Molecular Virology

kao Keizo Tomonaga, D.V.M., Ph.D. Professor btn

All viruses rely on the cellular machinery to complete their replication cycles. Therefore, understanding the host-virus interaction is to provide the mechanism of not only the viral pathogenesis and adaptation, but also the host responses. In our laboratory, we are analyzing the detailed life cycles, as well as the pathogenesis, of animal viruses, especially negative strand RNA viruses, in both in vivo and vitro systems. In addition, we are pursuing the nature of viruses by understanding the evolutionary relationship between virus and host.

Research and Education

 The researches carried out in this laboratory are focused on negative strand RNA viruses, which transcribe and replicate in the nucleus, such as bornaviruses and influenza viruses. All our projects aim to understand the fundamental mechanisms of the replication and pathogenesis of the viruses. In current researches, we are investigating the replication and persistent mechanisms of the bornaviruses in the cell nucleus. The understanding the biological significance of the endogenous element of bornavirus nucleoprotein (EBLN) in mammalian genomes is one of the main focuses of bornavirus researches. We also aim to develop a novel RNA virus vector using bornavirus, which can express stably functional small RNAs. In influenza virus researches, we examine the responses of host cells to the virus infection by analyzing the alteration of the expression profile of miRNA in infected human alveolar epithelial cells. Our laboratory belongs to the Institute for Virus Research and accepts graduate students from both Graduate School of Medicine and Graduate School of Biostudies.

r-097-1Photo1. Borna disease virus persistently infected neuronal cells. Left and right panels show DIC and confocal microscope images, respectively. The virus-specific dot structures (green) are formed in the cell nucleus (blue).
r-097-2Photo2. Reduction of Purkinje cell neurons in the cerebellum of transgenic mice expressing Borna disease virus phosphoprotein in astrocytes.

Recent Publications

1. Matsumoto Y, Hayashi Y, Omori H, Honda T, Daito T, Horie M, Ikuta K, Fujino K, Nakamura S, Schneider U, Chase J, Yoshimori T, Schwemmle M and Tomonaga K. Bornavirus closely associates and segregates with host chromosomes to ensure persistent intranuclear infection. Cell Host Microbe 11:492-503 (2012)
2. Daito T, Fujino K, Honda T, Matsumoto Y, Watanabe Y and Tomonaga K. A novel Borna disease virus vector system that stably expresses foreign proteins from an intercistronic noncoding region. J. Virol. 85: 12170-12178 (2011)
3. Honda T, Fujino K, Okuzaki D, Ohtaki N, Matsumoto Y, Horie M, Daito T, Itoh M and Tomonaga K. Upregulation of insulin-like growth factor binding protein 3 in astrocytes of transgenic mice that express Borna disease virus phosphoprotein. J. Virol. 85: 4567-4571 (2011)
4. Horie M, Honda T, Suzuki Y, Kobayashi Y, Daito T, Oshida T, Ikuta K, Jern P, Gojobori T, Coffin JM and Tomonaga K. Endogenous non-retroviral RNA virus elements in mammalian genomes. Nature 463:84-87 (2010)
5. Watanabe Y, Ohtaki N, Hayashi Y, Ikuta K and Tomonaga K. Autogenous translational regulation of the Borna disease virus negative control factor X from polycistronic mRNA using host RNA helicases. PLoS Pathog. 5:e1000654 (2009)


Professor Keizo Tomonaga
Associate Professor Makoto Hijikata
Assistant Professor Tomoyuki Honda
TEL +81-75-751-3997
FAX +81-75-751-4000