title: Unusual stage-specific embryonic antigen (TEC-4) defined by a monoclonal antibody to embryonal carcinoma cells defective in the expression of embryoglycan.
abstract: Most developmentally regulated epitopes identified on embryonal carcinoma cells and murine preimplantation embryos are associated with a glycoprotein-bound large glycan called embryoglycan. To prepare monoclonal antibodies recognizing other, less immunogenic stage-specific embryonic epitopes, we used embryoglycan-negative embryonal carcinoma cells P19XT.1.1 as immunogen. One monoclonal antibody prepared by this strategy was found to react specifically with mouse embryonal carcinoma and embryo-derived stem cell lines. The target epitope, TEC-4, was found to be expressed on eggs and two-cell embryos but was undetectable on later stages of mouse embryos and adult mouse tissues. NaDodSO4/PAGE of immunoaffinity-isolated antigen revealed that TEC-4 epitope is associated with glycoproteins of apparent Mr 120,000 and 240,000. The epitope was resistant to oxidation by sodium periodate and to digestion by endoglycosidase F but was sensitive to treatment with protein-denaturing agents and proteases, which suggested that the epitope is located in the protein moiety of the molecule. In the course of retinoic acid-induced differentiation of embryonal carcinoma cells the epitope disappeared before the onset of morphological differentiation. The combined data indicate that TEC-4 is an unusual stage-specific embryonic antigen that may be amenable to direct genetic analysis.
authors.affiliation: Department of Developmental Genetics, Czechoslovak Academy of Sciences, Prague.
authors.forename: P
authors.initials: P
authors.lastname: Dráber
authors.forename: J
authors.initials: J
authors.lastname: Nosek
authors.forename: Z
authors.initials: Z
authors.lastname: Pokorná
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000302:isolation & purification*; D014408:Biomarkers, Tumor / Q000032:analysis; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D006017:Glycolipids / Q000235:genetics / Q000302:isolation & purification*; D016256:Lewis X Antigen; D051379:Mice; D008970:Molecular Weight; D011134:Polysaccharides / Q000235:genetics*; D013724:Teratoma / Q000276:immunology; D014212:Tretinoin / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000166:cytology* / Q000187:drug effects / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D006017:Glycolipids; D016256:Lewis X Antigen; D011134:Polysaccharides; C045474:embryoglycan; D014212:Tretinoin