Figure 2.

Perinatal and neonatal mono-colonization of Escherichia coli Nissle 1917 (EcN)-Chim and EcN-Ctrl in germ-free (GF) mice reduced airway inflammation. (A) Schematic representation of the neonatal colonization of GF mice with recombinant EcN expressing EcN-Chim and EcN-Ctrl in a gnotobiotic mouse model of poly-sensitization. Eight-week-old GF mice were colonized with a single dose of either EcN-Chim or EcN-Ctrl by intragastric gavage and mated 10 days later. On day 21, all mono-colonized female offspring were separated from their mothers and divided into two groups. One group was sensitized and challenged with 5 µg rBet v 1, 5 µg rPhl p 1, and 5 µg rPhl p 5 and other not. Mice were sacrificed 72 h after the last challenge (B) Absolute numbers of macrophages, lymphocytes, eosinophils, and neutrophils in bronchoalveolar lavage (BAL). (C) Representative cytospins of BAL of one mouse per group stained with H&E 100x magnification). (D) IL-5 and (E) IL-13 cytokines in BAL. (F) Quantification of mucus-producing goblet cells. (G) Representative lung tissue sections of one mouse per group stained with Periodic Acid Schiff (PAS) (Red; 10x magnification; scale bars 100 µm); arrows indicate cell infiltration. (B, D–F) represents mean ± SEM from two experiments (total n = 7 to 10 mice per group). Error bars show mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 by the One-way ANOVA followed by the Bonferroni’s Multiple Comparison Test.