Parkinson's Disease-Related Proteins PINK1 and Parkin Repress Mitochondrial Antigen Presentation.

Antigen presentation is essential for establishing immune tolerance and for immune responses against infectious disease and cancer. Although antigen presentation can be mediated by autophagy, here we demonstrate a pathway for mitochondrial antigen presentation (MitAP) that relies on the generation and trafficking of mitochondrial-derived vesicles (MDVs) rather than on autophagy/mitophagy. We find that PINK1 and Parkin, two mitochondrial proteins linked to Parkinson's disease (PD), actively inhibit MDV formation and MitAP. In absence of PINK1 or Parkin, inflammatory conditions trigger MitAP in immune cells, both in vitro and in vivo. MitAP and the formation of MDVs require Rab9 and Sorting nexin 9, whose recruitment to mitochondria is inhibited by Parkin. The identification of PINK1 and Parkin as suppressors of an immune-response-eliciting pathway provoked by inflammation suggests new insights into PD pathology.