| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2002: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2001: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Research Abstract |
Recent human influenza A viruses (H3N2) isolated in MDCK cells after 1992 agglutinate human red blood cells but not chicken red blood cells (CRBC) (Ch- virus). Furthermore, binding assays revealed that A/Aichi/30/97, one of these viruses, exhibited less tight binding to native MDCK cells, compared to viruses isolated before 1992 that agglutinate CRBC (Ch+ virus). During proliferation in MDCK cells, Ch- virus exhibited limited sensitivity to the neuraminidase-specific inhibitor, zanamivir, compared to Ch+ virus. The reduced binding of Ch- virus to MDCK cells might have rendered the virus able to release from the cells with decreased dependency on NA activity. H3N2 human influenza viruses including Ch- virus are known to preferentially bind to sialic acids in α2,6Gal linkage. Characterization of sialic acids on MDCK cells revealed that half of the total sialic acids of sialyloligosaccharides on MDCK cells were in α2,6Gal linkage. Despite the decreased binding to native MDCK cells, A/Aichi/30/97 did bind tightly to derivatized MDCK cells resialylated with N-Acetyl-D-neuraminy]-α(2→6)-D-galactopyrano- syl-β(1→4)-N-acetyl-D-glucosamine. Preferred binding of A/Aichi/30/97 to the derivatized cells compared to their binding to native MDCK cells suggested that due to the change in binding to the receptor, Ch- virus developed the ability to distinguish the asialo portion of sialyloligosaccharides of native MDCK cells from that on the derivatized cells.
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