Extracellular vesicles: Messengers of allergic immune responses and novel therapeutic strategy

Extracellular vesicles (EVs) are nanosized particles released by nearly every cell type across all kingdoms of life. As a result, EVs are ubiquitously present in various human body fluids. Composed of a lipid bilayer, EVs encapsulate proteins, nucleic acids, and metabolites, thus playing a crucial role in immunity, for example, by enabling intercellular communication. More recently, there has been increasing evidence that EVs can also act as key regulators of allergic immune responses. Their ability to facilitate cell-to-cell contact and to transport a variety of different biomolecules enables active modulation of both innate and adaptive immune processes associated with allergic reactions. A comprehensive understanding of the intricate mechanisms underlying the interactions among allergens, immune cells, and EVs is imperative to develop innovative strategies for controlling allergic responses. This review highlights the recent roles of host cell- and bacteria-derived EVs in allergic diseases, presenting experimental and clinical evidence that underscores their significance. Additionally, the therapeutic potential of EVs in allergy management is outlined, along with the challenges associated with targeted delivery and cargo stability for clinical use. Optimization of EV composition and targeting strategies holds promise for advancing translational applications and establishing EVs as biomarkers or safe therapeutics for assessing allergic reactions. For these reasons, EVs represent a promising avenue for advancing both our understanding and management of allergic immune processes.