Expression and distribution of beta1 integrins in in vitro-induced M cells: implications for Yersinia adhesion to Peyer's patch epithelium.
Beta1 integrins are anchored on the basal membrane of enterocytes, but little is known about their localization in M cells, which are the main entry route into the intestinal mucosa for many bacterial pathogens. In particular, it has been suggested that adhesion of enteropathogenic Yersinia to M cells is mediated by interaction of the bacterial protein invasin and apical beta1 integrins. Using a novel in vitro model of M cells, we demonstrate an augmented apical and basolateral targeting of beta1 integrins in M cells associated with increased total alpha chain synthesis. The alpha3 and alpha6 subunits were targeted to the basal pole, but alpha2 subunit was targeted at both poles. No other alpha subunit was found associated with apical beta1 integrins on M cells. Interestingly, Y. enterocolitica still adhered to the apical surface of M cells, despite the fact that alpha2beta1 is not a receptor for invasin. We therefore studied the adhesive properties of invasin-mutant Y. enterocolitica and invasin-expressing Escherichia coli on the apical surface of M cells. We show that it is not invasin, but the product of an as yet unidentified bacterial chromosomal gene, that is involved in the adhesion of Y. enterocolitica to the apical membrane of M cells.
Laboratory of Lympho-epithelial Interactions, Department of Cell Biology and Infection, Institut Pasteur, 28 Rue du Docteur Roux, 75015 Paris, France.
Nadim
N
Hamzaoui
Sophie
S
Kernéis
Elise
E
Caliot
Eric
E
Pringault
D018829:Adhesins, Bacterial / Q000235:genetics / Q000378:metabolism; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000378:metabolism; D004847:Epithelial Cells / Q000276:immunology* / Q000382:microbiology; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity; D005786:Gene Expression Regulation; D005798:Genes, Bacterial; D039421:Integrin alpha2 / Q000235:genetics / Q000378:metabolism; D039422:Integrin alpha3 / Q000235:genetics / Q000378:metabolism; D039503:Integrin alpha6 / Q000235:genetics / Q000378:metabolism; D019012:Integrin beta1 / Q000235:genetics / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000276:immunology* / Q000382:microbiology; D009154:Mutation; D010581:Peyer's Patches / Q000166:cytology / Q000382:microbiology*; D037521:Virulence Factors / Q000378:metabolism; D015007:Yersinia / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*
D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D039421:Integrin alpha2; D039422:Integrin alpha3; D039503:Integrin alpha6; D019012:Integrin beta1; D037521:Virulence Factors; C053476:invasin, Yersinia