PhD Scientific Days 2025

Poster Session I. - A: Molecular Medicine

Non-conventional Pericardial Fluid T Cells in Dilated Cardiomyopathy

Name of the presenter

Opra Júlia

Institute/workplace of the presenter

Department of Genetics, Cell- and Immunobiology

Authors

Júlia Opra¹, Tamás Radovits², Benjámin Prokaj², Barbara Érsek¹, Béla Merkely², Edit Buzás¹

1: Department of Genetics, Cell- and Immunobiology
2: Heart and Vascular Center

Text of the abstract

Non-conventional T cell subsets typically express TCRs with limited diversity, recognize non-peptide antigens presented by non-polymorphic molecules without classical MHC restriction, and are capable of rapid responses with less confinement to lymphoid tissues. Their presence and function in pericardial fluid (PF) versus peripheral blood mononuclear cells (PBMC) remains underexplored.

This study aimed to compare the frequencies and cytotoxic activity of non-conventional T cell populations in PF and PBMC samples from patients with dilated cardiomyopathy to assess their potential local immunological role.
Paired PF and PBMC samples (n=11) were collected from dilated cardiomyopathy patients,excluding toxic, viral, oncological, chemotherapy, or HIV-related cases. Samples were processed within 12 hours and analyzed by multicolor flow cytometry for CD3, CD56, CD8, CD4, γ/δ TCR, α/β TCR, and Vα24Jα18 TCR markers. We also analyzed the extracellular vesicle content of PFs. CD107a expression after PMA/Ionomycin stimulation was used to assess cytotoxic activity.

The proportion of CD3+CD56+ NKT-like cells was elevated in PFs, though not significantly versus PBMC. In contrast, CD56+CD8+ T cells showed a significant increase in PFs. iNKT cells within CD3+ T cells were also significantly elevated in PFs. CD107a expression showed a non-significant but notable increase in PF lymphocytes, suggesting enhanced local cytotoxic potential. Analysis of PF extracellular vesicles showed that a high proportion of CD63/81-positive events were CD8+.

These findings show enrichment of cytotoxic non-conventional T cell subsets in PFs of
dilated cardiomyopathy patients compared to blood, suggesting local immune activation and a role in the cardiac microenvironment.

This research was funded by the NVKP_16-1-2016-0004 grant of the Hungarian National Research, Development and Innovation Office (NKFIH), VEKOP-2.3.2-162016-00002, VEKOP-2.3.3-15-2017-00016, the Therapeutic Thematic Programme TKP2021-EGA-23. This study was also supported by the grants RRF-2.3.121-2022-00003 (National
Cardiovascular Laboratory Program) and 2019-2.1.7-ERA-NET-2021-00015. The project has received funding from the EU’s Horizon 2020 Research and Innovation Programme under grant agreement No. 739593, as well as the NKFIH Advanced grant 150767.