Confocal analysis of fluorescent bead uptake by mouse Peyer's patch follicle-associated M cells.

Latex beads coated with secretory immunoglobulin (IgA) instilled into mouse intestinal loops are taken up by M cells present in Peyer's patch follicle-associated epithelial tissue. Bead adsorption and uptake is greater at the edge compared with the apex of follicle domes. Coating beads with bovine serum albumin (BSA) causes a fourfold reduction in adsorption and a twentyfold reduction in uptake. Results demonstrate selectivity between adsorption and uptake and between the ability of different proteins to facilitate uptake.