| Project/Area Number |
08670349
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Virology
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| Research Institution | NAGOYA CITY UNIVERSITY |
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Principal Investigator |
NOBUSAWA Eri NAGOYA CITY UNIVERSITY,MEDICAL SCHOOL,DEPARTMENT OF VIROLOGY,ASSISTANT PROFESSOR, 医学部, 講師 (90183904)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAJIMA Katsuhisa NAGOYA CITY UNIVERSITY,MEDICAL SCHOOL,DEPARTMENT OF VIROLOGY,PROFESSOR, 医学部, 教授 (40012778)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1997: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1996: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | influenza virus / receptor / hemagglutinin / インフルエンザウィルス / 血球凝集能 / レセプター結合特異性 |
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| Research Abstract |
Human influenza A viruses including H1 and H3 subtypes isolated after 1991 lost their ability to agglutinate chicken red blood cells (CRBC). The hemagglutinin (HA) molecules of those viruses were expressed on the Cos cells and their ability to bind to CRBC was examined. Study of chimeric and site specific mutant HAs showed that the amino acid changes at position 225 appearing after 1986 was responsible for loss of the ability of H1 HA to CRBC.Phylogenetic study showed this change has been retained among all H1 HAs up to 1995. On the other hand amino acid change at position 190 appearing after 1990 was responsible for the loss of the ability of H3 HAs to CRBC and this change has been retained among all H3 HA up to 1997.
On the other hand H3 viruses which do not agglutinate not only CRBC but goose red blood cells (GRBC) were isolated after 1996. To investigate the receptor binding ability of HA proteins of these viruses, we compare the ability to bind to GRBC between the HA proteins isolated before and after 1996. Results showed that amino acid changes at positions 189 and 190 on HAs of the viruses isolated before 1996 were responsible for the loss of the ability to bind to GRBC,while the amino acid change at position 226 of HAs of the viruses isolated after 1996 was responsible for the loss of the ability to bind to GRBC.Sialidase treatment of the Cos cells expressing HA of the viruses isolated before 1996 was effective for the HA to gain the ability to bind to GRBC,suggesting that the amino acid changes at position 189 and 190 affected the glycosylation of the HA.This study shows that recent influenza viruses have been changing the receptor binding specificity by substituting the amino acids locating on the receptor binding site of HA.
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