Standardised protocols for stem cell research
To date, there has been relatively little progress in the development of new culture technologies for the large-scale manufacture of mesenchymal stem cells (MSCs). The lack of standardised protocols for the characterisation, isolation or identification of MSCs from different tissues as well as cryopreservation hampers the clinical translation of MSCs. Scientists of the EU-funded PURSTEM (Utilisation of the mesenchymal stem cell receptome for rational development of uniform, serum-free culture conditions and tools for cell characterization) project wished to identify specific cell surface receptors on MSCs and develop reagents for their isolation and culture. Using a novel combination of transcriptional and biochemical approaches, they characterised the repertoire of MSC surface receptors and growth factors, and identified approximately 20 specific molecules that could be used to distinguish and isolate MSCs from other cell types. These surface receptors served as the basis for the development of antibodies for MSC isolation as well as for low-serum and serum-free culture methods. In turn, this reduced the need to use serum-based MSC culture conditions, thereby eliminating potential contamination issues. Further insight into MSC phenotype indicated that cultured MSCs were a heterogeneous population of undifferentiated and more-committed cells, which evolve during passaging towards cellular senescence. Using the unified protocols for the isolation and characterisation of MSCs, the variability of cells was reduced. Similarly, the standardised PURSTEM culture conditions produced cells with a consistent cell surface phenotype. Given that stem cell therapeutics are gaining momentum for tissue engineering or regenerative purposes, the standard operating procedures for the isolation and growth of MSCs will optimise the production of these cells for clinical use. Overall, the deliverables of the PURSTEM project will bridge the gap between demand and supply of consistent cells and support the development of promising stem cell therapies. Long-term, these will improve quality of life for patients and reduce the economic burden associated with chronic disease.
Keywords
Mesenchymal stem cells, PURSTEM, cell surface receptor, antibodies, serum-free culture methods
