TNF-α–deficient γδ T cells reconstitute O3-induced AHR in γ−/− mice. TNF-α–sufficient and TNF-α–deficient γδ T cells were injected intravenously into δ/- mice 16 hours before O3 exposure. (A) RL and Cdyn and (B) BAL cell composition. Data represent the mean ± SEM (n = 8). There were no significant differences between the groups.