LV modification of DC immune functions. (A) Diagram of LV constructs containinging different immune modulatory genes. (B) Up-regulation of T cell costimulators in DCs transduced with LV-CD80 or LV-CD86. Immature DCs were transduced with mock, LV-PLAP, LV-CD80, or LV-CD86 for 12 hr, induced to mature, and analyzed 24 hr later using anti-CD80 and anti-CD86 antibodies. The mean fluorescence intensity and percentage of positive cells are shown. (C) Th1/Th2 assay of DCs with up-regulated CD80 or CD86. The T-cell activation function of DCs was analyzed by DC:T cell co-culture. ICCS and FACS for T helper function were performed 8 days after co-culture. The percentages of different T-cell populations are shown. (D) Th1/Th2 assay of DCs co-transduced with different LV immune modulatory genes. DCs were transduced with LV (LV-PLAP), and co-transduced with LVs encoding different immune modulatory genes, including IL-12, CD40L, IFN-γ, FL, GM-CSF, and ICAM-1, or incubated with soluble IFN-γ. DCs were then treated with TNF-α and LPS and co-cultured with naïve CD4 T cells. The T cells were analyzed for IL-4 and IFN-γ expression by ICCS and FACS 9 days after co-culture. The percentages of different T cell populations are shown in the quadrants. The results are representative of six independent experiments.