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1.
J Med Virol ; 93(6): 3446-3454, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33325052

RESUMO

Since the elimination of the measles virus, patients with vaccination records for the measles-containing vaccine have increased in Japan. According to several studies, the transmission risk from previously immunized patients, especially those with secondary vaccine failure (SVF), is lower than that from those with primary measles infections. Immunological features of SVF were identified per specific immunoglobulin G (IgG) induction with high avidity and high plaque reduction neutralization antibody concentration. However, the virological features of SVF have not been well investigated. To examine not only immunological but also virological differences between SVF and immunologically naive patients, throat swabs and blood and urine specimens of 25 patients with confirmed measles infection after an outbreak at the Kansai International Airport in 2016 were analyzed. Patients were categorized as naive (n = 3) or with SVF (n = 22) based on measles-specific IgG antibody concentrations and their avidity. Virus isolation and quantitative real-time polymerase chain reaction were performed to quantify the viral load in clinical specimens and estimate the infectivity in each specimen. The number of viral genome copies in the blood specimens of those with SVF was significantly different and approximately 1 out of 100 of that in immunologically naive patients. However, genome copy numbers in throat swabs and urine specimens were not significantly different between the groups. The virus was isolated only from those in the naive group. Our study indicated low transmission risk of the virus in patients with SVF.


Assuntos
Aeroportos , Anticorpos Antivirais/sangue , Surtos de Doenças/estatística & dados numéricos , Vacina contra Sarampo/imunologia , Sarampo/epidemiologia , Sarampo/transmissão , Adulto , Anticorpos Neutralizantes/sangue , Feminino , Genoma Viral , Humanos , Imunização Secundária/estatística & dados numéricos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Japão , Masculino , Sarampo/sangue , Sarampo/imunologia , Vírus do Sarampo/genética , Vírus do Sarampo/imunologia , Vírus do Sarampo/isolamento & purificação , Vacinação , Carga Viral , Adulto Jovem
2.
Arch Virol ; 165(10): 2335-2340, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32719956

RESUMO

Sapoviruses are increasingly being recognized as pathogens associated with gastroenteritis in humans. Human sapoviruses are currently assigned to 18 genotypes (GI.1-7, GII.1-8, GIV.1, and GV.1-2) based on the sequence of the region encoding the major structural protein. In this study, we evaluated 11 polymerase chain reaction (PCR) assays using published and newly designed/modified primers and showed that four PCR assays with different primer combinations amplified all of the tested human sapovirus genotypes using either synthetic DNA or cDNA prepared from human sapovirus-positive fecal specimens. These assays can be used as improved broadly reactive screening tests or as tools for molecular characterization of human sapoviruses.


Assuntos
Infecções por Caliciviridae/virologia , Primers do DNA/química , Gastroenterite/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Sapovirus/genética , Proteínas Estruturais Virais/genética , Sequência de Bases , Infecções por Caliciviridae/diagnóstico , Primers do DNA/genética , Fezes/virologia , Gastroenterite/diagnóstico , Expressão Gênica , Genótipo , Humanos , Tipagem Molecular/métodos , Filogenia , Sapovirus/classificação , Sapovirus/isolamento & purificação , Alinhamento de Sequência
3.
Emerg Infect Dis ; 25(9): 1782-1784, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31237836

RESUMO

The largest outbreak of dengue fever in Tanzania is ongoing. Dengue virus type 1 was diagnosed in a traveler who returned from Tanzania to Japan. In phylogenetic analysis, the detected strain was close to the Singapore 2015 strain, providing a valuable clue for investigating the dengue outbreak in Tanzania.


Assuntos
Vírus da Dengue/isolamento & purificação , Dengue/diagnóstico , Adulto , Dengue/tratamento farmacológico , Dengue/virologia , Vírus da Dengue/genética , Humanos , Japão , Masculino , Filogenia , Tanzânia , Viagem
4.
J Med Virol ; 91(12): 2101-2107, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31368535

RESUMO

Norovirus (NoV) is a major cause of viral gastroenteritis, and GII.4 has been the predominant genotype worldwide since the mid-1990s. During the 2014 to 2015 winter, a rare genotype, NoV GII.17, emerged and became prevalent mainly in East Asia. Over the past two decades, NoV molecular surveillance in Osaka City, Japan, has revealed that NoV GII.17 was detected for the first time in February 2001 and that NoV GII.17-associated outbreaks remarkably increased during the 2014 to 2015 season, with higher incidence recorded in January to March 2015. Genetic analysis indicated that 28 GII.17 outbreak strains were closely related to the novel GII.P17-GII.17 variants represented by the Kawasaki308/2015/JP strain, similar to that in other regions. Statistical analysis showed that NoV GII.17 infections were more common in adults than GII.3 and GII.4 infections, suggesting that the affected adults most likely did not have antibodies against NoV GII.17 and the novel GII.17 variant had recently appeared. Regarding transmission, food was one of the most important factors involved in the spread of NoV GII.17 among adults; 61% of GII.17 outbreaks were foodborne, with oysters being the most common vehicle. Interplay between pathogens, hosts, and environmental factors was considered to be important in the 2014 to 2015 NoV GII.17 epidemic.


Assuntos
Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/virologia , Surtos de Doenças , Gastroenterite/epidemiologia , Norovirus/genética , Adulto , Animais , Anticorpos Antivirais/sangue , Infecções por Caliciviridae/transmissão , Criança , Cidades/epidemiologia , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/virologia , Gastroenterite/virologia , Genótipo , Humanos , Incidência , Japão/epidemiologia , Ostreidae/virologia , Filogenia , Estações do Ano
5.
J Med Virol ; 91(3): 370-377, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30320885

RESUMO

Sapoviruses are associated with acute gastroenteritis. Human sapoviruses are classified into four distinct genogroups (GI, GII, GIV, and GV) based on their capsid gene sequences. A TaqMan probe-based real-time reverse transcription-polymerase chain reaction (RT-PCR) assay that detects the representative strains of these four genogroups is widely used for screening fecal specimens, shellfish, and environmental water samples. However, since the development of this test, more genetically diverse sapovirus strains have been reported, which are not detectable by the previously established assays. In this study, we report the development of a broader-range sapovirus real-time RT-PCR assay. The assay can detect 2.5 × 107 and 2.5 × 10 1 copies of sapovirus and therefore is as sensitive as the previous test. Analysis using clinical stool specimens or synthetic DNA revealed that the new system detected strains representative of all the 18 human sapovirus genotypes: GI.1-7, GII.1-8, GIV.1, and GV.1, 2. No cross-reactivity was observed against other representative common enteric viruses (norovirus, rotavirus, astrovirus, and adenovirus). This new assay will be useful as an improved, broadly reactive, and specific screening tool for human sapoviruses.


Assuntos
RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real , Sapovirus/genética , Infecções por Caliciviridae/diagnóstico , Infecções por Caliciviridae/virologia , Primers do DNA/genética , Sondas de DNA , Fezes/virologia , Variação Genética , Genótipo , Humanos , Sapovirus/classificação , Sensibilidade e Especificidade
6.
J Med Virol ; 89(12): 2116-2121, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28771766

RESUMO

Hand, foot, and mouth disease (HFMD) is an acute febrile illness characterized by fever; sore throat; and vesicular eruptions on the hands, feet, and oral mucosa. Until 2010, HFMD was predominantly associated with enterovirus (EV) A71 and coxsackievirus (CV) A16 in Japan. In 2011, CV-A6 emerged as a primary causative agent, causing the largest HFMD epidemic in Japan since 1981. Since then, CV-A6 has caused large HFMD epidemics every 2 years. The phylogenetic analysis of complete Viral Protein 1 (VP1) sequences revealed that most CV-A6 strains detected from 2011 to 2015 in Osaka City were classified into a different clade compared with CV-A6 strains detected from 1999 until 2009. The majority of CV-A6 strains detected in 2011 and most CV-A6 strains detected from 2013 to 2015 were mainly divided into two distinct genetic groups. Each epidemic strain carried unique amino acid substitutions in the presumed DE, EF, and GH loops of the VP1 protein that is exposed on the surface of the virion. There is a possibility that the appearance of substitutions on the surface of the virion and an accumulation of a susceptible population are significant factors in recent HFMD epidemics.


Assuntos
Enterovirus Humano A/classificação , Enterovirus Humano A/genética , Epidemias , Doença de Mão, Pé e Boca/epidemiologia , Doença de Mão, Pé e Boca/virologia , Surtos de Doenças , Enterovirus Humano A/isolamento & purificação , Monitoramento Epidemiológico , Genótipo , Doença de Mão, Pé e Boca/diagnóstico , Humanos , Japão/epidemiologia , Filogenia , Proteínas Virais/genética
7.
PLoS Pathog ; 10(10): e1004417, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25340845

RESUMO

RIG-I-like receptor (RLR) plays a pivotal role in the detection of invading pathogens to initiate type I interferon (IFN) gene transcription. Since aberrant IFN production is harmful, RLR signaling is strictly regulated. However, the regulatory mechanisms are not fully understood. By expression cloning, we identified Pumilio proteins, PUM1 and PUM2, as candidate positive regulators of RIG-I signaling. Overexpression of Pumilio proteins and their knockdown augmented and diminished IFN-ß promoter activity induced by Newcastle disease virus (NDV), respectively. Both proteins showed a specific association with LGP2, but not with RIG-I or MDA5. Furthermore, all of these components were recruited to NDV-induced antiviral stress granules. Interestingly, biochemical analyses revealed that Pumilio increased double-stranded (ds) RNA binding affinity of LGP2; however, Pumilio was absent in the dsRNA-LGP2 complex, suggesting that Pumilio facilitates viral RNA recognition by LGP2 through its chaperon-like function. Collectively, our results demonstrate an unknown function of Pumilio in viral recognition by LGP2.


Assuntos
Antivirais/farmacologia , Citoplasma/metabolismo , Interferon beta/isolamento & purificação , Regiões Promotoras Genéticas/efeitos dos fármacos , Proteínas de Ligação a RNA/metabolismo , Fatores de Transcrição/metabolismo , Humanos , Infecções por Vírus de RNA/metabolismo , RNA de Cadeia Dupla , RNA Viral/metabolismo , Transdução de Sinais/imunologia
8.
J Med Virol ; 88(7): 1187-93, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26684081

RESUMO

Sapovirus (SaV) is a causative agent of gastroenteritis in humans in both sporadic cases and outbreaks. During the period from January 2005 to August 2014, SaV was detected in 30 (5.9%) of 510 gastroenteritis outbreaks in Osaka City, Japan using real-time RT-PCR. Seasonal distribution of SaV-associated outbreaks revealed an increase during the 2011-2012 season and the highest frequency of outbreaks during the 2012-2013 season. Genotyping analysis based on the capsid region demonstrated that the most common genotype was GI.2 (36.7%), in which the strains were closely related. The comparison of complete capsid gene sequences with 18 GI.2 strains (7 strains in this study and 11 from GenBank) between 1990 and 2013 showed that GI.2 strains were classified into at least three genetic clusters (1990-2000, 2004-2007, and 2008-2013) with chronologically unique amino acid residues and accumulation of mutations in the predicted P domain, suggesting the one of the causes of emergence and spread of GI.2 strains. This study will also be helpful for understanding the evolutionary mechanism of the SaV genome.


Assuntos
Infecções por Caliciviridae/epidemiologia , Surtos de Doenças/estatística & dados numéricos , Epidemias , Gastroenterite/epidemiologia , Gastroenterite/virologia , Sapovirus/genética , Adolescente , Adulto , Idoso , Infecções por Caliciviridae/virologia , Proteínas do Capsídeo/genética , Criança , Pré-Escolar , Fezes/virologia , Genoma Viral , Genótipo , Humanos , Vigilância Imunológica , Lactente , Recém-Nascido , Japão/epidemiologia , Pessoa de Meia-Idade , Mutação , Filogenia , RNA Viral/genética , Estações do Ano , Análise de Sequência de DNA , Adulto Jovem
9.
J Med Virol ; 87(8): 1311-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25907907

RESUMO

In a surveillance system in Osaka City, Japan, 48 sporadic rotavirus A (RVA) infections were detected during 2008/2009-2011/2012 seasons. The G/P-genotypes of detected RVAs were G1P[8], G2P[4], G3P[8], G9P[4], and G9P[8]. Although G9P[4] is a rare genotype that had not been reported in Japan, it was the second most prevalent genotype, following G1P[8], and accounted for 35.3% of RVA cases in the 2011/2012 season. Further genotyping revealed that the G9P[4] strain had genotype 2 internal protein genes except for NSP3: G9-P[4]-I2-R2-C2-M2-A2-N2-T1-E2-H2. Among detected RVA strains, G9P[4] and some G9P[8] strains shared high nucleotide identity in VP7 and NSP3 genes. Phylogenetic and BLAST search analyses showed that the G9P[4] strain in Japan shared high nucleotide identity in genotype 2 genes with common G2P[4] strains circulating globally, but was distinct from other G9P[4] strains circulating worldwide. These results suggest that the G9P[4] strain in Japan may have emerged through an independent reassortment between G9P[8] and G2P[4]. Finally, the role of NSP3 protein in the circulating RVA from an amino acid comparison between T1- and T2-type NSP3 is discussed. These findings provide an important insight into less problematic combinations of circulating RVA genes derived from different genotypes.


Assuntos
Genótipo , Infecções por Rotavirus/virologia , Rotavirus/classificação , Rotavirus/isolamento & purificação , Criança , Pré-Escolar , Análise por Conglomerados , Evolução Molecular , Feminino , Humanos , Lactente , Japão/epidemiologia , Masculino , Epidemiologia Molecular , Dados de Sequência Molecular , Filogenia , RNA Viral/genética , Vírus Reordenados/classificação , Vírus Reordenados/genética , Vírus Reordenados/isolamento & purificação , Rotavirus/genética , Infecções por Rotavirus/epidemiologia , Análise de Sequência de DNA , Homologia de Sequência
10.
Emerg Infect Dis ; 20(6): 1030-3, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24856174

RESUMO

Rotavirus A (RVA) genotype G1P[8], a hallmark of the Wa-like strain, typically contains only genotype 1 genes. However, an unusual RVA G1P[8] with genotype 2 genes was recently detected in Japan. We determined the complete genomic constellation of this RVA. Our findings suggest that mixed RVAs may be more competitive than once thought.


Assuntos
Surtos de Doenças , Gastroenterite/epidemiologia , Genoma Viral , Vírus Reordenados/genética , Infecções por Rotavirus/epidemiologia , Rotavirus/genética , Criança , Pré-Escolar , Gastroenterite/virologia , Genótipo , Humanos , Lactente , Japão/epidemiologia , RNA Viral/genética , Vírus Reordenados/classificação , Vírus Reordenados/isolamento & purificação , Rotavirus/classificação , Rotavirus/isolamento & purificação , Infecções por Rotavirus/virologia
11.
J Med Virol ; 86(12): 2019-25, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24415518

RESUMO

Enteric viruses are an important cause of viral food-borne disease. Shellfish, especially oysters, are well recognized as a source of food-borne diseases, and oyster-associated gastroenteritis outbreaks have on occasion become international occurrences. In this study, 286 fecal specimens from 88 oyster-associated gastroenteritis outbreaks were examined for the presence of 10 human enteric viruses using antigenic or genetic detection methods in order to determine the prevalence of these infections. All virus-positive patients were over 18 years old. The most common enteric virus in outbreaks (96.6%) and fecal specimens (68.9%) was norovirus (NoV), indicating a high prevalence of NoV infection associated with the consumption of raw or under-cooked oysters. Five other enteric viruses, aichiviruses, astroviruses, sapoviruses, enteroviruses (EVs), and rotavirus A, were detected in 30.7% of outbreaks. EV strains were characterized into three rare genotypes, coxsackievirus (CV) A1, A19, and EV76. No reports of CVA19 or EV76 have been made since 1981 in the Infectious Agents Surveillance Report by the National Infectious Diseases Surveillance Center, Japan. Their detection suggested that rare types of EVs are circulating in human populations inconspicuously and one of their transmission modes could be the consumption of contaminated oysters. Rapid identification of pathogens is important for the development of means for control and prevention. The results of the present study will be useful to establish an efficient approach for the identification of viral pathogens in oyster-associated gastroenteritis in adults.


Assuntos
Surtos de Doenças , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/virologia , Gastroenterite/epidemiologia , Gastroenterite/virologia , Vírus/classificação , Vírus/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Fezes/virologia , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Ostreidae , Análise de Sequência de DNA , Vírus/genética , Adulto Jovem
12.
J Clin Virol ; 160: 105377, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36682339

RESUMO

BACKGROUND: Since the first isolation of rubella virus (RuV) in 1962, comprehensive data regarding the quantitative evaluation of RuV shedding remain unavailable. In this study, we evaluated the shedding of viral RNA and infectious virus in patients with acute RuV infection. STUDY DESIGN: We analyzed 767 specimens, including serum/plasma, peripheral blood mononuclear cells (PBMCs), throat swabs, and urine, obtained from 251 patients with rubella. The viral RNA load and the presence of infectious RuV were determined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and virus isolation. RESULTS: Virus excretion peaked 0-2 days after rash onset and decreased over time. The median viral RNA load dropped to an undetectable level on day 3 after rash onset in serum/plasma, day 2 in PBMCs, days 10-13 in throat swabs, and days 6-7 in urine. Infectious virus could be isolated for up to day 2 after rash onset in serum/plasma, day 1 in PBMCs, days 8-9 in throat swabs, and days 4-5 in urine. The minimum viral RNA load that allowed virus isolation was 961 copies/mL in serum/plasma, 784 copies/mL in PBMCs, 650 copies/mL in throat swabs, and 304 copies/mL in urine. A higher viral RNA load indicated a higher likelihood of the presence of infectious virus. CONCLUSION: These findings would contribute to improve algorithms for rubella surveillance and diagnosis. In addition, this study indicates that the results of RT-qPCR enable efficient rubella control by estimating candidate patients excreting infectious virus, which could help prevent viral transmission at an early stage and eliminate rubella ultimately.


Assuntos
Exantema , Rubéola (Sarampo Alemão) , Humanos , Vírus da Rubéola/genética , RNA Viral/genética , Leucócitos Mononucleares , Rubéola (Sarampo Alemão)/diagnóstico , Eliminação de Partículas Virais
13.
J Virol ; 85(19): 9726-36, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21775448

RESUMO

APOBEC1 (A1) is a cytidine deaminase involved in the regulation of lipids in the small intestine. Herpes simplex virus 1 (HSV-1) is a ubiquitous pathogen that is capable of infecting neurons in the brain, causing encephalitis. Here, we show that A1 is induced during encephalitis in neurons of rats infected with HSV-1. In cells stably expressing A1, HSV-1 infection resulted in significantly reduced virus replication compared to that in control cells. Infectivity could be restored to levels comparable to those observed for control cells if A1 expression was silenced by specific A1 short hairpin RNAs (shRNA). Moreover, cytidine deaminase activity appeared to be essential for this inhibition and led to an impaired accumulation of viral mRNA transcripts and DNA copy numbers. The sequencing of viral gene UL54 DNA, extracted from infected A1-expressing cells, revealed G-to-A and C-to-T transitions, indicating that A1 associates with HSV-1 DNA. Taken together, our results demonstrate a model in which A1 induction during encephalitis in neurons may aid in thwarting HSV-1 infection.


Assuntos
Citidina Desaminase/imunologia , Citidina Desaminase/metabolismo , DNA/metabolismo , Encefalite por Herpes Simples/imunologia , Encefalite por Herpes Simples/virologia , Herpesvirus Humano 1/crescimento & desenvolvimento , Herpesvirus Humano 1/patogenicidade , Desaminase APOBEC-1 , Animais , DNA Viral/metabolismo , Modelos Animais de Doenças , Neurônios/imunologia , Neurônios/virologia , RNA Viral/metabolismo , Ratos , Doenças dos Roedores/imunologia , Doenças dos Roedores/virologia , Análise de Sobrevida , Virulência , Replicação Viral
14.
J Virol ; 85(2): 932-45, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21068238

RESUMO

Tetherin, also known as BST-2/CD317/HM1.24, is an antiviral cellular protein that inhibits the release of HIV-1 particles from infected cells. HIV-1 viral protein U (Vpu) is a specific antagonist of human tetherin that might contribute to the high virulence of HIV-1. In this study, we show that three amino acid residues (I34, L37, and L41) in the transmembrane (TM) domain of human tetherin are critical for the interaction with Vpu by using a live cell-based assay. We also found that the conservation of an additional amino acid at position 45 and two residues downstream of position 22, which are absent from monkey tetherins, are required for the antagonism by Vpu. Moreover, computer-assisted structural modeling and mutagenesis studies suggest that an alignment of these four amino acid residues (I34, L37, L41, and T45) on the same helical face in the TM domain is crucial for the Vpu-mediated antagonism of human tetherin. These results contribute to the molecular understanding of human tetherin-specific antagonism by HIV-1 Vpu.


Assuntos
Aminoácidos/genética , Aminoácidos/metabolismo , Antígenos CD/genética , Antígenos CD/metabolismo , Proteínas do Vírus da Imunodeficiência Humana/metabolismo , Mapeamento de Interação de Proteínas , Proteínas Virais Reguladoras e Acessórias/metabolismo , Animais , Linhagem Celular , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , HIV-1/patogenicidade , Humanos , Modelos Moleculares , Ligação Proteica , Estrutura Terciária de Proteína
15.
Sci Rep ; 10(1): 963, 2020 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-31969658

RESUMO

Mammalian orthoreovirus (MRV), also known as reovirus, was discovered in the 1950s and became the first reported segmented double-stranded RNA virus. MRVs have since been found in a variety of animal species, including humans. However, reports on MRV infections are scarce due to the rarity of their symptomatic occurrence. In Japanese surveillance studies, MRVs have been detected as gastrointestinal pathogens since 1981, with a total of 135 records. In Osaka City, Japan, MRV was first isolated in 1994 from a child with meningitis, and then in 2005 and 2014 from children with gastroenteritis. Here, we conducted the first molecular characterization of human MRV isolates from Japan and identified a novel human reovirus strain belonging to MRV type 2, designated the MRV-2 Osaka strain. This strain, with all three isolates classified, is closely related to MRV-2 isolates from sewage in Taiwan and is relatively close to an MRV-2 isolate from a bat in China. Our data suggest that the MRV-2 Osaka strain, which has circulated amongst humans in Japan for at least two decades, has spread internationally.


Assuntos
Genoma Viral , Orthoreovirus de Mamíferos/isolamento & purificação , Infecções por Reoviridae/virologia , Criança , Humanos , Japão , Orthoreovirus de Mamíferos/genética
16.
Retrovirology ; 6: 53, 2009 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-19490609

RESUMO

In this study, we first demonstrate that endogenous hBST-2 is predominantly expressed on the plasma membrane of a human T cell line, MT-4 cells, and that Vpu-deficient HIV-1 was less efficiently released than wild-type HIV-1 from MT-4 cells. In addition, surface hBST-2 was rapidly down-regulated in wild-type but not Vpu-deficient HIV-1-infected cells. This is a direct insight showing that provirus-encoded Vpu has the potential to down-regulate endogenous hBST-2 from the surface of HIV-1-infected T cells. Corresponding to previous reports, the aforementioned findings suggested that hBST-2 has the potential to suppress the release of Vpu-deficient HIV-1. However, the molecular mechanism(s) for tethering HIV-1 particles by hBST-2 remains unclear, and we speculated about the requirement for cellular co-factor(s) to trigger or assist its tethering ability. To explore this possibility, we utilize several cell lines derived from various species including human, AGM, dog, cat, rabbit, pig, mink, potoroo, and quail. We found that ectopic hBST-2 was efficiently expressed on the surface of all analyzed cells, and its expression suppressed the release of viral particles in a dose-dependent manner. These findings suggest that hBST-2 can tether HIV-1 particles without the need of additional co-factor(s) that may be expressed exclusively in primates, and thus, hBST-2 can also exert its function in many cells derived from a broad range of species. Interestingly, the suppressive effect of hBST-2 on HIV-1 release in Vero cells was much less pronounced than in the other examined cells despite the augmented surface expression of ectopic hBST-2 on Vero cells. Taken together, our findings suggest the existence of certain cell types in which hBST-2 cannot efficiently exert its inhibitory effect on virus release. The cell type-specific effect of hBST-2 may be critical to elucidate the mechanism of BST-2-dependent suppression of virus release.


Assuntos
Antígenos CD/fisiologia , Infecções por HIV/virologia , HIV-1/fisiologia , Glicoproteínas de Membrana/fisiologia , Eliminação de Partículas Virais , Animais , Gatos , Linhagem Celular , Chlorocebus aethiops , Cães , Proteínas Ligadas por GPI , Infecções por HIV/metabolismo , Interações Hospedeiro-Patógeno , Proteínas do Vírus da Imunodeficiência Humana/deficiência , Humanos , Vison , Potoroidae , Codorniz , Coelhos , Especificidade da Espécie , Suínos , Proteínas Virais Reguladoras e Acessórias/deficiência
17.
Jpn J Infect Dis ; 72(5): 334-336, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31061358

RESUMO

The second largest epidemic of hand, foot, and mouth disease since 1982 occurred in 2017, which involved 6,173 cases in Osaka City, Japan. The main causative agent was coxsackievirus A6 (CV-A6). Phylogenetic analysis revealed that the detected CV-A6 strains belonged to genetic groups A3 and A4 in clade A.


Assuntos
Enterovirus/classificação , Enterovirus/isolamento & purificação , Epidemias , Genótipo , Doença de Mão, Pé e Boca/epidemiologia , Pré-Escolar , Cidades/epidemiologia , Enterovirus/genética , Feminino , Humanos , Lactente , Japão/epidemiologia , Masculino
18.
Jpn J Infect Dis ; 72(6): 426-428, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31257241

RESUMO

Dengue fever (DF) is a mosquito-borne disease and a significant global public health problem. Although a few serological surveys in the literature suggest endemic DF in many parts of Africa, DF cases in these countries are generally underreported because of the lack of diagnostic testing and systematic surveillance; thus, little is known about the phylogenetic profile of circulating strains. In April 2015, DF was diagnosed in a Japanese national returning from the Democratic Republic of the Congo (DRC). Dengue virus 1 (DENV-1) RNA was detected in the patient's serum sample using real-time reverse transcription PCR. Phylogenetic analysis of the E gene revealed that the detected DENV-1 strain was classified as genotype V and was closely related, with 100% nucleotide identity, to the strain causing the 2013 DF epidemic in Angola, which is located directly south of the DRC. This is the first report to characterize the circulating DENV strain in the DRC, and the findings indicate that the DENV-1 strain causing the 2013 DF epidemic in Angola was also circulating in the DRC in 2015.


Assuntos
Vírus da Dengue/genética , Dengue/diagnóstico , Doença Relacionada a Viagens , República Democrática do Congo , Dengue/virologia , Vírus da Dengue/isolamento & purificação , Genótipo , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Filogenia , RNA Viral/genética , Proteínas do Envelope Viral/genética
19.
Jpn J Infect Dis ; 71(2): 152-154, 2018 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-29279450

RESUMO

Measles is a highly contagious infection caused by the measles virus (MV). This study performed long-term surveillance in order to survey the prevalence of MV. A total of 417 patients diagnosed with or suspected of having measles were tested for MV between January 2007 and December 2016 in Osaka City, Japan. Reverse transcription-polymerase chain reaction-based testing of clinical specimens showed that 54 patients (12.9%) were MV-positive. An MV epidemic occurred in 2007, in which all detected MV strains were genotype D5, an epidemic strain in Japan at that time. The detected wild-type MV strains in sporadic or outbreak-associated cases since 2011 included genotypes D4, D8, B3, and H1. Three vaccine strains (all genotype A) were also detected. Children <10 years of age accounted for 90.0% of the MV-positive patients in 2007. In contrast, adults (≥ 20 years of age) accounted for the majority of MV-positive cases since 2011, as follows: 100%, 50%, 71.4%, 100%, and 87.5% of cases in 2011, 2013, 2014, 2015, and 2016, respectively. The recent high rate of two-dose MV vaccination coverage among children in Japan may have contributed to the reduced risk of MV infection and onset of measles in young persons.


Assuntos
Vírus do Sarampo/genética , Sarampo/epidemiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Genótipo , Humanos , Lactente , Recém-Nascido , Japão/epidemiologia , Leucócitos Mononucleares/virologia , Pessoa de Meia-Idade , Vigilância da População , Prevalência , RNA Viral/análise , RNA Viral/genética , Adulto Jovem
20.
PLoS One ; 12(9): e0184335, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28902862

RESUMO

The first upsurge of enterovirus D68 (EV-D68), a causative agent of acute respiratory infections (ARIs), in Japan was reported in Osaka City in 2010. In this study, which began in 2010, we surveyed EV-D68 in children with ARIs and analyzed sequences of EV-D68 strains detected. Real-time PCR of 19 respiratory viruses or subtypes of viruses, including enterovirus, was performed on 2,215 specimens from ARI patients (<10 years of age) collected between November 2010 and December 2015 in Osaka City, Japan. EV-D68 was identified in 18 enterovirus-positive specimens (n = 4 in 2013, n = 1 in 2014, and n = 13 in 2015) by analysis of viral protein 1 (VP1) or VP4 sequences, followed by a BLAST search for similar sequences. All EV-D68 strains were detected between June and October (summer to autumn), except for one strain detected in 2014. A phylogenetic analysis of available VP1 sequences revealed that the Osaka strains detected in 2010, 2013, and 2015 belonged to distinct clusters (Clades C, A, and B [Subclade B3], respectively). Comparison of the 5' untranslated regions of these viruses showed that Osaka strains in Clades A, B (Subclade B3), and C commonly had deletions at nucleotide positions 681-703 corresponding to the prototype Fermon strain. Clades B and C had deletions from nucleotide positions 713-724. Since the EV-D68 epidemic in 2010, EV-D68 re-emerged in Osaka City, Japan, in 2013 and 2015. Results of this study indicate that distinct clades of EV-D68 contributed to re-emergences of this virus in 2010, 2013, and 2015 in this limited region.


Assuntos
Enterovirus Humano D/classificação , Enterovirus Humano D/genética , Infecções por Enterovirus/epidemiologia , Infecções por Enterovirus/virologia , Criança , Pré-Escolar , Doenças Transmissíveis Emergentes/virologia , Surtos de Doenças/estatística & dados numéricos , Feminino , Humanos , Lactente , Recém-Nascido , Japão/epidemiologia , Masculino , Filogenia , Infecções Respiratórias/virologia , Análise de Sequência de DNA , Urbanização , Proteínas Estruturais Virais/genética
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