Porcine IPEC-J2 intestinal epithelial cells in microbiological investigations

IPEC-J2 cells are porcine intestinal columnar epithelial cells that were isolated from neonatal piglet mid-jejunum. This cell line forms polarized monolayers with high transepithelial electrical resistance when cultured on 0.4 microm pore-size filters. The cell line is unique in that it is derived from small intestinal tissue (compared to the common human colon-derived lines HT-29, T84, and Caco-2) and is not transformed (compared to the porcine small intestinal line, IPI-2I). Porcine intestinal epithelial cells more closely mimic human physiology than analogous rodent cell lines (e.g. IEC-6 or IEC-18), which is important in studies of zoonotic infections; in addition, they provide specificity to study porcine-derived infections. IPEC-J2 cells are increasingly being used in microbiological studies to examine the interactions of various animal and human pathogens, including Salmonella enterica and pathogenic Escherichia coli, with intestinal epithelial cells. The IPEC-J2 cell line has also been employed in some probiotic studies, in which the cells have been used as an initial screening tool for adhesiveness and anti-inflammatory properties of the potential probiotic microorganisms. The validity of these studies is not clear as follow-up studies to assess the efficacy of the probiotics in vivo have not been published to date. The aims of this review are to provide a comprehensive overview of the microbiological studies that have been conducted with IPEC-J2 cells and a reference guide of key cellular and immune markers that have been identified in this cell line that may prove to be useful in future studies.