title: Characterization of the carcinoma-associated Tk antigen in helminth parasites.
abstract: Expression of Tk antigen, a truncated carbohydrate antigen, was examined in helmith parasites. Using the monoclonal antibody LM389, this antigen was detected in extracts from Taenia hydatigena, Mesocestoides vogae (syn corti), and Taenia crassiceps. No reactivity was observed in Thysanosoma spp., Dipylidium caninum, Fasciola hepatica, and Nyppostrongylus brasiliensis. On the basis of their electrophoretic mobility, different patterns of Tk-bearing glycoproteins were observed among T. hydatigena, M. corti and T. crassiceps by immunoblotting, with certain components resolved as broad bands typical of mucin-like glycoproteins. Most Tk-reactive material remained in the 0.6 N perchloric acid-soluble fraction, confirming that Tk epitopes are carried by mucin-type glycoproteins. Immunohistochemical analysis revealed that in T. hydatigena, Tk antigen is mainly expressed in the tegument, whereas in M. corti the reactivity was principally observed in the subtegumental parenchyma. The presence of a novel tumor-associated carbohydrate antigen in invertebrates, contributes to strengthen the notion that truncated mucin-type O-glycosylation is a normal phenomenon in parasitic worms and may help identify new biological characteristics of helminth parasites.
authors.affiliation: Depto. de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.
authors.forename: Luis
authors.initials: L
authors.lastname: Ubillos
authors.forename: Andrea
authors.initials: A
authors.lastname: Medeiros
authors.forename: Martín
authors.initials: M
authors.lastname: Cancela
authors.forename: Cecilia
authors.initials: C
authors.lastname: Casaravilla
authors.forename: Jenny
authors.initials: J
authors.lastname: Saldaña
authors.forename: Laura
authors.initials: L
authors.lastname: Domínguez
authors.forename: Carlos
authors.initials: C
authors.lastname: Carmona
authors.forename: Jacques
authors.initials: J
authors.lastname: Le Pendu
authors.forename: Eduardo
authors.initials: E
authors.lastname: Osinaga
mesh_terms: D000818:Animals; D000947:Antigens, Helminth / Q000032:analysis* / Q000737:chemistry; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000032:analysis* / Q000737:chemistry; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis / Q000737:chemistry; D005455:Fluorescent Antibody Technique; D006376:Helminths / Q000276:immunology*; D007150:Immunohistochemistry; D010472:Perchlorates / Q000737:chemistry; D012995:Solubility
chemical_list: D000947:Antigens, Helminth; D015295:Antigens, Tumor-Associated, Carbohydrate; D000939:Epitopes; D010472:Perchlorates