Cellular heterogeneity in the 16HBE14o- airway epithelial line impacts functional readouts [RNA-seq]

The airway epithelial cell line, 16HBE14o-, is an important cell model for studying airway disease. 16HBE14o- cells were originally generated from primary human bronchial epithelial cells by SV40-mediated immortalization, a process that is associated with genomic instability through long-term culture. Here we explore the heterogeneity of these cells, with respect to expression of the cystic fibrosis transmembrane conductance regulator (CFTR) transcript and protein. We isolate clones of 16HBE14o- with stably higher and lower levels of CFTR in comparison to bulk 16HBE14o-, designated CFTRhigh and CFTRlow. Detailed characterization of the CFTR locus in these clones by ATAC-seq and 4C-seq showed open chromatin profiles and higher order chromatin structure that correlate with CFTR expression levels. . Transcriptomic profiling of CFTRhigh and CFTRlow cells showed that the CFTRhigh cells had an elevated inflammatory/ innate immune response phenotype. These results encourage caution in interpreting functional data from clonal lines of 16HBE14o- cells, generated after genomic or other manipulations. Comparative gene expression profiling of 12 RNA-seq datasets (3 replicates each of 2 16HBE14o- CFTR-high clones or 2 16HBE14o- CFTR-low clones)