Immunohistochemical Toolkit for Tracking and Quantifying Xenotransplanted Human Stem Cells

Abstract

Aim: Biomarker-based tracking of human stem cells xenotransplanted into animal models is crucial for studying their fate in the field of cell therapy or tumor xenografting. Materials & methods: Using immunohistochemistry and in situ hybridization, we analyzed the expression of three human-specific biomarkers: Ku80, human mitochondria (hMito) and Alu. Results: We showed that Ku80, hMito and Alu biomarkers are broadly expressed in human tissues with no or low cross-reactivity toward rat, mouse or pig tissues. In vitro, we demonstrated that their expression is stable over time and does not change along the differentiation of human-derived induced pluripotent stem cells or human glial-restricted precursors. We tracked in vivo these cell populations after transplantation in rodent spinal cords using aforementioned biomarkers and human-specific antibodies detecting apoptotic, proliferating or neural-committed cells. Conclusion: This study assesses the human-species specificity of Ku80, hMito and Alu, and proposes useful biomarkers for characterizing human stem cells in xenotransplantation paradigms.

Keywords::

• cell therapy
• human-specific biomarker
• image quantification
• stem cells
• xenotransplantation

Acknowledgements

The authors are grateful to Audrey Verellen, Sébastien Sauvage and Sabine Paternot for technical assistance, and Song Liu for neurosurgery. The authors thank James T Campanelli (Q Therapeutics, Inc., UT, USA) for providing human glial-restricted progenitors.

Financial & competing interests disclosure

This work was supported by grants from Thierry Latran Foundation, INSERM and Institut Pasteur (to D Bohl). This work was also funded by the NIH (1R01NS079702 to AC Lepore) and the Craig H. Neilsen Foundation (#190140 to AC Lepore). XM Lopez is supported by the Télévie program of the ‘Fonds National de la Recherche Scientifique’ (FNRS, Brussels, Belgium) and Fonds Yvonne Boël. The CMMI is supported by the European Regional Development Fund and the Walloon Region. C Decaestecker is a Senior Research Associate with the FNRS. Q Therapeutics, Inc., has patents on human GRP and is currently developing these for potential clinical study. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate insti-tutional review board approval or have followed the princi-ples outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investi-gations involving human subjects, informed consent has been obtained from the participants involved.

Additional information

Funding

This work was supported by grants from Thierry Latran Foundation, INSERM and Institut Pasteur (to D Bohl). This work was also funded by the NIH (1R01NS079702 to AC Lepore) and the Craig H. Neilsen Foundation (#190140 to AC Lepore). XM Lopez is supported by the Télévie program of the ‘Fonds National de la Recherche Scientifique’ (FNRS, Brussels, Belgium) and Fonds Yvonne Boël. The CMMI is supported by the European Regional Development Fund and the Walloon Region. C Decaestecker is a Senior Research Associate with the FNRS. Q Therapeutics, Inc., has patents on human GRP and is currently developing these for potential clinical study. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. No writing assistance was utilized in the production of this manuscript.