Stem cell stained to show pluropotency marker
King’s College London researchers and Guy’s and St Thomas’ clinicians have produced the first clinical grade human embryonic stem cell lines that are free from animal products and intended for publicly-funded research. The cells have the potential to become the ‘gold standard’ lines for developing new stem cell-based therapies.
The ‘xeno-free’ cells are the first to be deposited in the UK Stem Cell Bank (UKSCB) under arrangements to ensure they are freely accessible to the wider research community. These cells will be grown and processed by the UKSCB to provide stem cell stocks that will be used for clinical research and treatment that will benefit patients.
Researchers say this is a significant milestone that will keep the UK at the forefront of regenerative medicine.
This first batch of cells is the culmination of nearly ten years of strategic research funded by the Medical Research Council (MRC) at KCL, in collaboration with the Assisted Conception Unit at Guy’s, as part of King’s Health Partners.
More than 20 ‘research grade’ embryonic stem cell lines have been provided by King’s to the UKSCB since it derived the first research grade hES cell lines in the UK in 2003; the challenge to date has been to establish appropriate derivation and growing conditions for the cells without the presence of any animal products, such as porcine enzymes, bovine serum or mouse feeder layers.
Clinical use of non xeno-free hES cells is already being explored in a number of phase 1 safety trials, such as spinal cord injury and macular degeneration. However, the hES cell lines used in these trials were reclassified from ‘research grade’ to ‘clinical grade’ for specified short-term clinical studies in selected disease states, because no xeno-free option was available. This route is not considered appropriate for the future of cell therapy because of the expense of the required testing and reclassification, and the significant risk of using cell lines derived on unqualified feeders, using unqualified reagents under undocumented environmental conditions in the embryology and stem cell labs and storage facilities. While it was reasonable to incur additional risks for these early pioneering studies, it is not reasonable to accept these risks for the long-term future of cell therapy. Therefore the highest standard of xeno-free lines are urgently needed, and the development of the new lines by KCL and Guy’s and St Thomas’ represents a major step forward.
The hES cells were grown from frozen embryos donated by patients who had previously undergone IVF treatment at the Assisted Conception Unit and no longer wished to use their remaining stored embryos. These embryos would otherwise have been discarded in line with HFEA requirements.
The team developed a comprehensive methodology and standards for derivation of the xeno-free hES cell lines that will be appropriate for studies in human subjects after suitable additional testing and processing by the UKSCB. Developed in line with these rigorous standards, researchers, physicians and industry can be reassured of the reliability of the seed stock – the essential base for translational applications. It is hoped that these standards will be recognised across academia, future users and policy agencies operating in and monitoring the field.
As the research that underpinned this work was funded by the MRC, the decision has been taken to submit these to the UKSCB for open-access therapeutic use for the public good. A number of additional xeno-free lines will follow shortly from King’s and from the stem cell team at the University of Manchester/Central Manchester NHS Trust, who have been similarly supported by MRC and have also developed clinical grade hES cells to submit to the UKSCB in the same way.
This R&D received widespread media coverage, including Nature, Financial Times, Daily Telegraph, and the Daily Mail.
Posted on Friday 16th December 2011