Immunomodulatory effects of aerobic training in obesity

Introduction. Physical inactivity and obesity are independent risk factors for atherosclerosis. We analyzed the immunomodulatory capacity of 10-week intensified exercise training (ET) in obese and lean athletes. Markers of the innate immune response were investigated in obese (ONE: ET≤40km/week) and lean athletes (LNE: ET≤40km/week and LE: ET≥55km/week). Methods. Circulating dendritic cells (DC) were analyzed by flow-cytometry for BDCA-1/-2-expression. TLR-2/-4/-7 and MyD88 were analyzed by RT-PCR and Western blot. Circulating oxLDL levels were analyzed by ELISA. Results. BDCA-1 expression at baseline was lower in ONE compared to both other groups (ONE 0.15; LNE 0.27; LE 0.33; P . 05), but significantly increased in ONE after training (+50; P . 05). In contrast, BDCA-2 expression at baseline was higher in ONE (ONE 0.25; LNE 0.11; LE 0.09; P . 05) and decreased in ONE after the 10-week training period (-27; P . 05). Gene activations of TLR-4 and TLR-7 with corresponding protein increase were found for all three groups (P . 01 / P . 05) compared to pre training. A reduction of oxLDL levels was seen in ONE (-61; P . 05). Conclusions. Intensified exercise induces an increase of BDCA-1+ DCs and TLR-4/-7 in obese athletes. We hereby describe new immune modulatory effects, whichthrough regular aerobic exercisemodulate innate immunity and pro-inflammatory cytokines in obesity.