Research activities

Research on the mechanisms of biofilms produced by respiratory pathogens and the investigation of inhibitory effects of biofilm formations

Recently, a biofilm was recognized as a contributing factor in many microbial infections, which becomes a clinical issue. Streptococcus pneumoniae and Haemophilus influenzae known as the important respiratory pathogens reside asymptomatically in the nasopharynx of healthy carriers, however, in susceptible individuals, which may cause many infections such as lower respiratory tract infections, otitis media, meningitis et al.. Recently, many studies have reported that these organisms were able to produce biofilms on tympanic membrane as well as respiratory tract epithelial cells. Our researches are focusing on the mechanisms of biofilm formations, which are implicated in intractable infectious diseases, as well as investigating the inhibitory effects of antibiotics on biofilms produced by these bacteria.

Research on the RNA polymerase of influenza A virus

Influenza genome is replicated and transcribed in the host nucleus by RNA polymerase which influenza virus uniquely possesses. This RNA polymerase is composed from three subunits called as PB1, PB2 and PA subunit respectively. We have recently shown that PB2 and PA subunits may be included into the mechanisms of the host adaptation and thermal sensitivity. More recently, it was also shown that the combination of subunits is important for the genetic reassortment of influenza virus. Therefore we are analyzing these roles in detail and aim at the discovery of the new function which will be related to develop drugs in the future.

Research on the human metapneumovirus (HMPV)

Since the discovery of human metapneumovirus (HMPV) in 2001, the virus has become one of the most common viral pathogens responsible for respiratory illness, particularly in infants and young children. We firstly described an HMPV outbreak in the elderly in a long-term care facility. Our research focuses on the molecular basis of HMPV life cycle and the development of new anti-HMPV drugs.

Research on the internal ribosomal entry site (IRES) of hepatitis C virus

Hepatitis C virus has a unique sequence which is called as IRES (Internal Ribosomal Entry Site) on the genome. Recently we have reported that the IRES is related not only to the replication but also to the sensibility to the combination therapy of interferon-ribavirin. This result can be used for the predictive factor to the combination therapy; therefore we are investigating the relationship between susceptive and non-susceptive clone, using the next-generation sequencing system.