Fig. 1

Gut exposure to DEP induces an inflammatory innate immune response in the gut. Wild-type mice were treated with 12 µg diesel exhaust particles (DEP) or phosphate-buffered saline (PBS) 5 times per week via gavage for up to 6 months. A Gating strategy and B representative flow cytometry plots, absolute numbers of total, CCR2⁺ inflammatory and CCR2⁻ anti-inflammatory/resident colon macrophages and their frequencies of total colon macrophages. C Frequencies of lamina propria CD4 and CD8 T-cells (of CD3⁺ cells) and regulatory T-cells (Foxp3⁺CD25⁺ of CD4⁺ T-cells). D Frequencies of dendritic cells (DCs) (CD64⁻MHCII⁺CD11c⁺) and their subpopulations according to CD103 and CD11b expression (DP: double positive). E Intraepithelial lymphocytes (IEL; CD45⁺CD3⁺) and their subtypes (of parent gate). Data are presented as mean±SEM pooled from two (C,E) or four (B) independent experiments with each data point representing an individual mouse. D depicts one representative experiment. ***p < 0.001, unpaired Mann-Whitney U test with two tailed distribution. For gating strategies see Additional File: Figure S1. DEP: Diesel exhaust particles, PBS: Phosphate-buffered saline