Fig 12.

EBOV exposure without infection is not sufficient for DC maturation. The indicated viruses were subjected to 1-h-long incubation at 56°C, overnight incubation at 4°C in tubes, or overnight incubation at 4°C in ELISA plates. The next day, the wells of ELISA plates containing the viruses were washed, and DC were added. Alternatively, DC were added to wells containing the viruses treated in tubes or fresh, untreated viruses. At 40 h, expression of CD86 was measured by flow cytometry. The CD86 MFI values were normalized to the level of expression in mock-infected DC (100%), indicated by the dashed line. Values for each donor are indicated by symbols, and the mean values are indicated by horizontal bars. The P values of the difference between the level of CD86 in DC exposed to EBOV/VP35-R312A preincubated in a plate at 4°C versus the same virus preincubated at 4°C in a tube (*) or untreated virus (**) are 0.02 and 0.007, respectively.