Related Experiment Videos
Schistosoma mansoni circulating anodic antigen but not circulating cathodic antigen interacts with complement
G J van Dam1, J Seino, J P Rotmans
1Laboratory of Parasitology, University of Leiden, The Netherlands.
European Journal of Immunology
|November 1, 1993
Summary
Schistosome parasites use circulating anodic antigen (CAA) to evade immune attacks. CAA binds to a complement protein, C1q, potentially protecting the parasite's gut from damage.
Area of Science:
- Immunology
- Parasitology
- Biochemistry
Background:
- Schistosome parasites reside in mammalian blood vessels, facing constant immune system exposure.
- The parasite's intestinal epithelium is particularly vulnerable to immune attack.
- Schistosome gut-associated antigens, CAA and CCA, are excreted into host circulation.
Purpose of the Study:
- To investigate the role of Schistosoma antigens CAA and CCA in evading complement-mediated immune attack.
- To determine if CAA or CCA interact with complement system components.
Main Methods:
- Testing the binding of purified complement component C1q to CAA and CCA.
- Assessing the interaction of CAA with C1q stalks and globular heads.
- Evaluating CAA's interaction with precursor human C1 and its ability to activate the complement system in vitro and in serum.
Main Results:
- Purified C1q significantly bound to CAA, a negatively charged glycoprotein.
- CCA did not bind to C1q.
- CAA bound to the collagen-like stalks of C1q, not the globular heads.
- CAA did not interact with precursor human C1 or activate complement in serum or in vitro.
Conclusions:
- CAA acts as a C1q receptor, suggesting a role in protecting the schistosome gut from complement-mediated damage.
- This interaction may be a key mechanism for schistosome immune evasion.