Figure 5.

CD28-ζ and CD28-ζ–OX40 CAR redirect CD56⁺ and CD56⁻ CIK cells with similar efficiency. (a) Rag^−/− common γ-chain^−/− mice were coinjected with CEA⁺ C15A3 tumor cells (1 × 10⁶ cells/mouse) and sorted cytokine-induced killer (CIK) cells with or without CAR (2.5 × 10⁵ cells/mouse; 5–7 animals/group). Tumor volume was recorded every 2–3 days. Mean values are shown; area under the curve (AUC) was calculated and P values were determined using Student's t-test. (b,c) Cryosections of explanted tumors were stained with an Alexa-Fluor 488 conjugated antihuman CD3 monoclonal antibody (mAb) and analyzed by confocal microscopy as described in Materials and Methods. (b) A representative tissue section of a tumor treated with CD28-ζ CAR CIK cells is shown. (c) The numbers of CD3⁺ T cells in the tumor tissue were determined as described in Material and Methods. P values were determined using Student's t-test. CAR, chimeric antigen receptor; CEA, carcinoembryonic antigen.