Activated γδ T cells in bronchoalveolar lavage following severe exercise

Intense exercise causes a transient disruption in the lung blood-gas barrier. Pulmonary γδ intraepithelial lymphocytes (IEL) are sentinel cells that monitor the epithelium for damage and then, in part, regulate inflammation and epithelial growth/repair by secreting cytokines and growth factors, and therefore may play an important modulator role in exercise induced lung injury. Five healthy cyclist completed bronchoalveolar lavages (BAL) at 2 and 24 hrs following repeated intense exercise bouts at sea level (SL) and 3810 meters altitude (ALT). Harvested T cells were analyzed by flow cytometry for lymphocyte subsets and lymphocyte activation (CD25 and CD103). The results are shown below as mean±SEM, where † and * are different (P<0.05) from 2 hrs and SL respectively. Sea Level Altitude BAL 2 hrs 24 hrs 2 hrs 24 hrs Protein μg/mL 107±33 117±21 109±16 172±23†* RBC 10⁴/mL 4.3±0.6 5.1±0.9 6.5±1.6 16±5.1†* WBC 10⁴/mL 7.4±0.6 7.0±0.7 5.8±1.5 10.7±2.1 % LYM 8.1±2.2 16.1±4.8† 8.3±0.1 14.7±5.0† % gd IEL 1.9±0.1 2.1±.01 4.2±0.3* 3.8±0.2* % CD25+ 8.8±2.0 12.5±2.3 43.6±3.3* 45.2±3.0* %CD103+ 42.0±2.4 31.3±2.7 50.3±3.1* 57.2±2.9* Intense exercise alters lung integrity resulting in leakage of cells and protein into the air space. Hypoxia augments the capillary leak. The increased numbers of activated γδ IEL at ALT suggest greaters epithelial injury.