Figure 3. T cells do not need CD25 expression to enter proliferation cycle if primed by CD25+ mDCs.
(a)
T cells derived from healthy donors were polyclonally activated and stained several times during the proliferation cycle for expression of CD25, CD122, and CD132 (open histograms) or the appropriate isotype controls (gray histograms) and served as positive control (left three histograms). T cells from an individual with genetic deletion of CD25 were activated and stained in parallel (right three histograms). Percentages are shown above the histograms. (b) Proliferation of CD25− CD4+ (pink; left panels) and CD8+ (blue; right panels) T cells derived from an individual with a genetic deletion of CD25 following co-incubation with Flu-HA-loaded HLA-matched CD25+ mDCs was measured by CFSE dilution after 7 d. Proliferation was inhibited when mDCs were treated with daclizumab prior to co-incubation (lower panels). Separate graphs (right panels) depict percentages and absolute numbers of CD4+ and CD8+ T cells from four replicas; *P < 0.05. Mean values are shown ± SD. (c) Cytokine production (IL-2, IFN-γ and IL-17) by proliferating CD25− CD4+ and CD8+ T cells following co-culture with CD25+ mDCs (upper panels) or mDCs pre-treated with daclizumab (lower panels).