Figure 2
The potential of IEC#17 for the efficient SARS-CoV-2 infection. (A) IEC#17 and Vero cells were seeded in a plate and infected with SARS-CoV-2 at an MOI of 0.1. The supernatants were collected at indicated time points. SARS-CoV-2 growth was measured by determining the TCID50 on VeroE6/TMPRSS2 cells. Each value is representative of at least three independent experiments and is shown as the mean ± SD from three wells of supernatants of each culture group. The significant differences were determined using two-way ANOVA. (B–D) The transmission electron microscopic analysis of IEC#17 monolayers infected with SARS-CoV-2. IEC#17 cells were seeded on Transwell membranes (C) or Cell Desks (D). Each colored squares indicate each magnified panels. (B) Schematic diagrams of the transmission electron microscopic analysis. The black arrow indicates the direction from which the photograph was taken. (C) The IEC#17 were cultured to harbor the polarity and infected with SARS-CoV-2 at an MOI of 0.1 from apical side. At 24 hpi, infected cells were fixed and analyzed. The photos were taken from vertical angle. The black and white arrows indicate SARS-CoV-2 particle and viral replication organelles (ROs), respectively. The scale bars indicate 0.5 µm. (D) The IEC#17 were cultured by the normal method (no polarity) and infected with SARS-CoV-2 at an MOI of 0.1. At 24 hpi, infected cells were fixed and analyzed. The photos were taken from horizontal angles. The black arrows indicate SARS-CoV-2 particle. The scale bars indicate 0.5 µm. (E, F) Immunofluorescence analysis of (E) SARS-CoV-2 NP and SP, or (F) ACE2, TMPRSS2, and SARS-CoV-2 SP in IEC#17 monolayers infected with SARS-CoV-2. The photo was taken from horizontal angles at 24 hpi. The scale bars indicate 50 µm.
