20 results on '"Jancovich JK"'
Search Results
2. Influence of temperature on Ranavirus infection in larval salamanders Ambystoma tigrinum
- Author
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Rojas, S, primary, Richards, K, additional, Jancovich, JK, additional, and Davidson, EW, additional
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- 2005
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3. transmission of the Ambystoma tigrinum virus to alternative hosts
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Jancovich, JK, primary, Davidson, EW, additional, Seiler, A, additional, Jacobs, BL, additional, and Collins, JP, additional
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- 2001
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4. Isolation of a lethal virus from the endangered tiger salamander Ambystoma tigrinum stebbinsi
- Author
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Jancovich, JK, primary, Davidson, EW, additional, Morado, JF, additional, Jacobs, BL, additional, and Collins, JP, additional
- Published
- 1997
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5. Age- and dose-dependent susceptibility of axolotls (Ambystoma mexicanum) by bath exposure to Ambystoma tigrinum virus (ATV).
- Author
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Steel R, Hamed M, Haugom JT, Ho T, Kenner N, Malfavon-Borja J, Morgans S, Salek SA, Seylani A, and Jancovich JK
- Subjects
- Animals, Ambystoma, Host-Pathogen Interactions, Larva, Ambystoma mexicanum, Ranavirus genetics
- Abstract
Ranaviruses are large, dsDNA viruses that have significant ecological and economic impact on cold-blooded vertebrates. However, our understanding of the viral proteins and subsequent host immune response(s) that impact susceptibility to infection and disease is not clear. The ranavirus Ambystoma tigrinum virus (ATV), originally isolated from the Sonoran tiger salamander (Ambystoma mavortium stebbinsi), is highly pathogenic at low doses of ATV at all tiger salamander life stages and this model has been used to explore the host-pathogen interactions of ATV infection. However, inconsistencies in the availability of laboratory reared larval tiger salamanders required us to look at the well characterized axolotl (A. mexicanum) as a model for ATV infection. Data obtained from five infection experiments over different developmental timepoints suggest that axolotls are susceptible to ATV in an age- and dose-dependent manner. These data support the use of the ATV-axolotl model to further explore the host-pathogen interactions of ranavirus infections., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)
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- 2023
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6. Optimization of translation enhancing element use to increase protein expression in a vaccinia virus system.
- Author
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Richard HB Jr, Minder S, Sidhu A, Juba AN, Jancovich JK, Jacobs BL, and Wellensiek BP
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- Animals, Cell Line, Chlorocebus aethiops, Humans, Vaccines, Attenuated biosynthesis, Vaccines, Synthetic biosynthesis, Smallpox prevention & control, Smallpox Vaccine biosynthesis, Vaccinia virus genetics, Vaccinia virus immunology
- Abstract
Since the successful use of vaccinia virus (VACV) in the immunization strategies to eliminate smallpox, research has been focused on the development of recombinant VACV strains expressing proteins from various pathogens. Attempts at decreasing the side effects associated with exposure to recombinant, wild-type viral strains have led to the development of attenuated viruses. Yet while these attenuated VACV's have improved safety profiles compared to unmodified strains, their clinical use has been hindered due to efficacy issues in stimulating a host immune response. This deficiency has largely been attributed to decreased production of the target protein for immunization. Efforts to increase protein production from attenuated VACV strains has largely centered around modulation of viral factors, while manipulation of the translation of viral mRNAs has been largely unexplored. In this study we evaluate the use of translation enhancing element hTEE-658 to increase recombinant protein production in an attenuated VACV system. Optimization of the use of this motif is also attempted by combining it with strategies that have demonstrated effectiveness in previous research. We show that extension of the 5' leader sequence containing hTEE-658 does not improve motif function, nor does the combination with other known translation enhancing elements. However, the sole use of hTEE-658 in an attenuated VACV system is shown to increase protein expression levels beyond those of a standard viral promoter when used with a wild-type virus. Taken together these results highlight the potential for hTEE-658 to improve the effectiveness of attenuated VACV vaccine candidates and give insights into the optimal sequence context for its use in vaccine design.
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- 2021
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7. Immunization of Pigs by DNA Prime and Recombinant Vaccinia Virus Boost To Identify and Rank African Swine Fever Virus Immunogenic and Protective Proteins.
- Author
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Jancovich JK, Chapman D, Hansen DT, Robida MD, Loskutov A, Craciunescu F, Borovkov A, Kibler K, Goatley L, King K, Netherton CL, Taylor G, Jacobs B, Sykes K, and Dixon LK
- Subjects
- African Swine Fever genetics, African Swine Fever prevention & control, African Swine Fever Virus genetics, Animals, Recombinant Proteins genetics, Recombinant Proteins immunology, Swine, Vaccines, DNA genetics, Vaccinia virus genetics, Viral Proteins genetics, African Swine Fever immunology, African Swine Fever Virus immunology, Immunization, Secondary, Vaccines, DNA immunology, Vaccinia virus immunology, Viral Proteins immunology
- Abstract
African swine fever virus (ASFV) causes an acute hemorrhagic fever in domestic pigs, with high socioeconomic impact. No vaccine is available, limiting options for control. Although live attenuated ASFV can induce up to 100% protection against lethal challenge, little is known of the antigens which induce this protective response. To identify additional ASFV immunogenic and potentially protective antigens, we cloned 47 viral genes in individual plasmids for gene vaccination and in recombinant vaccinia viruses. These antigens were selected to include proteins with different functions and timing of expression. Pools of up to 22 antigens were delivered by DNA prime and recombinant vaccinia virus boost to groups of pigs. Responses of immune lymphocytes from pigs to individual recombinant proteins and to ASFV were measured by interferon gamma enzyme-linked immunosorbent spot (ELISpot) assays to identify a subset of the antigens that consistently induced the highest responses. All 47 antigens were then delivered to pigs by DNA prime and recombinant vaccinia virus boost, and pigs were challenged with a lethal dose of ASFV isolate Georgia 2007/1. Although pigs developed clinical and pathological signs consistent with acute ASFV, viral genome levels were significantly reduced in blood and several lymph tissues in those pigs immunized with vectors expressing ASFV antigens compared with the levels in control pigs. IMPORTANCE The lack of a vaccine limits the options to control African swine fever. Advances have been made in the development of genetically modified live attenuated ASFV that can induce protection against challenge. However, there may be safety issues relating to the use of these in the field. There is little information about ASFV antigens that can induce a protective immune response against challenge. We carried out a large screen of 30% of ASFV antigens by delivering individual genes in different pools to pigs by DNA immunization prime and recombinant vaccinia virus boost. The responses in immunized pigs to these individual antigens were compared to identify the most immunogenic. Lethal challenge of pigs immunized with a pool of antigens resulted in reduced levels of virus in blood and lymph tissues compared to those in pigs immunized with control vectors. Novel immunogenic ASFV proteins have been identified for further testing as vaccine candidates., (Copyright © 2018 Jancovich et al.)
- Published
- 2018
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8. The Ambystoma tigrinum virus (ATV) RNase III gene can modulate host PKR activation and interferon production.
- Author
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Allen AG, Morgans S, Smith E, Aron MM, and Jancovich JK
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- Ambystoma virology, Animals, Cell Line, Eukaryotic Initiation Factor-2 metabolism, Fishes, Host-Pathogen Interactions, Humans, Immune Evasion, Phosphoproteins analysis, Phosphorylation, Protein Processing, Post-Translational, Recombinant Proteins genetics, Viral Proteins genetics, Virulence Factors genetics, eIF-2 Kinase metabolism, Interferons antagonists & inhibitors, Protein Kinase Inhibitors metabolism, Recombinant Proteins metabolism, Ribonuclease III metabolism, Viral Proteins metabolism, Virulence Factors metabolism, eIF-2 Kinase antagonists & inhibitors
- Abstract
The iridovirus RNase III gene is one of 26 conserved core genes among the family Iridoviridae. Initial studies suggest this viral protein functions to suppress RNA interference pathways that may attack viral RNA during infection. Therefore, to determine if the Ambystoma tigrinum virus (ATV) RNase III-like gene (ORF 25R) can modulate the host innate immune response fish and human cells ectopically expressing 25R were treated with polyI:C and monitored for interferon synthesis and phosphorylation of eIF2α and PKR. We found a decrease in cellular IFN production and modulation of the PKR pathway. In addition, ATV deleted of the RNase III gene (ATVΔ25R) shows reduced pathogenicity in tiger salamanders. Collectively our data suggest that the ATV 25R protein is a pathogenesis factor that may function to help evade the host's immune response by masking activators of the IFN pathway., (Copyright © 2017 Elsevier Inc. All rights reserved.)
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- 2017
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9. Characterization of a PKR inhibitor from the pathogenic ranavirus, Ambystoma tigrinum virus, using a heterologous vaccinia virus system.
- Author
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Huynh TP, Jancovich JK, Tripuraneni L, Heck MC, Langland JO, and Jacobs BL
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- Ambystoma virology, Animals, Arizona, Gene Expression, Genetic Vectors, Host-Pathogen Interactions, Immune Evasion, Ranavirus genetics, Recombinant Proteins genetics, Vaccinia virus genetics, Viral Proteins genetics, Virulence Factors genetics, Protein Kinase Inhibitors metabolism, Ranavirus pathogenicity, Recombinant Proteins metabolism, Viral Proteins metabolism, Virulence Factors metabolism, eIF-2 Kinase antagonists & inhibitors
- Abstract
Ambystoma tigrinum virus (ATV) (family Iridoviridae, genus Ranavirus) was isolated from diseased tiger salamanders (Ambystoma tigrinum stebbinsi) from the San Rafael Valley in southern Arizona, USA in 1996. Genomic sequencing of ATV, as well as other members of the genus, identified an open reading frame that has homology to the eukaryotic translation initiation factor, eIF2α (ATV eIF2α homologue, vIF2αH). Therefore, we asked if the ATV vIF2αH could also inhibit PKR. To test this hypothesis, the ATV vIF2αH was cloned into vaccinia virus (VACV) in place of the well-characterized VACV PKR inhibitor, E3L. Recombinant VACV expressing ATV vIF2αH partially rescued deletion of the VACV E3L gene. Rescue coincided with rapid degradation of PKR in infected cells. These data suggest that the salamander virus, ATV, contains a novel gene that may counteract host defenses, and this gene product may be involved in the presentation of disease caused by this environmentally important pathogen., (Copyright © 2017. Published by Elsevier Inc.)
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- 2017
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10. ICTV Virus Taxonomy Profile: Iridoviridae.
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Chinchar VG, Hick P, Ince IA, Jancovich JK, Marschang R, Qin Q, Subramaniam K, Waltzek TB, Whittington R, Williams T, Zhang QY, and Ictv Report Consortium
- Subjects
- Amphibians virology, Animals, Crustacea virology, DNA, Viral genetics, Fishes virology, Host Specificity, Insecta virology, Iridoviridae ultrastructure, Reptiles virology, Virion ultrastructure, Iridoviridae classification, Iridoviridae isolation & purification
- Abstract
The Iridoviridae is a family of large, icosahedral viruses with double-stranded DNA genomes ranging in size from 103 to 220 kbp. Members of the subfamily Alphairidovirinae infect ectothermic vertebrates (bony fish, amphibians and reptiles), whereas members of the subfamily Betairidovirinae mainly infect insects and crustaceans. Infections can be either covert or patent, and in vertebrates they can lead to high levels of mortality among commercially and ecologically important fish and amphibians. This is a summary of the current International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Iridoviridae, which is available at www.ictv.global/report/iridoviridae.
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- 2017
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11. Recombinant Ranaviruses for Studying Evolution of Host-Pathogen Interactions in Ectothermic Vertebrates.
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Robert J and Jancovich JK
- Subjects
- Animals, DNA Virus Infections pathology, DNA Virus Infections virology, Ranavirus genetics, Reverse Genetics, Vertebrates, DNA Virus Infections veterinary, Host-Pathogen Interactions, Molecular Biology methods, Ranavirus pathogenicity, Virology methods
- Abstract
Ranaviruses (Iridoviridae) are large DNA viruses that are causing emerging infectious diseases at an alarming rate in both wild and captive cold blood vertebrate species all over the world. Although the general biology of these viruses that presents some similarities with poxvirus is characterized, many aspects of their replication cycles, host cell interactions and evolution still remain largely unclear, especially in vivo. Over several years, strategies to generate site-specific ranavirus recombinant, either expressing fluorescent reporter genes or deficient for particular viral genes, have been developed. We review here these strategies, the main ranavirus recombinants characterized and their usefulness for in vitro and in vivo studies.
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- 2016
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12. Identification of essential and non-essential genes in Ambystoma tigrinum virus.
- Author
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Aron MM, Allen AG, Kromer M, Galvez H, Vigil B, and Jancovich JK
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- Animals, Cells, Cultured, Fishes, Open Reading Frames, Recombination, Genetic, Gene Knockout Techniques, Genes, Essential, Genes, Viral, Ranavirus genetics
- Abstract
Members of the genus Ranavirus (family Iridoviridae) are large double-stranded (ds) DNA viruses that are found world-wide infecting fish, amphibian and reptile ectothermic hosts. Ranavirus genomes range from 105 to 155kbp in length and they are predicted to encode around 90-125 genes. Currently, our knowledge of the function of ∼50% of these genes is known or inferred based on homology to orthologous genes characterized in other systems; however, the function of the remaining open reading frames (ORFS) is unknown. Therefore, in order to begin to uncover the function of unknown ORFs in ranaviruses we developed a standardized approach to generate a recombination cassette for any ORF in Ambystoma tigrinum virus (ATV). Our standardized approach quickly and efficiently assembles recombination cassettes and recombinant ATV. We have used this approach to identify two essential, one semi-essential and two non-essential genes in ATV., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
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13. The molecular biology of frog virus 3 and other iridoviruses infecting cold-blooded vertebrates.
- Author
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Chinchar VG, Yu KH, and Jancovich JK
- Subjects
- Amphibians virology, Animals, DNA Virus Infections virology, Fishes virology, Genome, Viral genetics, Iridoviridae genetics, Iridoviridae pathogenicity, Molecular Biology, Ranavirus genetics, Ranavirus pathogenicity, Ranavirus physiology, Recombinant Proteins genetics, Recombinant Proteins metabolism, Reptiles virology, Viral Proteins genetics, Virulence Factors genetics, Virulence Factors metabolism, DNA Virus Infections veterinary, Fish Diseases virology, Iridoviridae physiology, Vertebrates virology, Viral Proteins metabolism, Virus Replication physiology
- Abstract
Frog virus 3 (FV3) is the best characterized member of the family Iridoviridae. FV3 study has provided insights into the replication of other family members, and has served as a model of viral transcription, genome replication, and virus-mediated host-shutoff. Although the broad outlines of FV3 replication have been elucidated, the precise roles of most viral proteins remain unknown. Current studies using knock down (KD) mediated by antisense morpholino oligonucleotides (asMO) and small, interfering RNAs (siRNA), knock out (KO) following replacement of the targeted gene with a selectable marker by homologous recombination, ectopic viral gene expression, and recombinant viral proteins have enabled researchers to systematically ascertain replicative- and virulence-related gene functions. In addition, the application of molecular tools to ecological studies is providing novel ways for field biologists to identify potential pathogens, quantify infections, and trace the evolution of ecologically important viral species. In this review, we summarize current studies using not only FV3, but also other iridoviruses infecting ectotherms. As described below, general principles ascertained using FV3 served as a model for the family, and studies utilizing other ranaviruses and megalocytiviruses have confirmed and extended our understanding of iridovirus replication. Collectively, these and future efforts will elucidate molecular events in viral replication, intrinsic and extrinsic factors that contribute to disease outbreaks, and the role of the host immune system in protection from disease.
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- 2011
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14. Innate immune evasion mediated by the Ambystoma tigrinum virus eukaryotic translation initiation factor 2alpha homologue.
- Author
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Jancovich JK and Jacobs BL
- Subjects
- Animals, Antiviral Agents immunology, Antiviral Agents metabolism, Cell Line, Disease Models, Animal, Eukaryotic Initiation Factor-2 genetics, Eukaryotic Initiation Factor-2 immunology, Fishes, Gene Deletion, Interferons immunology, Interferons metabolism, Ranavirus genetics, Survival Analysis, Time Factors, Viral Plaque Assay, Viral Proteins genetics, Viral Proteins immunology, Virulence Factors genetics, Virulence Factors immunology, eIF-2 Kinase metabolism, Eukaryotic Initiation Factor-2 metabolism, Immune Evasion, Ranavirus immunology, Ranavirus pathogenicity, Viral Proteins metabolism, Virulence Factors metabolism
- Abstract
Ranaviruses (family Iridoviridae, genus Ranavirus) are large, double-stranded DNA (dsDNA) viruses whose replication is restricted to ectothermic vertebrates. Many highly pathogenic members of the genus Ranavirus encode a homologue of the eukaryotic translation initiation factor 2α (eIF2α). Data in a heterologous vaccinia virus system suggest that the Ambystoma tigrinum virus (ATV) eIF2α homologue (vIF2αH; open reading frame [ORF] 57R) is involved in evading the host innate immune response by degrading the interferon-inducible, dsRNA-activated protein kinase, PKR. To test this hypothesis directly, the ATV vIF2αH gene (ORF 57R) was deleted by homologous recombination, and a selectable marker was inserted in its place. The ATVΔ57R virus has a small plaque phenotype and is 8-fold more sensitive to interferon than wild-type ATV (wtATV). Infection of fish cells with the ATVΔ57R virus leads to eIF2α phosphorylation, in contrast to infection with wtATV, which actively inhibits eIF2α phosphorylation. The inability of ATVΔ57R to prevent phosphorylation of eIF2α correlates with degradation of fish PKZ, an interferon-inducible enzyme that is closely related to mammalian PKR. In addition, salamanders infected with ATVΔ57R displayed an increased time to death compared to that of wtATV-infected salamanders. Therefore, in a biologically relevant system, the ATV vIF2αH gene acts as an innate immune evasion factor, thereby enhancing virus pathogenesis.
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- 2011
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15. Evidence for multiple recent host species shifts among the Ranaviruses (family Iridoviridae).
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Jancovich JK, Bremont M, Touchman JW, and Jacobs BL
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- Animals, Base Sequence, Fish Diseases virology, Gene Library, Genome, Viral, Molecular Sequence Data, Open Reading Frames, Phylogeny, Ranavirus classification, Ranavirus physiology, Sequence Alignment, Turtles virology, Urodela virology, Anura virology, Fishes virology, Host-Pathogen Interactions genetics, Ranavirus genetics, Ranavirus pathogenicity
- Abstract
Members of the genus Ranavirus (family Iridoviridae) have been recognized as major viral pathogens of cold-blooded vertebrates. Ranaviruses have been associated with amphibians, fish, and reptiles. At this time, the relationships between ranavirus species are still unclear. Previous studies suggested that ranaviruses from salamanders are more closely related to ranaviruses from fish than they are to ranaviruses from other amphibians, such as frogs. Therefore, to gain a better understanding of the relationships among ranavirus isolates, the genome of epizootic hematopoietic necrosis virus (EHNV), an Australian fish pathogen, was sequenced. Our findings suggest that the ancestral ranavirus was a fish virus and that several recent host shifts have taken place, with subsequent speciation of viruses in their new hosts. The data suggesting several recent host shifts among ranavirus species increase concern that these pathogens of cold-blooded vertebrates may have the capacity to cross numerous poikilothermic species barriers and the potential to cause devastating disease in their new hosts.
- Published
- 2010
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16. Phylogenetic concordance analysis shows an emerging pathogen is novel and endemic.
- Author
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Storfer A, Alfaro ME, Ridenhour BJ, Jancovich JK, Mech SG, Parris MJ, and Collins JP
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- Animals, Animals, Wild, Biological Evolution, Communicable Diseases, Emerging transmission, Communicable Diseases, Emerging veterinary, Communicable Diseases, Emerging virology, Conservation of Natural Resources, DNA Virus Infections transmission, DNA Virus Infections virology, Demography, Humans, Phylogeny, Ranavirus classification, United States, Virulence genetics, DNA Virus Infections veterinary, Public Health, Ranavirus genetics, Ranavirus pathogenicity, Urodela virology
- Abstract
Distinguishing whether pathogens are novel or endemic is critical for controlling emerging infectious diseases, an increasing threat to wildlife and human health. To test the endemic vs. novel pathogen hypothesis, we present a unique analysis of intraspecific host-pathogen phylogenetic concordance of tiger salamanders and an emerging Ranavirus throughout Western North America. There is significant non-concordance of host and virus gene trees, suggesting pathogen novelty. However, non-concordance has likely resulted from virus introductions by human movement of infected salamanders. When human-associated viral introductions are excluded, host and virus gene trees are identical, strongly supporting coevolution and endemism. A laboratory experiment showed an introduced virus strain is significantly more virulent than endemic strains, likely due to artificial selection for high virulence. Thus, our analysis of intraspecific phylogenetic concordance revealed that human introduction of viruses is the mechanism underlying tree non-concordance and possibly disease emergence via artificial selection.
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- 2007
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17. Inhibition of PKR by RNA and DNA viruses.
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Langland JO, Cameron JM, Heck MC, Jancovich JK, and Jacobs BL
- Subjects
- Animals, DNA Viruses metabolism, Humans, Immunity, Innate, Interferons metabolism, RNA Viruses metabolism, eIF-2 Kinase metabolism, DNA Viruses pathogenicity, RNA Viruses pathogenicity, eIF-2 Kinase antagonists & inhibitors
- Abstract
Interferons were the first of the anti-viral innate immune modulators to be characterized, initially characterized solely as anti-viral proteins [reviewed in Le Page, C., Genin, P., Baines, M.G., Hiscott, J., 2000. Inteferon activation and innate immunity. Rev. Immunogenet. 2, 374-386]. As we have progressed in our understanding of the interferons they have taken a more central role in our understanding of innate immunity and its interplay with the adaptive immune response. One of the key players in function of interferon is the interferon-inducible enzyme, protein kinase (PKR, activatable by RNA). The key role played by PKR in the innate response to virus infection is emphasized by the large number of viruses, DNA viruses as well as RNA viruses, whose hosts range from insects to humans, that code for PKR inhibitors. In this review we will first describe activation of PKR and then describe the myriad of ways that viruses inhibit function of PKR.
- Published
- 2006
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18. Evidence for emergence of an amphibian iridoviral disease because of human-enhanced spread.
- Author
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Jancovich JK, Davidson EW, Parameswaran N, Mao J, Chinchar VG, Collins JP, Jacobs BL, and Storfer A
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- Animals, Canada, Capsid Proteins genetics, Demography, Humans, Iridoviridae classification, Iridoviridae genetics, Iridoviridae pathogenicity, Phylogeny, United States, Virus Diseases veterinary, Iridoviridae isolation & purification, Urodela virology
- Abstract
Our understanding of origins and spread of emerging infectious diseases has increased dramatically because of recent applications of phylogenetic theory. Iridoviruses are emerging pathogens that cause global amphibian epizootics, including tiger salamander (Ambystoma tigrinum) die-offs throughout western North America. To explain phylogeographical relationships and potential causes for emergence of western North American salamander iridovirus strains, we sequenced major capsid protein and DNA methyltransferase genes, as well as two noncoding regions from 18 geographically widespread isolates. Phylogenetic analyses of sequence data from the capsid protein gene showed shallow genetic divergence (< 1%) among salamander iridovirus strains and monophyly relative to available fish, reptile, and other amphibian iridovirus strains from the genus Ranavirus, suggesting a single introduction and radiation. Analysis of capsid protein sequences also provided support for a closer relationship of tiger salamander virus strains to those isolated from sport fish (e.g. rainbow trout) than other amphibian isolates. Despite monophyly based on capsid protein sequences, there was low genetic divergence among all strains (< 1.1%) based on a supergene analysis of the capsid protein and the two noncoding regions. These analyses also showed polyphyly of strains from Arizona and Colorado, suggesting recent spread. Nested clade analyses indicated both range expansion and long-distance colonization in clades containing virus strains isolated from bait salamanders and the Indiana University axolotl (Ambystoma mexicanum) colony. Human enhancement of viral movement is a mechanism consistent with these results. These findings suggest North American salamander ranaviruses cause emerging disease, as evidenced by apparent recent spread over a broad geographical area.
- Published
- 2005
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19. Genomic sequence of a ranavirus (family Iridoviridae) associated with salamander mortalities in North America.
- Author
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Jancovich JK, Mao J, Chinchar VG, Wyatt C, Case ST, Kumar S, Valente G, Subramanian S, Davidson EW, Collins JP, and Jacobs BL
- Subjects
- Animals, DNA Virus Infections mortality, DNA Virus Infections virology, Humans, Molecular Sequence Data, North America, Open Reading Frames, Phylogeny, Ranavirus genetics, Ranavirus pathogenicity, Sequence Alignment, Viral Proteins genetics, DNA Virus Infections veterinary, Genome, Viral, Ranavirus classification, Sequence Analysis, DNA, Urodela virology
- Abstract
Disease is among the suspected causes of amphibian population declines, and an iridovirus and a chytrid fungus are the primary pathogens associated with amphibian mortalities. Ambystoma tigrinum virus (ATV) and a closely related strain, Regina ranavirus (RRV), are implicated in salamander die-offs in Arizona and Canada, respectively. We report the complete sequence of the ATV genome and partial sequence of the RRV genome. Sequence analysis of the ATV/RRV genomes showed marked similarity to other ranaviruses, including tiger frog virus (TFV) and frog virus 3 (FV3), the type virus of the genus Ranavirus (family Iridoviridae), as well as more distant relationships to lymphocystis disease virus, Chilo iridescent virus, and infectious spleen and kidney necrosis virus. Putative open reading frames (ORFs) in the ATV sequence identified 24 genes that appear to control virus replication and block antiviral responses. In addition, >50 other putative genes, homologous to ORFs in other iridoviral genomes but of unknown function, were also identified. Sequence comparison performed by dot plot analysis between ATV and itself revealed a conserved 14-bp palindromic repeat within most intragenic regions. Dot plot analysis of ATV vs RRV sequences identified several polymorphisms between the two isolates. Finally, a comparison of ATV and TFV genomic sequences identified genomic rearrangements consistent with the high recombination frequency of iridoviruses. Given the adverse effects that ranavirus infections have on amphibian and fish populations, ATV/RRV sequence information will allow the design of better diagnostic probes for identifying ranavirus infections and extend our understanding of molecular events in ranavirus-infected cells.
- Published
- 2003
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20. What's your diagnosis? Ranavirus infection.
- Author
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Donnelly TM, Davidson EW, Jancovich JK, Borland S, Newberry M, and Gresens J
- Subjects
- Animals, DNA, Viral analysis, Edema pathology, Edema virology, Female, Hemorrhage pathology, Hemorrhage virology, Male, Polymerase Chain Reaction, RNA Virus Infections complications, RNA Virus Infections pathology, Ranavirus genetics, Ranavirus isolation & purification, Ranavirus pathogenicity, Skin Diseases pathology, Skin Diseases virology, Ambystoma mexicanum, Edema veterinary, Extremities pathology, Hemorrhage veterinary, Laboratory Animal Science, RNA Virus Infections veterinary, Skin Diseases veterinary
- Published
- 2003
- Full Text
- View/download PDF
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