New Insight into the Immunity during Echinococcus Granulosus Infection

Abstract

Echinococcus granulosus is a causative agent of cystic echinococcosis disease which represents a real challenge of health and economic sectors by threatening human and animal life. In E. granulosus-infected intermediate hosts, the local immune responses represent by balance between T helper-1 (Th1)/Th2 responses and involving of IL-10-secreting CD8+ T cells, as well as induction of antigen presentation and production of antibodies were suggested. Spill out of hydatid cyst fluid from ruptured cysts can induce deadly anaphylactic reactions. Although the host promotes effective immune responses against E. granulosus infection, the parasite can be survived, suggesting exist of mechanisms of immune evasion that help E. granulosus to grow and develop. Several mechanisms of immune evasion have been suggested during E. granulosus infection including; antigenic variation that lead to produce useless antibodies, alteration of Th1/Th2 cytokine profile, anti-apoptotic process, molecular mimicry and interfering with Antigen presentation, as well as fibrosis of hydatid cysts can be occurred in chronic cases. Furthermore, as an efficient drug against E. granulosus infection still not available, immunization of hosts could be necessary. Interestingly, combination of multiple EG95 proteins of oncospheres from the different isomers could possibly maximize the EG95 vaccine efficacy.