M cell transport of Vibrio cholerae from the intestinal lumen into Peyer's patches: a mechanism for antigen sampling and for microbial transepithelial migration.
Viable Vibrio cholerae O1 were inoculated into the intestinal lumen of nonimmune rabbits. The vibrios were phagocytosed by M cells over Peyer's patch lymphoid follicles, carried in vesicles through the epithelium, and discharged among underlying lymphocytes and macrophages. Autoradiography of V. cholerae labeled with [2-3H]adenine confirmed transport. Indigenous bacteria with and without capsules were also taken up from control loops and carried through M cells into Peyer's patches. V. cholerae killed by acidification, formalin, heat, or UV irradiation were not taken up, a result that may have relevance for development of oral vaccines. Ruthenium red stain revealed gaps in the layer of mucus over M cells, glycocalyx bridging the space between vibrios and M cell microvilli, and knobby projections over membranes of M cell microvilli; these projections were not found over absorptive cells. M cells thus convey viable enteric microbes, including V. cholerae that are not otherwise invasive, into intestinal lymphoid tissue, where mucosal immune responses are initiated. Uptake and transport by M cells may also assist certain pathogenic bacteria in traversing the mucosal barrier and initiating systemic infection.
R L
RL
Owen
N F
NF
Pierce
R T
RT
Apple
W C
WC
Cray
D000818:Animals; D001345:Autoradiography; D007413:Intestinal Mucosa / Q000166:cytology / Q000276:immunology / Q000382:microbiology*; D008297:Male; D008854:Microscopy, Electron; D010581:Peyer's Patches / Q000276:immunology*; D011817:Rabbits; D012430:Ruthenium Red; D014734:Vibrio cholerae / Q000276:immunology*
D012430:Ruthenium Red