Development and characterization of immortalized mouse intestinal epithelial cell lines.

Developing new tools for studying the intestinal epithelium aids in addressing unanswered questions in developmental biology, physiology, and disease pathology. Primary intestinal epithelial stem cell (ISC) cultures are an invaluable in vitro model system. However, their cultivation remains technically demanding and costly, limiting their accessibility and use. Though commonly utilized, most extant intestinal epithelial cell lines were derived from colon adenomas from various mammals, are largely uncharacterized, and possess a plethora of genetic abnormalities, thus restricting rigor, reproducibility, and physiological relevance. Here we derived immortalized intestinal epithelial cell lines (iIECs) from jejunal and colonic stem cell-enriched spheroid cultures from wild type C57BL/6 mice. We transduced ISCs with a lentiviral vector encoding the SV40 large T antigen, and subsequently selected lines through adaptation to growth on plastic. Additionally, we weaned these lines off conditioned medium including the growth factors Wnt3a, Rspo3, and Noggin. We found that iIECs have growth characteristics similar to conventional plastic adapted cell lines. While we observed transcriptional signatures of epithelial-–mesenchymal transition (EMT), these cells retained several epithelial characteristics including expression of junctional proteins, segment-specific identities, and mounted an innate immune response to viral infection. In addition, we found several fibroblastic clones secreted cytokines in response to LPS stimulation. We further demonstrated the utility of iIECs through transient and stable genetic manipulation, as well as pathogen infection. iIECs occupy an important experimental niche through offering a scalable, practical, and physiologically relevant model system that can function as a discovery platform before transitioning to primary spheroid cultures and/or animal models. We propose that they will be a valuable tool for advancing understanding of intestinal epithelial biology.