Figure 7.

Following the 14 days at the ALI, the enzyme papain was applied to the epithelial surface of single and cocultures, which was shown to disrupt tight junctions demonstrated by the measurement of TEERs (A) and by confocal imaging of ZO1 protein (B). The disruption to tight junctions from coculture was observed to be less than that of single cultures. TEER measurements were then performed for a further 14 days to monitor the healing process. The cocultures were observed to be recovering from the disruption with increase in TEERS and increase in the presence of ZO1. Single cultures did not appear to recover so well with TEER measurements remaining around the same value as when the cells were subjected to papain. Statistical analysis was performed using two-way ANOVA with Sidak̀s multiple comparison, showing that the difference between coculture and single Calu-3 culture that had been subjected to papain having a p value <0.0001.