Noncanonical intercellular communication in immune response

Figure 4 Exosome pathway. Exosome forms through endocytosis, which starts from the invagination of clathrin coated domain of plasma membrane (coated pit) bearing the receptors and other membrane-bound molecules. After entering cell interior, the coated vesicle loses clathrin coat and becomes the endosome. Subsequently, after acquiring variety of other molecules from Golgi apparatus and cytoplasm, the endosome membrane undergoes inward budding resulting in the formation of multivesiular multivesicular body (MVB) containing exososmes. Ultimately, the MVB fuses with plasma membrane and in the process of exocytosis releases exosomes outside the cell. The exososmes either fuse with the membrane of neighboring target cell or enter blood stream to be transported to distant targets. In the alternative outcome (not shown here), which serves as the pathway degradation pathway, the MVB fuses with lysosomes, which degrade its content[67,69].