Figure 4.

Evaluation of an inducible anchored murine IL-12 construct in vitro. (A) Schematic representation of retroviral vector inserts for murine IL-12 constructs. (B) Human T cells were transduced with the vectors in (A) and cell membrane expression of IL-12 was determined by flow cytometry. Gating is on live cells. Cells were stimulated with PMA/ionomycin overnight as indicated to the left of each row. The frequency of IL-12⁺ cells, and the geometric mean of the fluorescence intensity of IL-12 for each group is indicated on each histogram. (C) Transduced T cells (1×10⁶) were stimulated by PMA/ionomycin and cultured in 1 mL of culture medium overnight, and supernatant IL-12 concentration was determined with an ELISA. caIL-12, constitutive anchored interleukin-12; iaIL-12, inducible anchored interleukin-12; IL-12, interleukin-12; LTR, long-terminal repeat; NFAT, nuclear factor of activated T cells; PMA, phorbol12-myristate 13-acetate.