Identification of Different Extracellular Vesicles in the Hydatid Fluid of Echinococcus granulosus and Immunomodulatory Effects of 110 K EVs on Sheep PBMCs

Echinococcosis, mainly caused by Echinococcus granulosus, is one of the 17 neglected tropical diseases. Extracellular vesicles (EVs) play an essential role in the host–parasite interplay. However, the EVs in the hydatid fluid (HF) of E. granulosus are not fully characterized. Herein, three different types of HF EVs, designated as 2 K, 10 K, and 110 K EVs based on the centrifugal force used, were morphologically identified. A total of 97, 80, and 581 proteins were identified in 2 K, 10 K, and 110 K EVs, respectively, 39 of which were commonly shared. Moreover, 11, 8, and 25 miRNAs were detected, respectively, and all of the 7 selected miRNAs were validated by qPCR to be significantly lower abundant than that in protoscoleces. It was further deemed that 110 K EVs were internalized by sheep peripheral blood mononuclear cells (PBMCs) in a time-dependent manner and thus induced interleukin (IL)-10, tumor necrosis factor-α (TNF-α), and IRF5 were significantly upregulated and IL-1β, IL-17, and CD14 were significantly downregulated (p < 0.05). These data demonstrate the physical discrepancy of three HF EVs and an immunomodulatory effect of 110 K EVs on sheep PMBCs, suggesting a role in immune responses during E. granulosus infection.