Epithelial heterogeneity in the murine thymus: fucose-specific lectins bind medullary epithelial cells.
By means of histochemical techniques, two lectins with nominal specificity for L-fucose, Tetragonolobus purpureas agglutinin (TPA), and Ulex europeus agglutinin (UEA) were found to specifically label the medullary area of murine thymuses. Although the binding of both lectins was restricted to the medullary area of the thymus, each staining pattern was unique. Cells binding UEA formed a reticular network throughout the medulla, whereas cells binding TPA occurred as single cells or small clumps of cells and resembled Hassall's corpuscles. The cells binding either lectin were identified as epithelial on the basis of ultrastructural features (tonofilaments, desmosomes, and keratohyalin bodies) and resembled Ia+ medullary epithelial cells described previously. An age-related decline in UEA binding was observed, whereas labeling with TPA remained unchanged. On the basis of the labeling patterns obtained with UEA and TPA and the reported specificities of these two lectins, it is suggested that the majority of the fucose detected is associated with type 1 carbohydrate chains.
D000375:Aging; D000818:Animals; D001667:Binding, Competitive; D050260:Carbohydrate Metabolism; D004848:Epithelium / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D005643:Fucose / Q000378:metabolism*; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D037102:Lectins / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D037121:Plant Lectins; D013950:Thymus Gland / Q000166:cytology* / Q000378:metabolism / Q000502:physiology
D000949:Histocompatibility Antigens Class II; D037102:Lectins; D037121:Plant Lectins; C036850:Ulex europaeus lectins; C027112:fucose-binding lectin; D005643:Fucose