Figure 5.

CCR5-dependent homing of CD4⁺CD25⁺ regulatory T cells to infected dermal sites. Naive CD4⁺CD25⁺ T cells from Ly5.1 WT or Ly5.2 CCR5^−/− C57BL/6 mice and CD4⁺CD25⁻ T cells from Ly5.1 WT or Ly5.2 WT C57BL/6 mice were purified and coinjected i.v. at a ratio of 1 CD4⁺CD25⁺ for 10 CD4⁺CD25⁻ (3 × 10⁴/3 × 10⁵) into RAG2^−/− mice 1 d before i.d. infection with L. major. (A) Percentage of WT (Ly5.1⁺) or CCR5^−/− (Ly5.2⁺) CD4⁺ nTreg cells in the infected ear 3 wk after infection. Values represent the mean of four to six ears. The numbers represent the percentage of positive events in the quadrant. (B) Percentage of WT or CCR5^−/− nTreg cells in the skin, LN, and spleen during the course of the infection. Single cell suspensions from each tissue of individual mice were extracted and stained with anti–TCRβ chain, anti-CD4, and anti-Ly5.2/Ly5.1 antibodies. Percentage of Ly5.2⁺/Ly5.1⁺ cells (nTreg) was calculated on TCRβ⁺CD4⁺ gated events. (C) Absolute numbers of WT or CCR5^−/− nTreg cells in the skin, LN, and spleen during the course of the infection. Cells were analyzed as in B. Results represent the mean ± SD. *, P < 0.001 and **, P < 0.001, difference from WT mice. Similar results were obtained in three experiments performed.