Anti-CD3 preconditioning down-regulated CCR7 expression by CD103⁺ DCs in intestine LP and MLN, and this effect required anti-CD3 activation of host T cells. (A) Nine days after anti-CD3 preconditioning, CD11c⁺ DCs from LP, MLN, and spleen of the BALB/c mice with or without preconditioning were analyzed with flow cytometry. The gated CD11c⁺ DCs are shown in CD103 versus CCR7. The percentage of CCR7⁺CD103⁺ or CCR7⁻CD103⁺ cells among total DCs is shown next to the gating boxes. One representative of 4 replicate experiments is shown. The mean plus or minus SE of the percentage of total CD103⁺ DCs among total CD11c⁺ DCs in different tissues before and after anti-CD3 preconditioning is 85.4 (± 2.9) versus 72.9 (± 6.5), LP; 57.2 (± 1.8) versus 8.4 (± 0.8), MLN; and 7.1 (± 0.8) versus 28.9 (± 3.1), spleen. (B) Mean plus or minus SE of CCR7⁺ cells among CD103⁺ DCs. (C) Mean plus or minus SE of CCR7 expression level (mean fluorescence) by CD103⁺ DCs. (D) T cell–deficient Nu/Nu mice and IFN-γ^−/− mice as well as wild-type mice were preconditioned with anti-CD3 or PBS. Nine days later, the MLN cells were enriched with CD11c⁺ DCs, and the percentage of CD103⁺ DCs among total CD11c⁺ DCs was measured. One representative of 4 examined mice in each group is shown. (E) Mean plus or minus SE of the percentage of CD103⁺ DCs in MLN of 4 recipients with or without anti-CD3 preconditioning.