The rabbit M-cell marker vimentin is present in epithelial cells of the tonsil crypt

The epithelium of the rabbit palatine tonsil was studied with vimentin immunohistochemistry, using cryosections and paraffin sections labelled with three monoclonal antibodies. Vimentin-positive epithelia[ cells were detected in crypt regions overlying lymphoid follicles but were absent from the surrounding stratified pharyngeal epithelium. The cells lay in close contact with intra-epithelial lymphocytes and their apical cytoplasm had a membranous shape. Since vimentin is a sensitive, specific marker for M-cells of the rabbit intestine, the present findings indicate that M-cells similar to those in the gut-associated lymphoid tissue occur in the tonsil.