Figure 4. Blockage of Spike‐expressing pseudovirus entry into ACE2‐expressing cells by ACE2‐Fc.

• A
  ACE2‐Fc blocked the entry of Spike‐expressing pseudotyped lentivirus into HEK293T‐ACE2 and H1975‐ACE2 cells. The relative luciferase activities, normalized to the only virus group, represent the efficiency of virus entry. MOI: Multiplicity of infection.
• B–D
  Airway organoid model system. (B) Confocal microscopy images of the airway organoids. The green fluorescence represents the specific staining of indicated monoclonal antibodies and Alexa Fluor 488‐conjugated secondary antibodies. DAPI was used as a nuclear counterstain. Hematoxylin and eosin (H&E) stain: hematoxylin stained the nuclei in blue color; eosin stained the cytoplasm in pink color. Scale bars equal to 20 µm. (C) Lung cancer A549 cells, human normal bronchial epithelial cells (HBEpc), and HBEpc‐differentiated cells (airway organoids) were harvested for immunoblotting with the indicated antibodies. (D) Blockage of pseudovirus entry into airway organoids by ACE2‐Fc. Mixtures of pseudotyped lentivirus with or without ACE2‐Fc were cocultured with airway organoids for 72 h. The virus entry was determined by quantifying the luciferase activity in the cell lysates.

Data information: Error bars represent the standard deviation (SD), n = 3. Statistical analysis was performed by unpaired two‐tail t‐test. *P < 0.05, **P < 0.01, ***P < 0.001. Experiments were performed at least three times with similar results.