Figure 6

A2/NY-ESO-1₁₅₇ CAR- and BiTE-redirected T cells show sufficient functional avidity to induce anti-myeloma reactivity in vivo. (a) Functional avidities of A2/NY-ESO-1₁₅₇ CAR- and BiTE-redirected CD8⁺ T cells and CD4⁺ T cells were assessed using T2 cells pulsed with graded concentrations of NY-ESO-1₁₅₇ peptide as stimulator cells. Side-by-side experiments using similarly activated T cells derived from donor 1 as responder cells were performed. CAR- and BiTE-redirected T cells were incubated with target cells for 16 hours after adding BFA to measure IFN-γ production, and for 5 hours to examine target-specific lysis, respectively. % IFN-γ secreting ability (left, middle) and % killing activity (right) of CAR- and BiTE-redirected T cells are shown. The reactivity of responder cells against T2 cells pulsed with 10 μg/mL (IFN-γ) or 1 μg/mL (killing) NY-ESO-1₁₅₇ peptide is considered as 100%, and each reactivity is calculated relative to this value. The experiments were repeated twice, and representative data are shown. Error bars show the SD. (b) Two million U266/SLR cells were intravenously injected into NOG mice. After engraftment of U266/SLR cells had been confirmed by bioluminescence imaging assays on Day 11, 5.0 × 10⁶ CAR-T cells or control T cells were injected twice on Days 13 and 18 (top). Similarly activated bulk T cells were injected twice on Days 13 and 18 followed by intravenous injection of 10 μg A2/NY-ESO-1₁₅₇ BiTE or control BiTE on Days 13, 14, 18, and 19 (bottom). These experiments were performed side-by-side. Measured photon counts obtained from a mouse in both the prone and supine positions were aggregated, and calculated as arbitrary units for comparison between the groups. The experiments were repeated twice using distinct donor-derived T cells (donor 1), and representative data are displayed. Error bars indicate the SD. ****P < 0.0001; n.s., not significant.