Publications by authors named "Yoshihiro Kaku"

Article Synopsis
  • Getah virus (GETV) is a mosquito-borne virus that affects horses and pigs, causing symptoms like fever and rash, and has been reported in outbreaks primarily in Asia and Oceania.
  • A new strain of GETV (22IH8) was isolated from mosquitoes in Nagasaki, Japan in 2022, and genetic analysis shows it is more closely related to strains from China than those found in Japan in the past.
  • The current vaccine for horses in Japan (MI-110) is effective against the new strain, suggesting that existing vaccination efforts can still combat this emerging threat.
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  • A study investigated how susceptible domestic cats are to SARS-CoV-2, including different variants like gamma, delta, and omicron.
  • Researchers found that cats inoculated with wild-type, gamma, and delta variants could shed the virus for a week and showed no severe symptoms even after being infected with a small amount of the virus.
  • While cats developed a strong immune response to the earlier variants, the study revealed that the omicron variant was less effective at replicating in cats and elicited a weaker immune response.
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Rabies virus (RABV) causes fatal neurological disease. Pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) using inactivated-virus vaccines are the most effective measures to prevent rabies. In Japan, HEP-Flury, the viral strain, used as a human rabies vaccine, has historically been propagated in primary fibroblast cells derived from chicken embryos.

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Rabies is a fatal encephalitic infectious disease caused by the rabies virus (RABV). RABV is highly neurotropic and replicates in neuronal cell lines . The RABV fixed strain, HEP-Flury, was produced via passaging in primary chicken embryonic fibroblast cells.

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  • * SAYAV was not able to be cultured in lab settings but was studied by creating single-round infectious virus particles (SRIP) using its gene sequence, which helped in examining its endemic status.
  • * The presence of neutralizing antibodies against SAYAV in sika deer and wild boars indicates it is widespread in Japan, and phylogenetic analysis shows it evolved separately from other known flaviviruses, highlighting an innovative approach to studying uncultured viruses.
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  • Some lyssaviruses, like the rabies virus, can cause serious neurological symptoms in humans, but most vaccines have only been tested against rabies.
  • In a study, researchers evaluated the effectiveness of rabbit serum from RABV vaccines and other lyssaviruses in neutralizing different strains, finding that RABV vaccines worked well against some strains but poorly against others.
  • The results suggest a need for new vaccines for lyssaviral infections since current ones aren't effective across all lyssavirus types.
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  • Nipah virus (NiV) is a dangerous virus causing severe illness in humans with a mortality rate over 40%, primarily transmitted by fruit bats found in Southeast Asia.
  • Researchers developed recombinant vaccinia viruses that express NiV proteins to test their effectiveness at producing immune responses, finding that they successfully induced higher levels of neutralizing antibodies in hamsters than previous vaccine candidates.
  • The study suggests that the LC16m8-based vaccines have promising potential for future clinical use against NiV disease, marking a significant step towards effective prevention methods.
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  • Rabies is a severe neurological disease caused by lyssaviruses, with a focus on the rabies lyssavirus (RABV).
  • The study developed new serological neutralizing tests using vesicular stomatitis virus pseudotypes that mimic all 18 lyssavirus glycoproteins, revealing that current RABV vaccines are ineffective against most lyssaviruses.
  • The findings indicate that while some glycoproteins could provoke neutralizing antibodies across various lyssaviruses, this testing system could help create more effective, broad-protective vaccines in the future.
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  • The immune response to SARS-CoV-2 has become complex due to vaccinations and various infections, leading to diverse protective immunity in populations, especially with the emergence of the highly mutated Omicron variant.!* -
  • A study assessed how well different immune histories neutralized Omicron using blood samples from mRNA vaccinees and those with prior Alpha/Delta infections, finding that breakthrough infections enhanced neutralization against Omicron.!* -
  • Results showed that fully vaccinated individuals without breakthrough infections were less able to neutralize Omicron, while those with breakthrough infections produced stronger antibodies, emphasizing the importance of the vaccination-infection timing in determining immune response efficacy.!*
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Rabies is a highly neurotropic disease caused by rabies lyssavirus (RABV). Human rabies vaccines exist for pre- and postexposure prophylaxis; however, after clinical symptoms appear, the disease has an ∼100% mortality rate with no effective treatments available. In our previous study, mouse neuroblastoma cells transfected with a plasmid coding one clone of a single-chain variable fragment (scFv), scFv-P19, against RABV phosphoprotein (RABV-P) derived from an scFv phage-display library, before infection, exhibited reduced viral propagation after infection with the RABV-fixed strain, CVS11.

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Background: Nipah virus (NiV) is an emerging zoonotic paramyxovirus that causes severe encephalitis and respiratory disease with a high mortality rate in humans. During large outbreaks of the viral disease, serological testing of serum samples could be a useful diagnostic tool, which could provide information on not only the diagnosis of NiV disease but also the history of an individual with previous exposure to the virus, thereby supporting disease control. Therefore, an efficient method for the inactivation of NiV in serum samples is required for serological diagnosis.

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Background: The complete genome sequences of 44 Bacillus cereus group isolates collected from diverse sources in Japan were analyzed to determine their genetic backgrounds and diversity levels in Japan. Multilocus sequence typing (MLST) and core-genome single-nucleotide polymorphism (SNP) typing data from whole-genome sequences were analyzed to determine genetic diversity levels. Virulence-associated gene profiles were also used to evaluate the genetic backgrounds and relationships among the isolates.

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A novel indirect fluorescent antibody test (IFAT) for detection of IgM against Nipah virus (NiV) was developed using HeLa 229 cells expressing recombinant NiV nucleocapsid protein (NiV-N). The NiV IFAT was evaluated using three panels of sera: a) experimentally produced sera from NiV-N-immunized/pre-immunized macaques, b) post-infection human sera associated with a Nipah disease outbreak in the Philippines in 2014, and c) human sera from a non-exposed Malaysian population. Immunized macaque sera showed a characteristic granular staining pattern of the NiV-N expressed antigen in HeLa 229 cells, which was readily distinguished from negative-binding results of the pre-immunized macaque sera.

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Intracellular antibodies (intrabodies) are expected to function as therapeutics as well as tools for elucidating in vivo function of proteins. In this study, we propose a novel intrabody selection method in the cytosol of mammalian cells by utilizing a growth signal, induced by the interaction of the target antigen and an scFv-c-kit growth sensor. Here, we challenge this method to select specific intrabodies against rabies virus nucleoprotein (RV-N) for the first time.

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A versatile strategy to inhibit protein functions in the cytoplasmic environment is eagerly anticipated for drug discovery. In this study, we demonstrate a novel system to directly select functional intrabodies from a library in the mammalian cytoplasm. In this system, a target homo-oligomeric antigen is expressed together with a single-chain Fv (scFv) library that is linked to the cytoplasmic domain of a receptor tyrosine kinase (RTK) in the cytoplasm of murine interleukin-3 (IL-3)-dependent cells.

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We identified novel viruses in feces from cattle with diarrhea collected in 2009 in Hokkaido Prefecture, Japan, by using a metagenomics approach and determined the (near) complete sequences of the virus. Sequence analyses revealed that they had a standard picornavirus genome organization, i.e.

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We report the draft genome sequences of Bacillus anthracis strains Shikan-NIID, 52-40-NIAH, and 44-NIAH stored in Japan and belonging to the A3 cluster.

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In this study, G proteins of the rabies virus (RABV) Kyoto strain were detected in the cytoplasm but not distributed at the cell membrane of mouse neuroblastoma (MNA) cells. G proteins of CVS-26 were detected in both the cell membrane and perinuclear space of MNA cells. We found that N-glycosylation of street RABV G protein by the insertion of the sequon Asn(204) induced the transfer of RABV G proteins to the cell surface membrane.

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During 2014, henipavirus infection caused severe illness among humans and horses in southern Philippines; fatality rates among humans were high. Horse-to-human and human-to-human transmission occurred. The most likely source of horse infection was fruit bats.

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Background: In 2009, a novel influenza A/H1N1 virus (H1N1pdm) quickly spread worldwide and co-circulated with then-existing seasonal H1N1 virus (sH1N1). Distinguishing between these 2 viruses was necessary to better characterize the epidemiological properties of the emergent virus, including transmission patterns, pathogenesis, and anti-influenza drug resistance. This situation prompted us to develop a point-of-care virus differentiation system before entering the 2009-2010 influenza season.

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A novel antigen-capture sandwich ELISA system targeting the glycoproteins of the henipaviruses Nipah virus (NiV) and Hendra virus (HeV) was developed. Utilizing purified polyclonal antibodies derived from NiV glycoprotein-encoding DNA-immunized rabbits, we established a system that can detect the native antigenic structures of the henipavirus surface glycoproteins using simplified and inexpensive methods. The lowest detection limit against live viruses was achieved for NiV Bangladesh strain, 2.

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The central nervous system (CNS) tissue of mice infected with the CVS-11 strain of rabies virus (RABV) was subjected to gene expression analysis using microarray and canonical pathway analyses. Genes associated with innate immunity as well as inflammatory responses were significantly up-regulated, corroborating with the previous findings obtained using attenuated viruses that did not induce a fatal outcome in infected mice. Histopathological examination showed that neurons in the cerebellum had undergone apoptosis.

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Nipah virus (NiV), Paramyxoviridae, Henipavirus, is classified as a biosafety level (BSL) 4 pathogen, along with the closely related Hendra virus (HeV). A novel serum neutralization test was developed for measuring NiV neutralizing antibodies under BSL2 conditions using a recombinant vesicular stomatitis virus (VSV) expressing secreted alkaline phosphatase (SEAP) and pseudotyped with NiV F/G proteins (VSV-NiV-SEAP). A unique characteristic of this novel assay is the ability to obtain neutralization titers by measuring SEAP activity in supernatant using a common ELISA plate reader.

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