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Molecular characteristics of Polish field strains of Marek's disease herpesvirus isolated from vaccinated chickens

ACTA VETERINARIA SCANDINAVICA 2011年第1期53卷 10-17页

作者： Wozniakowski, Grzegorz Samorek-Salamonowicz, Elzbieta Kozdrun, Wojciech Natl Inst Vet Res Dept Poultry Viral Dis PL-24100 Pulawy Poland

Background: Twenty-nine Marek's disease virus (MDV) strains were isolated during a 3 year period (2007-2010) from vaccinated and infected chicken flocks in Poland. These strains had caused severe clinical symptoms and lesions. In spite of proper vaccination with mono-or bivalent vaccines against Marek's disease (MD), the chickens developed symptoms of MD with paralysis. Because of this we decided to investigate possible changes and mutations in the field strains that could potentially increase their virulence. We supposed that such mutations may have been caused by recombination with retroviruses of poultry - especially reticuloendotheliosis virus (REV). Methods: In order to detect the possible reasons of recent changes in virulence of MDV strains, polymerase chain reaction (PCR) analyses for meq oncogene and for long-terminal repeat (LTR) region of REV were conducted. The obtained PCR products were sequenced and compared with other MDV and REV strains isolated worldwide and accessible in the GeneBank database. Results: Sequencing of the meq oncogene showed a 68 basepair insertion and frame shift within 12 of 24 field strains. Interestingly, the analyses also showed 0.78, 0.8, 0.82, 1.6 kb and other random LTR-REV insertions into the MDV genome in 28 of 29 of strains. These genetic inserts were present after passage in chicken embryo kidney cells suggesting LTR integration into a non-functional region of the MDV genome. Conclusion: The results indicate the presence of a recombination between MDV and REV under field conditions in Polish chicken farms. The genetic changes within the MDV genome may influence the virus replication and its features in vivo. However, there is no evidence that meq alteration and REV insertions are related to the strains'

关键词： latency associate transcript Avian Leukosis Virus Duck Embryo Fibroblast Reticuloendotheliosis Virus Obtain Polymerase Chain Reaction Product

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Emerging roles of chicken and viral microRNAs in avian disease

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BMC proceedings 2011年第4期5 Suppl 4卷 S2页

作者： Joan Burnside Robin Morgan Delaware Biotechnology Institute University of Delaware 15 Innovation Way Newark Delaware 19711 USA. joan@udel.edu.

BACKGROUND:MicroRNAs are short RNAs (~22 nt) expressed by plants, animals and viruses that regulate gene expression post-transcriptionally, and their importance is highlighted by distinct patterns of expression in many physiological processes, including development, hematopoeisis, stress resistance, and disease. Our group has characterized the microRNAs encoded by the avian herpesviruses; namely, oncogenic Marek's disease (MD) virus (MDV1), non-oncogenic MDV (MDV2) herpesvirus of turkeys (HVT), and infectious laryngotracheitis virus (ILTV). METHODS:MicroRNAs encoded by the avian herpesviruses were identified using next generation sequencing technologies (454, Illumina). RESULTS:The microRNAs of each the avian herpesviruses have unique sequences, but the genomic locations are similar, in that the microRNAs tend to be clustered in the rapidly evolving repeat regions of the viral genomes. For a given viral species the microRNA sequence is highly conserved in different strains with the exception of a virulence-associated polymorphism in the putative promoter of the MDV1 microRNAs upstream of the meq oncogene. These microRNAs are relatively highly expressed in tumors produced by very virulent MDV1 isolates compared to tumors produced by less virulent strains. MDV1 and HVT encode homologs of the host microRNA, miR-221, which targets a gene important in cell cycle regulation. MDV1 encodes a microRNA (mdv1-miR-M4) that shares a seed sequence with miR-155, a microRNA important in immune function. Mdv-miR-M4 is highly expressed in MDV induced tumors, while miR-155 is present at very low levels. CONCLUSIONS:MicroRNAs are highly conserved among different field strains of MDV1, and they are expressed in lytic and latent infections and in MDV1-derived tumors. This suggests that these small molecules are very important to the virus, and roles in immune evasion, anti-apoptosis, or proliferation are likely.

关键词： Chicken Embryo Fibroblast latency associate transcript microRNA Sequence ICP4 Gene Infectious Laryngotracheitis Virus

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Effects of thyroid hormone on HSV-1 gene regulation: implications in the control of viral latency and reactivation

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CELL AND BIOSCIENCE 2011年第1期1卷 24-24页

作者： Hsia, Shao-Chung Bedadala, Gautam R. Balish, Matthew D. Univ Maryland Dept Pharmaceut Sci Eastern Shore Sch Pharm Princess Anne MD 21853 USA

Thyroid hormone (TH) is involved in many biological functions such as animal development, cell differentiation, etc. Variation and/or disruption of plasma TH level often led to abnormalities and physiological disorders. TH exerts the effects through its nuclear receptors (TR). Literature showed that procedures resulted in TH alteration also linked to reactivation of several viruses including Herpes Simplex Virus Type -1 (HSV-1). Bioinformatic analyses revealed a number of putative TH responsive elements (TRE) located in the critical regulatory regions of HSV-1 genes such as thymidine kinase (TK), latency associated transcript (LAT), etc. Studies using neuronal cell lines have provided evidences demonstrating that liganded TR regulated viral gene expression via chromatin modification and controlled viral replication. The removal of TH reversed the inhibition and induced the viral replication previously blocked by TH. These results suggest that TH may have implication to participate in the control of reactivation during HSV-1 latency.

关键词： Thyroid Hormone Thymidine Kinase Trigeminal Ganglion latency associate transcript Herpes Simplex Virus

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Comparative analysis of oncogenic genes revealed unique evolutionary features of field Marek's disease virus prevalent in recent years in China

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Virology journal 2011年第1期8卷 121页

作者： Mingxing Tian Yang Zhao Yan Lin Nianli Zou Cheng Liu Ping Liu Sanjie Cao Xintian Wen Yong Huang College of Veterinary Medicine Sichuan Agricultural University Ya'an Sichuan People's Republic of China.

BACKGROUND:Marek's disease (MD) is an economically important viral disease of chickens caused by Marek's disease virus (MDV), an oncogenic herpesvirus. This disease was well controlled since the widespread use of commercial vaccines, but field MDVs have shown continuous increasing in virulence and acquired the ability to overcome the immune response induced by vaccines. Nowadays, MD continues to be a serious threat to poultry industry, isolation and characterization of MDVs are essential for monitoring changes of viruses and evaluating the effectiveness of existing vaccines. RESULTS:Between 2008 and 2010, 18 field MDV strains were isolated from vaccinated chicken flocks in Sichuan province, China. Three oncogenic genes including Meq, pp38 and vIL-8 genes of the 18 isolates were amplified and sequenced. Homology analysis showed that the deduced amino acid sequences of these three genes exhibit 95.0-98.8%, 99.3-100% and 97.0-98.5% homology respectively with these of other reference strains published in GenBank. Alignment analysis of the nucleotide and deduced amino acid sequences showed that four amino acid mutations in Meq gene and two amino acid mutations in vIL-8 gene displayed perfect regularity in MDVs circulating in China, which could be considered as features of field MDVs prevalent in recent years in China. In addition, one amino acid mutation in pp38 gene can be considered as a feature of virulent MDVs from USA, and three amino acid mutations in Meq gene were identified and unique in very virulent plus (vv+) MDVs. Phylogenetic analysis based on Meq and vIL-8 protein sequences revealed that field MDVs in China evolved independently. Virulence studies showed that CVI988 could provide efficient protection against the field MDVs epidemic recently in China. CONCLUSIONS:This study and other published data in the GenBank have demonstrated the features of Meq, pp38 and vIL-8 genes of MDVs circulating in recent years in Sichuan, China. Mutations, deletions or insertio

关键词： Deduce Amino Acid Sequence Amino Acid Mutation latency associate transcript Avian Leukosis Virus Chicken Farm

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Expression of RNA interference triggers from an oncolytic herpes simplex virus results in specific silencing in tumour cells in vitro and tumours in vivo

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BMC CANCER 2010年第1期10卷 486-486页

作者： Anesti, Anna-Maria Simpson, Guy R. Price, Toby Pandha, Hardev S. Coffin, Robert S. Univ Surrey Oncol Grp Postgrad Med Sch Guildford GU2 5XH Surrey England Biovex Inc Res Grp Woburn MA USA

Background: Delivery of small interfering RNA (siRNA) to tumours remains a major obstacle for the development of RNA interference (RNAi)-based therapeutics. Following the promising pre-clinical and clinical results with the oncolytic herpes simplex virus (HSV) OncoVEX(GM-CSF), we aimed to express RNAi triggers from oncolytic HSV, which although has the potential to improve treatment by silencing tumour-related genes, was not considered possible due to the highly oncolytic properties of HSV. Methods: To evaluate RNAi-mediated silencing from an oncolytic HSV backbone, we developed novel replicating HSV vectors expressing short-hairpin RNA (shRNA) or artificial microRNA (miRNA) against the reporter genes green fluorescent protein (eGFP) and beta-galactosidase (lacZ). These vectors were tested in non-tumour cell lines in vitro and tumour cells that are moderately susceptible to HSV infection both in vitro and in mice xenografts in vivo. Silencing was assessed at the protein level by fluorescent microscopy, x-gal staining, enzyme activity assay, and western blotting. Results: Our results demonstrate that it is possible to express shRNA and artificial miRNA from an oncolytic HSV backbone, which had not been previously investigated. Furthermore, oncolytic HSV-mediated delivery of RNAi triggers resulted in effective and specific silencing of targeted genes in tumour cells in vitro and tumours in vivo, with the viruses expressing artificial miRNA being comprehensibly more effective. Conclusions: This preliminary data provide the first demonstration of oncolytic HSV-mediated expression of shRNA or artificial miRNA and silencing of targeted genes in tumour cells in vitro and in vivo. The vectors developed in this study are being adapted to silence tumour-related genes in an ongoing study that aims to improve the effectiveness of oncolytic HSV treatment in tumours that are moderately susceptible to HSV infection and thus, potentially improve response rates seen in human clinica

关键词： Herpes Simplex Virus Herpes Simplex Virus Infection Oncolytic Virus latency associate transcript Herpes Simplex Virus Vector Herpes Simplex Virus Herpes Simplex Virus Infection Oncolytic Virus latency associate transcript Herpes Simplex Virus Vector

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Prediction of viral microRNA precursors based on human microRNA precursor sequence and structural features

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VIROLOGY JOURNAL 2009年第1期6卷 1-8页

作者： Kumar, Shiva Ansari, Faraz A. Scaria, Vinod CSIR Inst Genom & Integrat Biol GN Ramachandran Knowledge Ctr Genome Informat Delhi 110007 India

MicroRNAs (small similar to 22 nucleotide long non-coding endogenous RNAs) have recently attracted immense attention as critical regulators of gene expression in multi-cellular eukaryotes, especially in humans. Recent studies have proved that viruses also express microRNAs, which are thought to contribute to the intricate mechanisms of host-pathogen interactions. Computational predictions have greatly accelerated the discovery of microRNAs. However, most of these widely used tools are dependent on structural features and sequence conservation which limits their use in discovering novel virus expressed microRNAs and non-conserved eukaryotic microRNAs. In this work an efficient prediction method is developed based on the hypothesis that sequence and structure features which discriminate between host microRNA precursor hairpins and pseudo microRNAs are shared by viral microRNA as they depend on host machinery for the processing of microRNA precursors. The proposed method has been found to be more efficient than recently reported ab-initio methods for predicting viral microRNAs and microRNAs expressed by mammals.

关键词： Support Vector Machine Support Vector Machine Algorithm latency associate transcript Hairpin Sequence microRNA Precursor

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microRNAs in viral oncogenesis

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RETROVIROLOGY 2007年第1期4卷 82-82页

作者： Scaria, Vinod Jadhav, Vaibhav CSIR Inst Genom & Integrat Biol GN Ramachandran Knowkedge Ctr Genome Informat Delhi 110007 India

MicroRNAs are a recently discovered class of small noncoding functional RNAs. These molecules mediate post-transcriptional regulation of gene expression in a sequence specific manner. MicroRNAs are now known to be key players in a variety of biological processes and have been shown to be deregulated in a number of cancers. The discovery of viral encoded microRNAs, especially from a family of oncogenic viruses, has attracted immense attention towards the possibility of microRNAs as critical modulators of viral oncogenesis. The host-virus crosstalk mediated by microRNAs, messenger RNAs and proteins, is complex and involves the different cellular regulatory layers. In this commentary, we describe models of microRNA mediated viral oncogenesis.

关键词： microRNA Expression latency associate transcript Viral Integration microRNA Biogenesis Viral Oncogenesis

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Host-virus interaction: a new role for microRNAs

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RETROVIROLOGY 2006年第1期3卷 1-9页

作者： Scaria, Vinod Hariharan, Manoj Maiti, Souvik Pillai, Beena Brahmachari, Samir K. CSIR Inst Genom & Integrat Biol GN Ramachandran Knowledge Ctr Genome Informat Delhi 110007 India

MicroRNAs ( miRNAs) are a new class of 18 - 23 nucleotide long non- coding RNAs that play critical roles in a wide spectrum of biological processes. Recent reports also throw light into the role of microRNAs as critical effectors in the intricate host- pathogen interaction networks. Evidence suggests that both virus and hosts encode microRNAs. The exclusive dependence of viruses on the host cellular machinery for their propagation and survival also make them highly susceptible to the vagaries of the cellular environment like small RNA mediated interference. It also gives the virus an opportunity to fight and/ or modulate the host to suite its needs. Thus the range of interactions possible through miRNA- mRNA cross- talk at the host- pathogen interface is large. These interactions can be further fine- tuned in the host by changes in gene expression, mutations and polymorphisms. In the pathogen, the high rate of mutations adds to the complexity of the interaction network. Though evidence regarding microRNA mediated cross- talk in viral infections is just emerging, it offers an immense opportunity not only to understand the intricacies of hostpathogen interactions, and possible explanations to viral tropism, latency and oncogenesis, but also to develop novel biomarkers and therapeutics.

关键词： Human Immunodeficiency Virus microRNA Target latency associate transcript microRNA Level microRNA Target Prediction

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