Culture supernatants prepared from reactogenic strains of Vibrio cholerae cause a decrease in the transcellular epithelial resistance of T84 intestinal cells. This decrease correlates with the presence of hemagglutinin/protease but not with the presence of other potential accessory toxins or proteases. These data suggest a possible role for hemagglutinin/protease in reactogenicity, although oth...

Sequence analyses show that the outbreak of pandemic (H1N1) 2009 resulted from the spread of a recently derived hemagglutinin through a population of ancient and more diverse neuraminidase segments. This pattern implies reassortment and suggests that the novel form of hemagglutinin conferred a selective advantage.

sequence analysis and phylogenetic study of hemagglutinin (ha) gene of h9n2 subtype of avian influenza virus isolates (outbreaks of 1998-2002) in tehran province (iran) were studied. two sets of forward and reverse primers in highly conserved regions, based on sequences of ha gene in genbank, were designed. pcr products of a 430-bp fragment of 16 isolates were sequenced and then were aligned wi...

background and aims: influenza a virus subtype h9n2 have continued to circulate in domestic poultry farms in asia since 1998. the virus circulates in live bird markets, missing link in epidemiology of avian influenza. regarding previous studies on h9n2 viruses of iran and having no data on this subject in iranian live bird markets this study was conducted to analyze genetically hemagglutinin pr...

The question of how membrane proteins are delivered from the TGN to the cell surface in fibroblasts has received little attention. In this paper we have studied how their post-Golgi delivery routes compare with those in epithelia] cells. We have analyzed the transport of the vesicular stomatitis virus G protein, the Semliki Forest virus spike glycoprotein, both basolateral in MDCK cells, and th...

A single amino acid substitution, Asp-63 to Asn-63, was detected in the hemagglutinin of an antigenic variant of the 1968 Hong Kong (H3) influenza virus that was selected by growth of the wild-type virus in the presence of a monoclonal antibody. The mutation generates an oligosaccharide attachment site, Asn-Cys-Thr at residues 63-65, that is glycosylated. Immunoprecipitation experiments with ex...

Severe human disease caused by the emerging H7N9 influenza virus in China warrants a rapid response. Here, we present a recombinant Newcastle disease virus expressing a North American lineage H7 influenza virus hemagglutinin. Sera from immunized mice were cross-reactive to a broad range of H7 subtype viruses and inhibited hemagglutination by the novel H7 hemagglutinin. Immunized mice were prote...