Figure 1.

Flavivirus NS1 proteins induce mislocalization of IJC proteins in human endothelial cells. Confluent monolayers of HUVECs (top panel) and HBMEC (lower panel) were treated individually with five different NS1 proteins from DENV, ZIKV, WNV, JEV, and YFV (5 μg/mL). Monolayers were fixed and processed 6 h post-treatment (hpt) by IFA staining of (A) VE-cadherin and (B) β-catenin (both in red). Untreated (no NS1) cells were used as a control for normal distribution/localization of VE-cadherin and β-catenin. Nuclei are depicted in blue (Hoechst). Mean fluorescence intensity (MFI) analysis of (C,D) VE-cadherin and (E,F) β-catenin staining (IFA) per NS1 treatment and control treatment of (C,E) HUVEC and (D,F) HBMEC are shown. Images are representative of three independent experiments (area: 29.16 mm²). White arrowheads indicate places of VE-cadherin and β-catenin mislocalization, suggesting disruption of the IJC. Scale bar: 10 μm. Magnification: 20×.