Figure 2. T. cruzi activate mainly the lectin and alternative complement pathways.

A) C4b deposition on T. cruzi epimastigotes of several strains. Parasites adsorbed in ELISA plates were incubated in 5% NHS from 5 to 60 minutes at 37°C, followed by anti-C4 antiserum incubation. Reactions were developed with ABTS-peroxidase solution measured at 405 nm. B) C4b deposition in epimastigotes of T. cruzi. Experiments were performed as in A, except that MBLs/L-ficolins-depleted sera were used. C) C4b deposition in epimastigotes of T. cruzi. Experiments were performed as in A, except that C1q-depleted sera were used. D) C3b deposition in T. cruzi epimastigotes. Experiments were performed as in A; except that sera treated with 10 mM EGTA and 7 mM MgCl₂ were used. Detection was made with anti-C3 antiserum.