Supplementary Figure 1.

Polarized monolayer of IECs derived from human iPSCs. (A) Differentiation of iPSC-derived IECs to enterocytes. Relative messenger RNA expression of the indicated genes in iPSC-derived IECs during the course of differentiation (days 0, 2, and 4) were determined by qPCR and normalized against the expression of GAPDH. The assays were performed in 3 independent biological replicates. Expression levels are presented as means ± SEM. SI, sucrase isomaltase. (B, D) Immunohistochemical analysis of monolayers harvested with the Transwell membrane after 6 days of culture. Sections were stained with anti-E-cadherin (green) and anti-villin-1 antibodies (red, B) or Ulex europaeus agglutinin-1 (red, D), and counterstained with DAPI (blue). Data are representative of 3 independent experiments. Scale bar = 10 μm. HBGA, histo-blood group antigen. (C) Transmission electron microscopic images of polarized monolayer of human iPSC–derived IECs. Lower panel is a magnification of the area in the blue box in the upper panel. Data are representative of 3 independent experiments. Scale bar = 2.5 μm. (E, F) GII.4 virus and VLPs bound to, and entered, the iPSC-derived IECs. Polarized iPSC-derived IECs on Transwell membranes were incubated with 8.3 × 10⁸ genome equivalents of GII.4 virus or 300 ng of VLPs for 3 hours, and then the Transwell membranes were whole-mount stained with anti-GII.4 antibody (E, red) or were sectioned and stained with anti-GII.4 antibody (F, red) simultaneously with anti-villin-1 antibody (F, green), and then counterstained with DAPI (blue). Lower panels are a magnification of the area in the yellow boxes in the upper panels. Data are representative of three independent experiments. Scale bar = 50 μm (E), 10 μm (F).