Kiyoko Iwatsuki-Horimoto

The University of Tokyo, Tokyo, Tokyo-to, Japan

Are you Kiyoko Iwatsuki-Horimoto?

Claim your profile

Publications (41)231.17 Total impact

  • [show abstract] [hide abstract]
    ABSTRACT: Influenza virus and human parainfluenza virus (HPIV) are major etiologic agents of acute respiratory illness in young children. Inactivated and live attenuated influenza vaccines are approved in several countries, yet no vaccine is licensed for HPIV. We previously showed that a replication-incompetent PB2-knockout (PB2-KO) virus that possesses a reporter gene in the coding region of the PB2 segment can serve as a platform for a bivalent vaccine. To develop a bivalent vaccine against influenza and parainfluenza virus, here, we generated a PB2-KO virus possessing the hemagglutinin-neuraminidase (HN) glycoprotein of HPIV type 3 (HPIV3), a major surface antigen of HPIV, in its PB2 segment. We confirmed that this virus replicated only in PB2-expressing cells and expressed HN. We then examined the efficacy of this virus as a bivalent vaccine in a hamster model. High levels of virus-specific IgG antibodies in sera and IgA, IgG, and IgM antibodies in bronchoalveolar lavage fluids against both influenza virus and HPIV3 were detected from hamsters immunized with this virus. The neutralizing capability of these serum antibodies was also confirmed. Moreover, the immunized hamsters were completely protected from virus challenge with influenza virus or HPIV3. These results indicate that PB2-KO virus expressing the HN of HPIV3 has the potential to be a novel bivalent vaccine against influenza and human parainfluenza viruses.
    Vaccine 10/2013; · 3.77 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Avian influenza A viruses rarely infect humans; however, when human infection and subsequent human-to-human transmission occurs, worldwide outbreaks (pandemics) can result. The recent sporadic infections of humans in China with a previously unrecognized avian influenza A virus of the H7N9 subtype (A(H7N9)) have caused concern owing to the appreciable case fatality rate associated with these infections (more than 25%), potential instances of human-to-human transmission, and the lack of pre-existing immunity among humans to viruses of this subtype. Here we characterize two early human A(H7N9) isolates, A/Anhui/1/2013 (H7N9) and A/Shanghai/1/2013 (H7N9); hereafter referred to as Anhui/1 and Shanghai/1, respectively. In mice, Anhui/1 and Shanghai/1 were more pathogenic than a control avian H7N9 virus (A/duck/Gunma/466/2011 (H7N9); Dk/GM466) and a representative pandemic 2009 H1N1 virus (A/California/4/2009 (H1N1pdm09); CA04). Anhui/1, Shanghai/1 and Dk/GM466 replicated well in the nasal turbinates of ferrets. In nonhuman primates, Anhui/1 and Dk/GM466 replicated efficiently in the upper and lower respiratory tracts, whereas the replicative ability of conventional human influenza viruses is typically restricted to the upper respiratory tract of infected primates. By contrast, Anhui/1 did not replicate well in miniature pigs after intranasal inoculation. Critically, Anhui/1 transmitted through respiratory droplets in one of three pairs of ferrets. Glycan arrays showed that Anhui/1, Shanghai/1 and A/Hangzhou/1/2013 (H7N9) (a third human A(H7N9) virus tested in this assay) bind to human virus-type receptors, a property that may be critical for virus transmissibility in ferrets. Anhui/1 was found to be less sensitive in mice to neuraminidase inhibitors than a pandemic H1N1 2009 virus, although both viruses were equally susceptible to an experimental antiviral polymerase inhibitor. The robust replicative ability in mice, ferrets and nonhuman primates and the limited transmissibility in ferrets of Anhui/1 suggest that A(H7N9) viruses have pandemic potential.
    Nature 07/2013; · 38.60 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Vaccination is an effective means to protect against influenza virus. Although inactivated and live-attenuated vaccines are currently available, each vaccine has disadvantages (e.g., immunogenicity and safety). To overcome these problems, we previously developed a replication-incompetent PB2-knockout (PB2-KO) influenza virus that replicates only in PB2 protein-expressing cells. Here, we generated two PB2-KO viruses whose PB2-coding regions were replaced with the HA genes of either A/California/04/2009 (H1N1pdm09) or A/Vietnam/1203/2004 (H5N1). The resultant viruses comparably, or in some cases more efficiently, induced virus-specific antibodies in the serum, nasal wash, and bronchoalveolar lavage fluid of mice relative to a conventional formalin-inactivated vaccine. Furthermore, mice immunized with these PB2-KO viruses were protected from lethal challenges with not only the backbone virus strain, but also strains from which their foreign HAs originated, indicating that PB2-KO viruses with antigenically different HAs could serve as bivalent influenza vaccines.
    Journal of Virology 05/2013; · 5.08 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: A novel swine-origin H1N1 influenza virus [A(H1N1)pdm09 virus] caused the 2009 influenza pandemic. Most patients exhibited mild symptoms similar to seasonal influenza, but some experienced severe clinical signs and, in the worst cases, died. Such differences in symptoms are generally associated with preexisting medical conditions, but recent reports indicate the possible involvement of viral factors in clinical severity. To better understand the mechanism of pathogenicity of the A(H1N1)pdm09 virus, here, we compared five viruses that are genetically similar but were isolated from patients with either severe or mild symptoms. In a mouse model, Norway3487 virus exhibited greater pathogenicity than did Osaka164 virus. By exploiting reassortant viruses between these two viruses, we found that viruses possessing the HA gene of Norway3487 in the genetic background of Osaka164 were more pathogenic in mice compared with other reassortant viruses, indicating a role for HA in the high virulence of Norway3487 virus. Intriguingly, a virus possessing HA, NA, and NS derived from Norway3487 exhibited greater pathogenicity in mice in concert with PB2 and PB1 derived from Osaka164 than did the parental Norway3487 virus. These findings demonstrate that reassortment between A(H1N1)pdm09 viruses can lead to increased pathogenicity and highlight the need for continued surveillance of A(H1N1)pdm09 viruses.
    Journal of Virology 12/2012; · 5.08 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Background The pathogenesis of influenza A virus subtype H5N1 (hereafter, "H5N1") infection in humans is not completely understood, although hypercytokinemia is thought to play a role. We previously reported that most H5N1 viruses induce high cytokine responses in human macrophages, whereas some H5N1 viruses induce only a low level of cytokine production similar to that induced by seasonal viruses.Methods To identify the viral molecular determinants for cytokine induction of H5N1 viruses in human macrophages, we generated a series of reassortant viruses between the high cytokine inducer A/Vietnam/UT3028II/03 clone 2 (VN3028IIcl2) and the low inducer A/Indonesia/UT3006/05 (IDN3006) and evaluated cytokine expression in human macrophages.ResultsViruses possessing the acidic polymerase (PA) gene of VN3028IIcl2 exhibited high levels of hypercytokinemia-related cytokine expression in human macrophages, compared with IDN3006, but showed no substantial differences in viral growth in these cells. Further, the PA gene of VN3028IIcl2 conferred enhanced virulence in mice.Conclusions These results demonstrate that the PA gene of VN3028IIcl2 affects cytokine production in human macrophages and virulence in mice. These findings provide new insights into the cytokine-mediated pathogenesis of H5N1 infection in humans.
    The Journal of Infectious Diseases 10/2012; · 5.85 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Vaccination is one of the most effective measures to protect against influenza virus infection. Inactivated and live-attenuated influenza vaccines are available; however, their efficacy is suboptimal. To develop a safe and more immunogenic vaccine, we produced a novel replication-incompetent influenza virus that possesses uncleavable hemagglutinin (HA) and tested its vaccine potential. The uncleavable HA was engineered by substituting the arginine at the C-terminus of HA1 with threonine, which prevents cleavage of HA into its HA1 and HA2 subunits, preventing fusion between the host and viral membranes. Although this fusion-deficient HA influenza virus that possesses uncleavable HA (uncleavable HA virus) could undergo multiple cycles of replication in only wild-type HA-expressing cells, it could infect normal cells and express viral proteins in infected cells, but could not generate infectious virus from infected cells due to the uncleavable HA. When C57BL/6 mice were intranasally immunized with the uncleavable HA virus, influenza-specific IgG and IgA antibodies were detected in nasal wash and bronchoalveolar lavage samples and in serum. In addition, influenza-specific CD8(+) T cells accumulated in the lungs of these mice. Moreover, mice immunized with the uncleavable HA virus were protected against a challenge of lethal doses of influenza virus, unlike mice immunized with a formalin-inactivated virus. These findings demonstrate that this fusion-deficient virus, which possesses uncleavable HA, is a suitable influenza vaccine candidate.
    Vaccine 08/2012; 30(42):6027-33. · 3.77 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Neutralizing antibody titers were determined before and after a single dose of pandemic (H1N1) 2009 influenza vaccine in HIV-1-positive Japanese adults in the first season of the pandemic and in those in the second season who had already received the vaccine in the first season. The antibody response rate at 2-month post-vaccination increased significantly from 49.0% (50/102, 95%CI: 39.0-59.1%) in the 2009/2010 season to 66.7% (42/63, 95%CI: 53.7-78.1%) in the 2010/2011 season. Geometric mean antibody titers (fold dilution) at baseline, at 2 months, and at 4 months also increased significantly from 4.4 (95%CI: 3.3-5.7), 19.0 (95%CI: 13.4-26.8) and 13.7 (95%CI: 9.3-20.2), respectively, in the 2009/2010 season to 8.3 (95%CI: 5.8-11.7), 47.0 (95%CI: 32.2-68.6) and 38.2 (95%CI: 23.8-61.4), respectively, in the 2010/2011 season. Although the vaccine response was low in the first season, it was improved in the second season.
    Vaccine 04/2012; 30(26):3819-23. · 3.77 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: We evaluated the immune response to a 2009 influenza A (H1N1) unadjuvanted vaccine in HIV-infected patients and assessed the boosting effect of a second dose. HIV-infected adults were enrolled and scheduled to receive the H1N1 unadjuvanted vaccine containing 15μg of A/California/7/2009 haemagglutinin. Anti-H1N1 antibody titers were measured at enrollment and 4-8 weeks after each vaccination by using haemagglutination inhibition (HI) and virus neutralization (NT) assays. One hundred and four patients were analyzed. Seroconversion, as measured by using HI and NT assays, was observed in 52 (50.0%) patients and 49 (47.1%) patients, respectively, after the first dose. Seroconversion rate evaluated by using NT, but not HI, antibody titers was associated with HIV RNA levels of <400copies/ml (odds ratio, 3.21; 95% CI, 1.15-8.96). Other parameters, including CD4 cell count, were not associated with seroconversion. In a cohort that received two vaccine doses at a 4-8-week interval (n=54), the seroconversion rate and geometric mean titer for HI antibodies were 44.4% (95% CI, 30.8-58.1%) and 30.5 (95% CI, 19.9-46.9) after the first dose, respectively, and 48.1% (95% CI, 34.4-61.9%) and 39.0 (95% CI, 26.1-58.2) after the second dose, respectively. Among HIV-infected patients, the seroconversion rate was around 50% after the first dose of unadjuvanted vaccine. A second dose of vaccine had a limited boosting effect on immunity in this patient cohort.
    Vaccine 11/2011; 29(49):9224-8. · 3.77 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: The first influenza pandemic of the 21st century was caused by novel H1N1 viruses that emerged in early 2009. An Asp-to-Gly change at position 222 of the receptor-binding protein hemagglutinin (HA) correlates with more-severe infections in humans. The amino acid at position 222 of HA contributes to receptor-binding specificity with Asp (typically found in human influenza viruses) and Gly (typically found in avian and classic H1N1 swine influenza viruses), conferring binding to human- and avian-type receptors, respectively. Here, we asked whether binding to avian-type receptors enhances influenza virus pathogenicity. We tested two 2009 pandemic H1N1 viruses possessing HA-222G (isolated from severe cases) and two viruses that possessed HA-222D. In glycan arrays, viruses possessing HA-222D preferentially bound to human-type receptors, while those encoding HA-222G bound to both avian- and human-type receptors. This difference in receptor binding correlated with efficient infection of viruses possessing HA-222G, compared to those possessing HA-222D, in human lung tissue, including alveolar type II pneumocytes, which express avian-type receptors. In a nonhuman primate model, infection with one of the viruses possessing HA-222G caused lung damage more severe than did infection with a virus encoding HA-222D, although these pathological differences were not observed for the other virus pair with either HA-222G or HA-222D. These data demonstrate that the acquisition of avian-type receptor-binding specificity may result in more-efficient infection of human alveolar type II pneumocytes and thus more-severe lung damage. Collectively, these findings suggest a new mechanism by which influenza viruses may become more pathogenic in mammals, including humans.
    Journal of Virology 09/2011; 85(24):13195-203. · 5.08 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Although raccoons (Procyon lotor) are susceptible to influenza viruses, highly pathogenic avian influenza virus (H5N1) infection in these animals has not been reported. We performed a serosurvey of apparently healthy feral raccoons in Japan and found specific antibodies to subtype H5N1 viruses. Feral raccoons may pose a risk to farms and public health.
    Emerging Infectious Diseases 04/2011; 17(4):714-7. · 6.79 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Highly pathogenic H5N1 avian influenza viruses have caused infection in humans, with a high mortality rate, since 1997. While the pathogenesis of this infection is not completely understood, hypercytokinaemia and alveolar macrophages are thought to play a role. To gain further insight into the cytokine-mediated pathogenesis of this infection in humans, we measured various cytokines produced by primary human macrophages infected with H5N1, pandemic H1N1 or seasonal influenza viruses. We found that many cytokines were produced at higher levels on infection with the H5N1 strains tested compared with seasonal influenza viruses. Interestingly, the extent of cytokine induction varied among the H5N1 strains and did not correlate with replicative ability in macrophages. Further, a pandemic H1N1 virus induced higher levels of several cytokines compared with seasonal viruses and some H5N1 strains. Our results demonstrate that high cytokine induction is not a universal feature of all H5N1 viruses.
    Journal of General Virology 03/2011; 92(Pt 6):1428-34. · 3.13 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Since its emergence, the 2009 pandemic H1N1 virus has spread rapidly throughout the world. Previously, we reported that most individuals born after 1920 do not have cross-reactive virus-neutralizing antibodies against pandemic (H1N1) 2009 virus, indicating that they were immunologically naïve to the pandemic virus prior to its emergence. This finding provided us with an excellent opportunity for a seroepidemiological investigation of the transmission mode of the pandemic virus in the community. To gain insight into its transmission within communities, we performed a serosurvey for pandemic virus infection with schoolchildren at an elementary school in Tokyo, Japan, and their parents. We observed a high prevalence of neutralizing antibodies to the pandemic virus in the children at this school, although the percentage of children positive for the neutralizing antibodies varied among classrooms. While a much lower prevalence was observed among parents, seropositivity of the parents correlated with that of their schoolchildren. Moreover, many adults appeared to have experienced asymptomatic infection with the pandemic virus. These data suggest that the pandemic virus was readily transmitted among schoolchildren in elementary schools and that it was also transmitted from schoolchildren to their parents.
    Clinical and vaccine Immunology: CVI 02/2011; 18(5):860-6. · 2.60 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Pandemic influenza A(H1N1) virus infection quickly circulated worldwide in 2009. In Japan, the first case was reported in May 2009, one month after its outbreak in Mexico. Thereafter, A(H1N1) infection spread widely throughout the country. It is of great importance to profile and understand the situation regarding viral mutations and their circulation in Japan to accumulate a knowledge base and to prepare clinical response platforms before a second pandemic (pdm) wave emerges. A total of 253 swab samples were collected from patients with influenza-like illness in the Osaka, Tokyo, and Chiba areas both in May 2009 and between October 2009 and January 2010. We analyzed partial sequences of the hemagglutinin (HA) and neuraminidase (NA) genes of the 2009 pdm influenza virus in the collected clinical samples. By phylogenetic analysis, we identified major variants of the 2009 pdm influenza virus and critical mutations associated with severe cases, including drug-resistance mutations. Our sequence analysis has revealed that both HA-S220T and NA-N248D are major non-synonymous mutations that clearly discriminate the 2009 pdm influenza viruses identified in the very early phase (May 2009) from those found in the peak phase (October 2009 to January 2010) in Japan. By phylogenetic analysis, we found 14 micro-clades within the viruses collected during the peak phase. Among them, 12 were new micro-clades, while two were previously reported. Oseltamivir resistance-related mutations, i.e., NA-H275Y and NA-N295S, were also detected in sporadic cases in Osaka and Tokyo.
    PLoS ONE 01/2011; 6(4):e18956. · 3.73 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: A novel influenza (H1N1) virus caused an influenza pandemic in 2009, while highly pathogenic H5N1 avian influenza viruses have continued to infect humans since 1997. Influenza, therefore, remains a serious health threat. Currently, neuraminidase (NA) inhibitors are the mainstay for influenza therapy; however, drug-resistant mutants of seasonal H1N1 and H5N1 viruses have emerged highlighting the need for alternative therapeutic approaches. One such approach is antibody immunotherapy. Here, we show that the monoclonal antibody C179, which recognizes a neutralizing epitope common among H1, H2, H5, and H6 hemagglutinins (HAs), protected mice from a lethal challenge with various H5N1 and pandemic (H1N1) 2009 viruses when administered either intraperitoneally or intranasally. The protective efficacy of intranasally inoculated C179 was comparable to that of intraperitoneal administration. Our results suggest that direct administration of this anti-influenza antibody to viral replication sites is an effective strategy for prophylaxis and therapy.
    Antiviral research 12/2010; 88(3):249-55. · 3.61 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: We previously characterised the matrix 1 (M1)-binding domain of the influenza A virus NS2/nuclear export protein (NEP), reporting a critical role for the tryptophan (W78) residue that is surrounded by a cluster of glutamate residues in the C-terminal region that interacts with the M1 protein (Akarsu et al., 2003). To gain further insight into the functional role of this interaction, here we used reverse genetics to generate a series of A/WSN/33 (H1N1)-based NS2/NEP mutants for W78 or the C-terminal glutamate residues and assessed their effect on virus growth. We found that simultaneous mutations at three positions (E67S/E74S/E75S) of NS2/NEP were important for inhibition of influenza viral polymerase activity, although the W78S mutant and other glutamate mutants with single substitutions were not. In addition, double and triple substitutions in the NS2/NEP glutamine residues, which resulted in the addition of seven amino acids to the C-terminus of NS1 due to gene overlapping, resulted in virus attenuation in mice. Animal studies with this mutant suggest a potential benefit to incorporating these NS mutations into live vaccines.
    Virus Research 10/2010; 155(1):240-8. · 2.75 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Pigs have long been considered potential intermediate hosts in which avian influenza viruses can adapt to humans. To determine whether this potential exists for pigs in Indonesia, we conducted surveillance during 2005-2009. We found that 52 pigs in 4 provinces were infected during 2005-2007 but not 2008-2009. Phylogenetic analysis showed that the viruses had been introduced into the pig population in Indonesia on at least 3 occasions. One isolate had acquired the ability to recognize a human-type receptor. No infected pig had influenza-like symptoms, indicating that influenza A (H5N1) viruses can replicate undetected for prolonged periods, facilitating avian virus adaptation to mammalian hosts. Our data suggest that pigs are at risk for infection during outbreaks of influenza virus A (H5N1) and can serve as intermediate hosts in which this avian virus can adapt to mammals.
    Emerging Infectious Diseases 10/2010; 16(10):1515-23. · 6.79 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: The highly pathogenic avian influenza virus H5N1 is known to induce high level of tumor necrosis factor alpha (TNF-alpha) from primary macrophages. However, it is still unclear whether current H5N1 strains also induce high TNF-alpha production, as most of the data were derived from extinct clade 0 H5N1 strain. Here, we show that current clade 1 and 2 H5N1 strains induce variable levels of TNF-alpha that are not necessarily higher than those induced by seasonal influenza viruses. The result suggests that hyper-induction of TNF-alpha in human macrophages is not always associated with a highly pathogenic phenotype. We further tested the contribution of the NS gene segment from H5N1 isolates to TNF-alpha induction by using reverse genetics. While NS conferred some variation in TNF-alpha induction when incorporated into an H1N1 virus genetic background, it did not affect TNF-alpha induction in an H5N1 virus genetic background, suggesting that other viral genes are involved.
    Archives of Virology 08/2010; 155(8):1273-9. · 2.03 Impact Factor
  • The Pediatric Infectious Disease Journal 06/2010; 29(6):578-9. · 3.57 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Highly pathogenic H5N1 influenza A viruses have spread across Asia, Europe, and Africa. More than 500 cases of H5N1 virus infection in humans, with a high lethality rate, have been reported. To understand the molecular basis for the high virulence of H5N1 viruses in mammals, we tested the virulence in ferrets of several H5N1 viruses isolated from humans and found A/Vietnam/UT3062/04 (UT3062) to be the most virulent and A/Vietnam/UT3028/03 (UT3028) to be avirulent in this animal model. We then generated a series of reassortant viruses between the two viruses and assessed their virulence in ferrets. All of the viruses that possessed both the UT3062 hemagglutinin (HA) and nonstructural protein (NS) genes were highly virulent. By contrast, all those possessing the UT3028 HA or NS genes were attenuated in ferrets. These results demonstrate that the HA and NS genes are responsible for the difference in virulence in ferrets between the two viruses. Amino acid differences were identified at position 134 of HA, at positions 200 and 205 of NS1, and at positions 47 and 51 of NS2. We found that the residue at position 134 of HA alters the receptor-binding property of the virus, as measured by viral elution from erythrocytes. Further, both of the residues at positions 200 and 205 of NS1 contributed to enhanced type I interferon (IFN) antagonistic activity. These findings further our understanding of the determinants of pathogenicity of H5N1 viruses in mammals.
    PLoS Pathogens 01/2010; 6(9):e1001106. · 8.14 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Influenza A viruses cause recurrent outbreaks at local or global scale with potentially severe consequences for human health and the global economy. Recently, a new strain of influenza A virus was detected that causes disease in and transmits among humans, probably owing to little or no pre-existing immunity to the new strain. On 11 June 2009 the World Health Organization declared that the infections caused by the new strain had reached pandemic proportion. Characterized as an influenza A virus of the H1N1 subtype, the genomic segments of the new strain were most closely related to swine viruses. Most human infections with swine-origin H1N1 influenza viruses (S-OIVs) seem to be mild; however, a substantial number of hospitalized individuals do not have underlying health issues, attesting to the pathogenic potential of S-OIVs. To achieve a better assessment of the risk posed by the new virus, we characterized one of the first US S-OIV isolates, A/California/04/09 (H1N1; hereafter referred to as CA04), as well as several other S-OIV isolates, in vitro and in vivo. In mice and ferrets, CA04 and other S-OIV isolates tested replicate more efficiently than a currently circulating human H1N1 virus. In addition, CA04 replicates efficiently in non-human primates, causes more severe pathological lesions in the lungs of infected mice, ferrets and non-human primates than a currently circulating human H1N1 virus, and transmits among ferrets. In specific-pathogen-free miniature pigs, CA04 replicates without clinical symptoms. The assessment of human sera from different age groups suggests that infection with human H1N1 viruses antigenically closely related to viruses circulating in 1918 confers neutralizing antibody activity to CA04. Finally, we show that CA04 is sensitive to approved and experimental antiviral drugs, suggesting that these compounds could function as a first line of defence against the recently declared S-OIV pandemic.
    Nature 08/2009; 460(7258):1021-5. · 38.60 Impact Factor

Publication Stats

1k Citations
231.17 Total Impact Points


  • 2003–2013
    • The University of Tokyo
      • • Department of Microbiology and Immunology
      • • Institute of Medical Science
      Tokyo, Tokyo-to, Japan
  • 2003–2011
    • University of Wisconsin, Madison
      • Department of Pathobiological Sciences
      Madison, MS, United States
  • 2010
    • Unit of Virus Host Cell Interactions
      Grenoble, Rhône-Alpes, France
    • Airlangga University
      Surabaya, West Java, Indonesia
  • 2009
    • Shiga University of Medical Science
      • Department of Pathology
      Ōtu, Shiga, Japan
  • 2008
    • National Institute of Hygiene and Epidemiology
      Hà Nội, Ha Nội, Vietnam
  • 2006
    • Hokkaido University
      • Laboratory of Microbiology
      Sapporo-shi, Hokkaido, Japan