Does the Caco-2 model reproduce M cell differentiation?
It might not be fair to ask whether the Caco-2 induction reproduces the M cell phenotype, since there are few known molecular correlates of the M cell phenotype. Thus, to help generate a better molecular profile of M cells, we used a gene expression profiling strategy to identify several mRNAs associated with FAE, including genes expressed by (although not exclusive to) M cells. The use of the Caco-2 cell culture model led to the identification of one gene (CPE-R) with enriched expression in mouse M cells, with similar distribution in human Peyer s patch FAE. Final confirmation of M cell expression in human FAE will require additional study, including detailed ultrastructural studies on cells both in human Peyer s patch and Caco-2 cultures. Other genes identified from the Caco-2 model showed less consistent expression patterns in mouse and human FAE; these differences may reflect species differences in Peyer s patch development and function or they may reflect regulation of genes not r
