# Pattern of Regulatory T Cells, Resident Memory T Cells, and Exhausted T Cells in Human Pericardial Fluid Samples of Cardiovascular Patients

## TL;DR

This study examines T cell patterns in pericardial fluid from cardiovascular patients, revealing immune changes in heart transplant recipients and bypass patients.

## Contribution

The study identifies distinct T cell subset patterns in pericardial fluid, offering new insights into immune regulation in cardiac diseases and transplantation.

## Key findings

- Tregs and Trm cells were enriched in heart transplant recipients.
- T cell exhaustion markers showed complex regulation across patient groups.
- CD4+ and CD8+ T cell subsets and migration markers varied significantly between groups.

## Abstract

This study investigates T cell subsets in pericardial fluid samples obtained from heart transplantation donors, heart transplantation recipients, and coronary artery bypass graft patients. Using flow cytometry, we characterized regulatory T cells (Tregs), tissue-resident memory T cells (Trm), and exhausted T cells based on specific markers. Our results showed significant alterations in the CD4+ and CD8+ T cell subsets, migration (CXCR3, CCR5), and exhaustion markers (PD-1, TIM3) across the groups. Notably, Tregs and Trm cells were enriched in recipients, while markers of T cell exhaustion showed a complex regulation. These findings provide novel insights into the local immune regulation in cardiac disease and transplantation.