Figure 3. Treg cell, lung resistance and lung tissue analysis after intervention with various ratios or doses of IL-2(PEG) and budesonide.

Female BALB/c mice were immunized with OVA i.p on days 1 and 8, followed by intranasal (i.n) 2% OVA challenges on days 9–14. Drugs were administrated intratracheally on days 12–14. On day 15, mice were sacrificed and analyzed. (a) Treg cell composition was analyzed by flow cytometry after intratracheal administration of various ratios of IL-2(PEG) and budesonide(Bud) for 3 days in asthma model mice. It showed that a ratio of 5,000 IU IL-2(PEG):1 μg Bud was optimal. (b) Treg cell analysis after intratracheal administration of different doses of IL-2(PEG) plus Bud combined in a fixed ratio of 5,000 IU IL-2(PEG):1 μg Bud for 3 days in asthma model mice. (c–e) AHR measurement and images of lung sections (scale bars, 200 μm) in asthma model mice treated with different drugs. Results represent the changes in lung resistance (Rl) as a measure of AHR. *p < 0.05. (a,b) Data are presented as means ± SEM (n = 8 per group and data point). Treated group versus untreated group by Student’s t test. (c) Data are presented as means ± SEM (n ≥ 4 per group and data point); here representative results from 1 of 2 experiments are shown. Other group versus Nacl group by Student’s t test. (d) Data are presented as means ± SEM (n ≥ 4 per group and data point); here representative results from 1 of 2 experiments are shown. Treated group versus blank group by Student’s t test. (e) Left, H&E staining; right, PAS staining. Blank group, health control mice. Nacl group, asthma model mice treated with normal saline.