Fig 1.
ZIKV infection of guinea pig cells in vitro.
GPL and Vero cells were infected at a low MOI with ZIKV. Cell culture supernatant was collected daily and titered on Vero cells. The mean titer from three replicate infections is shown, and the bars represent the standard error for each set of replicates.
Fig 2.
ZIKV infection of non-pregnant guinea pigs.
Groups of guinea pigs (N = 4) were infected with 1x107 or 1X108 PFU of ZIKV or sham injected. (A) The weight change of experimentally challenged guinea pigs over time was recorded. The mean weight change in each group of challenged animals and the standard error at each time point is plotted. (B) Viremia in whole blood from challenged guinea pigs was quantified using qRT-PCR. Solid symbols indicate animals challenged with 1X107 PFU; open symbols indicate animals challenged with 1X108 PFU. (C) Select plasma samples from guinea pigs challenged with 1X108 PFU of ZIKV were examined using a ZIKV NS1 ELISA. The number of ZIKV genome copies/ml and the magnitude of antigenemia, as assessed in ng/ml NS1 in blood or plasma from each animal at the indicated time point post-infection are shown. ND: not detectable.
Fig 3.
ZIKV infection of pregnant guinea pigs.
Pregnant guinea pigs were infected with 1X107 PFU of ZIKV (N = 21) or sham injected (N = 15) at GA 18–21. (A) Guinea pigs were weighed daily until a pre-determined experimental endpoint and the mean weight change for each group was plotted along with the standard error. Animals were euthanized at 10, 20, 30 or 40 days post-infection (N = 4 infected, 3 uninfected per group) or euthanized on the day of delivery (N = 5 infected, 3 uninfected per group). (B-F) Pups were weighed at the indicated endpoint post-infection. Symbol shape represents individual litters; open symbols indicate pups born dead. The bars indicate the standard error within each group.
Fig 4.
Anti-ZIKV antibody production by infected guinea pigs.
To assess whether an antibody response to ZIKV proteins is elicited in challenged guinea pigs, purified ZIKV Env and NS1 and semi-purified viral particles were resolved by SDS-PAGE, transferred to membranes, and immunoblotted. (A) Coomassie stained gel showing the sizes of input protein. (B-E) Proteins were transferred to membranes and immunoblotted using plasma collected from four ZIKV challenged pregnant guinea pigs either the day before viral challenge (D-1) or the day of delivery (Term).
Fig 5.
Evolution of the anti-NS1 response in pregnant dams.
The IgG response to ZIKV NS1 of pregnant guinea pigs and their pups was measured by ELISA. (A) The mean anti-NS1 titer of pregnant guinea pigs challenged with ZIKV (N = 5) or sham injected (N = 2) was measured over time and plotted; bars indicate the standard error for each time point. (B) The anti-NS1 titers of pregnant dams and pups were measured at each experimental endpoint. The bars indicate the mean antibody titer at each time point.