Figure 8: Effect of CpG treatment on allergic airway inflammation and requirement for TRIF but not MyD88 signalling.

Bronchial colonization with A. fumigatus was established in wild-type, Tlr9^−/−, Myd88^−/− and Ticam1^−/− Th2-primed mice with or without CpG treatment, to be assayed for A. fumigatus allergy at 1 week. Unsensitized, uncolonized wild-type mice (control) and genetically deficient mice (indicated) were present in all assays, and so were sensitized and colonized mice of all genotypes on CpG treatment. Control littermates were included in individual experiments to check for nonspecific effects of each genetic manipulation, and none were found. (a) Paraffin-embedded lung sections were stained with periodic acid-Schiff to visualize mucine, goblet cells and inflammatory cells. Data are representative of three independent experiments. Upper panels, scale bar, 200 μm; and lower panels, scale bar, 100 μm. CpG treatment alone was indistinguishable from control. (b) The abundance of eosinophils (eos), monocytes (mon), polymorphonucleates (pmn) and lymphocytes (lym) was assessed in BAL fluid. IgE antibodies were determined in sera, and secreted cytokines were measured in BAL fluid. Control, naïve C57BL/6 mice. Data are mean±s.d. of three experiments. *P<0.05 and **P<0.005; Student’s t-test. (c) Gata3 and Foxp3 transcripts were evaluated in CD4⁺ T cells from thoracic lymph nodes. Sorted CD4⁺ lymphocytes (5 × 10⁵ ml⁻¹) were activated with soluble antibodies to CD3 for 24 h. Gata3 and Foxp3 mRNAs were quantified by real-time PCR using Gapdh normalization. Data (mean±s.d. of three (Foxp3) or four (Gata3) experiments) are presented as normalized transcript expression in the samples relative to normalized transcript expression in the control culture (cells from naïve mice of the respective genotype; that is, fold change =1, dotted line).