Echinococcus granulosus down regulates the hepatic expression of inflammatory cytokines IL-6 and TNF alpha in BALB/c mice.

Hydatid disease is caused by the metacestode of Echinococcus granulosus. Different experimental models have been used to understand hydatid disease. In current studies BALB/c mice were used to evaluate the hepatic response of IL-6 and TNF alpha triggered by Echinococcus granulosus. BALB/c mice were intraperitoneally infected with protoscoleces from E. granulosus; hydatid cysts appeared on the liver eight weeks after inoculation. The RNA extracted from hepatic sections was used for RT-PCR amplification with primers for IL-6, TNF alpha, IL-10, TGF beta and G3PDH. In situ cytokine expression was assessed by FISH. Complete parasite cysts on the liver surface were observed 16 weeks after infection; controls were negative. The expression of IL-6 and TNF alpha was normal at baseline and declined progressively eight weeks after infection; in some animals such expression was abrogated 16 weeks after infection. On the other hand IL-10 and TGF beta were increased progressively. Controls expressed the cytokines normally. Present results suggest that E. granulosus induces a local immunosupression probably mediated by IL-10 and TGF beta; therefore it seems possible that such a mechanism would assist the parasite in escaping the harmful host cell-mediated response.