title: Cytokeratin 20-expressing M cells in tonsils take up particulate antigen. A site for the delivery of vaccines against oral pathogens?
abstract: Quantitative and qualitative control of oral bacterial flora is a major issue in oral pathology and in the prophylaxis against cavities. Recent findings suggest that it is possible to induce local immune responses delivering antigens on palatine tonsils. M cells play an important role in the start of the immune response. These cells are located in the epithelia overlaying mucosal lymphoid follicles and are responsible for the uptake of particulate antigens. The identification of reliable markers for M cell is therefore extremely important. Since it has been reported that tonsillar immunization leads to the secretion of high levels of specific salivary antibody, we undertook a study to identify a marker for tonsillar M cells in order to plan strategies of oral immunization against oral pathogens. We studied cytokeratin 20 expression in rabbit tonsils by immunofluorescence and confocal microscopy. Cytokeratin 20 immunoreactive cells were observed in all samples examined. These cells were identified as M cells as they co-expressed vimentin, a well-known marker of rabbit M cells, and they actively uptook particulate material. It is therefore possible to hypothesize the use of tonsil M cells as a possible site for antigen delivery of particle-based vaccines against oral pathogens.
authors.affiliation: Department of Pharmacology "Giorgio Segre ", Section of Anatomy, University of Siena, Siena, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Fonzi
authors.forename: A
authors.initials: A
authors.lastname: Masucci
authors.forename: A
authors.initials: A
authors.lastname: Gasparoni
authors.forename: E
authors.initials: E
authors.lastname: Bertelli
mesh_terms: D000818:Animals; D000941:Antigens / Q000276:immunology; D001428:Bacterial Vaccines / Q000008:administration & dosage; D015415:Biomarkers; D005455:Fluorescent Antibody Technique; D018928:Immunity, Mucosal; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins / Q000096:biosynthesis*; D053554:Keratin-20; D008297:Male; D018613:Microscopy, Confocal; D009061:Mouth Mucosa / Q000166:cytology* / Q000276:immunology; D014066:Palatine Tonsil / Q000166:cytology* / Q000276:immunology; D011817:Rabbits; D014746:Vimentin / Q000096:biosynthesis
chemical_list: D000941:Antigens; D001428:Bacterial Vaccines; D015415:Biomarkers; D007381:Intermediate Filament Proteins; D053554:Keratin-20; D014746:Vimentin