[Current basic understanding and clinical application of mesenchymal stromal/stem cells].

Mesenchymal stromal/stem cells (MSCs) exhibit various biological characteristics, including immunomodulation, tissue regeneration, anti-inflammation, and hematopoietic support. Extensive efforts have been made toward the development of cell therapy using MSCs to treat various diseases. In Japan, off-the-shelf allogeneic human bone marrow-derived MSC products from third-party donors are clinically available for treating patients with steroid-resistant/refractory acute graft-versus-host disease (GVHD). In this manuscript, we present an overview of the current status of clinical development of MSC-based cell therapy and the basic understanding of MSCs. We also introduce a novel approach to obtain the anti-GVHD effect utilizing bone marrow MSC-derived extracellular vesicles.