title: A tumor vaccine containing anti-CD3 and anti-CD28 bispecific antibodies triggers strong and durable antitumor activity in human lymphocytes.
abstract: We recently reported on newly designed virus-targeted bispecific CD3- and CD28-binding molecules for human T-cell activation. When bound via one arm to a human virus-modified tumor cell vaccine, these reagents caused a polyclonal T-cell response and overcame the potential various T-cell evasion mechanisms of tumor cells. In our current study, we demonstrated the induction of strong antitumor activity in human lymphocytes upon coincubation with a virus-modified tumor vaccine containing anti-CD3 and anti-CD28 bispecific antibodies. Blood mononuclear cells or purified T cells that were coincubated with such a tumor vaccine for 3 days were able to destroy monolayers of human breast carcinoma and other carcinoma cells. Serial transfer to new tumor cell monolayers revealed antitumor cytotoxic activity in such effector cells that lasted for about 10 days. Nontumor target cells appeared to be much less sensitive to the activated effector cells. Although the bispecific molecules alone did not activate effector cells, their binding to virus-infected tumor cells was important and more effective than their binding to free virus. Antitumor activity of the activated effector cells was mediated through soluble factors as well as through direct cell contact of effector cells with the nontargeted bystander tumor cells. Since the virus-modified tumor vaccine is well tolerated and already exhibits a certain effectiveness in cancer patients, the combination with new bispecific molecules has the potential to introduce additional antitumor effects. The reagents can also be combined with Newcastle Disease Virus (NDV)-based oncolytic virotherapy.
authors.affiliation: German Cancer Research Center, Division of Cellular Immunology, Heidelberg, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Haas
authors.forename: Maria
authors.initials: M
authors.lastname: Lulei
authors.forename: Philippe
authors.initials: P
authors.lastname: Fournier
authors.forename: Annette
authors.initials: A
authors.lastname: Arnold
authors.forename: Volker
authors.initials: V
authors.lastname: Schirrmacher
mesh_terms: D018033:Antibodies, Bispecific / Q000276:immunology*; D001943:Breast Neoplasms / Q000276:immunology* / Q000628:therapy; D018106:CD28 Antigens / Q000276:immunology*; D017252:CD3 Complex / Q000276:immunology*; D019496:Cancer Vaccines; D049109:Cell Proliferation; D005260:Female; D006801:Humans; D006825:Hybridomas; D016130:Immunophenotyping; D007167:Immunotherapy; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D013601:T-Lymphocytes / Q000276:immunology*; D014407:Tumor Cells, Cultured
chemical_list: D018033:Antibodies, Bispecific; D018106:CD28 Antigens; D017252:CD3 Complex; D019496:Cancer Vaccines