A billion-dollar industry has emerged around mesenchymal stromal cells (MSCs) fueled by their intriguing and broad-range therapeutic properties. But when and how were MSCs and their potential uses discovered?
Join me in a series of posts where we follow the history of MSCs. We’ll discuss their recognition and claimed uses as therapeutic tools – both extravagant and substantiated. We’ll examine their development and production as cellular active pharmaceutical ingredients (API). Finally, we’ll review initial clinical success stories.
An unassuming discovery
1966. The world’s attention is captivated by the first controlled landing of a space craft on the moon (Luna 9). In this climate of awe, a Russian team publishes an unassuming finding in a British embryology journal.
The young researcher Alexander Friedenstein and his colleagues are investigating the composition of bone marrow material. Having described two independent components – cells capable of hematopoiesis and others that form bone – they implant tissue culture chambers containing various proportions and densities of different bone marrow cells into mice. Initially, the team observes a loss of differentiated bone-forming cells and a multitude of hematopoietic and so-called reticular cells, ie., fibroblastic cells. They note that the latter soon represent the majority of dividing cells in the chambers and begin to form osteogenic structures, testing positive for the well-established osteogenic marker phosphatase A. Eventually, the originally fibroblastic cells exhibit characteristic features of osteoblasts.
Friedenstein and his colleagues establish that osteogenesis occurs only at certain cell densities. They uncover that fibroblastic cells arising from the original marrow material are proliferating and, in doing so, re-create the right conditions for osteogenesis.
A first sign of potential
This early paper already captured the defining qualities of MSCs: derived from primary tissues such as bone marrow, they can be purified, culture-expanded and can serve therapeutic purposes.
The original paper is fascinating. Download it from the link in the comment below. Enjoy!
Christian van den Bos