Allogeneic DC persistence in situ correlates with an enhanced Th2 priming. (A) WT or CD8^–/– B6 mice were injected subcutaneously with 2 × 10⁶ CB6F1 DCs. The kinetics of IL-4 and IFN-γ mRNA expression were performed on CD4⁺ T cells purified from draining lymph nodes at the indicated times. (B) Six days after immunization, purified CD4⁺ T cells (2 × 10⁵ cells/well) from pooled lymph node cells (LNCs) (3 mice per group) were stimulated with irradiated BALB/c splenocytes for 72 hours to measure proliferation and cytokine production. Results are expressed as mean plus or minus SEM of triplicate cultures. (C) To evaluate the frequency of ex vivo IL-4–producing cells, purified CD4 T cells were cultured for 8 hours with T-cell–depleted BALB/c splenocytes in the presence of anti-CD28 mAb. Intracytoplasmic staining for cytokines was then performed as indicated in “Materials and methods.” Percentages of CD69^pos CD4 T cells producing IL-4 are mentioned. Data are from 1 representative experiment of 3 performed.