CD4⁺ T cells are the predominant source of IL-10 in DEC.

<p>(<b>A</b>) Representative flow cytometry dot plots, and (<b>B</b>) percentages ± SEM (n = 4–6 pinnae), of IL-10^GFP+ DEC from 1x and 4x infected mice; gate shows proportions IL-10^GFP+ cells. Representative flow cytometry dot plots of IL-10^GFP+ DEC from infected (<b>C</b>) 1x and (<b>D</b>) 4x IL-10^+/GFP mice on day 4 after final exposure to infectious cercariae. Density plots show initial F4/80 <i>vs</i>. MHC-II gating strategy (left-hand plots) to yield R1 (double negative F4/80^-MHC-II^-), R2 (F4/80⁺MHC-II^-), R3 (F4/80⁺MHC-II^mid), R4 (F4/80^-MHC-II^high), and R4A (F4/80⁺MHC-II^high) cell populations. R1 was then gated according to CD4 <i>vs</i>. CD3 expression (right-hand plot). Proportions of IL-10^GFP+ DEC from infected (<b>E</b>) 1x and (<b>F</b>) 4x mice. (<b>G</b>) Proportion of IL-10^GFP+ CD3⁺CD4⁺ T cells of total IL-10^GFP+ cells in DEC from naïve, 1x or 4x infected mice on day 4 post-final infection. Symbols are values for cells obtained from independent tissue samples; horizontal bars are the means ± SEM; n = 4–6 pinnae. ANOVA and multiple comparisons tests (Sidak’s and Tukey’s) were performed to compare the means of selected groups (** = p<0.01; *** = p<0.001; **** = p<0.0001; ns = p>0.05).