Experimental Inoculation of Juvenile Rhesus Macaques With Primate Enteric Caliciviruses

PLoS One. 2012;7(5):e37973. doi: 10.1371/journal.pone.0037973. Epub 2012 May 30.

Abstract

Background: Tissue culture-adapted Tulane virus (TV), a GI.1 rhesus enteric calicivirus (ReCV), and a mixture of GII.2 and GII.4 human norovirus (NoV)-containing stool sample were used to intrastomacheally inoculate juvenile rhesus macaques (Macaca mulatta) in order to evaluate infection caused by these viruses. METHODOLOGY & FINDINGS: Two of the three TV-inoculated macaques developed diarrhea, fever, virus-shedding in stools, inflammation of duodenum and 16-fold increase of TV-neutralizing (VN) serum antibodies but no vomiting or viremia. No VN-antibody responses could be detected against a GI.2 ReCV strain FT285, suggesting that TV and FT285 represent different ReCV serotypes. Both NoV-inoculated macaques remained asymptomatic but with demonstrable virus shedding in one animal. Examination of duodenum biopsies of the TV-inoculated macaques showed lymphocytic infiltration of the lamina propria and villous blunting. TV antigen-positive (TV+) cells were detected in the lamina propria. In most of the TV+ cells TV co-localized perinuclearly with calnexin--an endoplasmic reticulum protein. A few CD20+TV+ double-positive B cells were also identified in duodenum. To corroborate the authenticity of CD20+TV+ B cells, in vitro cultures of peripheral blood mononuclear cells (PBMCs) from healthy macaques were inoculated with TV. Multicolor flow cytometry confirmed the presence of TV antigen-containing B cells of predominantly CD20+HLA-DR+ phenotype. A 2-log increase of viral RNA by 6 days post inoculation (p<0.05) suggested active TV replication in cultured lymphocytes.

Conclusions/significance: Taken together, our results show that ReCVs represent an alternative cell culture and animal model to study enteric calicivirus replication, pathogenesis and immunity.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antibodies, Viral / blood
  • Caliciviridae / immunology
  • Caliciviridae / pathogenicity*
  • Caliciviridae / physiology
  • Caliciviridae Infections / blood
  • Caliciviridae Infections / immunology
  • Caliciviridae Infections / pathology
  • Disease Models, Animal*
  • Humans
  • Intestine, Small / immunology
  • Intestine, Small / pathology
  • Intestine, Small / virology
  • Leukocytes, Mononuclear / immunology
  • Leukocytes, Mononuclear / virology
  • Macaca mulatta
  • Virus Replication

Substances

  • Antibodies, Viral