Figure 2.

Exaggerated basophil–mediated allergic airway inflammation and T_H2 cell responses in antibiotic–treated mice. (a) Histological sections of lungs from CNV or ABX mice exposed to PBS or HDM and stained with H&E (Large Bar = 100 μm; Small Bar = 20 μm; Arrows indicate eosinophilic infiltrates; CNV–PBS, n=2; ABX–PBS, n=1; CNV–HDM, n=3; ABX–HDM, n=2). (b) Flow cytometric analysis of day 3 popliteal LN (pLN) basophils from CNV or ABX mice treated with PBS and isotype control antibody. Numbers adjacent to outlined areas indicate percent cells in each gate. Gated on CD3⁻, CD4⁻, CD8⁻, CD19⁻, CD117⁻ cells. (c) Flow cytometric analysis of day 4 pLN IL–4/eGFP⁺CD4⁺ T_H2 cells from CNV or ABX mice treated with PBS and isotype control antibody. Gated on CD8⁻, CD19⁻, CD4⁺ cells. (d) Flow cytometric analysis of day 3 pLN basophils from CNV or ABX mice treated with papain and isotype control antibody. (e) Flow cytometric analysis of day 4 pLN IL–4/eGFP⁺CD4⁺ T_H2 cells from CNV or ABX mice treated with papain and isotype control antibody. (f) Flow cytometric analysis of day 3 pLN basophils from CNV or ABX mice treated with papain and anti–FcεRIα (αFcεRIα) antibody. (g) Flow cytometric analysis of day 4 pLN IL–4/eGFP⁺CD4⁺ T_H2 cells from CNV or ABX mice treated with papain and αFcεRIα antibody (CNV–PBS–ISO, n=2–5; ABX–PBS–ISO, n=2–5; CNV–PAP–ISO, n=5; ABX–PAP–ISO, n=5; CNV–PAP–αFcεRIα, n=2; ABX–PAP–αFcεRIα, n=2; significance determined by Mann–Whitney test; *, P ≤ 0.05). (h) Number of day 4 pLN IL–4/eGFP⁺CD4⁺ T_H2 cells from CNV or ABX mice treated with PBS or papain and isotype control (−) or αFcεRIα (+) antibody (means of three experiments ± s.d.; CNV–PBS–ISO, n=4; CNV–PAP–ISO, n=4; ABX–PAP–ISO, n=8; ABX–PAP–αFcεRIα, n=6; significance determined by 2 way ANOVA; ‡, P ≤ 0.06). Data representative of two or more independent experiments, results shown as mean ± s.d.