Immunobiology of parasitic worm extracellular vesicles

Helminth parasites (worms) have evolved a vast array of strategies to manipulate their vertebrate hosts. Extracellular vesicles (EVs) are secreted by all helminth species investigated thus far, and their salient roles in parasite–host interactions are being revealed. Parasite EVs directly interact with various cell types from their hosts, including immune cells, and roles for their molecular cargo in both regulation and promotion of inflammation in the host have been reported. Despite the growing body of literature on helminth EVs, limited availability of genetic manipulation tools for helminth research has precluded detailed investigation of specific molecular interactions between parasite EVs and host target cells. Here, we review the current state of the field and discuss innovative strategies targeting helminth EVs for the discovery and development of new therapeutic strategies, placing particular emphasis on both anti‐helminth vaccines and EV small RNAs for treating noninfectious inflammatory diseases. Parasitic worms secrete extracellular vesicles that are internalized by host target cells. This unique method of interspecies communication provides a novel source of molecular targets for designing anti‐helminth vaccines and anti‐inflammatory protein and miRNA therapeutics that exploit the immunoregulatory strategies of helminths that have been refined over millennia of host–parasite coevolution.