Isolation and characterization of WUPyV in polarized human airway epithelial cells.

BACKGROUND: Washington University polyomavirus (WUPyV) is a novel human polyomavirus detected in childwith acute respiratory infection in 2007. However, the relationship between WUPyV and respiratory diseases has yet to be established for lacking of a suitable in vitro culture system. METHODS: To isolate WUPyV with human airway epithelial (HAE) cells, the positive samples were incubated in HAE, and then the nucleic acid, VP1 protein and virions were detected using real-time PCR, immunofluorescence and electron microscopy respectively. RESULTS: The result showed that WUPyV could replicate effectively in HAE cells and virions with typical polyomavirus characteristics could be observed. Additionally, the entire genome sequence of the isolated strain (BJ0771) was obtained and phylogenetic analysis indicated that BJ0771 belongs to gene cluster I. CONCLUSIONS: Our findings demonstrated clinical WUPyV strain was successfully isolated for the first time in the world and this will help unravel the etiology and pathogenic mechanisms of WUPyV in respiratory infection diseases.