Fig. 2
From: The exosome journey: from biogenesis to uptake and intracellular signalling
Composition of exosomes. Exosomes are composed of various proteins: transmembrane proteins such as tetraspanins, antigen presenting molecules, glycoproteins and adhesion molecules; proteins in exosome lumen such as heat shock proteins (Hsp), cytoskeletal proteins, ESCRT components, membrane transport, fusion proteins, growth factors and cytokines. Exosomes also comprise of multiple lipids such as cholesterol, ceramides, sphingomyelin, phosphatidylinostol (PI), phosphatidylserine (PS), phosphatidylcholine (PC), phosphatidylethanolamine (PE) and gangliosides (GM) along with nucleic acids such as mRNA, miRNA, non-coding RNA and DNA in their lumen. Hsc = Heat shock cognate; TSG = tumor suspectibility gene; TNF = tumor necrosis factor; TGF = Transforming growth factor; TRAIL = TNF-related apoptosis-inducing ligand; FasL = Fas ligand; TfR = Transferrin receptor