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Acta virologica

Volume 46 / 2002 / number 3

 

 


VIRAL PROTEINASES – POSSIBLE TARGETS OF ANTIVIRAL DRUGS

T. MALIAR, Š. BALÁŽ, R. TANDLICH, E. ŠTURDÍK

Research Institute for Drugs, Horná 36, 900 01, Modra, Slovak Republic;
Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND, USA;
Department of Biochemical Technology, Faculty of Chemical Technology, Slovak Technical University, Bratislava, Slovak Republic

Summary. – Viral infections represent various types of human, veterinary and plant diseases with a significant economic, ethic and demographic impact. Over the years a significant effort has been made to develop various means of prevention and therapy of viral diseases. Proteinases play an important role in the process of virus replication as well as in the pathophysiology of many viral diseases. The aim of this review is to assess the prospects of the application of proteinase inhibitors in antiviral therapy and to characterize viral proteinases of various classes. Six Human immunodeficiency virus (HIV) proteinase inhibitors have been approved for therapeutic use and can serve as examples of prospective application of proteinase inhibitors to antiviral therapy.

Key words: viral proteinases; proteinase inhibitors; virus maturation; antiviral therapy
Acta virologica 46: 131 – 140, 2002

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APPLICATION OF CDNA MICROARRAY TECHNIQUE TO DETECTION OF GENE EXPRESSION IN HOST CELLS INFECTED WITH VIRUSES

J.H. NAM, C.H. YU, K.A. HWANG, J.S. KIM, S.H. AHN, J.Y. SHIN, W.Y. CHOI, Y.R. JOO, K.Y. PARK

Department of Virology, Korean National Institute of Health, 5 Nokbun-dong, Eunpyung-gu, Seoul, 122-701, Korea;
Genomictree, Taejeon, Korea

Summary. – cDNA microarray technique was used to monitor changes in mRNA levels in cells after Hantaan virus (HTNV) infection. The values of the ratio of medians for HTNV and Japanese encephalitis virus (JEV) at the early stage of infection were compared and found similar, suggesting that the same or similar genes are associated with the early events of infection with either virus. The reproducibility of values of the ”ratio of medians” for HTNV was examined. We found that applying cluster analysis to the gene expression data groups efficiently together genes with the same function. Therefore, in analyzing the effects of viral infection on host cells by the cDNA microarray technique, clustering data appear to be necessary for gaining biological meaning from a dump of gene expression profiles obtained from virus-infected cells.

Key words: cDNA microarray; cluster analysis; viral infection
Acta virologica 46: 141 – 146, 2002

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POLYCLONAL ANTIBODIES TO A RECOMBINANT COAT PROTEIN OF POTATO VIRUS A

N. ČEŘOVSKÁ, T. MORAVEC, J. VELEMÍNSKÝ

Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Na Karlovce 1a, 160 00 Prague 6, Czech Republic

Summary. – Specific mouse antibodies against a recombinant coat protein (CP) of Potato virus A (PVA) were produced. The PVA CP gene was cloned in an expression vector pMPM4W. After expression in Escherichia coli the presence of the expressed CP was proved by Western blot analysis using polyclonal and monoclonal antibodies (MAbs). The expressed CP was purified by centrifugation in CsCl density gradient or on a sucrose cushion. The production of virus-like particles (VLPs) was proved by electron microscopy. The purified CP was used for preparation of a mouse antiserum which had a titer of 1:1024 in ELISA and reacted specifically in Western blot analysis and indirect plate-trapped antigen ELISA (PTA-ELISA).

Key words: Potato virus A; recombinant coat protein; Escherichia coli
Acta virologica 46: 147 – 151, 2002

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COMPLETE GENOMES OF TWO HUMAN HEPATITIS A VIRUS ISOLATES FROM CHINA: ANALYSIS AND COMPARISON WITH OTHER ISOLATES

Y. HU, N. HU, G. LIU

Department of Vaccine Research, Institute of Medical Biology, Chinese Academy of Medical Sciences, Peking Union of Medical College, 379 Jiaoling Road, Kunming, 650118 Yunnan, P.R. China

Summary. – Complete sequences of the genomes of two wild type (wt) Human hepatitis A virus (HHAV) isolates, LU38 and LY6 from China were determined and compared with those of wt HHAV isolates AH1, AH2, AH3, FH1, FH2, FH3, GBM, HM175, LA and MBB. The genomes of both LU38 and LY6 consisting of 7477 nucleotides (nts) contained a 5'-non-translated region (5'-NTR, 733 nts), an open reading frame (ORF, 6681 nts), and a 3'-NTR (63 nts) followed by a poly(A)-tail. It encoded a polyprotein of 2227 amino acids (aa) Sequence comparison showed that LU38 shared the highest identities of 98.1% for nt (140 differences) and 99.2% for as (17 differences) with AH1, and the lowest identities of 91.4% for nt (741 differences) with HM175 and 98.1% for aa (43 differences) with GBM. LY6 shared the highest identities of 97.4% for nt (196 differences) and 98.7% for aa (28 differences) with H1 and the lowest identities of 91.2% for nt (642 differences) with HM175 and 97.7% for as (51 differences) with GBM. The subgenotyping revealed that the LU38 and LY6 isolates are of IA subgenotype. The phylogenetic analysis showed that LU38 is closest to AH1 and the LY6 to FH3, suggesting that the epidemiological link of hepatitis A (HA) had developed in China and Japan.

Key words: amino acid sequence; nucleotide sequence; Human hepatitis A virus, isolates; phylogenetic analysis; China
Acta virologica 46: 153 – 157, 2002

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UPSTREAM AUGS MODULATE PRION PROTEIN TRANSLATION IN VITRO

B. SCHRÖDER, R. NICKODEMUS, T. JÜRGENS, W. BODEMER

Department of Virology, Paul Ehrlich Institute, Langen, Germany;
German Primate Center, Kellnerweg, Göttingen, Germany

Summary. – The level of expression of the host PrP gene (PRNP) has been shown to affect the progression to a disease, transmissible spongiform encephalopathy (TSE). In order to define sequences that are responsible for translation of PRNP mRNA we have investigated a region comprising its 5'-leader sequence. Most remarkable, it consists of an almost identical Kozak mRNA sequence and two AUG initiation codons which seem to modulate translation of the prion protein mRNA in vitro. Although transcriptional regulation of the prion protein PRNP gene had been expected to dominate the translational modulation, our observations point to a translational regulation of the mouse prion protein synthesis controlled by ribosomal entry and usage of AUG codons.

Key words: prion; PrPC; PrPSC; transmissible spongiform encephalopathy; translation; regulation; expression; promoter; reinitiation
Acta virologica 46: 159 – 167, 2002

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MOLECULAR CHARACTERIZATION OF HEPATITIS C VIRUS (HCV) CORE REGION IN HCV-INFECTED THAI BLOOD DONORS

A. THEAMBOONLERS, T. CHINCHAI, K. BEDI, P. JANTARASAMEE, M. SRIPONTONG, Y. POOVORAWAN

Viral Hepatitis Research Unit, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand;
Inter-Department of Medical Microbiology, Faculty of Graduate School, Chulalongkorn University, Bangkok, Thailand

Summary. – In order to investigate the distribution of Hepatitis C virus (HCV) genotypes in Thailand, we performed phylogenetic analysis based on the virus core region and in this way we identified and reliably distinguished HCV genotypes 1–6 as well as subtypes. Among 100 plasma samples randomly selected from blood donors positive for antibodies to HCV (anti-HCV) 90 (90%) were found positive for HCV RNA and 77 of them were subjected to nucleotide sequencing. The following types and subtypes were identified in this group: 1a in 16 samples (20.8%), 1b in 14 samples (18.2%), 3a in 29 samples (37.7%), 3b in 5 samples (6.5%), and 6a in 13 samples (16.9%). Although this study allowed identification and characterization of HCV among blood donors, more extensive studies are needed to explore the HCV distribution in other population groups and in other geographical regions and to exploit the virus core-based characterization of HCV for evaluation of treatment and clinical outcome and epidemiological purposes.

Key words: HCV; virus core; blood donor; phylogenetic tree; genotype; subtype
Acta virologica 46: 169 – 173, 2002

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COMPARISON OF SIX AUSTRALIAN ISOLATES OF BOVINE HERPES VIRUS 2 BASED ON UL24 GENE AFTER A PASSAGE IN MDBK CELLS

J.T. MAY

Department of Microbiology, Faculty of Science, Technology and Engineering, LaTrobe University, Bundoora, Victoria 3086, Australia

Summary. – A region of the UL24 gene of six Australian field isolates of Bovine herpesvirus 2 (BHV-2) was sequenced after a passage in Madin-Darby bovine kidney (MDBK) cells by polymerase chain reaction (PCR). While the PCR product covered the first half of the UL24 gene, a particular interest was focused on the 274–297 nucleotide (nt) region in which a two nt deletion had previously been detected in the BHM-1 strain of BHV-2. Most isolates tested did not generate any defective UL24 genes during the passage. However, a third of the UL24 genes of BHM-1 strain contained the two nts deletion, but only when a high multiplicity of infection (MOI) was used. Also in the isolate 554 at least a half of the UL24 genes were found to be altered independently of the MOI used. These UL24 genes had an insertion of four nts within the 274–297 nt region. The predicted truncation of the UL24 protein of both viruses occurred at the same stop codon. The region of the gene in which these mutations of the UL24 gene occurred is common to all herpesviruses.

Key words: Bovine herpesvirus 2; Australian isolates; UL24 gene; MDBK cells; mutations
Acta virologica 46: 175 – 178, 2002

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HEPATITIS C VIRUS PHYLOGENY: A USEFUL CLINICAL TOOL

J. CRISTINA, S. MUKOMOLOV, R. COLINA, O. KALININA, L. GARCÍA, B. KHAN, C. MOGDASY, P. KARAYIANNIS

Departamento de Técnicas Nucleares Aplicadas, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay;
Saint Petersburg Pasteur Institute, Saint Petersburg, Russia;
Laboratorio de Biología Molecular, Asociación Espańola Primera de Socorros Mutuos, Montevideo, Uruguay;
Division of Human Health, International Atomic Energy Agency, Vienna, Austria;
Department of Medicine A, Faculty of Medicine, Imperial College of Science, Technology and Medicine, London, United Kingdom

Summary. – In order to type 45 recent isolates of Hepatitis C virus (HCV) originating from four different geographic regions of the world, we performed phylogenetic analysis of a 192 nucleotides (nts) long sequence from the 5'non-coding region (5'-NCR) of the virus genome and compared them with 55 HCV isolates/strains of known type. The results of this study showed that phylogenetic studies can assign an HCV isolate to the correct type in 100% and to the correct subtype in 98%. A comparison of this method with other methods using commercial kits revealed that it is appropriate for clinical use and is cost effective.

Key words: Hepatitis C virus; genotypes; genetic variability; virus typing; phylogenetic tree analysis
Acta virologica 46: 179 – 182, 2002

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EFFECT OF HUMAN CYTOMEGALOVIRUS AND GLUCOSE ON ADHESION MOLECULES EXPRESSION IN CULTURED HUMAN ENDOTHELIAL CELLS

T.S. ALTANNAVCH, K. ROUBALOVÁ, P. KUČERA, O. JUZOVÁ, M. ANDEL

Second Department of Internal Medicine, Third Faculty of Medicine, Charles University, Šrobárova 50, 100 34 Prague 10, Czech Republic;
National Institute of Public Health, Prague, Czech Republic;
Department of Immunology, Kralovske Vinohrady Hospital, Prague, Czech Republic

Summary. – The aim this study was to investigate the effect of glucose on the induction of adhesion molecules by Human cytomegalovirus (HCMV) in endothelial cells in vitro. Primary cultures of human umbilical vein endothelial cells (HUVECs) pretreated with 16.5 mmol/l glucose for 24 hrs were infected with a HCMV strain with tropism for endothelial cells. Expression of adhesion nmolecules (ICAM-1, VCAM-1 and ELAM-1) was measured by flow cytometry. While high concentrations of glucose per se activated the expression of all three adhesion molecules tested, HCMV induced the expression of ICAM-1 only. Moreover, it potentiated the expression of ICAM-1 in glucose-pretreated HUVECs, while it did not affect at all or slightly suppressed the glucose-activated expression of VCAM-1 and ELAM-1. The modulatory effect of glucose and HCMV on the expression of adhesion molecules in endothelial cells may be applied in increased vulnerability to patients with diabetes mellitus or atherosclerosis.

Key words: Human cytomegalovirus; glucose; adhesion molecule expression; human endothelial cells
Acta virologica 46: 183 – 186, 2002

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INHIBITION OF JAPANESE ENCEPHALITIS VIRUS MATURATION AND TRANSPORT IN PS CELLS TO CELL SURFACE BY BREFELDIN A

V.J. LAD, A.K. GUPTA

National Institute of Virology, Indian Council of Medical Research, 20-A, Dr. Ambedkar Road, P.B. No. 11, Pune 411 001, India

Summary. – A brefeldin A (BFA) treatment of porcine stable kidney (PS) cells resulted in inhibition of Japanese encephalitis virus (JEV) maturation and its transport to the cell surface. Interestingly, the antigenicity of the virus, in contrast, remained unaffected as no difference in epitope presentation/expression was observed in BFA-treated and control (untreated) infected cells even though in the former cells a loss of hemagglutinating (HA) activity was recorded. Thus it seems that the BFA treatment did not affect the glycoprotein E (gpE) synthesis and folding essentially required for the epitope presentation/expression in cells.

Key words: Japanese encephalitis virus; glycoprotein E; epitopes; PS cells; brefeldin A
Acta virologica 46: 187 – 190, 2002

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