Fig. 5: MSCs are taken up by phagocytic cells in the lungs.
From: Mesenchymal stromal cell apoptosis is required for their therapeutic function
a Flow cytometric gating strategy for identifying myeloid cell populations in the lungs. b Frequencies of lung phagocytes that had taken up CTV-labelled MSCs at various timepoints after i.v. injection into BALB/c mice. Data expressed as mean ± SEM, n = 3 mice per group, three independent experiments. c Expression levels and MFI of MHC class II in neutrophils, monocytes and AMs that had taken up CTV+ MSCs 1 h after injection, compared to phagocytes that had not (CTV−). Data expressed as mean ± SEM, n = 3 mice per group, three independent experiments. p values by unpaired Student’s t test (two-tailed). Right-most panel shows MHC class II expression in AMs isolated from the lungs of OVA-sensitised mice on Day 12. SEN = OVA-sensitised mice; SEN + MSC = OVA-sensitised mice that received MSCs. Data representative of three independent experiments. d Flow cytometric plots of various phagocyte populations in the lungs, following injection of pHrodoTMRED-labelled MSCs. Data representative of two independent experiments; n = 3 mice per group. e Snapshots from live-cell imaging, showing CTG-labelled AMs (grey arrow) approach, attach and engulf pHrodoTMRED-labelled BH3-mimetic drug-treated MSCs (blue arrow), resulting in a signal flare (Supplementary Movie 1). BH3-mimetic drug-treated BKX-MSCs were not engulfed by AMs (Supplementary Movie 2). Magnification, 10x; Scale bars, 50 µM. Data representative of three experiments. f Bioluminescent images and total flux at various timepoints following injection of MSCs into untreated (n = 6) and clodronate-treated (AM-depleted; n = 5) BALB/c mice. Data expressed as mean ± SEM, 5–6 mice per group. Source data are provided as a Source Data file.
