The VP8* Domain of Neonatal Rotavirus Strain G10P[11] Binds to Type II Precursor Glycans

Abstract

e 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 Gal␤1-4GlcNAc 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 agerestricted infectivity of neonatal viruses.

Human Intestinal Enteroids: a New Model To Study Human Rotavirus Infection, Host Restriction, and Pathophysiology

“…However, vaccine efficacy remains suboptimal in lowincome settings, where the burden of disease is greatest (13)(14)(15). Recent studies have distinguished HRVs from animal rotaviruses (ARVs) based on their respective receptor usages for initial infection, with most HRVs binding human histo-blood group antigens (HBGAs) and ARVs binding sialylated glycans (16)(17)(18)(19). HBGAs, namely, ABH and Lewis antigens, have been suggested to be genetic factors that determine host susceptibility (20), and both secretor status and Lewis status (regulated by the fucosyltransferase 2 [FUT2] and fucosyltransferase 3 enzymes, respectively) have been proposed to mediate susceptibility to infection and possibly vaccination in a rotavirus genotype-dependent manner (21).…”

Functional and Structural Characterization of P[19] Rotavirus VP8* Interaction with Histo-blood Group Antigens

“…Furthermore, the electrostatic potential surface comparison revealed the similarities and differences among different P genotypes, which may explain to some extent the various binding patterns observed in the functional assays (11,12,(16)(17)(18)36). However, for the potential binding site of P [19], the surface presentation of P [3] and Sia, P [14] and A, P [11] and LNnT, and P [19] showed that there was indeed a cavity in the potential binding site in P [19] VP8* (Fig.…”

“…P [11] showed obvious binding to type 1/type 2 precursors (16,17). In addition, P [9], P [14], and P [25] all bound to A type HBGA (A-HBGA) (18).…”

Acute Gastroenteritis Viruses

“…Recent data challenges this view. The VP8* of some human strains have been shown to bind nonsialylated glycans, including histo-blood group antigens (HBGAs) on cell surfaces (Hu et al, 2012;Huang et al, 2012;Liu et al, 2012;Ramani et al, 2013). It appears that interactions with sialoglycans are not an absolute requirement for initial cell attachment for many human rotaviruses, and virus genotype-dependent variations in glycan specificity may have implications for other aspects of rotavirus pathogenesis, such as interspecies transmission.…”