Cellular immunotherapy for follicular lymphoma using genetically modified CD20-specific CD8+ cytotoxic T lymphocytes.

Publication Type:

Journal Article

Source:

Molecular therapy : the journal of the American Society of Gene Therapy, Volume 9, Issue 4, p.577-86 (2004)

Keywords:

Antigens, CD20, Antigens, CD3, Blotting, Southern, Blotting, Western, Caspases, CD8-Positive T-Lymphocytes, Cell Line, Tumor, Cell Membrane, Cells, Cultured, Chromium, Cloning, Molecular, Electroporation, Gene Transfer Techniques, Genetic Therapy, Humans, IMMUNOTHERAPY, Interleukin-2, Kanamycin Kinase, Lymph Nodes, Lymphoma, Lymphoma, Follicular, Plasmids, Receptors, Antigen, T-Cell, T-Lymphocytes, Time Factors, Transfection, Transgenes

Abstract:

Humoral immunotherapy using the monoclonal anti-CD20 antibody rituximab induces remissions in approximately 60% of patients with relapsed follicular lymphoma; however, most patients eventually relapse despite continued expression of CD20 on lymphoma cells. We have hypothesized that cellular immunotherapy targeting CD20(+) cells might provide a more effective mechanism for eliminating lymphoma cells than anti-CD20 antibodies and are therefore investigating the utility of cytotoxic T lymphocytes (CTL) genetically modified to target the CD20 antigen. Peripheral blood mononuclear cells were activated with anti-CD3 antibody (OKT3) and recombinant human interleukin-2 and electroporated with a plasmid containing a CD20-specific scFvFc:zeta chimeric T cell receptor gene and a neomycin phosphotransferase gene (neo(R)). Transfected cells were selected using the antibiotic G418 and cloned by limiting dilution. Using this approach, we have generated CD8(+) CTL clones with CD20-specific cytotoxicity, which specifically lysed CD20(+) target cells, including actual tumor cells from patients with follicular lymphoma, small lymphocytic lymphoma, splenic marginal zone lymphoma, diffuse large B cell lymphoma, and chronic lymphocytic leukemia. The CTL clones have been expanded to numbers sufficient for therapy ( approximately 10(9) cells). Our data indicate the feasibility of generating and expanding CD20-specific CTL and, for the first time, demonstrate that such CTL exhibit specific cytotoxicity against actual tumor cells isolated from patients with a variety of B lymphoid malignancies. In view of these promising findings, a Phase I clinical trial for relapsed follicular lymphoma is being initiated.