title: Properly folded bacterially expressed H1N1 hemagglutinin globular head and ectodomain vaccines protect ferrets against H1N1 pandemic influenza virus.
abstract: BACKGROUND
  In the face of impending influenza pandemic, a rapid vaccine production and mass vaccination is the most effective approach to prevent the large scale mortality and morbidity that was associated with the 1918 "Spanish Flu". The traditional process of influenza vaccine production in eggs is time consuming and may not meet the demands of rapid global vaccination required to curtail influenza pandemic.
  
  
  RESULTS
  Recombinant technology can be used to express the hemagglutinin (HA) of the emerging new influenza strain in a variety of systems including mammalian, insect, and bacterial cells. In this study, two forms of HA proteins derived from the currently circulating novel H1N1 A/California/07/2009 virus, HA1 (1-330) and HA (1-480), were expressed and purified from E. coli under controlled redox refolding conditions that favoured proper protein folding. However, only the recombinant HA1 (1-330) protein formed oligomers, including functional trimers that bound receptor and caused agglutination of human red blood cells. These proteins were used to vaccinate ferrets prior to challenge with the A/California/07/2009 virus. Both proteins induced neutralizing antibodies, and reduced viral loads in nasal washes. However, the HA1 (1-330) protein that had higher content of multimeric forms provided better protection from fever and weight loss at a lower vaccine dose compared with HA (1-480). Protein yield for the HA1 (1-330) ranged around 40 mg/Liter, while the HA (1-480) yield was 0.4-0.8 mg/Liter.
  
  
  CONCLUSIONS
  This is the first study that describes production in bacterial system of properly folded functional globular HA1 domain trimers, lacking the HA2 transmembrane protein, that elicit potent neutralizing antibody responses following vaccination and protect ferrets from in vivo challenge. The combination of bacterial expression system with established quality control methods could provide a mechanism for rapid large scale production of influenza vaccines in the face of influenza pandemic threat.
authors.affiliation: Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America.
authors.forename: Surender
authors.initials: S
authors.lastname: Khurana
authors.forename: Swati
authors.initials: S
authors.lastname: Verma
authors.forename: Nitin
authors.initials: N
authors.lastname: Verma
authors.forename: Corey J
authors.initials: CJ
authors.lastname: Crevar
authors.forename: Donald M
authors.initials: DM
authors.lastname: Carter
authors.forename: Jody
authors.initials: J
authors.lastname: Manischewitz
authors.forename: Lisa R
authors.initials: LR
authors.lastname: King
authors.forename: Ted M
authors.initials: TM
authors.lastname: Ross
authors.forename: Hana
authors.initials: H
authors.lastname: Golding
mesh_terms: D000818:Animals; D002850:Chromatography, Gel; D002942:Circular Dichroism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005289:Ferrets / Q000276:immunology* / Q000821:virology*; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000235:genetics / Q000276:immunology*; D009976:Orthomyxoviridae Infections / Q000276:immunology*; D017510:Protein Folding; D020349:Surface Plasmon Resonance
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines