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Published on: June 22, 2016
Increased CD4+/CD8+ double-positive T cells in chronic Chagasic patients
Nicolas A Giraldo1, Natalia I Bolaños, Adriana Cuellar
1Grupo de Ciencias Básicas Médicas, Facultad de Medicina, Universidad de los Andes, Bogotá, Colombia.
Plos Neglected Tropical Diseases
|September 3, 2011
Summary
Double positive (DP) T cells are elevated in Chagas disease patients and show T. cruzi specificity. These cells infiltrate heart tissue, suggesting a role in parasite infection pathogenesis.
Area of Science:
- Immunology
- Parasitology
- Infectious Diseases
Background:
- CD4+/CD8+ double positive (DP) T cells are found in healthy individuals and in various diseases.
- In chronic viral infections, DP T cells exhibit an effector memory phenotype and antigen specificity.
- Previous research has not investigated DP T cells in the context of parasitic infections.
Purpose of the Study:
- To investigate the presence and characteristics of DP T cells in chronic Chagas disease.
- To determine if DP T cells in Chagas disease patients display antigen specificity towards T. cruzi.
- To explore the potential role of DP T cells in cardiac tissue infiltration during Chagas disease.
Main Methods:
- Analysis of peripheral blood from chronic Chagasic patients and non-infected donors.
- Flow cytometry to assess T cell populations (CD3, CD4, CD8) and activation markers (HLA-DR, CD38).
- Tetramer staining for T. cruzi K1 epitope specificity and assessment of effector functions (CD107, IFN-γ).
- Immunohistochemistry on heart tissue to detect DP T cell infiltration.
Main Results:
- Chagasic patients exhibited significantly higher frequencies of circulating DP T cells compared to healthy and non-chagasic cardiomyopathy controls.
- DP T cells in Chagasic patients expressed increased activation markers (HLA-DR, CD38) and intracellular perforin.
- A higher proportion of DP T cells in Chagasic patients demonstrated specificity for T. cruzi K1 epitopes.
- DP T cells were found to infiltrate the cardiac tissue of a chronic Chagasic patient.
Conclusions:
- Chagasic patients present with increased circulating DP T cells characterized by activation markers and T. cruzi specificity.
- While producing limited IFN-γ, these T. cruzi-specific DP T cells showed degranulation activity, particularly in symptomatic patients.
- DP T cells are capable of migrating to and infiltrating heart tissue in Chagas disease.
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