Engineered CD20-specific primary human cytotoxic T lymphocytes for targeting B-cell malignancy.
BACKGROUND
Immunotherapy for B-cell lymphomas has evolved significantly with the advent of CD20-targeted Ab-based therapeutics. Strategies to invoke or augment cellular anti-lymphoma immune responses may also have considerable therapeutic potential and serve to further augment the clinical efficacy of MAbs.


METHODS
We report here the aquisition by priming human cytotoxic T lymphocyte (CTL) effectors of re-directed CD20 specificity by their genetic modification to express a chimeric immunoreceptor consisting of an anti-CD20 single chain Ab extracellular domain molecularly fused to the T-cell receptor complex CD3-zeta cytoplasmic tail (scFvFczeta). Peripheral blood-derived human T-cells were transduced with naked DNA plasmid vector by electoporation then selected for G418 resistance.


RESULTS
Following cloning in limiting dilution and ex vivo expansion to large numbers scFvFczeta+ TCRalpha/beta+ CD4- CD8+ CTL display re-directed HLA-unresricted CD20-specific lymphoma cell cytolysis proportional to the cell-surface density of the chimeric immunoreceptor. Engineered CTL clones are also activated through the chimeric immunoreceptor to produce Tc1 cytokines (IFN-gamma) upon co-culture with CD20+ lymphoma stimulator cells. Additionally, CD20-specific CTL proliferate in the presence of lymphoma stimulators and IL-2 (5 U/mL).


CONCLUSIONS
These studies provide the rationale for exploring the clinical utility of adoptive therapy with CD20-specific CTL as a component of immunotherapeutic targeting of CD20+ malignancy.
Division of Pediatric Hematology-Oncology, City of Hope National Medical Center and Beckman Research Institute, Duarte, CA 91010, USA.
M C
MC
Jensen
L J N
LJ
Cooper
A M
AM
Wu
S J
SJ
Forman
A
A
Raubitschek
D018951:Antigens, CD20 / Q000276:immunology*; D017252:CD3 Complex / Q000276:immunology; D002999:Clone Cells / Q000276:immunology; D005818:Genetic Engineering / Q000379:methods*; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D016393:Lymphoma, B-Cell / Q000276:immunology* / Q000628:therapy*; D011956:Receptors, Cell Surface / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000627:therapeutic use; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014407:Tumor Cells, Cultured
D018951:Antigens, CD20; D017252:CD3 Complex; C121704:CD3 antigen, zeta chain; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins