F(ab')2 antibody fragments against Trypanosoma cruzi calreticulin inhibit its interaction with the first component of human complement
Biol. Res
;
38(2/3): 187-195, 2005. ilus, graf
Article
Dans Anglais
| LILACS
| ID: lil-424722
ABSTRACT
Trypanosoma cruzi calreticulin (TcCRT), described in our laboratory, retains several important functional features from its vertebrate homologues. We have shown that recombinant TcCRT inhibits the human complement system when it binds to the collagenous portion of C1q. The generation of classical pathway convertases and membrane attack complexes is thus strongly inhibited. In most T. cruzi-infected individuals, TcCRT is immunogenic and mediates the generation of specific antibodies. By reverting the C1q / TcCRT interaction, a parasite immune evasion strategy, these antibodies contribute to the host / parasite equilibrium. In an in vitro correlate of this situation, we show that the C1q / TcCRT interaction is inhibited by F(ab')2 polyclonal anti-TcCRT IgG fragments. It is therefore feasible that in infected humans anti-TcCRT antibodies participate in reverting an important parasite strategy aimed at inhibiting the classical complement pathway. Thus, membrane-bound TcCRT interacts with the collagenous portion C1q, and this C1q is recognized by the CD91-bound host cell CRT, thus facilitating parasite internalization. Based on our in vitro results, it could be proposed that the in vivo interaction between TcCRT and vertebrate C1q could be inhibited by F(ab')2 fragments anti-rTcCRT or against its S functional domain, thus interfering with the internalization process.
Texte intégral:
Disponible
Indice:
LILAS (Amériques)
Sujet Principal:
Trypanosoma cruzi
/
Calréticuline
Limites du sujet:
Animaux
/
Humains
langue:
Anglais
Texte intégral:
Biol. Res
Thème du journal:
Biologie
Année:
2005
Type:
Article
/
descriptif de projet
Pays d'affiliation:
Chili
/
États-Unis d'Amérique
/
Royaume-Uni
Institution/Pays d'affiliation:
Universidad de Chile/CL
/
University of Leicester/GB
/
University of Texas/US
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