Efficient antigen cross-presentation by TLR-stimulated mDC. DC subsets obtained from HLA-A2⁺ donors were cocultured for 20 hours with HLA-A2 pp65-specific CD8⁺ T cells with recombinant soluble CMV pp65 protein in the absence (−) or presence of TLR agonists (A) or CD40L transfectants (B). Shown is the percentage of IFN-γ production by CD8⁺ T cells normalized on IFN-γ production in response to pp65_495-503 peptide. Data are from 7 donors that were analyzed in 4 experiments. Primary data of 1 representative experiment is shown in supplemental Figure 3. (C) A total of 5 × 10⁴ CFSE-labeled CD8⁺ T cells with or without 5 × 10⁴ autologous CD4⁺ T cells were incubated with autologous purified DC subsets in the presence of CMV-derived proteins and the fraction of proliferating CD8⁺ T cells analyzed. Shown are results of 10 HCMV⁺ donors in different experiments. ns, not significant. *P < .05; **P < .005; ***P < .0005.