title: Both α2,3- and α2,6-linked sialic acids on O-linked glycoproteins act as functional receptors for porcine Sapovirus.
abstract: Sapovirus, a member of the Caliciviridae family, is an important cause of acute gastroenteritis in humans and pigs. Currently, the porcine sapovirus (PSaV) Cowden strain remains the only cultivable member of the Sapovirus genus. While some caliciviruses are known to utilize carbohydrate receptors for entry and infection, a functional receptor for sapovirus is unknown. To characterize the functional receptor of the Cowden strain of PSaV, we undertook a comprehensive series of protein-ligand biochemical assays in mock and PSaV-infected cell culture and/or piglet intestinal tissue sections. PSaV revealed neither hemagglutination activity with red blood cells from any species nor binding activity to synthetic histo-blood group antigens, indicating that PSaV does not use histo-blood group antigens as receptors. Attachment and infection of PSaV were markedly blocked by sialic acid and Vibrio cholerae neuraminidase (NA), suggesting a role for α2,3-linked, α2,6-linked or α2,8-linked sialic acid in virus attachment. However, viral attachment and infection were only partially inhibited by treatment of cells with sialidase S (SS) or Maackia amurensis lectin (MAL), both specific for α2,3-linked sialic acid, or Sambucus nigra lectin (SNL), specific for α2,6-linked sialic acid. These results indicated that PSaV recognizes both α2,3- and α2,6-linked sialic acids for viral attachment and infection. Treatment of cells with proteases or with benzyl 4-O-β-D-galactopyranosyl-β-D-glucopyranoside (benzylGalNAc), which inhibits O-linked glycosylation, also reduced virus binding and infection, whereas inhibition of glycolipd synthesis or N-linked glycosylation had no such effect on virus binding or infection. These data suggest PSaV binds to cellular receptors that consist of α2,3- and α2,6-linked sialic acids on glycoproteins attached via O-linked glycosylation.
authors.affiliation: Laboratory of Veterinary Pathology, College of Veterinary Medicine, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Deok-Song
authors.initials: DS
authors.lastname: Kim
authors.affiliation: Laboratory of Veterinary Pathology, College of Veterinary Medicine, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Myra
authors.initials: M
authors.lastname: Hosmillo
authors.affiliation: Laboratory of Veterinary Pathology, College of Veterinary Medicine, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Mia Madel
authors.initials: MM
authors.lastname: Alfajaro
authors.affiliation: Laboratory of Veterinary Pathology, College of Veterinary Medicine, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Ji-Yun
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Laboratory of Veterinary Pathology, College of Veterinary Medicine, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Jun-Gyu
authors.initials: JG
authors.lastname: Park
authors.affiliation: Laboratory of Veterinary Pathology, College of Veterinary Medicine, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Kyu-Yeol
authors.initials: KY
authors.lastname: Son
authors.affiliation: Laboratory of Veterinary Pathology, College of Veterinary Medicine, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Eun-Hye
authors.initials: EH
authors.lastname: Ryu
authors.affiliation: Division of Virology, Department of Pathology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Frederic
authors.initials: F
authors.lastname: Sorgeloos
authors.affiliation: Bioindustry Research Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup, Republic of Korea.
authors.forename: Hyung-Jun
authors.initials: HJ
authors.lastname: Kwon
authors.affiliation: Bioindustry Research Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup, Republic of Korea.
authors.forename: Su-Jin
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Bioindustry Research Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup, Republic of Korea.
authors.forename: Woo Song
authors.initials: WS
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, Chonnam National University Hwasun Hospital, Jeollanam-do, Republic of Korea.
authors.forename: Duck
authors.initials: D
authors.lastname: Cho
authors.affiliation: Division of Life Science, Korea Basic Science Institute, Daejeon, Republic of Korea.
authors.forename: Joseph
authors.initials: J
authors.lastname: Kwon
authors.affiliation: Division of Life Science, Korea Basic Science Institute, Daejeon, Republic of Korea.
authors.forename: Jong-Soon
authors.initials: JS
authors.lastname: Choi
authors.affiliation: Laboratory of Veterinary Pathology, College of Veterinary Medicine, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Mun-Il
authors.initials: MI
authors.lastname: Kang
authors.affiliation: Division of Virology, Department of Pathology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Ian
authors.initials: I
authors.lastname: Goodfellow
authors.affiliation: Laboratory of Veterinary Pathology, College of Veterinary Medicine, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Kyoung-Oh
authors.initials: KO
authors.lastname: Cho
mesh_terms: D000818:Animals; D017250:Caliciviridae Infections / Q000473:pathology / Q000662:veterinary / Q000821:virology; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005759:Gastroenteritis / Q000473:pathology / Q000662:veterinary / Q000821:virology; D006031:Glycosylation / Q000187:drug effects; D054884:Host-Pathogen Interactions / Q000187:drug effects; D006801:Humans; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism / Q000473:pathology / Q000821:virology*; D008024:Ligands; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D055550:Protein Stability; D011991:Receptors, Virus / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D029341:Sapovirus / Q000187:drug effects / Q000472:pathogenicity / Q000502:physiology*; D012794:Sialic Acids / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D013237:Stereoisomerism; D034421:Sus scrofa; D013552:Swine; D013553:Swine Diseases / Q000473:pathology / Q000821:virology
chemical_list: D004791:Enzyme Inhibitors; D008024:Ligands; D008562:Membrane Glycoproteins; D011991:Receptors, Virus; D012794:Sialic Acids