CTL induction with peptide-pulsed and live rVV-infected DCs. (A) Comparison of EBNA-3A peptide-pulsed DCs with rVV-infected DCs. Live rVV-TK⁻ was used as negative control. (B) Comparion of monocytes and DCs as APCs in eliciting EBNA-3A–specific CTL responses in a 7-day culture assay. The top panel shows that rVV-EBNA-3A–infected DCs (DC:T cell ratio 1:30) stimulate T cells that recognize FLRGRAYGL- and FLRGRAYGI-pulsed HLA B8⁺ B-LCLs. The lower panel from the same experiment shows that rVV-EBNA-3A–infected monocytes (ER⁻:T-cell ratio 1:2) are unable to stimulate T cells that recognize FLRGRAYGL- or FLRGRAYGI-pulsed HLA B8⁺ B-LCLs. (C) Comparison of EBNA-3A peptide-pulsed DCs with PLWUV, rVV-EBNA-3A–infected DCs; PLWUV rVV-TK⁻ was used as a negative control. (D) Comparison of live versus PLWUV rVV-EBNA-3A–infected DCs. (E) Comparison of DCs infected with live influenza A or with live or PLWUV rVV-influenza-matrix in eliciting responses to the immunodominant matrix peptide for HLA-A2.1. In all of the experiments, the DC:T-cell ratio was 1:30, the effector T-cell:target cell ratio was 1:20, and no IL-2 was used.