Fig. 2

Circulating immune cell population characterization. a UMAP visualization of the 10 cell types identified by integrating the datasets of the days 0 and + 2 after MSC infusion. b Dot plot graph showing the top three marker genes for each cell population used to manually annotate each UMAP-associated cluster. c Top 20 marker genes by average log fold-change of the blood-derived neutrophil cluster and heatmap with their mean normalized expression in the bronchoalveolar lavage fluid-derived neutrophil sub-clusters. The heatmap is scaled for rows. d Peripheral blood samples were analyzed at day 0 and at day + 8 after MSC infusion by flow cytometry. Numbers of cells/μl were reported for leukocytes, neutrophils, B cells, T cells, CD8⁺ T cells, CD4⁺ T cells, naïve CD8⁺ T cells, central memory CD8⁺ T cells, effector memory CD8⁺ T cells, NK cells, NKT cells, monocytes, Cl. monocytes, intermediate monocytes and non-Cl. monocytes. In b, d, and f, the red arrow indicates the time points in which MSC infusion was performed. For comments, see the text. Cl., classic; IFN, interferon; Inter., intermediate; MSC, mesenchymal stromal cell; NK, natural killer; RBC, red blood cells; TEM, T-effector memory; UMAP, Uniform Manifold Approximation and Projection