The surface proteins of several Bordetella strains and their modulated derivatives were examined by surface radioiodination, cell fractionation, and Western blotting. A surface protein with a high Mr, missing in a mutant lacking the filamentous hemagglutinin, was identified in virulent Bordetella pertussis and Bordetella parapertussis cells and was absent in avirulent B. pertussis strains. The ...

Cross-reactive antibody responses of 3 trivalent, live attenuated intranasal influenza vaccine (FluMist) formulations containing 3 different H1N1 strains (A/Texas/36/91, A/Shenzhen/227/95, and A/Beijing/262/95) were evaluated in initially seronegative children. FluMist containing A/Shenzhen/227/95 was more likely to induce cross-reactive hemagglutination inhibition (HAI) antibody against A/Texa...

Influenza inflicts significant global mortality and morbidity that can be combated by effective immunization. However, the protective efficacy of current vaccines is limited by both the significant antigenic diversity of the viral hemagglutinin protein and the capacity for rapid antigenic change. This necessitates global influenza surveillance efforts, frequent vaccine reformulation and annual ...

Nineteen highly pathogenic avian influenza (HPAI) H5N8 viruses were isolated from wild birds in the Donglim reservoir in Gochang, Jeonbuk province, Korea, which was first reported to be an outbreak site on January 17, 2014. Most genes from the nineteen viruses shared high nucleotide sequence identities (i.e., 99.7% to 100%). Phylogenetic analysis showed that these viruses were reassortants of t...

BACKGROUND The hemagglutinin molecule of influenza virus is considered as an ideal model to study biological processes as well as the effect of glycosylation on the function of glycoproteins. OBJECTIVES The large subunit of the influenza virus A/New Caledonia/20/99 (H1N1) hemagglutinin (HA1) was expressed in recombinant Escherichia coli containing the glycosylation system of Campylobacter jej...

Newcastle disease virus (NDV)-induced membrane fusion requires formation of a complex between the hemagglutinin-neuraminidase (HN) and fusion (F) proteins. Substitutions for NDV HN stalk residues A89, L90, and L94 block fusion by modulating formation of the HN-F complex. Here, we demonstrate that a nearby L97A substitution, though previously shown to block fusion, allows efficient HN-F complex ...

The filamentous hemagglutinin (FHA) of Bordetella pertussis plays an important role in establishing infection by attaching the bacteria to the ciliated respiratory epithelial cells. Expression of DNA encoding residues 1141 to 1279 of FHA in Escherichia coli yields a protein of 18,000 Da that exhibits some of the carbohydrate recognition properties of FHA (S. M. Prasad, Y. Yin, E. Rodzinski, E. ...

At low pH, the hemagglutinin (HA) of influenza virus undergoes an irreversible conformational change that potentiates its essential membrane fusion function. We have probed the details of this conformational change using a panel of 14 anti-HA-peptide antibodies. Whereas some antibodies reacted equally well with both the neutral and low-pH HA conformations, others reacted to a significantly grea...

D222G/N substitutions in A(H1N1)pdm09 hemagglutinin may be associated with increased binding of viruses causing low respiratory tract infections and human pathogenesis. We assessed the impact of such substitutions on the balance between hemagglutinin binding and neuraminidase cleavage, viral growth and in vivo virulence.Seven viruses with differing polymorphisms at codon 222 (2 with D, 3 G, 1 N...

For most paramyxoviruses, virus type-specific interaction between fusion (F) protein and attachment protein (hemagglutinin-neuraminidase [HN], hemagglutinin [H], or glycoprotein [G]) is a prerequisite for mediating virus-cell fusion and cell-cell fusion. Our previous cell-cell fusion assay using the chimeric F proteins of human parainfluenza virus 2 (HPIV2) and simian virus 41 (SV41) suggested ...