Comparison of complement activation in vitro by different Echinococcus granulosus extracts.
In the present study we have investigated and compared in vitro the specific complement (C) activating activity of three metacestode preparations of Echinococcus granulosus. Extracts from hydatid cyst fluid (HCF-ext), protoscoleces (PSC-ext) and hydatid cyst membrane (HCM-ext) activated human C producing C3 conversion and generating the C5b6 complex and the terminal C complex (TCC). HCM-ext showed much lower C activating activity than PSC-ext and HCF-ext. Moreover, its ability to generate C5b6 and TCC was lower than its ability to convert C3. On the other hand, PSC-ext and HCF-ext proved to be good C activators when their specific C activating activities were compared with that of inulin. However, PSC-ext produced lower levels of TCC than those produced by HCF-ext, in spite of the fact that both produced practically the same levels of C3d and C5b6. These results may be consistent with the existence of several mechanisms of C modulation involved in the defence of the parasite against host C damage.
Irigoín
F
F
Cátedra de Immunología, Facultad de Quimica/Facultad de Ciencias, Universidad de la República, Montevidco, Uruguay.
Würzner
R
R
Sim
R B
RB
Ferreira
A M
AM
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology; D003167:Complement Activation; D003176:Complement C3 / Q000378:metabolism; D004443:Echinococcosis / Q000276:immunology / Q000662:veterinary; D004446:Echinococcus / Q000254:growth & development / Q000276:immunology*; D006801:Humans; D066298:In Vitro Techniques
D003176:Complement C3