Elucidation of mutation mechanism of norovirus using persistent infection culture system

2016 Fiscal Year Final Research Report

• Project/Area Number: 26660231
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Veterinary medical science
• Research Institution: National Institute of Infectious Diseases (2015-2016); Iwate Medical University (2014)
• Principal Investigator: Ken-Ichi Hanaki 国立感染症研究所, 動物管理室, 室長 (40376421)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: ノロウイルス / 持続感染 / 細胞培養

Outline of Final Research Achievements

Persistent infection with murine norovirus strain S7 (MNV-S7) in RAW264.7 cells was established. Transmissible electron microscopy and electron tomography showed that MNV-S7 virions aggregated in subcellular vesicles of persistently infected cells. Confocal immunofluorescence microscopy showed co-localization of MNV-S7 antigen with Rab7. The copy number of extracellular MNV-S7 RNA showed a high linear correlation with the number of non-viable cells, and virus replication was only observed in apoptotic cells. Based on these knowledges, the life cycle of persistent infection with MNV-S7 in RAW264.7 cells can be supposed as follows. Nearly 100% of persistently infected cells harbored MNV-S7 virions in Rab7-positive late endosomes. MNV-S7 replicated in a small number of the cells, which were identified by apoptotic morphological changes, and progeny virus was released into the culture supernatant from the apoptotic cells. The progeny virus was taken up by living RAW264.7 cells again.

Free Research Field

実験動物学