Masahiro Niikura

Biography

Dr. Niikura is a virologist with a veterinary background. He completed formal veterinary education at the Veterinary School, Hokkaido University in Japan and earned his PhD at the same institution by working on the antigenicity of viral proteins of Marek’s disease virus (MDV) and Newcastle disease virus, both cause serious diseases in poultry. After earning his degrees, he engaged in various aspects of virus research in numbers of academic and governmental institutions, including The University of Tokyo, Japan (1991-1992), NERC Institute of Virology and Environmental Microbiology, Oxford, U.K. (1992-1993), Thomas Jefferson University, Philadelphia, PA (1993-1995), USDA-ARS Avian Disease and Oncology Laboratory, East Lansing, MI (1995-1997, 2001-2002), National Institute of Infectious Diseases, Tokyo, Japan (1997-2001) and Michigan State University, East Lansing, MI (2002-2007). During this period, he worked on MDV, HIV, filoviruses, hantavirus and hepatitis E virus. Most recently, his research was focused on the pathogenesis and evolution of MDV using infectious bacterial artificial chromosome (BAC) clones he generated. He joined Simon Fraser University in 2007.

Research Interests

Dr. Niikura’s research interest is to develop a molecular understanding of viruses-host interactions. He is currently interested in two systems, Marek’s disease virus (MDV) and hepatitis E virus-like particles (HEV-VLP) in vaccine research.

MDV is an avian herpesvirus and interesting for several reasons. From the agricultural perspective, MDV remains a ubiquitous threat to the global poultry industry. As virulent MDV co-exists with vaccine virus in the host, MDV strains with “increased virulence” appear in the host. These highly virulent MDV strains cause more vaccine breaks and acute illness. From the scientific aspect, MDV is the only known alphaherpesvirus that causes tumors in naturally infected animals. Live vaccines can prevent this tumor but not the infection. One of the major challenges in MDV research is its unique strict cell-association. This virus does not produce cell-free progeny virus either in vitro or in vivo. He is tackling this problem by using BAC-cloned MDV in combination with recombination technologies called recombineering. Solving this problem should improve MDV vaccine and shed light on herpesvirus replication mechanisms from a unique angle.

Another system that Dr. Niikura is currently interested in is hepatitis E virus (HEV)-like particles that stimulate mucosal immunity by oral administration. HEV is a non-enveloped virus, which spreads via fecal-oral transmission. The viral particle of HEV consists of only one self-assembling protein encoded by a viral gene, ORF2. By expressing chimeric ORF2 protein in a baculovirus expression system, he and colleagues have demonstrated that this virus-like particle (VLP) can stimulate mucosal and systemic immunity by oral administration. As many viral and bacterial infections initiate through mucosal surface as exemplified by influenza virus and E. coli O157, it is now widely recognized that mucosal immunity is one of the keys for successful immunization. One major advantage of this HEV-VLP over other VLPs is that this VLP can encapsulate DNA vaccines by controlling calcium ion concentration. This characteristic greatly enhances the potential use of this HEV-VLP by extending the size limitation of presenting antigenic proteins. He is interested in exploring the potential of this system as mucosal vaccine vehicles.

Publications and Activities

Funding