Exosomes are nanometer-sized biovesicles that are released into surrounding body fluids after the fusion of the multivesicular bodies and the plasma membrane. They have been shown to contain specific amounts of proteins, lipids and genetic material for each cell, and can be selectively absorbed by neighboring or distant cells far from release, reprogramming the recipient cells based on their bioactive compounds. Therefore, the regulated formation of exosomes, the specific composition of their cargo and the specificity to target cells are of immense biological interest, considering the very high potential of exosomes as non-invasive diagnostic biomarkers, as well as as therapeutic nanocarriers.
In the present review, we describe and analyze recent advances in the elucidation of the regulatory mechanisms of exosome biogenesis, the molecular composition of exosomes, and the technologies used in exosome research
.In addition, we focus on the potential use of exosomes as valuable diagnostic and prognostic biomarkers for their specific cell lineage content and state, and on possibilities as therapeutic vehicles for drug and gene delivery. Exosome research is taking its first steps. A thorough understanding of the subcellular components and mechanisms involved in the formation of exosomes and in the selection of specific cells will shed light on their physiological activities. Exosomes also play a critical role in antigen presentation, a process by which immune cells display fragments of foreign substances, such as viruses or bacteria, to activate other immune cells.
Exosomes can carry antigens from infected or cancerous cells to dendritic cells, which then present them to T cells to initiate a response immune. In addition, exosomes derived from tumor cells can suppress the immune response by inhibiting immune cell activation and proliferation. Therefore, exosomes can act as friends and enemies in the context of cancer development. Exosomes have also been investigated as potential biomarkers for cancer detection.
Several studies have shown that exosomes derived from cancer cells can be detected in various body fluids, such as blood, urine and saliva. In addition, the molecular content of exosomes may reflect the characteristics of the original tumor, making them attractive candidates for liquid biopsy. Electric vehicles in circulation carry genetic material and proteins from their cell of origin, proteotranscriptomic signatures that act as biomarkers. In the case of cancer cells, exosomes may show differences in size, shape, morphology, and canonical markers compared to donor cells.
They can encapsulate relevant information that can used for disease detection. Consequently, there is a growing interest in the clinical applications of electric vehicles as biomarkers and as therapies, which has led to the creation of an International Society for Extracellular Vesicles (ISEV) and a scientific journal dedicated to electric vehicles, the Journal of Extracellular Vesicles. Exosomes have enormous potential to complement chimeric antigen-receiving T cells (CAR-T) to attack cancer cells. CAR exosomes, which are released from CAR-T cells, carry CAR on their surface and express a high level of cytotoxic molecules and inhibit tumor growth.
28 exosomes derived from cancer cells carrying associated antigens have also been shown to recruit an anti-tumor immune response.29 Neuronal exosomes are essential for communication with other types of cells in brain tissue; this includes cells that function to support axon integrity and myelination, microglia. However, expanding the manufacturing process and ensuring the purity and safety of exosome-based therapeutic products remains a challenge. Although apoptotic bodies, ectosomes and exosomes are approximately the same size (usually 40 to 100 nm) and all also contain “gulps” of cytosol, they are different species of vesicles and understanding the differences between them is extremely important, but too often overlooked. Overall, the role of exosomes in the development of the disease is an active area of research, and more studies are needed to fully understand their mechanisms of action and their potential clinical applications. Exosomes are released naturally from mesenchymal stem cells, and MSCs have the most exosomes of any cell.
In this way, they promoted the transfer, mediated by exosomes, of functionally active intercellular lncRNA as a mechanism of intercellular signaling in the CHC. These molecules have been shown to be physically associated with exosomes, further supporting this evidence. Exosomes are small extracellular vesicles secreted by cells and can be found in several biological fluids, such as blood, urine, cerebrospinal fluid, and malignant ascites. Based on their unique miRNA profiles and their load of active molecules, exosomes can induce specific pathological events.
The importance of intercellular communication through exosomes was demonstrated in the evolutionary process preserved in the formation of these vesicles. Exosomes are small extracellular vesicles that play a crucial role in cell-to-cell communication by transporting functional proteins, lipids, microRNAs, and mRNAs. Exosomes are of general interest because of their role in cell biology and for their potential therapeutic and diagnostic applications. Cells exposed to bacteria release exosomes that act as decoys for toxins, suggesting a protective effect during infection.
Treatment of inflammatory brain diseases by administering anti-inflammatory drugs encapsulated in exosomes from the nasal region to the brain. In summary, exosomes are essential mediators of the immune response and can influence the behavior of immune cells through a variety of mechanisms.
