title: The VP8* domain of neonatal rotavirus strain G10P[11] binds to type II precursor glycans.
abstract: Naturally occurring bovine-human reassortant rotaviruses with a P[11] VP4 genotype exhibit a tropism for neonates. Interaction of the VP8* domain of the spike protein VP4 with sialic acid was thought to be the key mediator for rotavirus infectivity. However, recent studies have indicated a role for nonsialylated glycoconjugates, including histo-blood group antigens (HBGAs), in the infectivity of human rotaviruses. We sought to determine if the bovine rotavirus-derived VP8* of a reassortant neonatal G10P[11] virus interacts with hitherto uncharacterized glycans. In an array screen of >600 glycans, VP8* P[11] showed specific binding to glycans with the Galβ1-4GlcNAc motif, which forms the core structure of type II glycans and is the precursor of H type II HBGA. The specificity of glycan binding was confirmed through hemagglutination assays; GST-VP8* P[11] hemagglutinates type O, A, and B red blood cells as well as pooled umbilical cord blood erythrocytes. Further, G10P[11] infectivity was significantly enhanced by the expression of H type II HBGA in CHO cells. The bovine-origin VP4 was confirmed to be essential for this increased infectivity, using laboratory-derived reassortant viruses generated from sialic acid binding rotavirus SA11-4F and a bovine G10P[11] rotavirus, B223. The binding to a core glycan unit has not been reported for any rotavirus VP4. Core glycan synthesis is constitutive in most cell types, and modification of these glycans is thought to be developmentally regulated. These studies provide the first molecular basis for understanding neonatal rotavirus infections, indicating that glycan modification during neonatal development may mediate the age-restricted infectivity of neonatal viruses.
authors.affiliation: Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Sasirekha
authors.initials: S
authors.lastname: Ramani
authors.forename: Nicolas W
authors.initials: NW
authors.lastname: Cortes-Penfield
authors.forename: Liya
authors.initials: L
authors.lastname: Hu
authors.forename: Sue E
authors.initials: SE
authors.lastname: Crawford
authors.forename: Rita
authors.initials: R
authors.lastname: Czako
authors.forename: David F
authors.initials: DF
authors.lastname: Smith
authors.forename: Gagandeep
authors.initials: G
authors.lastname: Kang
authors.forename: Robert F
authors.initials: RF
authors.lastname: Ramig
authors.forename: Jacques
authors.initials: J
authors.lastname: Le Pendu
authors.forename: B V Venkataram
authors.initials: BV
authors.lastname: Prasad
authors.forename: Mary K
authors.initials: MK
authors.lastname: Estes
mesh_terms: D000818:Animals; D016466:CHO Cells; D036022:Capsid Proteins / Q000235:genetics* / Q000378:metabolism*; D002417:Cattle; D006224:Cricetinae; D003412:Cricetulus; D006386:Hemagglutination Tests; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000821:virology*; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000235:genetics; D012401:Rotavirus / Q000235:genetics*; D012400:Rotavirus Infections / Q000235:genetics / Q000378:metabolism*; D053585:Virus Attachment
chemical_list: D036022:Capsid Proteins; D011134:Polysaccharides; C060339:VP4 protein, Rotavirus; D019158:N-Acetylneuraminic Acid