Background information
Human mesenchymal stem cells or stromal cells (MSCs) hold great promise for regenerative applications like bone- and cartilage repair, as well as for immunomodulatory applications. However, MSCs can be isolated from a variety of tissues, expanded under different conditions, and characterized with regard to differentiation potential as well as cell surface marker expression.
Minimal criteria for a common definition of human MSCs were defined by the Mesenchymal and Tissue Stem Cell Committee of the International Society for Cellular Therapy (ISCT) to facilitate a better comparability of data amongst investigators, accelerating new scientific discoveries, and facilitating the development of novel cellular therapies.¹ The committee proposed that MSCs should be plastic adherent when maintained under standard culture conditions. Also MSCs should differentiate to osteoblasts, adipocytes, and chondrocytes under standard
in vitro
differentiating conditions. When measured by flow cytometry, ≥95% of the MSC population must express CD73, CD90, and CD105, and these cells must lack expression (≤2% positive) of CD34, CD45, CD11b or CD14, CD19 or CD79α, and HLA-DR.
Overview