Fig. 1

Primary human Th17 cells take up mitochondria after co-culture with BM-MSCs. a MitoTracker-labeled BM-MSCs were co-cultured with PBMCs for 4 h, and then mitochondrial transfer to naive CD4⁺ T cells, CD8⁺ T cells, and B cells was evaluated by flow cytometry. b Sorted Th17 cells were co-cultured with MitoTracker-labeled BM-MSCs for 4 and 24 h, and mitochondrial transfer was assessed by flow cytometry analysis. Mitochondrial transfer is expressed as the percentage of MitoTracker-positive T cells relative to all T cells and as the mean fluorescence intensity (MFI). c 3D reconstruction of confocal microscopy images of BM-MSC mitochondrial transfer to T cells after co-culture for 4 h (MSC to T cell ratio = 1:25). BM-MSCs and T cells were labeled with MitoTracker Red CMXRos and CellTracker Green, respectively, before co-culture. Confocal microscopy images obtained immediately after co-culture show T cells attached to BM-MSCs (left panels) and non-adherent T cells (right panels). Scale bar 10 μm. d Detection of BM-MSC mitochondrial DNA (mtDNA) by qPCR in T cells before c-culture (CTL), after 4 h of co-culture, and then at 24, 48, and 72 h. Data are the mean ± SEM of at least 3 independent experiments using T cells from five different PBMC donors and BM-MSCs from three donors