| Budget Amount *help |
¥3,780,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥480,000)
Fiscal Year 2007: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
Fiscal Year 2006: ¥1,700,000 (Direct Cost: ¥1,700,000)
|
|---|
| Research Abstract |
Influenza epidemics occur every winter in Japan, as in European and North American countries. Over the past 20 years, influenza B virus strains have caused epidemics in humans, as have the H1 and H3 subtype strains of the influenza A virus. Although the antigenicities of the influenza B virus are more stable than those of the influenza A virus, antigenic variants appear constantly. Our studies have focused on the antigenicities of the influenza B virus with monoclonal antibodies, along with genetic analysis of the hemagglutinin molecule. The antigenic variants appear during the epidemic season, and have been isolated foam clinical specimens along with the vaccine-type strains. With the virus plaque-cloning method, it was demonstrated that the vaccine-type strains and the variants are present in isolates from individual patients. Therefore, these findings suggest that humans are infected with a mixture of viral strains for a certain period, after which the next major virus is selected under human acquired immunity. This led to the idea of applying high-resolution melting curve analysis to distinguish antigenic variants from vaccine-type strains of the influenza B virus. By means of melting curve analysis with LCGreen, an antigenic variant done and a vaccine-type clone were clearly distinguished. In addition, the proportions of the antigenic variants in the mixture-type isolates were estimated. The clinical isolates were detected as the vaccine-type strains, antigenic variants, or a mixture of both. It became dear that humane were infected with a mixture of the vaccine-type strains and the antigenic variants for a certain period after which the viral antigenicities vary. This technique will contribute to the analysis of antigenic shifts in influenza B virus and apply the different fields of studies, such that drug-resistant bacteria change process or others
|
