Dock8^−/− DCs fail to activate T cells effectively in the draining LNs after subcutaneous injection. (A) Effect of DOCK8 deficiency on T-cell response 7 days after OVA immunization. The number of CD4⁺ T cells in the popliteal LNs (n = 3 mice per group) and their proliferative response to OVA were compared between Dock8^+/− and Dock8^−/− mice. (B) Serum concentrations of OVA-specific IgG1, IgG2a, IgG2b, and IgM were compared between Dock8^+/− and Dock8^−/− mice 14 days after immunization (n = 4 mice per group). (C-D) Effect of DOCK8 deficiency in donor T cells (C; n = 8 mice per group) or recipient mice (D; n = 6 mice per group) on proliferation and expansion of the OT-II–transgenic CD4⁺ T cells was analyzed 72 hours after OVA immunization. PBS was used as a control. (E) Effect of DOCK8 deficiency in BM-derived DCs on proliferation and expansion of the OT-II–transgenic CD4⁺ T cells was analyzed 72 hours after subcutaneous injection of OVA peptide–pulsed DCs (n = 6 mice per group). In panels C through E, the OT-II–transgenic CD4⁺ T cells were inoculated 24 hours before immunization or DC transfer. Data are expressed as means ± SD with representative flow cytometric profiles. *P < .05; **P < .01. Data are representative of 4 (A) or 2 (B) independent experiments, and are from 8 (C) or 6 (D-E) separate experiments.