Comparison Of In Vitro Adherence, Proliferation And Osteogenesis Of Equine Bone Marrow-Derived Mesenchymal Stem Cells To Identify An Allogeneic Donor

Equine mesenchymal stem cells (eMSCs) are promising candidates to repair and to regenerate damaged tissue in horses. To avoid immune reactions, the use of autologous eMSCs is desired, but the number of cells obtained from biopsies is generally too low for direct implantation. As a result, it takes several weeks for in vitro expansion of eMSC cultures to generate enough numbers for injection into the same horse. The only way to satisfy this high demand for eMSCs is the use of allogeneic eMSCs. eMSCs lack major histocompatibility complex II antigens and are able to avoid immune recognition allowing for allogeneic administration of these cells. Similar to humans, equine bone marrow‐derived MSCs exhibit variability in their rates of proliferation and differentiation in vitro . Experiments were carried out to identify a “reliable” donor and establish MSC cultures in order to generate off‐the‐shelf allogeneic cell stocks for immediate administration into client cases. Results of experiments to compare the cell viability (live/dead staining), proliferation (MTS assay), in vitro differentiation into osteoblasts (alkaline phosphatase and alizarin red staining), and gene expression from 7 horses are presented. Only one out of seven horses demonstrated a high rate of proliferation, and potential for in vitro osteogenesis, hence, was found to be superior to the others. This research is sponsored by a grant from the Center of Excellence in Livestock Diseases and Human Health.