Monocytes and imDCs pulsed with recombinant IE1 protein and differentiated and/or matured to mDCs similarly restimulate HCMV-specific T-lymphocyte expansion, while only antigen-loaded mDCs induce cytokine expression in preexpanded T lymphocytes. (A) Surface marker expression during differentiation of monocytes (mono; day 0) to imDCs (day 5) and maturation to mDCs (day 8); 1 of 4 similar experiments is shown. (B) Restimulation of HLA-A*03⁺ HCMV-specific CD8⁺ T lymphocytes during incubation for 12 days with either IE1 pulsed monocytes or imDCs that were differentiated to mDCs (mono + IE1 and imDC + IE1, respectively) (means ± 95% confidence interval [CI], n = 4). **P ≤ .03, 2-tailed Mann-Whitney U test. (C) IL-2 and TNF-α expression of preexpanded HCMV⁺ T lymphocytes derived from HLA-A02:01⁺ donors cocultured with pp65-pulsed autologous monocytes or mDCs (means ± 95% CI, n = 3). Preexpanded T cells were additionally incubated with anti-CD28 antibody plus a crosslinking antibody (costim) to mimic costimulation. **P ≤ .005; *P ≤ .05; Kruskal-Wallis test with Dunn’s correction for multiple comparison.