The classical activation pathway of the human complement system is specifically inhibited by calreticulin from Trypanosoma cruzi

Ferreira, V; Valck C.; Sánchez G; Gingras, A; Tzima, S; Molina, MC; Simó R.; Schwaeble, W; Ferreira A.

Abstract

The high resistance of Trypanosoma cruzi trypomastigotes, the causal agent of Chagas' disease, to complement involves several parasite strategies. In these in vitro studies, we show that T. cruzi calreticulin (TcCRT) and two subfragments thereof (TcCRT S and TcCRT R domains) bind specifically to recognition subcomponents of the classical and lectin activation pathways (i.e., to collagenous tails of C1q and to mannan-binding lectin) of the human complement system. As a consequence of this binding, specific functional inhibition of the classical pathway and impaired mannan-binding lectin to mannose were observed. By flow cytometry, TcCRT was detected on the surface of viable trypomastigotes and, by confocal microscopy, colocalization of human C1q with surface TcCRT of infective trypomastigotes was visualized. Taken together, these findings imply that TcCRT may be a critical factor to the contributing to the ability of trypomastigotes to interfere at the earliest stages of complement activation.

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Título según WOS: The classical activation pathway of the human complement system is specifically inhibited by calreticulin from Trypanosoma cruzi
Título según SCOPUS: The Classical Activation Pathway of the Human Complement System Is Specifically Inhibited by Calreticulin from Trypanosoma cruzi
Título de la Revista: JOURNAL OF IMMUNOLOGY
Volumen: 172
Número: 5
Editorial: AMER ASSOC IMMUNOLOGISTS
Fecha de publicación: 2004
Página de inicio: 3042
Página final: 3050
Idioma: English
Notas: ISI, SCOPUS