Dendritic Cells Are Involved in the Effects of Exercise in a Model of Asthma

Introduction: This study investigated the effects of aerobic exercise (AE) on both the maturation of dendritic cells (DC) and the activation of lymphocytes in a mouse model of chronic allergic airway inflammation. Methods: C57BL/6 mice distributed into control, exercise, ovalbumin (OVA), and OVA + exercise groups were submitted to OVA sensitization and challenge. Treadmill training was performed for 4 wk, and mice were assessed for classical features of chronic allergic airway inflammation as well as dendritic cell activation and T-lymphocyte response. Results: AE reduced OVA-induced eosinophilic inflammation as observed in bronchoalveolar lavage fluid (P < 0.001), airway walls (P < 0001), and also reduced collagen deposition (P < 0.001). AE also reduced bronchoalveolar lavage fluid cytokines (interleukin [IL]-4, P < 0.001; IL-5, P < 0.01; IL-6, P < 0.001; IL-13, P < 0.01; and tumor necrosis factor >, P < 0.01). Cells derived from mediastinal lymphnodes of AE animals that were restimulated with OVA produced less IL-4 (P < 0.01), IL-5 (P < 0.01), and IL-13 (P < 0.001). In addition, AE reduced both DC activation, as demonstrated by reduced release of IL-6 (P < 0.001), CXCL1/KC (P < 0.01), IL-12p70 (P < 0.01), and tumor necrosis factor > (P < 0.05) and DC maturation, as demonstrated by lower MCH-II expression (P < 0.001). Conclusion: AE attenuated dendritic cell and lymphocyte activation and maturation, which contributed to reduced airway inflammation and remodeling in the OVA model of chronic allergic airway inflammation.