# TcEVdb: a database for T-cell-derived small extracellular vesicles from single-cell transcriptomes

## TL;DR

TcEVdb is a database that explores T-cell-derived extracellular vesicles using single-cell RNA sequencing data to better understand immune regulation and disease.

## Contribution

TcEVdb introduces a comprehensive database and analysis tools for T-cell-derived extracellular vesicles using the SEVtras method.

## Key findings

- TcEVdb contains 277,265 EV droplets from 51 T-cell types across 21 projects and 221 samples.
- The database reveals increased EV secretion in CD4+ T exhausted cells in diffuse large B-cell lymphoma compared to healthy controls.
- Distinct EV clusters are associated with genes related to cell motility and mitochondrial function.

## Abstract

T-Cell-derived extracellular vesicles (TcEVs) play key roles in immune regulation and tumor microenvironment modulation. However, the heterogeneity of TcEV remains poorly understood due to technical limitations of EV analysis and the lack of comprehensive data. To address this, we constructed TcEVdb, a comprehensive database that explores the expression and cluster of TcEV by the SEVtras method from T-cell single-cell RNA sequencing data. TcEVdb contains 277 265 EV droplets from 51 T-cell types across 221 samples from 21 projects, covering 9 tissue sources and 23 disease conditions. The database provides two main functional modules. The Browse module enables users to investigate EV secretion activity indices across samples, visualize TcEV clusters, analyze differentially expressed genes (DEGs) and pathway enrichment in TcEV subpopulations, and compare TcEV transcriptomes with their cellular origins. The Search module allows users to query specific genes across all datasets and visualize their expression distribution. Furthermore, our analysis of TcEV in diffuse large B-cell lymphoma revealed increased EV secretion in CD4+ T exhausted cells compared to healthy controls. Subsequent analyses identified distinct droplet clusters with differential expression genes, including clusters enriched for genes associated with cell motility and mitochondrial function. Overall, TcEVdb serves as a comprehensive resource for exploring the transcriptome of TcEV, which will contribute to advancements in EV-based diagnostics and therapeutics across a wide range of diseases.

Database URL: https://guolab.wchscu.cn/TcEVdb