Fig. 1

TREG depletion/OVA – sensitization and challenge/exercise training timeline. BALB/c mouse experimental groups (Figs. 2-5): (a) Sedentary non-sensitized (S); (b) Exercised non-sensitized (E); (EO); (c) Sedentary OVA-sensitized (SO); (d) Exercised OVA-sensitized. Briefly, OVA-sensitized (SO and EO) mice were intraperitoneally (i.p.) injected with 50 μg of alum-precipitated, chicken egg OVA (or PBS for non-sensitized - S and E) on Days + 0 and + 14 [antigen SENSITIZATION]. On Days + 21–25 [AEROSOL CHALLENGE], OVA-sensitized mice (SO and EO) were challenged with OVA at 5 mg/mL (or saline for non-sensitized – S and E) via 30 min daily aerosolization for 5 consecutive days. On Days + 28–49 [AEROSOL CHALLENGE], OVA-sensitized mice (SO and EO) were further challenged with OVA at 5 mg/mL (or saline for non-sensitized – S and E) for 10 min at 3 doses/week. Additionally, on Days + 28–49 [EXERCISE], exercised mouse groups (E and EO) were placed on a treadmill for a moderate aerobic exercise (45 min at 13.5 m/min) one hour after the aerosol challenge. (*) In experiments that required TREG depletion (Fig. 6), on Day − 8, mice were initially intravenously (i.v.) injected with 100 μg anti-CD25 mAb (PC61.5) or control IgG mAb. On Day − 7 [ADTX], 24 h depleted mice received either 5 × 10⁵ wildtype BALB/c or β2-adrenergic^−/− BALB/c CD4⁺CD25⁺ TREG adoptively transferred cells by i.v. Additional mouse experimental groups: (a) Sedentary OVA-sensitized – IgG control (SO-IgG); (b) Exercised OVA-sensitized – IgG control (EO-IgG); (c) Sedentary OVA-sensitized – WT ADTX (SO-wt) (d) Exercised OVA-sensitized – WT ADTX (EO-wt); (e) Sedentary OVA-sensitized – β2-AR^−/− ADTX (SO-ko) (d) Exercised OVA-sensitized – β2-AR^−/− ADTX (EO-ko)