Uirusu最新文献

Viral diseases are responsible for substantial morbidity and mortality and continue to be of great concern. To ensure better control of viral infections, I have been tackling the issue as a medical doctor, an academic researcher, and a public health officer. Especially, I have studied respiratory viruses, such as the influenza virus, from the perspectives of molecular virology, theoretical modeling, and field epidemiology. RNA biology and its involvement with viral life-cycle and pathogenicity are central topics of molecular study, while mathematical models of transmission dynamics and phylogenetics are major components of theoretical research. As a field epidemiologist, I work with public health authorities during viral disease outbreaks. I was deployed to West Africa for viral hemorrhagic fever outbreak responses as a WHO consultant, and I have served the Japanese Government as an advisor for COVID-19 countermeasures. I would like to integrate various approaches from clinical medicine to epidemiology, theoretical modeling, evolutionary biology, genetics, and molecular biology in my research. In that way, we could gain a more comprehensive understanding of viral diseases. I hope these findings will help ease the disease burden of viral infections around the world.

In recent years, numerous emerging and reemerging infectious diseases have occurred worldwide and have seriously threatened our society. As a countermeasure against the pathogens responsible for serious diseases (classified as class 4 pathogens), we are preparing for full operation of the first suit-type biosafety level 4 (BSL-4) facility available for basic and applied research at Nagasaki University. For the safe operation of these facilities, experienced and qualified personnel with appropriate skills and knowledge of biorisk management must be certified. Developing an appropriate training system is a prerequisite for ensuring the safety of users involved in research in a BSL-4 laboratory. Here, we introduce an overview of the content of the training program that we are currently establishing for the BSL-4 facility at Nagasaki University. We are designing this program to follow national and international guidelines and regulations in part by referring to experiences and materials derived from multiple BSL-4 facilities in other countries. The established training program system, including the formulation processes, will serve as a reference and will provide practical materials for other research organizations to develop their own high-containment laboratory training programs.

We isolated five mAbs with potent neutralizing activities against SARS-CoV-2 from two convalescent COVID-19 patients infected with prototype virus. Among them, the 9-105 antibody that have a highest affinity for the receptor-binding domain (RBD), cross-neutralize variants, such as B.1.1.7 (alfa), mink cluster 5 variant, B.1.351 (beta), P.1 (gamma), C.37 (lambda), B.1.617.1 (kappa), B.1.617.2 (delta) and B.1.621 (mu). A single amino acid mutation at K417 of RBD decreased neutralization sensitivity of 9-105. A 9-105 homology model revealed that 9-105 light chain binds to RBD including K417 by the same angle as ACE2.

Antibodies against the receptor binding domain of the spike protein of SARS-CoV-2 play an important role in preventing infection as neutralizing antibodies. However, antibodies that recognize a specific site on the N-terminal domain of the spike protein induce an open domain of receptor binding that increases the binding of ACE2 and enhances the infectivity of SARS-CoV-2. Furthermore, the presence of the infectivity-enhancing antibodies reduces the neutralizing activity of the neutralizing antibodies. Therefore, when considering the antibody response to SARS-CoV-2, it is necessary to consider not only neutralizing antibodies but also the balance between neutralizing and infectivity-enhancing antibodies. In this article, function and mechanism of infectivity-enhancing antibodies are introduced.

013-2016 Ebola virus disease (EVD) outbreak was the largest EVD outbreak ever documented that started earlier in Guinea and later widely spread throughout West Africa, ending up a total of > 28,000 human infections. In this review, we outline research findings on Ebola virus (EBOV) variant Makona, a new EBOV variant isolated from the 2013-2016 EVD outbreak, and introduce the unique biological and pathogenic characteristics of Makona variant. We also discuss about the relevance of persistent infection of EBOV in EVD survivors with resurgence of EVD outbreak in Guinea in 2021. Moreover, this review covers a recent case report of EVD relapse and deliberates new interpretations of EBOV biology and EVD outbreak.

A new etiological agent of an acute febrile illness following tick bite has been found in Hokkaido, Japan, in 2019 and designated as Yezo virus. Seven cases of Yezo virus infection were identified from 2014 to 2020 by passive and retrospective surveillance. Yezo virus is classified into the genus Orthonairovirus, family Nairoviridae and forms Sulina genogroup together with Sulina virus, which was identified in ticks in Romania. The Sulina genogroup viruses are closely related to the Tamdy genogroup viruses recently reported as causative agents of febrile illness in China and distant from known orthonairovirus pathogens, such as Crimean-Congo hemorrhagic fever virus. Since only limited information is available for the emerging orthonairovirus diseases, including Yezo virus infection, their occurrence should be carefully monitored.