title: Role of perforin, granzymes and the proliferative state of the target cells in apoptosis and necrosis mediated by bispecific-antibody-activated cytotoxic T cells.
abstract: Bispecific monoclonal antibodies (bi-mAb), directed against a tumor-associated antigen and the CD3 or CD28 antigen on T lymphocytes, induce activation of resting T lymphocytes and target-specific tumor cell lysis. We now show that both necrosis and apoptosis contribute to T-cell-mediated tumor cell destruction. Even though T cells up-regulate FAS/APO-1 expression upon bi-mAb stimulation, FAS/APO-1-mediated apoptosis does not contribute to bi-mAb-mediated destruction of Hodgkin's cells. CD8+ lymphocytes were the most potent effectors of bi-mAb-mediated cytotoxicity and had the highest levels of mRNA coding for perforin and granzyme A and B. Ca2+-complexing agents, which abrogate perforin activity, led to decreased levels of necrosis, while inhibition of granzyme activity in effector or target cells had a similar effect on apoptosis. Granzyme-mediated apoptosis critically dependent on the proliferative state of the target cells, while perforin-induced necrosis was not cell-cycle-dependent. Our results underline the importance of the expression levels of perforin and granzymes in the effector T cells and of the proliferative state of the target cells in bi-mAb-mediated apoptosis and necrosis of tumor cells.
authors.affiliation: Med. Klinik I, Universität des Saarlandes, Homburg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Renner
authors.forename: G
authors.initials: G
authors.lastname: Held
authors.forename: S
authors.initials: S
authors.lastname: Ohnesorge
authors.forename: S
authors.initials: S
authors.lastname: Bauer
authors.forename: K
authors.initials: K
authors.lastname: Gerlach
authors.forename: J P
authors.initials: JP
authors.lastname: Pfitzenmeier
authors.forename: M
authors.initials: M
authors.lastname: Pfreundschuh
mesh_terms: D018033:Antibodies, Bispecific / Q000276:immunology*; D000920:Antibody-Dependent Cell Cytotoxicity / Q000276:immunology*; D015703:Antigens, CD / Q000276:immunology; D017209:Apoptosis; D015152:Blotting, Northern; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D053938:DNA Fragmentation; D053804:Granzymes; D006689:Hodgkin Disease / Q000473:pathology; D006801:Humans; D008213:Lymphocyte Activation / Q000502:physiology; D008562:Membrane Glycoproteins / Q000502:physiology*; D009336:Necrosis; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D012697:Serine Endopeptidases / Q000502:physiology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D019014:fas Receptor / Q000502:physiology
chemical_list: D018033:Antibodies, Bispecific; D015703:Antigens, CD; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D019014:fas Receptor; D054353:Perforin; C509213:GZMB protein, human; D053804:Granzymes; D012697:Serine Endopeptidases; C509212:GZMA protein, human