Apoptotic Cells Release IL1 Receptor Antagonist in Response to Genotoxic Stress

Apoptosis is a controlled means of eliminating damaged cells without causing an inflammatory response or tissue damage. The mechanisms that contribute to the suppression of an inflammatory response upon apoptosis of cells are poorly understood. Here, we report that apoptotic cells release the interleukin-1 receptor antagonist (IL1RA). The release of IL1RA depended on the DNA damage response, caspase 9, and caspase 3. De novo translation, classical secretion pathways, or N-glycosylation was not required for the release of IL1RA. The amounts of IL1RA released by apoptotic cells impaired IL1-induced expression of IL6. In summary, we demonstrate that the release of IL1RA in response to genotoxic stress contributes to the immunosuppressive effects of apoptotic cells. (C) 2016 AACR.