Treg depletion attenuates irradiation-induced pulmonary fibrosis by reducing fibrocyte accumulation, inducing Th17 response, and shifting IFN-γ, IL-12/IL-4, IL-5 balance.

Irradiation-induced pulmonary fibrosis results from thoracic radiotherapy and severely limits radiotherapy approaches. CD4+ CD25+ FoxP3+ regulatory T cells (Tregs) are involved in experimentally induced murine lung fibrosis. However, the precise contribution of Tregs to irradiation-induced pulmonary fibrosis still remains unclear.