FIG 1.

In vitro human BBB is permissive to ZIKV infection and replication without strong deleterious effects on its integrity. (a) CT-, ZIKV AF-, and ZIKV AS-infected (MOI, 0.1) hBLECs of BBB model grown on cell culture inserts fixed at 6 dpi. Indirect IF confocal studies of CT- and ZIKV-infected hBLECs using an actin probe (green) and antibodies against ZIKV (pan-flavivirus, magenta) and ZO-1 (cyan). Nuclei are labeled with Hoechst (blue). Bars, 15 μm. (b) CT-, ZIKV AF-, and ZIKV AS-infected (MOI, 1) BBB model grown on cell culture inserts were fixed at 10 dpi. Indirect IF confocal studies show actin (green), ZIKV (magenta), ZO-1 (cyan), and nuclei (blue). ZO-1 labeling highlights cell-cell adhesion, characteristic of polarized endothelia. Bars, 30 μm. (c) Indirect IF studies of BBB model at 7 dpi (MOI, 1) showing actin (green), ZIKV (magenta), claudin-5 (cyan), and nuclei (blue). Bars, 15 μm. (d) Viral titers in supernatants from ZIKV AF- and ZIKV AS-infected (MOI, 1) BBB model in apical and basolateral (BL) sides at various time points postinfection determined using the TCID₅₀ method. Results are expressed as means ± standard errors of the means (SEMs) from 3 independent experiments. (e) Paracellular permeability of CT-, ZIKV AF-, and ZIKV AS-infected (MOI, 1) BBB model grown on cell culture inserts at 7 and 10 dpi. Doxorubicin and DMSO are two positive controls. Results are expressed as means ± SEMs (n = 3) and analyzed using a Wilcoxon-Mann-Whitney test. *, P < 0.05 (ZIKV AF/AS compared to CT). (f) Transendothelial electrical resistance (TEER) of CT-, ZIKV AF-, and ZIKV AS-infected (MOI, 1) BBB grown on cell culture inserts was measured at 10 dpi. DMSO is a positive control. Each bar represents the mean ± SEM from 3 independent experiments and analyzed using a Wilcoxon-Mann-Whitney test. **, P < 0.01 (compared to CT).