Electronic Library of Scientific Literature
Electronic Library of Scientific Literature
Volume 41 / April 1997 / number 2
J. SERKEDJIEVA, E. IVANOVA
Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str. 26, 1113 Sofia, Bulgaria
Summary. - The protective effect of an immunostimulatory bacterial preparation, cytoplasmic membranes of Escherichia coli WF+ stable protoplast type L-forms (CM) alone and in combination with the selective antiviral drug rimantadine was evaluated in experimental influenza A/Aichi/2/68 (H3N2) virus infection in mice. In sublethal infection, CM administered intraperitoneally (i.p.) 7 days before virus exposure in a single dose of 25 mg/kg did not reduce significantly the virus lung titers. In lethal infection, CM applied in the same way weakly reduced the mortality rate. The combined application of CM with rimantadine resulted in synergistically increased protection, determined on the basis of virus lung titers, lung consolidation, mortality rates, protective indices, and survival times.
Key words: experimental influenza infection; bacterial cytoplasmic
membranes; rimantadine; combined protective effect
Acta virologica 41: 65-70, 1997
V. REPKA
Laboratory of Molecular Biology and Virology, Complex Research Institute of Viticulture and Enology, Matúškova 25, 833 11 Bratislava, Slovak Republic
Summary. - Cucumber (Cucumis sativus L. cv. Laura) contains three different isoforms of chitinase (EC 3.2.1.14), thought to be involved in the defense against a pathogen. Using a highly specific rabbit antiserum raised against a predominant, extracellularly localized, virus-inducible acidic chitinase (p28), two additional enzyme isoforms with differential mode of compartmentalization were identified. Immunoblot analysis of the fractionated plant extracts separated by denaturing and native (anodic and cathodic) polyacrylamide gel electrophoresis (PAGE) revealed that the chitinase p25 (Mr 25.5 K), is a basic, etxracellular isoform and the chitinase p24 (Mr 24.6 K) is an acidic, probably intracellular isoform of the enzyme.
Key words: cucumber; chitinase isoforms; immunoblot analysis;
tobacco necrosis virus
Acta virologica 41: 71-75, 1997
R. TASNEEN, K. YOSHIIE, T. OHKAWA, H. ODA
Department of Bacteriology, Faculty of Medicine, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890, Japan
Summary. - We studied the effect of recombinant murine interferons (rMuIFNs) on the growth of Orientia (formerly Rickettsia) tsutsugamushi Gilliam in mouse L929 cells. Rickettsial growth was measured by flow cytometry. rMUIFN-gamma inhibited the growth of O. tsutsugamushi at the concentrations of 100 IU/ml and 1,000 IU/ml in accord with previous reports. Relatively low concentrations (10 IU/ml and 100 IU/ml) of rMUIFN-beta also inhibited the growth of O. tsutsugamushi. On the other hand, high concentrations (1,000 IU/ml and 10,000 IU/ml) of rMuIFN-beta enhanced the growth of the rickettsia. This enhancement of rickettsial growth was blocked by anti-murine IFN-beta monoclonal antibody (MoAb). rMuIFN-beta also enhanced the growth of Rickettsia sibirica 246 in L929 cells to some extent.
Key words: rickettsia; Orientia tsutsugamushi; L929
cells; interferon
Acta virologica 41: 77-82, 1997
F. ÈIAMPOR, E. ZÁVODSKÁ, D. CMARKO, J. CMARKOVÁ, E. VAREÈKOVÁ
Institute of Virology, Slovak Academy of Sciences, Dúbravská cesta 9, 842 46 Bratislava, Slovak Republic
Summary. - Brefeldin A (BFA) decreased the expression of influenza A virus haemagglutinin (HA) and M2 protein on the plasma membrane of virus-infected MDCK cells. It caused a retention of M1 protein in the cell nucleus and a decrease of its expression on the plasma membrane. On the other hand, an increased labelling of the cytoplasmic domain of M2 protein on the plasma membrane in BFA-treated cells was observed in contrast to the labelling in BFA-untreated cells. The effects of BFA on the microtubules and cellular motors are discussed.
Key words: influenza virus; MDCK cells; haemagglutinin;
M1 protein; M2 protein; Brefeldin A
Acta virologica 41: 83-91, 1997
R. GAUT, J.T. MAY
School of Microbiology, La Trobe University, Bundoora, Victoria, 3083 Australia
Summary. - The nucleotide (nt) sequence of the thymidine kinase (TK) gene (a 918 nt long coding region) of two TK-deficient (TK-) strains of bovine herpesvirus 2 (BHV-2) was determined. The candidate vaccine strain C290BU5, which was no longer able to cause disease, was found to have an A deletion after nt 887 of the TK gene with a predicted change of His 296 to Pro, altering the last 10 amino acids (aa) and extending the gene by another 34 aa. The strain which still caused disease, C290BU3, had a T insertion after nt 16 causing a predicted chain termination after only 16 aa.
Key words: bovine herpesvirus 2; candidate vaccine
strain; thymidine kinase
Acta virologica 41: 93-95, 1997
I.B. SEMENOVA, A.K. KALENDEROV, V.V. VARGIN, B.F. SEMENOV
Gamaleya Research Institute of Epidemiology and Microbiology, Gamaleya
Str. 18, 123 096 Moscow;
Chumakov Research Institute of Poliomyelitis and Viral Encephalitides,
Moscow Region, Russia
Summary. - The successive injection of non-immunomodulating doses of Tahyna virus (100 LD50) and non-immunomodulating doses of immunomodulating drugs, such as purified staphylococcal toxoid or glucosaminylmuramyldipeptide (Likopid), to mice were accompanied by a decrease in the IgM plaque-forming cell response to sheep red blood cells.
Key words: Tahyna virus; immunosuppression; immunomodulators
Acta virologica 41: 97-99, 1997
K. PETRZIK, P. SVOBODA
Institute of Plant Molecular Biology, Academy of Sciences of the
Czech Republic, Branišovská 31, 370 05 Èeské
Budìjovice, Czech Republic;
Hop Research Institute Co. Ltd., Žatec, Czech Republic
Summary. - Thirteen cultivars of hop (Humulus lupulus L.) were tested by reverse transcription-polymerase chain reaction (RT-PCR) for the presence of apple mosaic virus (ApMV). The virus was detected in various amounts in all tested cultivars. Control hop clones derived from tissue cultures, treated by thermotherapy and maintained in greenhouse were virus-free. The procedure for sample preparation and RT-PCR of ApMV is described in detail.
Key words: apple mosaic virus; detection; direct-binding
polymeras chain reaction; primers
Acta virologica 41: 101-103, 1997
C. ROZERA, S. BACCARINI, M. GENTILE, M.R. TORRISI, E. PROIETTI, M. FEDERICO, S. PULCIANI
Istituto Superiore di Sanita, Laboratorio di Virologia, Viale Regina
Elena 299, 00161 Roma;
Istituto di Virologia, Universita di Roma La Sapienza, Roma;
Dipartimento di Medicina Sperimentale e Patologia, Universita di Roma La
Sapienza, Roma, Italy
Summary. - In order to generate HIV (murine leukemia virus (MuLV)) pseudotypes, HIV genome was transfected into the ecotropic murine packaging cell line (GP+E86) and four of the nine transfected clones were extensively characterized. One clone (801), harbouring a full copy of integrated HIV sequences, exhibited a detectable level of intracellular HIV p24 antigen expression. Northern blot analysis revealed that clone 801 expressed all three classes of HIV mRNAs. Multispliced 2kb mRNAs were detected in another clone (8.14). Two other clones (1.31 and 1.32) also exhibited a complete HIV provirus, but did not show any viral expression, as evaluated by Northern blot analysis or HIV p24 ELISA. Reverse transcription-polymerase chain reaction (RT-PCR) experiments revealed the presence of full length genomic RNA in four transfected clones, which were extensively characterized. A co-cultivation of clone 801 with human CD4+ cells resulted in syncytia formation. By electron microscopy, mature HIV particles were observed after co-cultivation of uninfected C8166 cells with 801 cells. These results demonstrated that the murine clone was stably transfected with the complete HIV genome and was capable of shuttling infectious HIV to human cells. Clone 801 was co-cultivated with murine NIH-3T3 fibroblasts. In several experiments, HIV infection of NIH-3T3 cells was revealed by PCR technique. Thus, 801 cells appear to produce low levels of HIV (MuLV) pseudotypes capable of transferring the HIV genome into mouse cells.
Key words: human immunodeficiency virus; provirus; transfection;
packaging cells; pseudotypes; murine leukemia virus
Acta virologica 41: 105-110, 1997
L. DOUMANOVA, M. ALEXANDROV
Department of Virology, Central Veterinary Research Institute, P.
Slavejkov Blvd. 15, 1606 Sofia;
Institute of Comparative Pathology and Parasitology, Bulgarian Academy
of Sciences, Sofia, Bulgaria
Summary. - Various electron microscopic (EM) and immunoelectron microscopic (IEM) techniques were used to demonstrate and identify the Newcastle disease virus (NDV) infection. By IEM, the number of virions in native allantoic fluids was increased 50 - 100 times in comparison with direct EM. The immunogold staining showed that a number of immunogold particles were specifically bound to the antigen determinants located on the virion surface and these results were much easier to interpret. The obtained results showed that the EM and IEM can be successfully employed for a precise and rapid detection of NDV as well as for identification of this infection among other viral or bacterial infections.
Key words: Newcastle disease virus; detection; identification;
electron microscopy; immunoelectron microscopy; immunogold method
Acta virologica 41: 111-114, 1997
M. GREŠÍKOVÁ, M. KALUZOVÁ
Institute of Virology, Slovak Academy of Sciences, Dúbravská cesta 9, 842 46 Bratislava, Slovak Republic
Summary. - Tick-borne encephalitis (TBE) virus is an important human pathogen belonging to the genus Flavivirus within the family Flaviviridae. The genome of the TBE virus is a single-stranded RNA (ssRNA) molecule of positive polarity encoding all the viral proteins within a single open reading frame (ORF). TBE virus shares common physical and genetic characteristic of the flavivirus genus. Two subtypes of the TBE virus have been described: (1) European, endemic in many parts of Europe and transmitted by Ixodes ricinus ticks, and (2) Far Eastern (Russian spring summer encephalitis (RSSE) virus), endemic in Far East and transmitted by Ixodes persulcatus ticks.
Key words: tick-borne encephalitis virus; biology
Acta virologica 41: 115-124, 1997