Human cell models to study small intestinal functions: Recapitulation of the crypt-villus axis

The intestinal epithelium is continuously and rapidly renewed by a process involving cell generation, migration, and differentiation, from the stem ce ll population, located at; the bottom of the crypt to the extrusion of the terminally differentiated cells at the tip of the villus. Because of the la ck of normal human intestinal cell models, most of our knowledge about the regulation of human intestinal cell functions has been derived from studies conducted on cell cultures generated from experimental animals and human c olon cancers. However, important advances have been achieved over recent ye ars in the generation of normal human intestinal cell models. These models include (a) intestinal cell lines with typical crypt cell proliferative non committed characteristics, (b) conditionally immortalized intestinal cell l ines that can be induced to differentiate, and (c) primary cultures of diff erentiated villuslike cells that can be maintained in culture for up to 10 days. Each of these models should help in the investigation of the specific aspects of human intestinal function and regulation. Furthermore, taken to gether, these models provide an integrated system that allows an in vitro r ecapitulation of the entire crypt-villus axis of the normal human small int estine. Microsc. Res. Tech. 49:394-406, 2000. (C) 2000 Wiley-Liss. Inc.