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Updated: Jan 19, 2026
Quantitative 3D Imaging of Trypanosoma cruzi-Infected Cells, Dormant Amastigotes, and T Cells in Intact Clarified Organs
Published on: June 23, 2022
Co-infection with distinct Trypanosoma cruzi strains induces an activated immune response in human monocytes
Luísa M D Magalhães1, Lívia S A Passos1, Egler Chiari2
1Departamento de Morfologia, Laboratório de Biologia das Interações Celulares, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
Insights
Human monocytes exhibit distinct inflammatory responses to single Trypanosoma cruzi infections. Co-infection with T. cruzi strains IV and V leads to a strong immune response that may aid in parasite control.
Area of Science:
- Immunology
- Infectious Diseases
- Parasitology
Background:
- Trypanosoma cruzi (T. cruzi) causes Chagas disease.
- Discrete Typing Units (DTUs) IV and V represent distinct T. cruzi strains.
- Monocytes play a crucial role in the innate immune response to T. cruzi.
Purpose of the Study:
- To investigate the immune response of human monocytes upon initial exposure to T. cruzi DTUs IV and V.
- To determine if co-infection with these T. cruzi strains alters monocyte immune profiles.
- To explore how altered monocyte responses might influence Chagas disease outcomes.
Main Methods:
- In vitro infection of human monocytes with T. cruzi strains AM64 (DTU IV) and 3253 (DTU V).
- Evaluation of monocyte immunological characteristics, including inflammatory markers (IL-10, TNF).
- Assessment of single and co-infection dynamics over 15 and 72 hours.
Main Results:
- Single infection with AM64 induced anti-inflammatory responses, while 3253 induced inflammatory responses.
- Co-infection occurred in over 50% of monocytes at 15 hours, decreasing significantly by 72 hours.
- Co-infection led to high monocyte activation with increased IL-10 and TNF, but decreased TNF-expressing cells at 72 hours.
Conclusions:
- Exacerbated immune response during co-infection correlates with reduced co-infected cells, suggesting enhanced parasite control.
- These findings offer insights for developing novel preventive strategies against Chagas disease.
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.
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