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1.
J Chem Phys ; 147(10): 104304, 2017 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-28915746

RESUMO

The single, double, and triple Auger decays from the 1s shake-up states of O2 have been studied using a multi-electron coincidence method. Efficient populations of two-hole final states are observed in single Auger decays of the π-π* shake-up states, which is understood as a characteristic property of the Auger transitions from shake-up states of an open-shell molecule. The O23+ populations formed by double Auger decays show similar profiles for both the O1s-1 and shake-up states, which is due to the contributions from cascade double Auger processes. While the cascade contributions to the double Auger decays increase with the initial shake-up energy, the probability of direct double Auger processes remains unchanged between the O1s-1 and shake-up states, which implies a weak influence of the excited electron on the double Auger emission that originates from the electron correlation effect.

2.
Epidemiol Infect ; 145(2): 272-284, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27682641

RESUMO

In temperate zones, human respiratory syncytial virus (HRSV) outbreaks typically occur in cold weather, i.e. in late autumn and winter. However, recent outbreaks in Japan have tended to start during summer and autumn. This study examined associations of meteorological conditions with the numbers of HRSV cases reported in summer in Japan. Using data from the HRSV national surveillance system and national meteorological data for summer during the period 2007-2014, we utilized negative binomial logistic regression analysis to identify associations between meteorological conditions and reported cases of HRSV. HRSV cases increased when summer temperatures rose and when relative humidity increased. Consideration of the interaction term temperature × relative humidity enabled us to show synergistic effects of high temperature with HRSV occurrence. In particular, HRSV cases synergistically increased when relative humidity increased while the temperature was ⩾28·2 °C. Seasonal-trend decomposition analysis using the HRSV national surveillance data divided by 11 climate divisions showed that summer HRSV cases occurred in South Japan (Okinawa Island), Kyushu, and Nankai climate divisions, which are located in southwest Japan. Higher temperature and higher relative humidity were necessary conditions for HRSV occurrence in summer in Japan. Paediatricians in temperate zones should be mindful of possible HRSV cases in summer, when suitable conditions are present.


Assuntos
Infecções por Vírus Respiratório Sincicial/epidemiologia , Vírus Sincicial Respiratório Humano/isolamento & purificação , Humanos , Umidade , Incidência , Japão/epidemiologia , Conceitos Meteorológicos , Estações do Ano , Temperatura
3.
East Mediterr Health J ; 22(7): 547-551, 2016 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-27714749

RESUMO

Despite the significant burden of influenza outbreaks, active disease monitoring has been largely absent in the Middle East, including Lebanon. In this study we characterized influenza virus in 440 nasopharyngeal swabs collected from patients with acute respiratory infections during two influenza seasons in Lebanon. Influenza A(H3N2) was dominant in the 2013/14 season while the A(H1N1)pdm09 and B/Yamagata strains were most prevalent in the 2014/15 season. All tested isolates were susceptible to 4 neuraminidase inhibitors (oseltamivir, zanamivir, peramivir and laninamivir). Genetic analysis of the haemagglutinin gene revealed multiple introductions of influenza viruses into Lebanon from different geographic sources during each season. Additionally, large data gaps were identified in the Middle East region, as indicated by the lack of current influenza sequences in the database from many countries in the region.


Assuntos
Surtos de Doenças , Influenza Humana/epidemiologia , Estações do Ano , Humanos , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Líbano/epidemiologia
4.
East. Mediterr. health j ; 22(7): 543-547, 2016-07.
Artigo em Inglês | WHO IRIS | ID: who-260105

RESUMO

Despite the significant burden of influenza outbreaks, active disease monitoring has been largely absent in the Middle East, including Lebanon. In this study we characterized influenza virus in 440 nasopharyngeal swabs collected from patients with acute respiratory infections during two influenza seasons in Lebanon. Influenza A[H3N2] was dominant in the 2013/14 season while the A[H1N1]pdm09 and B/Yamagata strains were most prevalent in the 2014/15 season. All tested isolates were susceptible to 4 neuraminidase inhibitors [oseltamivir, zanamivir, peramivir and laninamivir]. Genetic analysis of the haemagglutinin gene revealed multiple introductions of influenza viruses into Lebanon from different geographic sources during each season. Additionally, large data gaps were identified in the Middle East region, as indicated by the lack of current influenza sequences in the database from many countries in the region


Malgré la lourde charge que représentent les flambées de grippe, la surveillance active de la maladie était jusqu'à présent inexistante au Moyen-Orient, et notamment au Liban. Dans la présente étude, le virus de la grippe a été caractérisé dans 440 sécrétions rhinopharyngées prélevées par écouvillonnage chez des patients ayant souffert d'infections respiratoires aiguës pendant deux saisons grippales au Liban. Le virus de la grippe A[H3N2] était prédominant pendant la saison 2013/2014, tandis que celui de la grippe A[H1N1]pdm09 et les souches de grippe B/Yamagata étaient les plus courants pendant la saison 2014/2015. Tous les isolats testés étaient sensibles à quatre inhibiteurs de la neuraminidase [l'oseltamivir, le zanamivir, le peramivir, et le laninamivir]. L'analyse génétique du gène de l'hémagglutinine a révélé de multiples introductions des virus de la grippe au Liban, depuis différentes sources géographiques au cours de chaque saison. De plus, d'importantes lacunes dans les données ont été constatées dans la région du Moyen-Orient, comme le montre l'absence des séquences génétiques actuelles de la grippe dans les bases de données de nombreux pays de la region


Assuntos
Doenças Transmissíveis , Influenza Humana , Orthomyxoviridae , Infecções Respiratórias , Oseltamivir , Vírus da Influenza A Subtipo H3N2
5.
mBio ; 5(6)2014 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-25505124

RESUMO

In recent years, controversy has arisen regarding the risks and benefits of certain types of gain-of-function (GOF) studies involving avian influenza viruses. In this article, we provide specific examples of how different types of data, including information garnered from GOF studies, have helped to shape the influenza vaccine production process-from selection of candidate vaccine viruses (CVVs) to the manufacture and stockpiling of safe, high-yield prepandemic vaccines for the global community. The article is not written to support a specific pro- or anti-GOF stance but rather to inform the scientific community about factors involved in vaccine virus selection and the preparation of prepandemic influenza vaccines and the impact that some GOF information has had on this process.


Assuntos
Descoberta de Drogas/métodos , Vírus da Influenza A/patogenicidade , Vacinas contra Influenza/isolamento & purificação , Influenza Aviária/virologia , Influenza Humana/prevenção & controle , Pandemias/prevenção & controle , Zoonoses/prevenção & controle , Animais , Humanos , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Vacinas contra Influenza/imunologia , Influenza Aviária/transmissão , Influenza Humana/epidemiologia , Influenza Humana/imunologia , Influenza Humana/virologia , Aves Domésticas , Tecnologia Farmacêutica/métodos , Zoonoses/epidemiologia , Zoonoses/imunologia , Zoonoses/virologia
6.
Euro Surveill ; 19(1)2014 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-24434172

RESUMO

Six influenza A(H1N1)pdm09 viruses were detected in Sapporo, Japan, between November and December 2013. All six viruses possessed an H275Y substitution in the neuraminidase protein, which confers cross-resistance to oseltamivir and peramivir. No epidemiological link among the six cases could be identified; none of them had received neuraminidase inhibitors before specimen collection. The haemagglutinin and neuraminidase genes of the six viruses were closely related to one another, suggesting clonal spread of a single resistant virus.


Assuntos
Antivirais/farmacologia , Ciclopentanos/farmacologia , Guanidinas/farmacologia , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/tratamento farmacológico , Oseltamivir/farmacologia , Ácidos Carbocíclicos , Antivirais/uso terapêutico , Criança , Pré-Escolar , Ciclopentanos/uso terapêutico , DNA Viral , Farmacorresistência Viral , Feminino , Guanidinas/uso terapêutico , Humanos , Lactente , Vírus da Influenza A Subtipo H1N1/classificação , Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/virologia , Japão/epidemiologia , Masculino , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Mutação , Neuraminidase/genética , Neuraminidase/uso terapêutico , Oseltamivir/uso terapêutico , Filogenia , Análise de Sequência de DNA , Resultado do Tratamento
7.
J Chem Phys ; 137(19): 191101, 2012 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-23181286

RESUMO

Double Auger decay of O1s(-1) and its satellite states in H(2)O has been studied with a multi-electron coincidence method, and a process leading to autoionizing O* fragments has been revealed. The breaking of the two O-H bonds producing the autoionizing O* fragments occurs for highly excited H(2)O(2+) populated by the initial Auger decay. The O* fragments are more favorably produced in the decay from the satellite states, resulting from the larger population of highly excited H(2)O(2+) states inheriting the valence excitation in the initial state.

8.
Mucosal Immunol ; 1(3): 208-18, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-19079180

RESUMO

In a nasal vaccine against influenza, the activation of natural killer T (NKT) cells by intranasal coadministration of alpha-galactosylceramide (alpha-GalCer) can potently enhance protective immune responses. The results of this study show that the NKT cell-activated nasal vaccine can induce an effective cross-protection against different strains of influenza virus, including H5 type. To analyze the mechanism of NKT cell activation by this nasal vaccine, we prepared fluorescence-labeled alpha-GalCer by which we detect a direct interaction between NKT cells and alpha-GalCer-stored dendritic cells in nasal mucosa-associated tissues. Accordingly, although very few NKT cells exist at mucosa, the nasal vaccination induced a localized increase in NKT cell population, which is partly dependent on CXCL16/CXCR6. Furthermore, we found that NKT cell activation stimulates mucosal IgA production by a mechanism that is dependent on interleukin (IL)-4 production. These results strengthen the basis of nasal vaccination via NKT cell activation, which can induce immune cross-protection.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Galactosilceramidas/administração & dosagem , Vírus da Influenza A/imunologia , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Células T Matadoras Naturais/efeitos dos fármacos , Vacinação/métodos , Administração Intranasal , Animais , Especificidade de Anticorpos , Quimiocina CXCL16 , Quimiocina CXCL6/imunologia , Reações Cruzadas , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Corantes Fluorescentes , Humanos , Imunoglobulina A/biossíntese , Imunoglobulina A/imunologia , Virus da Influenza A Subtipo H5N1/imunologia , Vírus da Influenza B/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Influenza Humana/virologia , Interleucina-4/imunologia , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Mucosa Nasal/imunologia , Células T Matadoras Naturais/imunologia , Receptores CXCR/imunologia , Receptores CXCR6
9.
Arch Virol ; 148(10): 1873-84, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14551812

RESUMO

In Influenza A virus and Influenza B virus, the NS2 protein (nuclear export protein) has been proposed to mediate the nucleocytoplasmic trafficking of viral ribonucleoprotein (vRNP) by forming NS2-vRNP complexes. While the binding interactions of NS2 in these complexes have been well characterized for Influenza A virus, much less is known about Influenza B virus NS2 (B/NS2). In this report, we developed a specific antiserum against B/NS2 protein and demonstrated that B/NS2 was synthesized late in infection and packaged into virions after nucleocytoplasmic transport. Fractionation of detergent-disrupted virions in several conditions showed that B/NS2 remained associated with vRNP after separation of matrix protein M1 from vRNP, whereas Influenza A virus NS2 (A/NS2) was easily separated from vRNP and remained associated with M1, in accord with previous findings that A/NS2 associates with vRNP only through its binding of encapsidated M1. The results indicated that complex formation among vRNP, M1 and NS2 of Influenza B virus was different from that of Influenza A virus, and that B/NS2 associated with vRNP in the absence and presence of M1.


Assuntos
Vírus da Influenza B/metabolismo , Ribonucleoproteínas/metabolismo , Proteínas não Estruturais Virais/metabolismo , Transporte Ativo do Núcleo Celular , Sequência de Aminoácidos , Animais , Anticorpos Antivirais/biossíntese , Anticorpos Antivirais/imunologia , Western Blotting , Linhagem Celular , Núcleo Celular/metabolismo , Cães , Humanos , Vírus da Influenza A/metabolismo , Dados de Sequência Molecular , Testes de Precipitina , Proteínas da Matriz Viral/metabolismo , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/imunologia
10.
Virology ; 289(1): 95-102, 2001 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-11601921

RESUMO

We used an antibody raised against a synthetic peptide corresponding to amino acid residues 70-88 for characterizing the L* protein of Theiler's murine encephalomyelitis virus (TMEV), which is only synthesized in DA subgroup strains from an alternative AUG and is out of frame with the viral polyprotein; evidence suggests that L* protein is critical to viral persistence, demyelination, and growth in murine macrophage cell lines. It was synthesized with kinetics similar to that of other viral proteins, although less in amount. After synthesis, it remained stable in the cytoplasm and was not incorporated into virions. Immunofluorescent staining and immunoblotting of microtubule preparations demonstrated that it is associated with microtubules. Expression of L* protein also demonstrated that the 5' one third of the coding region may be responsible for the association. The association of L* protein with microtubules may be important in the disease-inducing and in vitro characters of L* protein.


Assuntos
Proteínas de Membrana/metabolismo , Microtúbulos/metabolismo , Theilovirus/fisiologia , Proteínas Virais/metabolismo , Animais , Western Blotting , Linhagem Celular , Cricetinae , Imunofluorescência , Cinética , Proteínas de Membrana/biossíntese , Camundongos , Microtúbulos/virologia , Proteínas Virais/biossíntese , Vírion/metabolismo
11.
J Vet Med Sci ; 62(11): 1223-5, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11129872

RESUMO

Japanese cedar pollinosis is a type I allergic disease mediated by immunoglobulin E (IgE) antibodies to Japanese cedar (Cryptomeria japonica) pollen antigen (CPAg). By using 22 dogs consisting of 20 dogs aged 3 months and 2 dogs aged 3 years, immunization was performed by subcutaneous injections of CPAg with aluminum hydroxide gel. Variable levels of CPAg-specific IgE antibody response were detected in 21 of the 22 immunized dogs two weeks after the second immunization. This study provided an experimental sensitization system with CPAg in dogs, which will be useful for further immunological studies on Japanese cedar pollinosis.


Assuntos
Hipersensibilidade/veterinária , Imunização/veterinária , Imunoglobulina E/sangue , Pólen/imunologia , Animais , Formação de Anticorpos , Cycadopsida , Cães , Feminino , Hipersensibilidade/imunologia , Japão , Masculino , Árvores
12.
J Virol ; 74(10): 4898-901, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10775632

RESUMO

We sought to confirm the importance of L* protein for growth of Theiler's murine encephalomyelitis virus (TMEV) in a macrophage-like cell line, J774-1. The protein is out of frame with the polyprotein and synthesized in DA but not GDVII subgroup strains of TMEV. A recombinant virus, DANCL*/GD, which substitutes the DA 5' noncoding and L* coding regions for the corresponding regions of GDVII and synthesizes L* protein, grew with little restriction in J774-1 cells. In contrast, another recombinant virus, DANCL*-1/GD, which has an ACG rather than an AUG as the starting codon of L* protein at nucleotide 1079, resulting in no synthesis of L* protein, did not grow well. No significant difference between the rates of adsorption to J774-1 cells of these viruses was observed. RNase protection assay demonstrated that DANCL*/GD viral RNA significantly increased, whereas only a minimal increase was observed for DANCL*-1/GD. The present study suggests that L* protein is required for virus growth in macrophages.


Assuntos
Macrófagos/virologia , Proteínas de Membrana/metabolismo , Theilovirus/crescimento & desenvolvimento , Proteínas Virais/metabolismo , Sequência de Aminoácidos , Animais , Linhagem Celular , Cinética , Proteínas de Membrana/química , Camundongos , Dados de Sequência Molecular , Proteínas Recombinantes/metabolismo , Ribonucleases/metabolismo , Theilovirus/genética , Theilovirus/metabolismo , Proteínas Virais/química
13.
FEMS Microbiol Lett ; 185(2): 221-4, 2000 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-10754251

RESUMO

The nucleotide sequence of a 15600-bp DNA fragment containing the staphylokinase gene (sakNU3-1) of methicillin-resistant Staphylococcus aureus (MRSA) NU3-1 was determined. The sak gene was found within the ply gene encoding N-acetylmuramyl-L-alanine amidase and thus the ply gene should be inactivated. In the flanking region of the sak gene, the tandem repeat sequences (GAAGTGTT and GAATGGTT) were present as possible junction points between the sak and ply genes. No sequences characteristic of the presence of an IS-like element were found. Upstream from the ply gene, the kdpA, kdpB and kdpC homologues were present. Downstream from the ply gene, the tagA, tagH and tagG homologues were present. The sak gene was inserted into the same position of ply in 5/6 of sak(+) MRSA isolates with different genotypes. In all of these sak(+) isolates, Sak was detected in the culture supernatant.


Assuntos
Metaloendopeptidases/genética , Resistência a Meticilina , N-Acetil-Muramil-L-Alanina Amidase/genética , Clonagem Molecular , Genes Bacterianos , Humanos , Metaloendopeptidases/metabolismo , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/enzimologia , Staphylococcus aureus/genética
14.
Vet Immunol Immunopathol ; 73(2): 193-204, 2000 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-10690934

RESUMO

Clinically important allergens for the diagnosis and treatment of atopic dermatitis vary geographically. In order to identify the most prevalent allergens in atopic dogs in Japan, 42 dogs with a clinical diagnosis of atopy were tested using both in vivo (intradermal skin test (IDST)) and in vitro (antigen-specific IgE assay) allergy tests. Allergens used for IDST included 26 allergen extracts from eight allergen groups: trees, weeds, grasses, house dust mites (HDM), molds, foods, epithelia, and arthropods. Immunodot assay was used to measure antigen-specific IgE against 24 allergens from these eight groups and against fish such as cod and sole. In the 42 dogs, the most common positive allergen reaction was to HDM on both IDST (29/42 dogs or 69%) and in vitro testing (23/42 or 54.8%). The second most frequent positive allergen reaction was to Japanese cedar pollen (21/42 or 50.0% for IDST and 7/42 or 16.7% for in vitro testing). In both tests, less than 20% of dogs had positive reactions to molds or foods. Positive reactions to cat epithelia were frequently found on IDST, but rarely found on in vitro testing. Agreement between the two tests was found in 26 instances: HDM (21 dogs), Japanese cedar pollen (five dogs) and wheat (one dog). In this study, the two most common allergens involved in atopic dermatitis in dogs in Japan were HDM and Japanese cedar pollen.


Assuntos
Alérgenos/imunologia , Dermatite Atópica/veterinária , Doenças do Cão/imunologia , Pólen/imunologia , Animais , Anticorpos Monoclonais , Artrópodes , Western Blotting/veterinária , Dermatite Atópica/epidemiologia , Dermatite Atópica/imunologia , Doenças do Cão/epidemiologia , Cães , Poeira , Feminino , Fungos , Testes Intradérmicos/veterinária , Japão/epidemiologia , Masculino , Ácaros , Poaceae , Prevalência , Kit de Reagentes para Diagnóstico/veterinária , Árvores
16.
J Infect Chemother ; 6(1): 30-4, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11810528

RESUMO

The Etest (AB Biodisk, Solna, Sweden), a susceptibility testing method, was used for fosfomycin and was evaluated by comparison with the agar dilution method for 73 clinical isolates of Escherichia coli, including two resistant strains, and an optimal Etest method for fosfomycin was determined. Media and culture conditions greatly affected the minimum inhibitory concentrations (MICs) determined by the Etest for fosfomycin, as shown for the agar dilution methods. Our results showed that the most favorable conditions for the Etest for fosfomycin were with Mueller-Hinton agar (Becton-Dickinson Japan, Tokyo, Japan) under aerobic conditions. However, the MICs for the resistant strains were much higher than those determined by agar dilution methods, using Nutrient agar (Becton-Dickinson Japan) under anaerobic conditions. The addition of glucose-6-phosphate did not significantly affect the Etest results.


Assuntos
Antibacterianos/farmacologia , Meios de Cultivo Condicionados/química , Escherichia coli/efeitos dos fármacos , Fosfomicina/farmacologia , Testes de Sensibilidade Microbiana/métodos , Ágar/análise , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/isolamento & purificação , Humanos , Técnicas In Vitro
17.
Carbohydr Lett ; 4(1): 13-20, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11469333

RESUMO

5a-Carba-alpha-L-fucopyranose and -alpha-DL-fucopyranosylamine were synthesized in conventional manner starting from 2,3,4-tri-O-acetyl-6-bromo-6-deoxy-5a-carba-beta-D- and -DL-glucopyranosyl bromides, respectively, and assayed for inhibitory activity against alpha-fucosidase (bovine kidney). Although the former proved to be only a moderate inhibitor (Ki = 4.3 x 10(-5) M), the latter could be shown to possess strong inhibitory potential (Ki = 2.3 x 10(-7) M). Diastereoisomeric imino-linked 5a'-carbadisaccharides were synthesized by coupling of the racemic 5a-carba-alpha-fucopyranosylamine and 1,6:3,4-dianhydro-2-azido-2-deoxy-beta-D-galactopyranose, in order to estimate approximately the inhibitory activity of individual optical antipodes of 5a-carba-alpha-fucopyranosylamine.


Assuntos
Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Fucose/síntese química , Fucose/farmacologia , alfa-L-Fucosidase/antagonistas & inibidores , Animais , Bovinos , Inibidores Enzimáticos/química , Fucose/análogos & derivados , Fucose/química , Técnicas In Vitro , Inositol/análogos & derivados , Inositol/síntese química , Inositol/química , Inositol/farmacologia , Rim/enzimologia , Cinética , Espectroscopia de Ressonância Magnética , Estereoisomerismo , Relação Estrutura-Atividade
18.
Microbiol Immunol ; 43(9): 885-92, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10553681

RESUMO

GDVII subgroup strains of Theiler's murine encephalomyelitis virus (TMEV) are highly virulent and produce acute polioencephalomyelitis in mice. Neither viral persistence nor demyelination is demonstrated in the few surviving mice. In contrast, DA subgroup strains are less virulent and establish a persistent central nervous system infection which results in demyelinating disease. We previously reported a subgroup-specific infection in a macrophage-like cell line, J774-1 cells; i.e., GDVII strain does not replicate in J774-1 cells, whereas the DA strain actively replicates in these cells. In addition, this subgroup-specific virus growth is shown to be related to the presence of L* protein, a 17 kDa protein translated out-of-frame of the viral polyprotein from an AUG located 13 nucleotides downstream from the polyprotein's AUG. The present paper demonstrated that this subgroup-specific infection is observed in murine monocyte/macrophage lineage cell lines, but not in other murine cell lines including neural cells. An RNase protection assay also suggested that L* protein-related virus growth is regulated at the step of viral RNA replication. As macrophages are reported to be the major cell harboring virus during the chronic demyelinating stage, the activity of L* protein with respect to virus growth in macrophages may be a key factor in clarifying the mechanism(s) of TMEV persistence, which is probably a trigger to spinal cord demyelination.


Assuntos
Glioma/virologia , Macrófagos/virologia , Monócitos/virologia , Theilovirus/fisiologia , Animais , Linhagem Celular , Camundongos , RNA Viral/análise , Theilovirus/classificação , Replicação Viral
19.
Microbiol Immunol ; 43(1): 83-6, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10100752

RESUMO

Theiler's murine encephalomyelitis virus (TMEV) belongs to the Picornaviridae genus. DA subgroup strains of this virus induce early, non-fatal polioencephalomyelitis followed by demyelination in the spinal cord, with virus persistence. We investigated the use of DA strain as a vector for the introduction of a foreign gene into the central nervous system. Human lymphotoxin (LT) gene was inserted in the L region, the most upstream part of the polyprotein coding region of DA genome. Expression of LT was demonstrated by an immunoblot and an enzyme-linked immunosorbent assay on BHK-21 cells that were infected with the recombinant virus. In addition, the expressed LT showed cytotoxicity against L-929 cells.


Assuntos
Vetores Genéticos/genética , Linfotoxina-alfa/genética , Linfotoxina-alfa/toxicidade , Theilovirus/genética , Animais , Linhagem Celular , Sobrevivência Celular , Cricetinae , Ensaio de Imunoadsorção Enzimática , Humanos , Immunoblotting , Linfotoxina-alfa/biossíntese , Camundongos , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/toxicidade , Transfecção
20.
J Virol ; 72(6): 4950-5, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9573263

RESUMO

Strain GDVII and other members of the GDVII subgroup of Theiler's murine encephalomyelitis virus (TMEV) are highly virulent and cause acute polioencephalomyelitis in mice. Neither viral persistence nor demyelination is demonstrated in the few surviving mice. On the other hand, strain DA and other members of the TO subgroup of TMEV are less virulent and establish a persistent infection in the spinal cord, which results in a demyelinating disease. We previously reported that GDVII does not actively replicate in a murine macrophage-like cell line, J774-1, whereas DA strain productively infects these cells (M. Obuchi, Y. Ohara, T. Takegami, T. Murayama, H. Takada, and H. Iizuka, J. Virol. 71:729-733, 1997). In the present study, we used recombinant viruses between these strains of the two subgroups to demonstrate that the DA L coding region of DA strain is important for virus growth in J774-1 cells. Additional experiments with a mutant virus indicate that L* protein, which is synthesized out of frame with the polyprotein from an additional alternative initiation codon in the L coding region of TO subgroup strains, is a key determinant responsible for the cell-type-specific restriction of virus growth. L* protein may play a critical role in the DA-induced restricted demyelinating infection by allowing growth in macrophages, a major site for virus persistence.


Assuntos
Macrófagos/virologia , Proteínas de Membrana/fisiologia , Theilovirus/fisiologia , Proteínas Virais/fisiologia , Replicação Viral/fisiologia , Animais , Linhagem Celular , DNA Complementar/genética , Camundongos , Mutação
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