Authors
A Fanthome1; P M Brophy1; R M Morphew1; 1 Aberystwyth University Discussion
Exosomes are membranous extracellular organelles of diameter 30-100nm. Typical exosome cargo includes proteins and mRNA. Exosome like vesicles (EVs) are produced by several platyhelminth and nematode species studied to date, including Fasciola hepatica, a master of immune-modulation. EVs from several helminths have been shown to be taken up by host cells and to potentially direct the manipulation of host immune responses, thereby contributing to parasite establishment and long-term survival in the host. The ancestral role of worm EVs is not resolved. For example, molecules resembling antimicrobial peptides have been identified in the EV cargo of the free living model nematode Caenorhabditis elegans. However, exactly how helminth EVs interact with host cells and the environment is not yet fully understood, and it is unclear if EV host interaction is a prerequisite for worm parasitism. We report on an EV discovery and purification pipeline in nematodes and flatworms using an ultracentrifugation strategy. EVs were isolated from the excretory/secretory products of the cestode Moniezia expansa and the economically important ruminant nematode Haemonchus contortus. To investigate whether antimicrobial activity is conserved in parasitic helminth EVs, isolated M. expansa EVs were screened against Escherichia coli K12 strain, with the aim of determining minimum inhibitory concentrations for antibiotic activity.
