Single-cell targeted transcriptomics reveals subset-specific immune signatures differentiating asymptomatic and cardiac patients with chronic Chagas disease.

Background: Human infection with Trypanosoma cruzi leads to Chagas disease that induces profound changes in the immune response across different cell subsets, influencing parasite control and disease pathology. Dissecting the functional characteristics of distinct immune cells in patients with the asymptomatic (indeterminate - IND) or with the cardiac (CCC) clinical forms is crucial for unveiling mechanisms of disease progression and pathology and identifying disease markers.

Methods: Here, immune-gene targeted single-cell RNA sequencing was applied to peripheral blood mononuclear cells (PBMCs) obtained from IND and CCC patients to unravel the immune landscape in this polar, well-characterized, clinical groups.

Results: Our findings revealed different myeloid and lymphoid cell clusters in both cohorts, each exhibiting unique gene expression patterns. CCC was characterized by an increased frequency of KLRB1+CD4+, TBX21+CD8+ T cells, and NK cells, which exhibited upregulation of genes associated with cytotoxic and apoptotic responses. Furthermore, we observed monocyte, B cell subsets, along with dendritic cells, expressing inflammatory and notably cytotoxic genes.

Conclusions: These results reveal cell-specific changes in CCC compared to IND chronic Chagas disease patients, highlighted by distinct gene expression patterns. These nuanced changes indicate immune signature linked to the clinical forms of chronic Chagas disease, which provide information regarding disease pathology, indicating potential markers related to the disease progression.