biostudies-literatureSomova VUniverzita Karlova v PrazeGrantová Agentura České RepublikyGrantová Agentura, Univerzita Karlovae70073https://www.ebi.ac.uk/biostudies/studies/S-EPMC12434451biostudies-literatureUnknown55(10)<h4>Background</h4>Mitochondrial transfer is becoming recognized as an important immunomodulatory mechanism used by mesenchymal stem cells (MSCs) to influence immune cells. While effects on T cells and macrophages have been documented, the influence on B cells remains unexplored. This study investigates the modulation of B lymphocyte fate by MSC-mediated mitochondrial transfer.<h4>Methods</h4>MSCs labelled with MitoTracker dyes or derived from mito::mKate2 transgenic mice were co-cultured with splenocytes. Flow cytometry assessed mitochondrial transfer, reactive oxygen species (ROS) levels, apoptosis and mitophagy. Glucose uptake was measured using the 2-NBDG assay. RNA sequencing analysed gene expression changes in CD19+ mitochondria recipients and nonrecipients. Pathway analysis identified affected processes. In an LPS-induced inflammation model, mito::mKate2 MSCs were administered, and B cells from different organs were analysed for mitochondrial uptake and phenotypic changes. MSC-derived mitochondria were also isolated to confirm uptake by FACS-sorted CD19+ cells.<h4>Results</h4>MSCs transferred mitochondria to CD19+ cells, though less than to other immune cells. Transfer correlated with ROS levels and mitophagy induction. Mitochondria were preferentially acquired by activated B cells, as indicated by increased CD69 expression and glycolytic activity. Bidirectional transfer occurred, with immune cells exchanging dysfunctional mitochondria for functional ones. CD19+ recipients exhibited increased viability, proliferation and altered gene expression, with upregulated cell division genes and downregulated antigen presentation genes. In vivo, mitochondrial acquisition reduced B cell activation and inflammatory cytokine production. Pre-sorted B cells also acquired isolated mitochondria, exhibiting a similar anti-inflammatory phenotype.<h4>Conclusions</h4>These findings highlight mitochondrial trafficking as a key MSC-immune cell interaction mechanism with immunomodulatory therapeutic potential.European journal of clinical investigationMesenchymal stem cell-mediated mitochondrial transfer regulates the fate of B lymphocytes.PMC1243445121‐04607X21-04607X98723Vasek DJaborova NFikarova NKrulova MSomova VNahacka ZNeuzil JPorubska BPrevorovsky MfalseMesenchymal stem cell-mediated mitochondrial transfer regulates the fate of B lymphocytes.<h4>Background</h4>Mitochondrial transfer is becoming recognized as an important immunomodulatory mechanism used by mesenchymal stem cells (MSCs) to influence immune cells. While effects on T cells and macrophages have been documented, the influence on B cells remains unexplored. This study investigates the modulation of B lymphocyte fate by MSC-mediated mitochondrial transfer.<h4>Methods</h4>MSCs labelled with MitoTracker dyes or derived from mito::mKate2 transgenic mice were co-cultured with splenocytes. Flow cytometry assessed mitochondrial transfer, reactive oxygen species (ROS) levels, apoptosis and mitophagy. Glucose uptake was measured using the 2-NBDG assay. RNA sequencing analysed gene expression changes in CD19+ mitochondria recipients and nonrecipients. Pathway analysis identified affected processes. In an LPS-induced inflammation model, mito::mKate2 MSCs were administered, and B cells from different organs were analysed for mitochondrial uptake and phenotypic changes. MSC-derived mitochondria were also isolated to confirm uptake by FACS-sorted CD19+ cells.<h4>Results</h4>MSCs transferred mitochondria to CD19+ cells, though less than to other immune cells. Transfer correlated with ROS levels and mitophagy induction. Mitochondria were preferentially acquired by activated B cells, as indicated by increased CD69 expression and glycolytic activity. Bidirectional transfer occurred, with immune cells exchanging dysfunctional mitochondria for functional ones. CD19+ recipients exhibited increased viability, proliferation and altered gene expression, with upregulated cell division genes and downregulated antigen presentation genes. In vivo, mitochondrial acquisition reduced B cell activation and inflammatory cytokine production. Pre-sorted B cells also acquired isolated mitochondria, exhibiting a similar anti-inflammatory phenotype.<h4>Conclusions</h4>These findings highlight mitochondrial trafficking as a key MSC-immune cell interaction mechanism with immunomodulatory therapeutic potential.2025-01-01T00:00:00Z2025 Oct2026-06-02T05:49:44.94Z2026-04-14T03:14:24.269ZS-EPMC124344514037193910.1111/eci.70073