Abstract

Helminths secrete a variety of molecules implicated in host-parasite interactions, either as soluble molecules or packed within extracellular vesicles (EVs). These EVs can be categorised in exosomes, microvesicles or apoptotic bodies depending on their size and origin, and can harbour many different proteins, lipids, glycans and genetic material such as miRNAs and mRNAs. Helminth-derived EVs, particularly exosome-like vesicles, have been shown to interact with the host in many different ways. They can be internalised by a variety of cells including immune cells such as macrophages and dendritic cells, as well as by intestinal cells, and liver cells; and can promote or inhibit the secretion of different cytokines. EVs secreted by some nematodes and trematodes have a potent immunomodulatory effect, and can ameliorate the symptoms of chemically-induced colitis in mice. Furthermore, EVs from different helminths contain vaccine candidates, showing the potential of EVs to be used as a source to develop new control strategies against helminth infections.