title: Expression of the APO-1 antigen in Burkitt lymphoma cell lines correlates with a shift towards a lymphoblastoid phenotype.
abstract: APO-1 is a cell surface molecule that induces apoptosis when ligated with the monoclonal antibody anti-APO-1. Expression of APO-1 and response to anti-APO-1 was investigated in a number of Epstein-Barr virus (EBV)-positive and -negative Burkitt lymphoma (BL) cell lines, in EBV-immortalized lymphoblastoid cell lines, and in cells from fresh BL biopsies. APO-1 was not expressed in EBV-negative cell lines and in EBV-positive BL cell lines with a phenotype corresponding to BL tumor biopsy cells (CD10+, CD21-, CD23-, CD30-, CD39-, CDw70-, CD77+). Accordingly, fresh BL cells obtained from three BL biopsies were APO-1 negative. EBV-positive BL cell lines that had acquired a lymphoblastoid phenotype (CD10-, CD21+, CD23+, CD30+, CD39+, CDw70+, CD77-) upon prolonged in vitro cultivation, as well as normal B-lymphoblastoid cell lines, expressed a high density of APO-1. APO-1 may, therefore, be regarded as a B-cell activation marker. APO-1 expression is not the only prerequisite for anti-APO-1-induced apoptosis because 6 of 7 APO-1-expressing EBV-positive BL cell lines were not sensitive to anti-APO-1, whereas all lymphoblastoid cell lines were killed by anti-APO-1. The sensitivity of lymphoblastoid cell lines to anti-APO-1-mediated apoptosis may open a new therapeutic approach for the treatment of EBV-induced lymphoproliferative lesions in immunocompromised individuals, because these are composed of cells with a lymphoblastoid phenotype.
authors.affiliation: Institut für Klinische Molekularbiologie und Tumorgenetik, GSF, München, Germany.
authors.forename: M H
authors.initials: MH
authors.lastname: Falk
authors.forename: B C
authors.initials: BC
authors.lastname: Trauth
authors.forename: K M
authors.initials: KM
authors.lastname: Debatin
authors.forename: C
authors.initials: C
authors.lastname: Klas
authors.forename: C D
authors.initials: CD
authors.lastname: Gregory
authors.forename: A B
authors.initials: AB
authors.lastname: Rickinson
authors.forename: A
authors.initials: A
authors.lastname: Calender
authors.forename: G M
authors.initials: GM
authors.lastname: Lenoir
authors.forename: J W
authors.initials: JW
authors.lastname: Ellwart
authors.forename: P H
authors.initials: PH
authors.lastname: Krammer
mesh_terms: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000032:analysis*; D000954:Antigens, Surface / Q000032:analysis*; D015153:Blotting, Western; D002051:Burkitt Lymphoma / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D002455:Cell Division; D005455:Fluorescent Antibody Technique; D004854:Herpesvirus 4, Human; D006801:Humans; D016130:Immunophenotyping; D008214:Lymphocytes / Q000473:pathology*; D014407:Tumor Cells, Cultured; D019014:fas Receptor
chemical_list: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D019014:fas Receptor