title: Carcinoembryonic antigen, a tumor-associated glycoprotein induces defective lymphocyte function.
abstract: Standard carcinoembryonic antigen(s) (CEA) obtained commercially, and CEA preparations from cell membranes and spent media of cultured human malignant melanotic melanoma (HMMC-ShAc and HMMC-ShAm) and of human colon adenocarcinomas (Levo c, Levo m, SW-403 c and SW-403 m) suppressed human peripheral blood lymphocyte (PBL). CEA preparations obtained from products of in vitro synthesis mediated by mRNA coding for CEA enhanced, whereas glycosylation-deficient preparations of CEA obtained from tumor cells harvested from growth media supplemented with nontoxic levels, i.e. 0.3 microgram/ml of tunicamycin, had no effect on immunoglobulin synthesis by human PBL. CEA caused defective lymphocyte: sheep red blood cell rosette production. It is suggested that CEA is an immunoregulatory glycoprotein synthesized by human tumor cells. The carbohydrate moiety of the glycoprotein is the regulatory determinant.
mesh_terms: D002272:Carcinoembryonic Antigen / Q000235:genetics / Q000276:immunology*; D002460:Cell Line; D002478:Cells, Cultured; D006801:Humans; D008214:Lymphocytes / Q000276:immunology*; D008545:Melanoma / Q000276:immunology; D012333:RNA, Messenger / Q000235:genetics; D012397:Rosette Formation; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D002272:Carcinoembryonic Antigen; D012333:RNA, Messenger