title: In vitro antitumoral activity of baculovirus-expressed chimeric recombinant anti-CD4 antibody 13B8.2 on T-cell lymphomas.
abstract: A baculovirus-expressed chimeric recombinant IgG1 (rIgG1) antibody, with Cgamma1 and Ckappa human constant domains, was derived from the murine monoclonal antibody 13B8.2, which is specific for the CDR3-like loop of the CD4 molecule. The recombinant IgG1 antibody 13B8.2 was previously shown to inhibit HIV-1 replication and to abrogate the one-way mixed-lymphocyte reaction and block proliferation of CD3-stimulated peripheral blood CD4 lymphocytes from healthy donors. Before testing this recombinant anti-CD4 antibody in in vivo preclinical trials, in vitro mechanisms of action of rIgG1 13B8.2 were assessed using various CD4 T-cell lymphomas. The baculovirus-expressed rIgG1 13B8.2 antibody led to 14% to 40% proliferation inhibition of the lymphoblastic leukaemia-derived SUP-T1, the acute T lymphoma-derived CCRF-CEM and Jurkat, and the cutaneous T-Cell lymphoma-derived HUT-78 cell lines, but it did not affect the cell cycle nor induce cell apoptosis. rIgG1 antibody 13B8.2 bound the C1q fraction, leading to 9% to 17% complement-mediated lysis of the HUT-78, H9, Sup-T1, and the CCRF-CEM cell lines. No correlation was observed between cell sensitivity to rIgG1 13B8.2-triggered complement-dependent lysis and CD35-, CD46-, CD55-, and CD59-surface expression on T lymphoma cells. Using fluorescence-activated cell sorter analysis, the antibody was shown to bind to FcgammaRI/CD64-transfected IIA1.6, FcgammaRII/CD32-transfected CDw32L, and FcgammaRIII/CD16-transfected Jurkat CD16 cell lines. In correlation with these findings, rIgG1 13B8.2 induced 11% to 31% antibody-dependent cell-mediated cytotoxicity of the CCRF-CEM, SUP-T1, A2.01 CD4, and Jurkat cell lines. These convincing results on the activity of the recombinant chimeric anti-CD4 antibody 13B8.2 have led us to perform in vivo preclinical study in a murine xenograft model of CD4 lymphomas.
authors.affiliation: CNRS UMR 5160, Centre de Pharmacologie et Biotechnologie pour la Santé, Faculté de Pharmacie, Montpellier, France.
authors.forename: Samuel
authors.initials: S
authors.lastname: Troadec
authors.forename: Myriam
authors.initials: M
authors.lastname: Chentouf
authors.forename: Martine
authors.initials: M
authors.lastname: Cérutti
authors.forename: Brigitte
authors.initials: B
authors.lastname: Nguyen
authors.forename: Daniel
authors.initials: D
authors.lastname: Olive
authors.forename: Cédric
authors.initials: C
authors.lastname: Bès
authors.forename: Thierry
authors.initials: T
authors.lastname: Chardès
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000494:pharmacology*; D000920:Antibody-Dependent Cell Cytotoxicity / Q000276:immunology; D017209:Apoptosis; D016367:Baculoviridae / Q000235:genetics; D015704:CD4 Antigens / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000737:chemistry; D049109:Cell Proliferation / Q000187:drug effects; D015922:Complement C1q / Q000276:immunology*; D006801:Humans; D016399:Lymphoma, T-Cell / Q000276:immunology*; D051379:Mice; D017452:Receptors, IgG / Q000276:immunology
chemical_list: C110023:13B8-2 monoclonal antibody; D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D017452:Receptors, IgG; D015922:Complement C1q