Regulatory T cell mobilization following an acute bout of exercise in human and murine models. (102.5)

Abstract

Our lab is interested in how exercise affects regulatory T cells (Tregs). While we have shown that exercise training significantly increases Treg frequency and function in mice, the effects of exercise on human Tregs is less characterized. In the present study we sought to determine if exercise alters Treg frequency in humans following acute exercise. Adult males (n=14) performed a single bout of moderate exercise. Blood was sampled pre-, immediately post-, and 1hr post-exercise and examined for changes in Treg frequency. While a significant increase in CD4+ T cells was seen post-exercise, this was not due to an increase in Tregs. We found a modest increase (~5%) in peripheral Tregs that was due to an increase in total lymphocytes trafficked to the periphery. On a per cell basis, Tregs did not increase following exercise while effector T cells increased significantly (p < 0.05). Only one study has examined Treg responses to acute exercise. In that study, increases in Tregs were seen in elite-level adolescent swimmers. It was hypothesized that during exercise Tregs migrated to interstitial lung tissue. To determine this, we performed an acute bout of exercise in mice. Exercised mice had significantly greater Tregs in their lungs (p < 0.05) when compared to sedentary mice. While exercise-induced leukocytosis is well-documented in human and animal models, this does not appear to be true with Tregs. Tregs do not appear to be mobilized in the same manner as are other leukocytes.