Lymphoepithelial interactions trigger specific regulation of gene expression in the M cell-containing follicle-associated epithelium of Peyer's patches.
In the intestine, the follicle-associated epithelium (FAE) of Peyer's patches (PP) performs Ag sampling as the first step in developing immune responses. Depending on the species, this epithelium contains 10-50% of M cells, which act as regulated gates in epithelial barriers that can be used opportunistically by pathogens to invade their host. However, the mechanisms involved in the differentiation and uptake processes of M cells are not known, in part because their limited number in the intestinal mucosa has hampered molecular and biochemical studies. In this work we provide evidence that PP lymphocytes can themselves modulate gene expression in PP in vivo and in an in vitro model of FAE. Transgenic mice carrying a reporter gene under the control of a modified L-pyruvate kinase promoter (SVPK) exhibit strong transgene expression in PP and FAE, but not in the adjacent villous cells. We used the mouse intestinal epithelial cell line m-IC(cl2) transfected with the SVPK promoter fused to beta-galactosidase to investigate the direct effect of PP lymphocytes on SVPK promoter activity. beta-Galactosidase expression was 4.4-fold higher in transfected m-IC(cl2) cells when they were cultured with PP lymphocytes. Conversely, green fluorescent protein expression was 1.8-fold lower in stably transfected differentiated intestinal Caco-2(cl1) cells with the sucrase isomaltase promoter fused to green fluorescent protein cDNA when they were cultured with PP lymphocytes, indicating that the in vivo FAE down-regulation of sucrase isomaltase promoter is transcriptionally regulated.
El Bahi
Sophia
S
Laboratoire des Interactions Lympho-Epithéliales, Département de Biologie Cellulaire et Infection, Institut Pasteur, Paris, France.
Caliot
Elise
E
Bens
Marcelle
M
Bogdanova
Anna
A
Kernéis
Sophie
S
Kahn
Axel
A
Vandewalle
Alain
A
Pringault
Eric
E
D000818:Animals; D030801:Animals, Genetically Modified; D002450:Cell Communication / Q000235:genetics / Q000276:immunology*; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002460:Cell Line; D018920:Coculture Techniques; D015536:Down-Regulation / Q000235:genetics / Q000276:immunology; D004847:Epithelial Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000276:immunology*; D007413:Intestinal Mucosa / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D007421:Intestine, Small / Q000166:cytology / Q000201:enzymology / Q000276:immunology; D016131:Lymphocyte Subsets / Q000166:cytology / Q000201:enzymology / Q000276:immunology; D051379:Mice; D010581:Peyer's Patches / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011770:Pyruvate Kinase / Q000235:genetics; D013394:Sucrase-Isomaltase Complex / Q000037:antagonists & inhibitors / Q000235:genetics
D011770:Pyruvate Kinase; D013394:Sucrase-Isomaltase Complex