Sigma Class Glutathione Transferase of F. hepatica www.plosntds.org exposed to rFhGST-S1 showed elevated levels of Th2 cytokines after 24 h [48] . In this study, the effects of rFhGST-S1 exposure onprostanoid synthesis in host immune cells was investigated. The results of which show the stimulation of PGD 2 and PGE 2 in both DCs and macrophage cell lines suggesting FhGST-S1 is one such helminth derived molecule capable of driving the Th2 response.