title: Immunotherapy of human tumors with T-cell-activating bispecific antibodies: stimulation of cytotoxic pathways in vivo.
abstract: Bispecific monoclonal antibodies (Bi-mAbs) specific for a tumor-associated antigen and the CD3 or CD28 antigen on T lymphocytes represent one of the most successful experimental strategies for the immunotherapy of cancer. We report that the in vivo administration of both alpha-CD3/CD30 and alpha-CD28/CD30 Bi-mAbs results in the specific activation of xenotransplanted, resting human T cells infiltrating the CD30-positive Hodgkin's tumor. Bi-mAb treatment resulted in enhanced expression of cytokines such as interleukin 1beta, interleukin 2, tumor necrosis factor type alpha, and activation markers including Ki-67, CD25, and CD45RO in tumor-infiltrating lymphocytes. This antigen-dependent, local T-cell stimulation led to the activation of the cytolytic machinery in T lymphocytes, determined by the up-regulation of mRNA-encoding perforin and the cytotoxic serine-esterases granzymes A and B. The Bi-mAb-induced generation of CTLs depended on the presence of the CD30 antigen and the combined application of both Bi-mAbs. Our findings suggest that the combined application of T-cell-activating Bi-mAbs is able to achieve a tumor site-specific activation of the T-cell cytolytic machinery in vivo. The fact that these cytotoxic cells do not home in tumor-associated antigen-negative tissue and do not enter circulation might explain our previous observations (C. Renner et al., Blood, 87: 2930-2937, 1996) of a high cure rate in preclinical models even at an advanced stage of disease.
authors.affiliation: Medical Department I, Saarland University Medical School, Homburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Bauer
authors.forename: C
authors.initials: C
authors.lastname: Renner
authors.forename: J P
authors.initials: JP
authors.lastname: Juwana
authors.forename: G
authors.initials: G
authors.lastname: Held
authors.forename: S
authors.initials: S
authors.lastname: Ohnesorge
authors.forename: K
authors.initials: K
authors.lastname: Gerlach
authors.forename: M
authors.initials: M
authors.lastname: Pfreundschuh
mesh_terms: D000818:Animals; D018033:Antibodies, Bispecific / Q000627:therapeutic use*; D016207:Cytokines / Q000378:metabolism; D006801:Humans; D007167:Immunotherapy; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000276:immunology / Q000628:therapy*; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D012697:Serine Endopeptidases / Q000378:metabolism; D014407:Tumor Cells, Cultured; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000096:biosynthesis; D015854:Up-Regulation
chemical_list: D018033:Antibodies, Bispecific; D016207:Cytokines; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D054353:Perforin; D012697:Serine Endopeptidases