Production and characterization of a bispecific IgG capable of inducing T-cell-mediated lysis of malignant B cells

Abstract

Bispecific monoclonal antibodies (bsabs) recognizing both CD3 and a tumor antigen can redirect T-cell-mediated cytotoxicity toward cells bearing that antigen. Such bsabs have been shown to be more effective than monospecific monoclonal antibodies (MoAbs) at preventing tumor growth in animal models of B-cell malignancy. The current studies describe the production and preliminary evaluation of a bsab designed to induce the lysis of malignant human B cells by human T cells. The bsab was obtained from a hybrid-hybridoma cell line produced by fusing OKT3-secreting hybridoma cells with hybridoma cells that secrete 1D10. 1D10 is an MoAb that recognizes an antigen found on a majority of malignant human B cells that has not been detected to a significant degree on normal resting or activated lymphocytes. High performance liquid chromatography (HPLC) was used to separate bsab from monospecific antibodies that were also present in the hybrid-hybridoma antibody product. The bsab was then evaluated in vitro for its ability to induce lysis of malignant B cells by activated T cells. The bsab consistently induced extensive lysis in vitro of 1D10 (+) cells, including both cell lines and cells obtained from patients with a variety of B-cell malignancies. No such effect was seen with activated T cells alone or activated T cells with monospecific antibody. No increased lysis was seen with 1D10 (-) cell lines. The bsab also mediated lysis of malignant B cells by autologous T cells. We conclude bsab containing an OKT3 arm and a 1D10 arm can induce T-cell-mediated lysis in a manner that is both potent and specific. This supports further evaluation of this bsab as a potential immunotherapy of B-cell malignancy.

T cells, particularly activated CD4+ cells, maintain anti-CD20-mediated NK cell viability and antibody dependent cellular cytotoxicity

“…S7). Similar results were found following addition of a bispecific anti-HLA-DR/anti-CD3 monoclonal antibody developed in our laboratory [11] designated IDT3D (Fig. 6).…”

Anti-CD3-based bispecific antibody designed for therapy of human B-cell malignancy can induce T-cell activation by antigen-dependent and antigen-independent mechanisms

“…Production and purification of a murine bsIgG that reacts with 1D10 (ϩ) lymphoma cells and human CD3 have been described previously (Link and Weiner, 1993). Briefly, bsIgG was isolated from a hybrid-hybridoma produced by fusing cells that secrete 1D10 (murine IgG 1 -kappa) with cells that secrete OKT3 (murine IgG 2a -kappa).…”

“…1D10 also binds to normal peripheral blood B cells and monocytes from some individuals (data not shown). Previous studies demonstrated that bsIgG produced from a hybridhybridoma recognizing CD3 and the 1D10 antigen induces T-cellmediated lysis of fresh and cultured malignant B cells bearing the 1D10 antigen (Link and Weiner, 1993).…”

Molecular Cloning and Characterization of a Transmembrane Surface Antigen in Human Cells

“…Cloned antigens have been used to generate antibodies with higher affinities or with more useful effector functions, either through their use as immunogens (Chen et al, 1994) or as targets to reshape the antigen-binding site of the original antibody (Stenzel-Johnson et al, 1994), or to generate bispecific antibodies to redirect T-cell-mediated cytotoxicity towards tumor cells (Ferrini et al, 1991 ;Link and Weiner, 1993). Tumor-specific antigens can also be used as recombinant vaccines to prevent tumors in subjects at risk, or to arrest tumor growth in patients at early stages (Hareuveni et al, 1990;Lanzavecchia, 1993).…”