Finally, glycans from schistosomes are known to have a major role in the stimulation of innate immune responses [35]. We previously reported that the cytokine-inducing activity of 0–3 h RP is heat labile (declining at

temperatures above 50°C), and glycan dependent [8], with a key role for the mannose receptor [9]. Here we show that the production of all 3 cytokines assayed (IL-8, TNFα and IL-10) in WB cultures was reduced after 0–3 h RP was treated with sodium meta-periodate to disrupt the glycosylated moieties. This shows that glycans influence both pro-inflammatory and regulatory cytokine induction in S. mansoni-infected humans. MS-275 chemical structure However, as molecules released by the mature schistosome egg are also glycosylated [7], and as there is sharing of glycan moieties between different life cycle stages [36], it is possible that innate immune cells that respond to 0–3 h RP (e.g. through C-type lectins such as the macrophage mannose receptor) [9] are also responsive to antigens released by other parasite stages (e.g. the egg)[37], which maintain or down regulate cell responsiveness after initial parasite infection. Therefore, production of cytokines in response to cercarial glycosylated E/S material may be reinforced in response to egg deposition,

which may in turn feedback to affect the response to subsequent exposure to cercariae. It is also possible that the Th2-polarized adaptive response dominant after chronic infection in turn influence the Selleck AZD2014 ability of innate immune cells to produce IL-10 to cercarial E/S products. It is therefore likely that there will be ongoing communication, or crosstalk, between the innate and adaptive immune systems to regulate reactivity to both

Selleckchem Decitabine cercariae and eggs released by adult worm pairs. In conclusion, this study is the first to examine immune responses to cercarial E/S antigens, specifically the early production of cytokines indicative of the innate or early adaptive immune response, in human subjects. Our data show that cercarial E/S material induces the production of IL-10 in S. mansoni-infected individuals and suggests that cercarial E/S antigens are initial stimulants of a ‘regulated’ immune phenotype, which is prevalent after repeated and chronic infection with schistosomiasis. We gratefully thank the population of Diokhor Tack and the village chief, Daoure Mbaye, for their hospitality and participation in this study. This study would not have been possible without the field workers in Richard Toll, Abdoulaye Yague, Mankeur Diop, Moussa Wade and Ngary Sy, who assisted in the blood sample collection and microscopic analysis. We would also like to thank the medical and technical staff of the Health Centre in Richard Toll for their support. The authors would also like to thank Ann Bamford for help in preparation of antigen material. This study was supported by The European Union (EU INCO-CT-2006-032405 to APM, SM, and K P).