Plaque quantitation and virus neutralization assays for human astroviruses.
Astroviruses, 28 nm-diameter, RNA-containing viruses which have been implicated in gastroenteritis can be cultivated in cell cultures containing trypsin, but do not show distinguishable cytopathic effects. However, with the 5 known astrovirus serotypes which we have been able to cultivate, 3 (types 1, 2, and 5) formed well-defined plaques in LLCMK2 cell cultures under an agar overlay containing trypsin. A virus neutralization assay based on plaque reduction was applied to these 3 serotypes. It was found that rabbit antisera prepared against individual serotypes neutralized virus type-specifically, and no cross-neutralization titers were obtained with any of the antisera to the 5 astrovirus serotypes. The type-specific neutralization observed agreed with the specificities seen by immunofluorescence (IF), whereas ELISA tests with the same antisera show cross-reactivity among all 5 serotypes. There was no virus neutralization detected with astrovirus monoclonal antibodies which were reactive with 5 serotypes by ELISA and IF. The results we have obtained permit quantitative techniques to be applied to epidemiological and biological studies of the human astroviruses.
Hudson
R W
RW
Division of Infectious Diseases, University of Massachusetts Medical School, Worcester.
Herrmann
J E
JE
Blacklow
N R
NR
D000914:Antibodies, Viral / Q000276:immunology; D006801:Humans; D001257:Mamastrovirus / Q000254:growth & development* / Q000276:immunology; D009500:Neutralization Tests; D012703:Serotyping; D014357:Trypsin; D010948:Viral Plaque Assay; D014713:Viruses, Unclassified / Q000254:growth & development*
D000914:Antibodies, Viral; D014357:Trypsin