Defective interfering (DI) particles of the flavivirus West Nile (WN) were generated after as few as two high multiplicity serial passages in Vero and LLC-MK2 cells. Six cell lines (Vero, LLC-MK2, L, HeLa, BHK-21 and SW13) were used to assay interference by DI particles in a yield reduction assay. Interference was found to vary depending on the cell type used. The highest levels of interference were obtained in LLC-MK2 cells, whereas no detectable effect was observed in BHK-21 and SW13 cells. The ability of DI virus to be propagated varied depending on the cell line used; no detectable propagation of DI virus was observed in SW13 cells. Optimum interference was obtained following co-infection of cells with DI virus and standard virus at a multiplicity of 5. Interference between DI and standard viruses occurred only when they were co-infected or when cells were infected with DI virus 1 h before standard virus. Investigation of heterotypic interference by DI particles of WN virus strains from Sarawak, India and Egypt revealed that interference was dependent on the strain of WN virus or flavivirus used as standard virus. A measure of the similarity between five strains of WN virus and other flaviviruses was made on the basis of interference by DI viruses, and was found to be similar to that based on haemagglutination inhibition tests using a panel of monoclonal antibodies.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error