Establishment of Respiratory Syncytial Virus Infection Model Using Tree Shrew
To establish a novel model for respiratory syncytial virus(RSV) infection in primate animal,twenty-eight tree shrews were divided into seven groups and inoculated through intranasal route with 100μl RSV of 10~7 plaque forming units(PFU).Another seven tree shrews set up as control received 100μl Hep-2 cell culture fluid.At every 24h tree shrews in one experimental group and one in control group were killed.Their right lungs were removed under aseptic condition,homogenized and centrifuged,the supernatants were collected for virus isolation and quantification of virus consecutively.Left lungs were collected for histopathological examination and detection of expression of RSV mRNA by RT-PCR.Results showed that: ⑴Tree shrews infected by RSV did not show any respiratory symptom;⑵The lung homogenate of tree shrews when inoculated onto Hep-2 cell,the cytopathogenic effect was observed in 3th,4th,5th experimental groups;⑶The pathological changes were obvious at day 3 to day 7,the most apparent change was interstitial pneumonitis;⑷Inoculated with 10~6PFU RSV,viral replication in tree shrew lungs were at low level,replication reached to maximum within 3 to 5 days,peak at day 4.The results suggest that tree shrew have potential for establishing RSV infection animal model.