TRYPANOSOMA CRUZI TRYPOMASTIGOTES TRANSMIGRATE THROUGH 3DCULTURES BY A PARACELLULAR ROUTE IN A PROTEASE-DEPENDENT MANNER

RODRIGUEZ, MATIAS EXEQUIEL; CAEIRO, LUCAS; MASIP, YAMIL; RIZZI, MARIANA; TEKIEL, VALERIA

Congreso; XXXV Meeting of the Brazilian Society of Protozoology, XLV Annual Meeting on Basic Research in Chagas?s disease; 2019

The mechanisms associated to dissemination and tissue colonization in T. cruzi infection are largelyspeculative. Transmigration is the capacity of traverse biological barriers enabling pathogens to spreaddeeper into tissues. The role of transmigration in the biology of T. cruzi is still unknown. This is probablybecause the extremely simplicity of monolayer cultures to reproduce a tissue-mimicking environment, aswell as, the extremely complexity of animal models. Three-D cultures could be an excellent alternativebecause they reproduce the microarchitecture of tissues, providing an environment similar to theencountered during natural infections. In this work, we used 3D-spheroids of Hela-RFP cells to analyzethe transmigration ability of T. cruzi trypomastigotes (tryp) of CL Brener (highly virulent) and SylvioX10(low virulent) strains. In previous studies we determined that CL Brener tryp transmigrate and penetratedeeply inside spheroids, while most SylvioX10 parasites remain on the superficial layers. CL Brener trypwere usually found in between cell-cell contact sites, suggesting that they are using a paracellularmigration pathway. Accordingly, disruption of cell-cell contacts (tight and adherent junctions) increasedtryp transmigration and invasion. On the other hand, protease inhibitors strongly blocked the transmigrationprocess of CL Brener tryp. Finally, comparative surface proteomes of tryp from CL Brener and SylvioX10revealed more than 200 proteins exclusively expressed on the membrane of migrant parasites. Amongthem, we highlight extracellular matrix (ECM) binding proteins (gp85, CRT), proteases (gp63) and flagellarmotility-related proteins (FM7, RSP11). Alltogether the results indicate that transmigration of T. cruzitrypomastigotes is a multistep process, which possibly involve (1) the disruption of cell-cell junctions; (2)the degradation of ECM; (3) the interaction with components of ECM and (4) the motility of parasites.Supported by:PICT-2016-0108; PICT-2017-2644, ANPyCT, Argentina Keywords: 3d-cultures;transmigration; trypanosoma cruzi