Cross-reactivity among sapovirus recombinant capsid proteins

Arch Virol. 2005 Jan;150(1):21-36. doi: 10.1007/s00705-004-0406-8. Epub 2004 Sep 24.

Abstract

Sapovirus (SaV), a member of the genus Sapovirus in the family Caliciviridae, is an agent of human and porcine gastroenteritis. SaV strains are divided into five genogroups (GI-GV) based on their capsid (VP1) sequences. Human SaV strains are noncultivable, but expression of the recombinant capsid protein (rVP1) in a baculovirus expression system results in the self-assembly of virus-like particles (VLPs) that are morphologically similar to native SaV. In this study, rVP1 constructs of SaV GI, GII, and GV strains were expressed in a baculovirus expression system. The structures of the GI, GII, and GV VLPs, with diameters of 41-48 nm, were morphologically similar to those of native SaV. However a fraction of GV VLPs were smaller, with diameters of 26-31 nm and spikes on the outline. This is the first report of GII and GV VLP formation and the first identification of small VLPs. To examine the cross-reactivities among GI, GII, and GV rVP1, hyperimmune rabbit antisera were raised against Escherichia coli-expressed GI, GII, and GV N- and C-terminal VP1. Western blotting showed the GI antisera cross-reacted with GV rVP1 but not GII rVP1; GII antisera cross-reacted weakly with GI rVP1 but did not cross-react with GV rVP1; and GV antisera reacted only with GV rVP1. Also, hyperimmune rabbit and guinea pig antisera raised against purified GI VLPs were used to examine the cross-reactivities among GI, GII, and GV VLPs by an antigen enzyme-linked immunosorbent assay (ELISA). The ELISA showed that the GI VLPs were antigenically distinct from GII and GV VLPs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Viral / immunology
  • Baculoviridae / genetics*
  • Baculoviridae / metabolism
  • Caliciviridae / genetics
  • Caliciviridae / immunology*
  • Caliciviridae / metabolism
  • Caliciviridae Infections / veterinary
  • Caliciviridae Infections / virology
  • Capsid / immunology*
  • Capsid / metabolism
  • Cloning, Molecular
  • Cross Reactions
  • Enzyme-Linked Immunosorbent Assay
  • Guinea Pigs
  • Molecular Sequence Data
  • Phylogeny
  • Rabbits
  • Recombinant Proteins / immunology
  • Spodoptera
  • Virion / immunology*
  • Virus Assembly

Substances

  • Antibodies, Viral
  • Recombinant Proteins

Associated data

  • GENBANK/AY237422
  • GENBANK/AY603425