To confirm a role for HBoV1 infection in disruption of the barrier function of the epithelium, we examined the distribution of the tight junction protein Zona occludens-1 (ZO-1) [39] . Infected B-HAE showed dissociation of ZO-1 from the periphery of cells started from 7 days p.i., compared with mock-infected B-HAE ( Figure 5A ), which likely plays a role in reducing TEER. Cumulatively, these results demonstrate that HBoV1 infection disrupts the integrity of HAE and that this may involve breakdown of polarity and redistribution of the tight junction protein ZO-1. To confirm a role for HBoV1 infection in the loss of cilia, we examined expression of the b-tubulin IV, which is a marker of cilia [40, 41] . In HBoV1-infected B-HAE, expression of b-tubulin IV was drastically decreased at 7 days p.i., and was not detected at 22 days p.i., in contrast to that in mock-infected B-HAE ( Figure 5B ). These results confirmed that HBoV1 infection caused the loss of cilia in infected B-HAE. Notably, infected B-HAE showed changes of nuclear enlargement, which became obvious at 22 days p.i. (Figure 5 , DAPI), indicating airway epithelial cell hypertrophy.