title: Antibodies to influenza nucleoprotein cross-react with human hypocretin receptor 2.
abstract: The sleep disorder narcolepsy is linked to the HLA-DQB1*0602 haplotype and dysregulation of the hypocretin ligand-hypocretin receptor pathway. Narcolepsy was associated with Pandemrix vaccination (an adjuvanted, influenza pandemic vaccine) and also with infection by influenza virus during the 2009 A(H1N1) influenza pandemic. In contrast, very few cases were reported after Focetria vaccination (a differently manufactured adjuvanted influenza pandemic vaccine). We hypothesized that differences between these vaccines (which are derived from inactivated influenza viral proteins) explain the association of narcolepsy with Pandemrix-vaccinated subjects. A mimic peptide was identified from a surface-exposed region of influenza nucleoprotein A that shared protein residues in common with a fragment of the first extracellular domain of hypocretin receptor 2. A significant proportion of sera from HLA-DQB1*0602 haplotype-positive narcoleptic Finnish patients with a history of Pandemrix vaccination (vaccine-associated narcolepsy) contained antibodies to hypocretin receptor 2 compared to sera from nonnarcoleptic individuals with either 2009 A(H1N1) pandemic influenza infection or history of Focetria vaccination. Antibodies from vaccine-associated narcolepsy sera cross-reacted with both influenza nucleoprotein and hypocretin receptor 2, which was demonstrated by competitive binding using 21-mer peptide (containing the identified nucleoprotein mimic) and 55-mer recombinant peptide (first extracellular domain of hypocretin receptor 2) on cell lines expressing human hypocretin receptor 2. Mass spectrometry indicated that relative to Pandemrix, Focetria contained 72.7% less influenza nucleoprotein. In accord, no durable antibody responses to nucleoprotein were detected in sera from Focetria-vaccinated nonnarcoleptic subjects. Thus, differences in vaccine nucleoprotein content and respective immune response may explain the narcolepsy association with Pandemrix.
authors.affiliation: Global Clinical Sciences, Novartis Vaccines Srl, Siena 53100, Italy. sohail.q.ahmed@gsk.com steinman@stanford.edu.
authors.forename: Syed Sohail
authors.initials: SS
authors.lastname: Ahmed
authors.affiliation: Informatics and Information Technology, Atreca Inc., Redwood City, CA 94063, USA.
authors.forename: Wayne
authors.initials: W
authors.lastname: Volkmuth
authors.affiliation: Computer-Aided Drug Discovery, Novartis Institutes for BioMedical Research, Cambridge, MA 02139, USA.
authors.forename: José
authors.initials: J
authors.lastname: Duca
authors.affiliation: Formulation Analytics, Novartis Vaccines Srl, Siena 53100, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Corti
authors.affiliation: Formulation Analytics, Novartis Vaccines Srl, Siena 53100, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Pallaoro
authors.affiliation: In Vitro Cell Biology, Novartis Vaccines Srl, Siena 53100, Italy.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Pezzicoli
authors.affiliation: Integrated Biologics Profiling Unit, Novartis Pharma AG, Basel 4057, Switzerland.
authors.forename: Anette
authors.initials: A
authors.lastname: Karle
authors.affiliation: Quantitative Sciences, Novartis Vaccines Srl, Siena 53100, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Rigat
authors.affiliation: Research, Novartis Vaccines Srl, Siena 53100, Italy.
authors.forename: Rino
authors.initials: R
authors.lastname: Rappuoli
authors.affiliation: Development, Novartis Vaccines, Cambridge, MA 02139, USA.
authors.forename: Vas
authors.initials: V
authors.lastname: Narasimhan
authors.affiliation: National Institute for Health and Welfare (THL), Helsinki 00300, Finland. Virology, University of Turku, Turku 20520, Finland.
authors.forename: Ilkka
authors.initials: I
authors.lastname: Julkunen
authors.affiliation: National Institute for Health and Welfare (THL), Helsinki 00300, Finland.
authors.forename: Arja
authors.initials: A
authors.lastname: Vuorela
authors.affiliation: National Institute for Health and Welfare (THL), Helsinki 00300, Finland.
authors.forename: Outi
authors.initials: O
authors.lastname: Vaarala
authors.affiliation: National Institute for Health and Welfare (THL), Helsinki 00300, Finland.
authors.forename: Hanna
authors.initials: H
authors.lastname: Nohynek
authors.affiliation: Internal Medicine, Policlinico Santa Maria alle Scotte, Azienda Ospedaliera Universitaria Senese, Siena 53100, Italy. Medical Science, Surgery, and Neuroscience, University of Siena, Siena 53100, Italy.
authors.forename: Franco Laghi
authors.initials: FL
authors.lastname: Pasini
authors.affiliation: Molecular and Developmental Medicine, University of Siena, Siena 53100, Italy. VisMederi Srl, Siena 53100, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Montomoli
authors.affiliation: Molecular and Developmental Medicine, University of Siena, Siena 53100, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Trombetta
authors.affiliation: Stanford University Mass Spectrometry, Stanford University School of Medicine, Palo Alto, CA 94305 USA.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Adams
authors.affiliation: Immunology, Stanford University School of Medicine, Palo Alto, CA 94305, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Rothbard
authors.affiliation: Neurology and Neuroscience, Stanford University School of Medicine, Stanford, CA 94305, USA. sohail.q.ahmed@gsk.com steinman@stanford.edu.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Steinman
mesh_terms: D000595:Amino Acid Sequence; D000914:Antibodies, Viral / Q000276:immunology*; D002460:Cell Line; D002648:Child; D003429:Cross Reactions / Q000276:immunology*; D006801:Humans; D007109:Immunity; D007074:Immunoglobulin G / Q000097:blood; D007252:Influenza Vaccines / Q000276:immunology; D007251:Influenza, Human / Q000276:immunology / Q000821:virology; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009290:Narcolepsy / Q000276:immunology; D019590:Nucleocapsid Proteins; D064446:Orexin Receptors / Q000737:chemistry / Q000276:immunology*; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000276:immunology*; D016865:Reassortant Viruses / Q000276:immunology; D012621:Seasons; D016415:Sequence Alignment; D014611:Vaccination; D014758:Viral Core Proteins / Q000737:chemistry / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007252:Influenza Vaccines; C048842:NP protein, Influenza A virus; D019590:Nucleocapsid Proteins; D064446:Orexin Receptors; D010455:Peptides; D016601:RNA-Binding Proteins; D014758:Viral Core Proteins; C558220:focetria; C556153:pandemrix