The research in this department focuses on prions and several viruses that target the immune, respiratory, or central nervous systems, with the aim of understanding the mechanisms by which they replicate and cause disease. We are also searching for means to control and rapidly diagnose these infectious agents. In addition, we are developing ways to remove them from blood products.
(1) Infections of the immune system
We are working on the mechanism(s) by which HIV establishes a persistent/latent infection in the immune system. In addition, we are searching for the host factors that can inhibit HIV replication. We are also characterizing the mechanism by which dengue virus induces hemorrhagic fever. The studies using the Thai isolates of dengue virus and HIV are being performed in collaboration with the Thailand-Japan Research Collaboration Center on Emerging and Re-emerging infections (RCC-ERI) which was established in 2005 in the National Institute of Health (NIH) in the Department of Medical Sciences (DMSc), Ministry of Public Health, Nonthaburi, Thailand.
(2) Infections of the respiratory system
SARS-CoV and influenza virus are typical of the microorganisms that induce acute infectious diseases in the respiratory region. In collaboration with RCC-ERI, we are characterizing the replication and pathogenesis mechanisms of these viruses by using H5N1 clinical isolates from patients in Thailand.
(3) Infections of the central nervous system
Borna disease virus (BDV) has several unique infection features, including its highly neurotropic, noncytopathic replication and its ability to generate a long-lasting and persistent infection. Epidemiological studies have demonstrated that BDV naturally infects a wide variety of vertebrate species. Interestingly, BDV has also been suggested to be associated with human neuropsychiatric disorders. We are interested in the epidemiology and replication of this virus and the mechanisms promoting its persistence and its neuropathogenesis. We are also working on the Scrapie agent that induces prion disease in sheep, as this is a model of BSE. In particular, we are interested in the mechanism of prion infection and replication in the central nervous system, and the effect of persistent neurotropic viral infections in the central nervous system (such as BDV) on prion-induced pathogenesis. We are also characterizing the physiological functions of cellular prion protein and its role in prion infection.
(4) Food-borne infections
Of the various agents that induce human hepatitis, hepatitis E virus (HEV) is the only zoonotic agent that is transmitted in a food-borne manner. We are working on Japanese swine isolates of HEV and, in collaboration with RCC-ERI, on Thai swine isolates.
(5) Blood-borne infections
In collaboration with a company, we are determining how infectious agents such as parvovirus B19, HEV, and prions can be removed from contaminated blood products.
(6) Near-infrared spectroscopy (NIRS)
There are many techniques by which virus infections can be diagnosed, including immunofluorescence, ELISA, Western blot, and PCR assays. However, each assay has its own advantages and disadvantages. We are currently assessing the feasibility of using NIRS to diagnose viral infections in certain diseases (such as AIDS and influenza) and some central nervous system disorders (including prion disease and chronic fatigue syndrome).
