Abstract

Fascioliasis is a parasitic disease of grazing livestock and a threat to global food security through reduced production in sheep, goats and cattle. Moreover, the zoonotic parasite is also a re-emerging food borne threat to human populations. In the absence of vaccines and limited anthelmintic options new control methods are urgently required. Previously, we have reported the identification of a Sigma class glutathione transferase (GST), a Hematopoietic Prostaglandin D synthase, from Fasciola hepatica (FhGST-S1) with confirmed prostaglandin synthase activity and immune-modulation via suppression of Th17 responses in host dendritic cells. Following initial vaccine trials FhGST-S1 immunisation reduced liver pathology and thus represents a useful addition to future cocktail vaccines. It is likely FhGST-S1 exerts its immunomodulatory effects through secretion as we provide evidence for FhGST-S1 as an integral surface component of released extracellular vesicles (EV). More recently, we have discovered a second sigma class GST (FhGST-S2) utilising a bioinformatics lead approach. Given the immunomodulatory roles of FhGST-S1, understanding the function of FhGST-S2 is of significant interest. At present we have demonstrated an increased activity towards reactive aldehyde compared to FhGST-S1 suggesting a role in protection from lipid peroxidation. To further understand Sigma class GSTs from Fasciola we have begun to investigate FhGST-S1 protein-protein interactions using a novel imaging ellipsometry approach potentially offering diagnostic potential.