Immune complexes in chronic Chagas disease patients are formed by exovesicles from Trypanosoma cruzi carrying the conserved MASP N-terminal region

DÍAZ LOZANO IM; DE PABLOS ML; LONGHI SA; ZAGO MP; SCHIJMAN AG; OSUNA A

scientific report

Springer Nature

Año: 2017

2045-2322

The exovesicles (EVs) are involved in pathologic host-parasite immune associations and have beenrecently used as biomarkers for diagnosis of infectious diseases. The release of EVs by Trypanosomacruzi, the causative agent of Chagas disease, has recently been described, with different protein cargoesincluding the MASP multigene family of proteins MASPs are specific to this parasite and characterizedby a conserved C-terminal (C-term) region and an N-terminal codifying for a signal peptide (SP). In thisinvestigation, we identified immature MASP proteins containing the MASP SP in EVs secreted by theinfective forms of the parasite. Those EVs are responsible for the formation of immune complexes (ICs)containing anti-MASP SP IgGs in patients with different (cardiac, digestive and asymptomatic) chronicChagas disease manifestations. Moreover, purified EVs as well as the MASP SP inhibit the action ofthe complement system and also show a significant association with the humoral response in patientswith digestive pathologies. These findings reveal a new route for the secretion of MASP proteins in T.cruzi, which uses EVs as vehicles for immature and misfolded proteins, forming circulating immunecomplexes. Such complexes could be used in the prognosis of digestive pathologies of clinical forms ofChagas disease.