A. CAR T cell potency was evaluated via co-culture killing assay, anti-CD19 T cells were cultured with target cancer cells (NALM6 or MV-4-11). Samples were then analyzed by flow cytometry. NALM6, MV-4-11, and T cells were identified with monoclonal antibodies (mAb) specific for their surface proteins and cell survival was identified using viability dye.
B. Histograms show MV-4-11 (control) has no CD19 expression in contrast to NALM6 cells. Expression levels were determined in the absence (-) or presence (+) of an anti-CD19 mAb.
C. Target and T cell populations from NALM6 cell killing assay were identified by analyzing CD19 and CD3 expression, and total target cells were counted. Engineered CAR T cells are highly potent and effectively killed target cells. 0:1 – 0 T cells for 1 target cell, 2:1 – 2 T
cells for 1 target cell.
D. Results from MV-4-11 killing assay. CAR T cells are specific. Negligible cell death was observed when engineered T cells were cultured with MV-4-11 cells (no CD-19 expression). Data is representative of triplicate wells for each T cell: Target cell ratio.
E. CAR T cell cytokine production was determined using an INF-γ ELISA when T cells were co-culutred with NALM6 target cells.