Fig. 5. DIPs and their DI-290 RNA are a transmissible VLP.

Vero cells or Vero-ORF expressing DENV-2 S and NS proteins were treated with cell-free culture supernatant of HEK-DI-290 (black bars, a negative control) or DIP supernatant of HEK-DI-290-ORF cells (red bars) for 12 h when the culture medium was replaced. After 48 h, RNA samples were prepared from A cells and B culture supernatant and used in RT-qPCR assays to measure levels of DI-290 RNA. The cellular levels of DI-290 were normalized to GAPDH mRNA in the same sample. The relative level of DI-290 in Vero cells treated with negative control supernatant was set as 1. The error bars indicate the SD. A representative of three experiments with similar results is shown. .