Th cell proliferation was increased in B6.CCR6^−/− mice.

<p>B6.WT and B6.CCR6^−/− mice were infected s.c. with 3×10⁶<i>L. major</i> promastigotes. Lymph node cells were isolated at the indicated time points and cells were analyzed by flow cytometry. (A) Mice were given BrdU in drinking water three days before analysis. Cells stained for CD4 and BrdU were gated on CD4⁺ cells. The percentage of BrdU⁺ events is shown (n = 3 per time point and genotype, data represent one experiment). (B–C) Lymph node cells were labeled with CFSE and stimulated with LAg <i>in vitro</i> for 4 d. Cells were gated on CD4⁺ events. (B) One representative histogram plot of proliferating cells is shown. (C) The percentage of proliferating cells is shown (n = 3 mice per time point and genotype, data represent one experiment, *p<0.05). (D) Lymph node cells were stimulated with PMA and ionomycin in the presence of BFA. Live cells were gated on CD4⁺ events. The percentage of IFNγ⁺ cells is shown (d 0–10, n = 9 mice; day 14, n = 6 mice per time point and genotype, pooled data of three independent experiments, *p<0.05, B6.WT; ^# p<0.05, B6.CCR6^−/−). (E) For analysis of IL-4 expression lymph nodes were harvested, total RNA was isolated and IL-4 mRNA was quantified by RT-PCR. Data show the expression of IL-4 mRNA relative to β-actin mRNA (n = 3 mice per time point and genotype, data represent one experiment, *p<0.05).