M cell, FAE and VAE expresssion profiles

M cells are specialized epithelial cells occurring in the follicle-associated epithelium (FAE) overlying the Peyer’s patch. M cells transcytose macromolecules and microorganisms from the gut lumen to the underlying organized mucosal lymphoid follicles. Thus, M cells are a portal to the mucosal immune system and are crucial for the study of pathogenesis and mucosal vaccine design. Although characterization has been primarily performed to date using immunohistochemistry and in vitro cell culture techniques, little is known about the genetic factors in vivo distinguishing M cells from other intestinal epithelial cells. Our aim was to develop a method to isolate viable murine M cells for the purpose of generating an expression profile of murine M cells compared to FAE enterocytes and villus associated enterocytes (VAE). Peyer’s patches were microdissected from murine small intestine and the FAE isolated by enzymatic digestion. M cells were isolated using magnetic bead cell sorting of FITC-UEAI lectin stained FAE. Analysis of M cell, FAE and VAE gene expression was performed using cDNA arrays and Real-time RT-PCR. Altered expression of several genes involved with cell structure, differentiation and cell-interaction was observed. In murine M cells; E-cadherin, Ccl20, Ccl25 and Lamr1 were increased in expression, compared to the neighboring FAE enterocytes. Cxcr4 and PIN were found increased, with Il-18 and Bad decreased in expression, in both M cell and FAE enterocytes compared to VAE.This gene expression profile of in vivo murine M cells, FAE and VAE provides a portal into M cell biology previously undiscovered. This expression profile of M cells will aid in understanding pathogen-host immune interactions and contribute to the understanding of intestinal M cell biology. Keywords: Cell type comparison The aim of the experiment was to identify the expression profile of M cells related to FAE , VAE and PPL. Cells were isolated and expression profiles determined using cDNA arrays. Each normalised expression value represents a duplicate of the sample analysed .Expression changes were confirmed by RT-PCR on seperate samples isolated using the same technique