Ren Xiaolei, Saleem Waqar, Haes Robin, Xie Jiexiong, Theuns Sebastiaan, Nauwynck Hans J
Laboratory of Virology, Department of Translational Physiology, Infectiology and Public Health, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
PathoSense BV, Lier, Belgium.
Front Microbiol. 2022 Aug 17;13:989242. doi: 10.3389/fmicb.2022.989242. eCollection 2022.
Rotavirus A (RVA) is an important pathogen causing acute gastroenteritis in animals and humans. Attachment to the host receptor is a crucial step for virus replication. The VP8* domain is the distal terminal region of the RVA spike protein VP4 (expressed by the P gene) and is important for rotavirus binding and infectivity. Recent studies have indicated a role for non-sialylated glycans, including mucin core 2 and histo-blood group antigens (HBGAs), in the infectivity of human and animal group A rotaviruses. In the present study, we determined if porcine rotavirus-derived recombinant VP8* of the endemic strains 14R103 G5P[6], 13R054 G5P[7], 12R010 G4P[13], 12R046 G9P[23], and 12R022 G2P[27] interact with hitherto uncharacterized glycans. We successfully produced five recombinant GST-VP8* proteins of genotype P[6], P[7], P[13], P[23], and P[27]. The hemagglutination assay showed genotypes P[7] and P[23] hemagglutinate porcine and human red blood cells. In an array screen of > 300 glycans, recombinant VP8* of rotavirus genotype P[6], P[7], and P[13] showed specific binding to glycans with a Gal-β-1,4-Glc (β-lactose) motif, which forms the core structure of HBGAs. The specificity of glycan-binding was confirmed through an ELISA-based oligosaccharide binding assay. Further, 13R054 G5P[7] and 12R046 G9P[23] infectivity was significantly reduced by β-lactose in MA104 cells and primary porcine enterocytes. These data suggest that lactose, the main natural sugar in milk, plays an important role in protecting piglets from enteric viral replication and diarrhea.
A组轮状病毒（RVA）是导致人和动物急性胃肠炎的重要病原体。附着于宿主受体是病毒复制的关键步骤。VP8结构域是RVA刺突蛋白VP4（由P基因表达）的远端末端区域，对轮状病毒的结合和感染性很重要。最近的研究表明，包括粘蛋白核心2和组织血型抗原（HBGA）在内的非唾液酸化聚糖在人和动物A组轮状病毒的感染性中发挥作用。在本研究中，我们确定了地方性毒株14R103 G5P[6]、13R054 G5P[7]、12R010 G4P[13]、12R046 G9P[23]和12R022 G2P[27]的猪轮状病毒衍生重组VP8是否与迄今未鉴定的聚糖相互作用。我们成功制备了基因型为P[6]、P[7]、P[13]、P[23]和P[27]的五种重组GST-VP8蛋白。血凝试验表明，基因型P[7]和P[23]能凝集猪和人的红细胞。在对300多种聚糖的阵列筛选中，轮状病毒基因型P[6]、P[7]和P[13]的重组VP8显示出与具有Gal-β-1,4-Glc（β-乳糖）基序的聚糖特异性结合，该基序构成了HBGA的核心结构。通过基于ELISA的寡糖结合试验证实了聚糖结合的特异性。此外，在MA104细胞和原代猪肠细胞中，β-乳糖显著降低了13R054 G5P[7]和12R046 G9P[23]的感染性。这些数据表明，牛奶中的主要天然糖乳糖在保护仔猪免受肠道病毒复制和腹泻方面发挥着重要作用。
