Immune cells associated with M cells in the follicle-associated epithelium of Peyer's patches in the rat. An electron- and immuno-electron-microscopic study.
Follicle-associated epithelium of Peyer's patches can be differentiated from nearby villous epithelium by the presence of M cells which are antigen-sampling epithelial cells, and by an increase in intraepithelial lymphocytes that are in close contact with M cells. The phenotype of the immune cells close to the M cells of the follicle-associated epithelium of rat Peyer's patches was determined by immunohistochemistry and compared with that of the intra-epithelial lymphocytes of the villous epithelium. Lymphoid T cells, predominantly of the cytotoxic/suppressor phenotype, were observed both in follicle-associated epithelium and in villous epithelium. Lymphoid B cells, mainly immunoblasts and plasma cells containing intracytoplasmic IgM, were present only in the follicle-associated epithelium, near M cells. Macrophages were also present, in contact with M cells, in follicle-associated epithelium, but not in villous epithelium. In addition, M cells bore Ia molecules on their apical membranes. These findings reinforce the concept of immune specialization of the follicle-associated epithelium, by demonstrating that this epithelium contains all the effector cells of immune responses.
Jarry
A
A
Unité U239 INSERM, Faculté de Médecine X., Bichat, Paris, France.
Robaszkiewicz
M
M
Brousse
N
N
Potet
F
F
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology / Q000648:ultrastructure; D004847:Epithelial Cells; D004848:Epithelium / Q000276:immunology / Q000648:ultrastructure; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D008264:Macrophages / Q000276:immunology / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron / Q000379:methods; D010581:Peyer's Patches / Q000166:cytology* / Q000276:immunology / Q000502:physiology; D010641:Phenotype; D051381:Rats; D011919:Rats, Inbred Strains; D013601:T-Lymphocytes / Q000276:immunology / Q000648:ultrastructure
D000949:Histocompatibility Antigens Class II