title: A Haemophilus influenzae strain associated with Fisher syndrome expresses a novel disialylated ganglioside mimic.
abstract: The non-typeable Haemophilus influenzae strain DH1 was isolated from a 25 year old male patient with Fisher syndrome, a postinfectious autoimmune condition characterized by the presence of anti-GQ1b IgG antibodies that target and initiate damage to peripheral nerves. DH1 was found to display an alphaNeuAc(2-8)alphaNeuAc(2-3)betaGal branch bound to the tetraheptosyl backbone core of its lipooligosaccharide (LOS). The novel sialylation pattern was found to be dependent on the activity of a bifunctional sialyltransferase, Lic3B, which catalyzes the addition of both the terminal and subterminal sialic acid residues. Patient serum IgGs bind to DH1 LOS, and the reactivity is significantly influenced by the presence of sialylated glycoforms. The display by DH1, of a surface glycan that mimics the terminal trisaccharide portion of disialosyl-containing gangliosides, provides strong evidence for its involvement in the development of Fisher syndrome.
authors.affiliation: Institute for Biological Sciences, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada.
authors.forename: R Scott
authors.initials: RS
authors.lastname: Houliston
authors.forename: Michiaki
authors.initials: M
authors.lastname: Koga
authors.forename: Jianjun
authors.initials: J
authors.lastname: Li
authors.forename: Harold C
authors.initials: HC
authors.lastname: Jarrell
authors.forename: James C
authors.initials: JC
authors.lastname: Richards
authors.forename: Varvara
authors.initials: V
authors.lastname: Vitiazeva
authors.forename: Elke K H
authors.initials: EK
authors.lastname: Schweda
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Yuki
authors.forename: Michel
authors.initials: M
authors.lastname: Gilbert
mesh_terms: D000328:Adult; D002240:Carbohydrate Sequence; D005732:Gangliosides / Q000378:metabolism*; D006193:Haemophilus influenzae / Q000502:physiology*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D013058:Mass Spectrometry; D019846:Miller Fisher Syndrome / Q000382:microbiology*; D018716:Molecular Mimicry; D008969:Molecular Sequence Data
chemical_list: D005732:Gangliosides