Differential expression of lectin-binding sites defines mouse intestinal M-cells.
We investigated the binding of four lectins to the follicle-associated epithelium (FAE) overlying fixed mouse small intestinal Peyer's patches to identify M-cell-specific surface markers. Wheat germ agglutinin and peanut agglutinin displayed heterogeneous staining patterns, binding most avidly to the intestine goblet cells. In contrast, the lectins Ulex europaeus 1 (UEA 1) and Psophocarpus tetragonolobus (winged bean; WBA) were almost exclusively M-cell specific. When confocal laser scanning images of tissues stained with fluorescein isothiocyanate (FITC)-conjugated UEA1 or WBA were compared with the appearance of the same tissues under the scanning electron microscope (SEM), UEA1 strongly stained 97.2% (106/109) of M-cells, 0.6% (3/516) enterocytes, and 0% (0/28) goblet cells, whereas WBA stained 100% (83/83) M-cells, 1.7% (6/361) enterocytes, and 5.3% (1/19) goblet cells. The M-cell specificity of the lectin binding was further demonstrated by localization of horseradish peroxidase (HRP)-conjugated lectins under the transmission electron microscope (TEM). This is the first demonstration of carbohydrates in the glycocalyx of M-cells that are not expressed elsewhere on the FAE surface. These carbohydrates not only provide a means to identify mouse M-cells by LM but may also contribute to the occurrence of specific interactions between microorganisms and the M-cell apical membrane.
Clark
M A
MA
Gastrointestinal Drug Delivery Research Centre, University of Newcastle upon Tyne, Medical School, United Kingdom.
Jepson
M A
MA
Simmons
N L
NL
Booth
T A
TA
Hirst
B H
BH
D000818:Animals; D001665:Binding Sites; D005260:Female; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D006735:Horseradish Peroxidase; D007421:Intestine, Small / Q000378:metabolism / Q000648:ultrastructure; D037102:Lectins / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D010581:Peyer's Patches / Q000378:metabolism* / Q000648:ultrastructure; D013194:Staining and Labeling
D005456:Fluorescent Dyes; D037102:Lectins; D008562:Membrane Glycoproteins; D006735:Horseradish Peroxidase; D016650:Fluorescein-5-isothiocyanate