Am. Ferreira et al., STUDY OF THE IN-VITRO ACTIVATION OF THE COMPLEMENT ALTERNATIVE PATHWAY BY ECHINOCOCCUS-GRANULOSUS HYDATID CYST FLUID, Parasite immunology, 17(5), 1995, pp. 245-251
In the present study we have investigated the fluid phase activation o
f the complement (C) alternative pathway by Echinococcus granulosus sh
eep hydatid cyst fluid (SHCF) and its higher molecular weight fraction
(SHCF-I) by quantitating the formation of both the terminal C interme
diary C5b6 complex and the terminal C complex (TCC). Our results show
that in vitro C activation progresses beyond the C5 step suggesting th
at potentially lytic complexes may be generated in vivo. In addition,
SHCF and SHCF-I glucidic moieties are probably involved in C activatio
n since 80% and 86% of SHCF and SHCF-I activity respectively was destr
oyed by periodate oxidation. Furthermore, partial deglycosylation with
Peptide N-Glycosidase F of SHCF-I which had been digested with Pronas
e E, released an active fl action (MW <14 KDa) which bound to Soybean
agglutinin, suggesting that N-linked oligosaccharides containing alpha
- or beta-linked N-acetyl galactosamine play a role in C activation by
SHCF.