Figure 6.

Interleukin‐10 (IL‐10) administration attenuated regulatory T (Treg) cell‐mediated suppression of asthma airway inflammation. (a) At 12 weeks after infection, CD4⁺ CD25⁺ Treg cells (5 × 10⁵ cells/200 μl PBS/mouse) were purified from Schistosoma japonicum‐infected mice and adoptively transferred into ovalbumin (OVA) ‐sensitized asthma mice by caudal vein injection. Recipient mice were immediately injected intraperitoneally with regulatory mouse (rm) IL‐10 or PBS for five consecutive days of the OVA airway challenge stage (as seen in the Supplementary material, Fig. S2c; n = 6 per group). All mice were killed 24 hr after the final airway challenge to assess respiratory inflammation. Haematoxylin & eosin‐stained lung sections (40×) were analysed for leucocyte infiltrate and epithelial hypertrophy. (b) The degree of inflammation and the extent of leucocyte infiltration, epithelial cell hypertrophy and mucus production in the periodic acid–Schiff and haematoxylin analyses were assessed. A semi‐quantitative rating scale ranged from 0 (none) to 4 (maximal). Each average score per category was multiplied by the extent of appearance in the lungs (also rated 0–4) to yield an overall inflammation index. (c) Differential cell counts of bronchoalveolar lavage fluid were performed. Images are representative and data (mean ± SD) are representative of two independent experiments. *P < 0·05, **P < 0·01, ***P < 0·001.