Co‐infection with distinct Trypanosoma cruzi strains induces an activated immune response in human monocytes

• Published in: Parasite immunology Vol. 41; no. 11; pp. e12668 - n/a
• Main Authors: Magalhães, Luísa M.D., Passos, Lívia S.A., Chiari, Egler, Galvão, Lúcia M.C., Koh, Carolina C., Rodrigues‐Alves, Marina L., Giunchetti, Rodolfo C., Gollob, Kenneth, Dutra, Walderez O.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01-11-2019
• Subjects: Adolescent; Adult; Cell activation; Cell culture; Cells, Cultured; Chagas disease; Chagas Disease - immunology; Chagas Disease - parasitology; Coinfection; co‐infection; discrete typing units; human; Humans; Immune response; Infections; Inflammation; Interleukin-10 - metabolism; Middle Aged; Monocytes; Monocytes - immunology; parasitemia; strains; Trypanosoma cruzi; Trypanosoma cruzi - classification; Trypanosoma cruzi - immunology; Tumor necrosis factor; Tumor Necrosis Factor-alpha - metabolism; Young Adult; monocytes; co-infection; parasitemia; discrete typing units; strains; human; Trypanosoma cruzi
• ISSN: 0141-9838; 1365-3024
• DOI: 10.1111/pim.12668

Aims
The aim of the study was to evaluate the immune response triggered by the first contact of human monocytes with two T cruzi strains from distinct discrete typing units (DTUs) IV and V, and whether co‐infection with these strains leads to changes in monocyte immune profiles, which could in turn influence the subsequent infection outcome.
Methods and results
We evaluated the influence of in vitro single‐ and co‐infection with AM64 and 3253 strains on immunological characteristics of human monocytes. Single infection of monocytes with AM64 or 3253 induced opposing anti‐inflammatory and inflammatory responses, respectively. Co‐infection was observed in over 50% of monocytes after 15 hours of culture, but this percentage dropped ten‐fold after 72 hours. Co‐infection led to high monocyte activation and an increased percentage of both IL‐10 and TNF. The decreased percentage of co‐infected cells observed after 72 hours was associated with a decreased frequency of TNF‐expressing cells.
Conclusion
Our results show that the exacerbated response observed in co‐infection with immune‐polarizing strains is associated with a decreased frequency of co‐infected cells, suggesting that the activated response favours parasite control. These findings may have implications for designing new Chagas disease preventive strategies.