We compared the replication kinetics of wild-type and live attenuated influenza viruses, including H1N1, H3N2, H9N2, and B strains, in Madin-Darby canine kidney (MDCK) cells, primary epithelial cells derived from human adenoids, and human bron- chial epithelium (NHBE cells). Our data showed that despite the fact that all tissue culture models lack a functional adaptive im- mune system, differentiated cultures of human epithelium exhibited …

Differential Virus Host-Ranges Of The Fuselloviridae Of Hyperthermophilic Archaea: Implications For Evolution In Extreme Environments, Ruben Michael Ceballos, Caleb D. Marceau, Joshua O. Marceau, Steven Morris, Adam J. Clore, Kenneth M. Stedman

Biological Sciences Faculty Publications and Presentations

An emerging model for investigating virus-host interactions in hyperthermophilic Archaea is the Fusellovirus-Sulfolobus system. The host, Sulfolobus, is a hyperthermophilic acidophile endemic to sulfuric hot springs worldwide. The Fuselloviruses, also known as Sulfolobus Spindle-shaped Viruses (SSVs), are “lemon” or “spindle”-shaped double-stranded DNA viruses, which are also found worldwide. Although a few studies have addressed the host-range for the type virus, Sulfolobus Spindle-shaped Virus 1 (SSV1), using common Sulfolobus strains, a comprehensive host-range study for SSV-Sulfolobus systems has not been performed. Herein, we examine six bona fide SSV strains (SSV1, SSV2, SSV3, SSVL1, SSVK1, SSVRH) and their respective infection characteristics on …

Murine Gammaherpesvirus 68 Lana Acts On Terminal Repeat Dna To Mediate Episome Persistence, Aline C. Habison, Chantal Beauchemin, J. Pedro Simas, Edward J. Usherwood

Dartmouth Scholarship

Murine gammaherpesvirus 68 (MHV68) ORF73 (mLANA) has sequence homology to Kaposi’s sarcoma-associated herpesvirus (KSHV) latency-associated nuclear antigen (LANA). LANA acts on the KSHV terminal repeat (TR) elements to mediate KSHV episome maintenance. Disruption of mLANA expression severely reduces the ability of MHV68 to establish latent infection in mice, consistent with the possibility that mLANA mediates episome persistence. Here we assess the roles of mLANA and MHV68 TR (mTR) elements in episome persistence. mTR-associated DNA persisted as an episome in latently MHV68-infected tumor cells, demonstrating that the mTR elements can serve as a cis-acting element for MHV68 episome maintenance. In some …

Cell-Mediated Immunity In Porcine Reproductive And Respiratory Syndrome Virus, Rajeshwari Parida

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Porcine reproductive and respiratory syndrome virus is a significant swine pathogen which exhibits considerable sequence diversity. In an attempt to identify highly conserved T-cell epitopes contained in proteins of this virus, we examined heptadecamer peptides spanning the sequence of the PRRSV nonstructural proteins 9, 10 and 11, all of them are highly conserved, for their ability to elicit a recall proliferative and interferon-gamma response in peripheral blood mononuclear cells obtained from pigs immunized against the type-II PRRSV strain FL-12. These studies led to the identification of seven peptides, two from each NSP 9 and NSP 10 and, three from NSP …

Effect Of The Infection With Porcine Reproductive And Respiratory Syndrome Virus On The Regulation Of Cytokines: Tumor Necrosis Factor-Alpha And Interleukin-10, Sakthivel Subramaniam

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Porcine reproductive and respiratory syndrome virus (PRRSV) causes late-term abortion in sows and pneumonia in growing piglets. PRRSV evades the host immune response by several mechanisms, including the modulation of cytokine secretions in infected pigs, which is the subject of this dissertation. Particularly, PRRSV reduces the secretion of the pro-inflammatory cytokine, tumor necrosis factor-α (TNF-α) but increases the secretion of the anti-inflammatory cytokine interleukin-10 (IL-10). The latter effect, however, is PRRSV strain-specific. In this dissertation, we have examined mechanisms by which PRRSV regulates TNF-α and IL-10 expressions. The pathogenic strain FL12, derived from a PRRSV infectious clone, consistently suppressed TNF-α …

Role Of Porcine Reproductive And Respiratory Syndrome Virus Non-Structural Protein 1 In Viral Replications And Pathogenesis, Lalit Kumar Beura

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Porcine reproductive and respiratory syndrome virus (PRRSV) is an infectious agent of significant concern to the global swine industry. PRRSV infection of pigs is initiated by a long viremia after which the virus enters in an extended persistent phase of 3-4 months that ultimately is resolved by the immune system. The delayed and weak host adaptive response is responsible for the protracted convalescence period. An initial sub-optimal innate immune response is postulated to be the reason behind such meager adaptive immune response. A major focus of the studies undertaken in this dissertation was to identify the viral non-structural proteins (nsps) …

Identification Of Host Proteins Required For Vesicular Stomatitis Virus Infection, Debasis Panda

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Viruses usurp host cell pathways for different stages of their infection. Understanding virus-host interaction will be invaluable to elucidate molecular mechanisms of virus infection and to identify drug targets. In order to identify such critical cellular genes in vesicular stomatitis virus (VSV, a model non-segmented negative strand RNA virus) infection, we developed a stable cell line constitutively expressing replication proteins of VSV. Attempts to establish a cell line replicating a sub-genomic replicon was not successful because of induction of interferon response by replication of viral genomic analog. Subsequently, we used siRNA technology and conducted a genome-wide siRNA screen in HeLa …

Minimal Art: Or Why Small Viral K+ Channels Are Good Tools For Understanding Basic Structure And Function Relations, Gerhard Thiel, Dirk Baumeister, Indra Schroeder, Stefan M. Kast, James L. Van Etten, Anna Moroni

James Van Etten Publications

Some algal viruses contain genes that encode proteins with the hallmarks of K+ channels. One feature of these proteins is that they are less than 100 amino acids in size, which make them truly minimal for a K+ channel protein. That is, they consist of only the pore module present in more complex K+ channels. The combination of miniature size and the functional robustness of the viral K+ channels make them ideal model systems for studying how K+ channels work. Here we summarize recent structure/function correlates from these channels, which provide insight into functional properties such as gating, pharmacology and …

Functional Hak/Kup/Kt-Like Potassium Transporter Encoded By Chlorella Viruses, Timo Greiner, José Ramos, Maria C. Alvarez, James Gurnon, Ming Kang, James L. Van Etten, Anna Moroni, Gerhard Thiel

James Van Etten Publications

Chlorella viruses are a source of interesting membrane transport proteins. Here we examine a putative K+ transporter encoded by virus FR483 and related chlorella viruses. The protein shares sequence and structural features with HAK/KUP/KT-like K+ transporters from plants, bacteria and fungi. Yeast complementation assays and Rb+ uptake experiments show that the viral protein, termed HAKCV (high-affinity K+ transporter of chlorella virus), is functional, with transport characteristics that are similar to those of known K+ transporters. Expression studies revealed that the protein is expressed as an early gene during viral replication, and proteomics data indicate that it is not packaged in …

Giant Viruses, James L. Van Etten

James Van Etten Publications

The common view of viruses, mostly true, is of tiny burglars that sneak into cells, grab the biosynthetic controls and compel the cell to make huge numbers of progeny that break out of the cell and keep the replication cycle going. Viruses are supposed to be diminutive even compared to cells that are just a micrometer (1,000 nanometers) in diameter. They are supposed to travel light, making do with just a few well-adapted genes.

In 1992, a new microorganism was isolated from a power-plant cooling tower in Bradford, England, where Timothy Robotham, a microbiologist at Leeds Public Health Laboratory, was …

A Functional Calcium-Transporting Atpase Encoded By Chlorella Viruses, Maria Cristina Bonza, Holger Martin, Ming Kang, Gentry L. Lewis, Timo Greiner, Sonia Giacometti, James L. Van Etten, Maria Ida De Michelis, Gerhard Thiel, Anna Moroni

James Van Etten Publications

Calcium-transporting ATPases (Ca²⁺ pumps) are major players in maintaining calcium homeostasis in the cell and have been detected in all cellular organisms. Here, we report the identification of two putative Ca²⁺ pumps, M535L and C785L, encoded by chlorella viruses MT325 and AR158, respectively, and the functional characterization of M535L. Phylogenetic and sequence analyses place the viral proteins in group IIB of P-type ATPases even though they lack a typical feature of this class, a calmodulin-binding domain. A Ca²⁺ pump gene is present in 45 of 47 viruses tested and is transcribed during virus infection. Complementation analysis of …

Identification Of An L-Rhamnose Synthetic Pathway In Two Nucleocytoplasmic Large Dna Viruses, Madhu Parakkottil Chothi, Garry A. Duncan, Andrea Armirotti, Chantal Abergel, James R. Gurnon, James L. Van Etten, Cinzia Bernardi, Gianluca Damonte, Michela Tonetti

James Van Etten Publications

Nucleocytoplasmic large DNA viruses (NCLDVs) are characterized by large genomes that often encode proteins not commonly found in viruses. Two species in this group are Acanthocystis turfacea chlorella virus 1 (ATCV-1) (family Phycodnaviridae, genus Chlorovirus) and Acanthamoeba polyphaga mimivirus (family Mimiviridae), commonly known as mimivirus. ATCV-1 and other chlorovirus members encode enzymes involved in the synthesis and glycosylation of their structural proteins. In this study, we identified and characterized three enzymes responsible for the synthesis of the sugar L-rhamnose: two UDP-D-glucose 4,6-dehydratases (UGDs) encoded by ATCV-1 and mimivirus and a bifunctional UDP-4-keto-6-deoxy-D-glucose epimerase/reductase (UGER) from mimivirus. Phylogenetic …

Influence Of Type 2 Bovine Viral Diarrhea Virus NPro On Enhancement Of Bovine Respiratory Syncytial Virus Replication Mediated By Antagonism Of Host Cell Interferon Type I Responses, Abdulrahman Abdulaziz A. Alkheraif

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Bovine viral diarrhea virus (BVDV) is a member of the genus Pestivirus, Family Flaviviridae. The virus can infect many species of animals of the order Artiodactyla. The BVDV genome encodes an auto protease, N^pro, that degrades interferon regulatory factor-3 (IRF-3) reducing type I interferon (IFN-I) production from host cells. Bovine respiratory syncytial virus (BRSV) is a member of the genus Pneumovirus, Family Paramyxoviridae. Concurrent infection with BVDV and BRSV causes more severe respiratory and enteric disease than infection with either virus alone. Our hypothesis was that N^pro modulates the innate immune responses to BVDV infection …