IMMUNOLOGICAL, FUNCTIONAL, AND MORPHOLOGICAL CHARACTERIZATION OF 3 NEW HUMAN SMALL-INTESTINAL EPITHELIAL-CELL LINES

Background & Aims: Epithelial cell cultures can be used for the study of epithelial cell biology, although human small intestinal cultures h ave not been available to date. The aim of this study was to character ize three cell lines derived from normal human duodenum. Methods: Cell s were cultured from tissue fragments obtained from endoscopic biopsy specimens and characterized with respect to morphology and cytokine ge ne expression acid for the presence of vectorial transport. Results: A ll cell lines grew as polarized continuous monolayers and were mostly cuboidal in shape but were not immortalized. Cells showed junctional c omplexes and sparse microvilli. Ail cell lines showed cytokeratins and mucin antigen but not chromagranin and messenger RNA for epidermal gr owth factor, interleukin 6, and vascular cell adhesion molecule 1. Dis accharidase activities were low and correlated with the low proportion of cells (1%-10%), showing positive immunocytochemistry for sucrase. Monolayer resistance varied from 30 to 200 Omega. One monolayer (BN) c onsistently showed secretion in response to forskolin (10 mu mol/L), w hich could be inhibited by chloride-free buffer and apical addition of the chloride channel blocker diphenylamine decarboxylate. No monolaye r had evidence of glucose transport. Conclusions: These three nonimmor talized lines show morphological, phenotypic, and transport characteri stics of crypt-like intestinal epithelial cells. The pattern of messen ger RNA expression suggests a growth-promoting and immunomodulatory ro le.