Autophagocytosis ― cellular self-eating ― may be crucial for maintaining a balanced immune response by clearing damaged mitochondria and preventing excessive inflammation, reports an article published online this week in Nature Immunology.
Autophagy is a crucial physiological process wherein cells engulf and digest their own organelles, such as mitochondria, which are cellular power plants. Unlike other cellular components encoded by nuclear genes, mitochondria carry their own DNA.
Augustine Choi and colleagues find that damaged mitochondria ― as can occur during infection ― release DNA, which when detected triggers secretion of inflammatory molecules IL-1 and IL-18. The authors show that autophagocytosis is crucial for degrading such damaged mitochondria before they can trigger an inflammatory response. Failure to do so results in hyper-inflammation.