Antigen-independent and antigen-dependent methods to numerically expand CD19-specific CD8+ T cells

ObjectivePreclinical and clinical trials are investigating the potential of T cells genetically modified to express a first-generation CD19-specific chimeric antigen receptor (CAR), designated CD19R, for adoptive immunotherapy of B-lineage leukemias and lymphomas. Currently, our genetically modified CD19-specific CD8+ (CD19R+CD8+) T cells are expanded ex vivo using a rapid expansion protocol (REP) to clinically meaningful numbers after antigen-independent activation with anti-CD3ɛ and recombinant human interleukin-2 on a double-cell feeder-layer of γ-irradiated allogeneic peripheral blood mononuclear cells and a lymphoblastoid cell line. We now compare the ability of the REP with CD19-dependent numerical expansion using CD19+