FACS analysis of rVV-infected mature DCs. (A) The top row shows staining for VV1-6B6 early vaccinia protein in uninfected, PLWUV rVV-TK⁻ and live rVV-TK⁻-infected DCs at an MOI of 2:1. The lower row shows comparable staining for CD25 and CD83, 2 markers for DC maturation, on uninfected DCs (···), PLWUV rVV-infected DCs (—-), and rVV-infected DCs (—). (B) rVV-infected DCs stimulate T-cell proliferative responses in the MLR. Bulk T cells were used as responders towards graded doses of allogeneic DCs that were uninfected or infected with rVV-TK⁻ and PLWUV rVV-TK⁻. Cultures were pulsed on day 5 for 8 hours with 4 μCi/mL of ³H-TdR. Results are the means of triplicates (mean cpm).