Extracellular vesicles as a target for the development of anti-helminth vaccines

There is a rapidly growing body of evidence that production of extracellular vesicles (EVs) is a universal feature of cellular life. More recently, EVs have been identified in a broad range of both unicellular and multicellular parasites where they play roles in parasite–parasite intercommunication as well as parasite–host interactions. Parasitic helminth-derived EVs traverse host target cell membranes whereupon they offload their molecular cargo — proteins, lipids, and genetic information such as mRNAs and miRNAs — which are thought to hijack the target cell and modulate its gene expression to promote parasite survival. As such, EVs represent a novel mechanism of intercellular communication that could be targeted for vaccine-mediated interruption, given the abundance of surface antigens expressed on helminth EVs, and the ability of antibodies to block their uptake by target cells. In this Perspective article, we review recent developments in the field of helminth-derived EVs and highlight their roles in helminth vaccine discovery and development.