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Onchocerca volvulus microfilariae avoid complement attack by direct binding of factor H.
- Source :
-
The Journal of infectious diseases [J Infect Dis] 2002 Jun 15; Vol. 185 (12), pp. 1786-93. Date of Electronic Publication: 2002 May 31. - Publication Year :
- 2002
-
Abstract
- The filarial parasite Onchocerca volvulus is the causative agent of river blindness. The adult worms produce microfilariae (mf), which are responsible for the disease pathogenesis; mf activate the complement system, but the activation stops before the formation of terminal complement complexes. Because of the arrest of complement activation, this study analyzed binding of the main alternative pathway regulator, factor H (fH), to the mf. The mf bound fH after incubation in nonimmune human serum or with purified radiolabeled fH. In the presence of factor I, mf-bound fH promoted the cleavage of complement 3 molecule b (C3b) to iC3b. An analysis with recombinant constructs of fH showed that the C-terminal short consensus repeats (SCRs) 8-20 of fH bound to mf, whereas the N-terminal SCRs 1-7 containing the complement-regulatory domains in SCRs 1-5 did not. Thus, mf of the nematode O. volvulus may evade human complement by binding fH and by promoting inactivation of C3b into iC3b.
Details
- Language :
- English
- ISSN :
- 0022-1899
- Volume :
- 185
- Issue :
- 12
- Database :
- MEDLINE
- Journal :
- The Journal of infectious diseases
- Publication Type :
- Academic Journal
- Accession number :
- 12085326
- Full Text :
- https://doi.org/10.1086/340649