Strong correlation between air-liquid interface cultures and in vivo transcriptomics of nasal brush biopsy.

Air-liquid interface (ALI) cultures are extensively used ex vivo models to study the epithelium of patients with chronic respiratory diseases. However, the in vitro conditions impose a milieu different from that encountered in the patient, in vivo, and the degree to which this alters gene expression remains unclear. In this study, we employed RNA sequencing and compared the transcriptome of fresh brushings of nasal epithelial cells with those which have been cultured in ALI from the same patients. We observed a strong correlation between cells cultured at the ALI and cells obtained from the brushed nasal epithelia and 96% of expressed genes showed similar expression profiles, although there was greater similarity between the brushed samples. We observed that while ALI model does provide an excellent representation of the in vivo airway epithelial transcriptome for mechanistic studies, there are several pathways effected by the change in milieu.