Figure 5. SARS-CoV-2 entry and replication are dependent on serine proteases in human airway organoids.

(A and B) Differentiated bronchiolar (A) or bronchial (B) hAO cultures were infected at an MOI of 2. Sixteen hours (A) or 24 hr (B) postinfection they were fixed and stained for viral nucleoprotein (red). Nuclei were stained with hoechst (blue) and actin was stained using phalloidin (white). AcTub stains ciliated cells (green). Scale bars indicate 200 μm in (A) and 50 μm in (B). Representative images are shown from two independent experiments. (C–E) Replication kinetics of SARS-CoV-2 in bronchiolar hAO cultures pretreated with camostat or carrier (DMSO). (C and D) TCID50 equivalents (eq.) per mL are shown in culture medium (C) and lysed organoids (D). Circles indicate DMSO-treated organoids, whereas squares indicate camostat-treated organoids. (E) Live virus titers (TCID50/mL) in lysed organoids. Dotted line indicates limit of detection. (F) Replication kinetics of SARS-CoV-2 in 2D tracheal air–liquid interface airway cultures pretreated with camostat or carrier (DMSO). TCID50 eq./mL in apical washes are shown. Two-way ANOVA was performed for statistical analysis. Error bars indicate SEM. *p<0.05. DMSO, dimethyl sulfoxide; hAO, human airway organoid; H p.i., hours postinfection; MOI, multiplicity of infection.