Fig. 1

Classification and subtypes of MDVs. MDVs can be classified based-on their membranes and specific cargos. The single-membrane MDVs contain outer mitochondrial membrane (OMM) proteins, whereas double-membrane MDVs contain OMM and inner mitochondrial membrane (IMM) proteins as well as mitochondrial matrix proteins. Based on these different cargos, there are specific protein markers for subtype classification. Mitochondria-anchored protein ligase (MAPL) and translocase of outer mitochondrial membrane 20 (TOMM20) are the common markers for single-membrane MDVs. Peroxisome is the terminal of MALP⁺-MDVs, while TOMM⁺-MDVs are excreted by multivesicular body (MVB) process like exosomes. Pyruvate dehydrogenase (PDH) are the specific protein marker for double-membrane MDVs, which are excreted by the MVB process. Moreover, MDVs formation in the presence of Rab7 (a small GTPase that monitors vesicular transport to late endosomes and lysosomes) and Rab9 can mediate antigen presentation via MHC class I