Control of host complement activation by the Echinococcus granulosus hydatid cyst.
Cystic hydatid disease is caused by the multicellular parasite Echinococcus granulosus. The hydatid cyst, being a long-lived, large, antigenic structure lodged in the host's internal organs, could potentially elicit major inflammatory responses. However, in practice, the cyst causes only minimal local inflammation. The complement system is a major pathway to immune-mediated inflammation. Recent results have shown that the host-exposed structure of the cyst, the hydatid cyst wall (HCW), fails to trigger the complement system strongly. We have carried out a wide survey for the mechanisms making the cyst wall relatively complement-inert. The results of those studies are summarised in this work, with emphasis on the most recently identified of the complement inhibitory mechanisms. This is based on a non-protein heat-stable, parasite inhibitor of the activation of host complement factor B.
MRC Immunochemistry Unit, Department of Biochemistry, University of Oxford, UK.
A
A
Díaz
F
F
Irigoín
F
F
Ferreira
R B
RB
Sim
D000818:Animals; D003167:Complement Activation / Q000276:immunology*; D004443:Echinococcosis / Q000276:immunology*; D004446:Echinococcus; D006790:Host-Parasite Interactions / Q000276:immunology; D006801:Humans