TRAIL agonists rescue mice from radiation-induced lung injury

Cancer therapy is often limited by toxicity from pneumonitis. This often-lethal side effect is known to be impacted by innate immunity, and in particular the pathways regulated by the TRAIL death receptor DR5. We investigated whether DR5 agonists could rescue mice from the lethal effects of radiation. We found that two different agonists, parenteral PEGylated trimeric-TRAIL (TLY012) and oral TRAIL-Inducing Compound #10 (TIC10/ONC201), could achieve this goal. Both compounds could completely protect mice from lethality by reducing pneumonitis, alveolar-wall thickness, and oxygen desaturation. At the molecular level, this protection appeared to be due to the inhibition of CCl22, a macrophage-derived chemokine previously associated with radiation pneumonitis and pulmonary fibrosis. The discovery that short-term treatment with TRAIL pathway agonists effectively rescues animals from high doses of radiation exposure has important translational implications. One Sentence SummaryPrevention of lethality, pneumonitis, lung fibrosis and skin dermatitis post-{psi}-irradiation by short- term treatment with innate immune TRAIL pathway agonists