title: EBV B lymphoma cell lines from patients with post-transplant lymphoproliferative disease are resistant to TRAIL-induced apoptosis.
abstract: Lymphomas associated with post-transplant lymphoproliferative disease (PTLD) represent a significant complication of immunosuppression in transplant recipients. In immunocompetent individuals, EBV-specific cytotoxic T lymphocytes (CTL) prevent the outgrowth of activated B lymphoblasts through apoptosis induction. Soluble versions of TNF-related apoptosis-inducing ligand/Apo2 ligand (TRAIL) can induce apoptosis in numerous tumor cell types. Given the therapeutic potential of TRAIL, we examined the sensitivity of EBV+ spontaneous lymphoblastoid cell lines (SLCL) derived from patients with PTLD to treatment with soluble TRAIL. Despite abundant expression of TRAIL receptors (TRAIL-R), resistance to TRAIL-induced apoptosis was observed in all SLCL examined. This resistance could not be overcome by concomitant treatment with several pharmacological agents. Unlike BJAB positive control cells, for each SLCL tested, cleavage and activation of caspase 8 was inhibited due to failed recruitment of FADD and caspase 8 to TRAIL receptors upon stimulation. Further indicative of a proximal defect, TRAIL receptor aggregation could not be detected on the cell surface of SLCL following ligand engagement. These results suggest that the use of TRAIL for eliminating PTLD-associated tumors may be of limited clinical utility, and illustrate another mechanism by which EBV+ B lymphoma cells can evade tumor surveillance at the level of death receptor signaling.
authors.affiliation: Program in Immunology, Department of Surgery, Stanford University School of Medicine, Stanford, California 94305-5492, USA.
authors.forename: A L
authors.initials: AL
authors.lastname: Snow
authors.forename: M
authors.initials: M
authors.lastname: Vaysberg
authors.forename: S M
authors.initials: SM
authors.lastname: Krams
authors.forename: O M
authors.initials: OM
authors.lastname: Martinez
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000627:therapeutic use; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins / Q000494:pharmacology*; D045744:Cell Line, Tumor; D003520:Cyclophosphamide / Q000008:administration & dosage; D004317:Doxorubicin / Q000008:administration & dosage; D020031:Epstein-Barr Virus Infections / Q000453:epidemiology*; D005434:Flow Cytometry; D004854:Herpesvirus 4, Human / Q000302:isolation & purification*; D006801:Humans; D016393:Lymphoma, B-Cell / Q000209:etiology / Q000473:pathology / Q000821:virology*; D008232:Lymphoproliferative Disorders / Q000150:complications*; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D011241:Prednisone / Q000008:administration & dosage; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D014750:Vincristine / Q000008:administration & dosage
chemical_list: D051017:Apoptosis Regulatory Proteins; D008562:Membrane Glycoproteins; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D014750:Vincristine; D004317:Doxorubicin; D003520:Cyclophosphamide; D011241:Prednisone