Role of exosomes in viral infections: a narrative review

Exosomes are a type of extracellular vesicles (EVs) released by cells under normal and pathological conditions. These lipid-enclosed vesicles play a key role in intracellular communication by delivering various molecules, such as proteins, nucleic acids, and lipids, thereby influencing the activity of recipient cells. In recent years, exosomes have attracted considerable attention for their involvement in viral infections and immune system evasion. Many viruses hijack the exosome biogenesis machinery to facilitate their replication, spread infection, and evade immune defenses. Therefore, gaining insights into how exosomes modulate the immune system or contribute to viral infectivity is crucial. This review explores how viral exosomes interact with host mammalian cells, highlighting their unique ability to transfer genetic material and proteins to recipient cells independent of virus-receptor interaction. Additionally, we examine the role of viral exosomes in intercellular communication, particularly how they may both promote viral infectivity and transmission, as well as participate in antiviral defense and immune regulation. Unlike previous reviews, our study integrates findings across both human and animal viral infections, critically discusses methodological standardization in exosome research, and introduces emerging therapeutic approaches such as engineered exosomes and exosome mimetics.