We show indirect immunofluorescence analysis with anti-IFITM3 and anti-NP antibodies of HSAEpCs in Figure S6. No unspecific signal is detected in the cytosol of HSAEpCs, indicating that the observed cytoplasmic NP stain is specific. Nuclear NP stain is detected at 10 h p.i., and this may indeed indicate delayed replication compared to A549 cells as suggested by the reviewer, but no direct side-by-side comparison of replication kinetics in different cells was performed.
(Fig. S2B), as was previously described by others.