Mitochondria in innate immune responses

Mitochondria are emerging as important players in innate immunity: they act as signalling platforms for antiviral molecules, produce reactive oxygen species that influence both antiviral and antibacterial immune responses and are a source of factors that initiate sterile inflammation. The innate immune system has a key role in the mammalian immune response. Recent research has demonstrated that mitochondria participate in a broad range of innate immune pathways, functioning as signalling platforms and contributing to effector responses. In addition to regulating antiviral signalling, mounting evidence suggests that mitochondria facilitate antibacterial immunity by generating reactive oxygen species and contribute to innate immune activation following cellular damage and stress. Therefore, in addition to their well-appreciated roles in cellular metabolism and programmed cell death, mitochondria appear to function as centrally positioned hubs in the innate immune system. Here, we review the emerging knowledge about the roles of mitochondria in innate immunity.