The influenza hemagglutinins are viral coat glycoproteins that facilitate viral binding to the host cell wall; as a result, the virulence of any strain of flu depends significantly on how well the hemagglutinin of that strain promotes that binding. Characterizing the evolution of the hemagglutinins is thus fundamental to predicting the virulence of the virus. Here, I describe a linear regressio...

A single-chain variable fragment (scFv) antibody library against Bordetella pertussis was constructed using M13 phage display. The library was enriched for phages surface displaying functional scFv by biopanning against B. pertussis immobilized on polystyrene plates. Two hundred eighty-eight individual clones from the enriched library were screened for binding to B. pertussis cells, filamentous...

Pertactin and filamentous hemagglutinin (FHA), proteins present on the surface of the gram-negative organism Bordetella pertussis, have been shown to contain the putative cell-binding sequence arginine-glycine-aspartic acid (RGD) and to promote eukaryotic cell attachment. The attachment of epithelial cells to purified pertactin and the entry of B. pertussis into human HeLa cells are both inhibi...

Bordetella pertussis, the human pathogen of whooping cough, when grown at 22 degrees C is nonvirulent and unable to bind eukaryotic cells. In response to a temperature shift to 37 degrees C, the bacterium acquires the ability to bind eukaryotic cells in a time-dependent fashion. By studying in vitro the temperature-induced transition, from the nonvirulent to the virulent state, we found that bi...

Attachment of microorganisms to host tissue is regarded as an important step in the pathogenesis of infections. Staphylococcus saprophyticus adheres to various epithelial cells and hemagglutinates sheep erythrocytes. The hemagglutinin has been identified, but a human target for this surface protein is still not known. In our report, we show that hemagglutinating strains of S. saprophyticus bind...

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...

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...

Filamentous hemagglutinin (FHA) is a cell surface protein of Bordetella pertussis which functions as an adhesin for this organism. It is a component of many new acellular pertussis vaccines. The proposed role of FHA in immunity to pertussis is based on animal studies which have produced some conflicting results. To clarify this situation, we reexamined the protective activity of FHA in an adult...

Pseudomonas fluorescens is a common bacterial pathogen to a wide range of aquaculture animals including various species of fish. In this study, we employed proteomic analysis and identified filamentous hemagglutinin (FHA) as an iron-responsive protein secreted by TSS, a pathogenic P. fluorescens isolate. In vitro study showed that compared to the wild type, the fha mutant TSSfha (i) exhibited a...

introduction: in recent years, influenza viruses have caused moderate to severe infections all around the world while so far there is no influenza vaccine that can protect people with only one dose of injection. in this regard, producing a universal vaccine based on virus-like-particles (vlp) could be an ideal approach.  methods: in this study, the full-length orf of influenza hemagglutinin (ha...