Immunosuppressive Exosomes: A New Approach for Treating Arthritis
Figure 1
Exosome biogenesis and molecular composition. (a) Exosomes are small membrane vesicles formed by invagination of the multivesicular bodies (MVBs) in the late endocytic compartment. They are released upon the fusion of MVBs with the plasma membrane. (b) Exosomes are typically enriched in certain molecules including targeting/adhesion molecules, membrane trafficking molecules, cytoskeleton molecules, proteins involved in MVB formation, chaperones, cytoplasmic enzymes, signal transduction proteins, and functional mRNA and microRNA populations. *APC-derived exosomes contain antigen-presenting molecules including MHC class I, MHC class II, and co-stimulatory molecules. **Exosomes also contain cell-specific antigens (e.g., tumor antigens in tumor-derived exosomes). ***Immunosuppressive molecules such as FasL, TRAIL, or TGF- are present on certain APC or tumor-derived exosomes.
