Effect of CD40 ligation and role of adhesion molecules in transgenic expression by mature DCs. (A) Blockade of CD11a, CD18, CD54, CD102, or DC-SIGN significantly inhibited transgene expression by mature DCs. No inhibition was detected after blocking CD11b (P > .05). Transgene expression by mature DCs transfected and cultured with irrelevant IgGs or IgMs were included as controls. Means ± 1 SD from 10 independent experiments are shown. (B-C) Coculture of naive or memory CD4⁺ T cells with transfected mature DCs increases transgene expression. (B) Coculture of naive or memory CD4⁺ T cells with mature DCs increased transgene expression by mature DCs up to 4-fold compared with transfected mature DCs in medium alone (P > .0001). (C) Specific blockade of CD18, DC-SIGN, and CD40 ligand (CD40L) significantly inhibited the expression of transgenic luciferase (P < .0001). Means ± 1 SD from 5 independent experiments are shown.