Induced pluripotent stem cell-derived mesenchymal stem cells from the Tasmanian devil (Sarcophilus harrisii) express immunomodulatory factors and a tropism towards devil facial tumour cells.

Abstract

Marsupials have long attracted scientific interest because of their unique biological features and their position in mammalian evolution. Mesenchymal stem cells (MSCs) are of considerable research interest in translational medicine due to their immunomodulatory, anti-inflammatory and regenerative properties. MSCs have been harvested from various tissues in numerous eutherian species; however, there are no descriptions of MSCs derived from a marsupial. In this study, we have generated Tasmanian devil (Sarcophilus harrisii) MSCs from devil induced pluripotent stem cells (iPSCs), thus providing an unlimited source of devil MSCs and circumventing the need to harvest tissues from live animals. Devil iPSCs were differentiated into MSCs (iMSCs) through both embryoid body formation assays (EB-iMSCs) and via inhibition of the transforming growth factor beta (TGF-β)/Activin signalling pathway (SB-iMSCs). Both EB-iMSCs and SB-iMSCs are highly proliferative and express the MSC-specific surface proteins CD73, CD90 and CD105, in addition to the pluripotency transcription factors OCT4/POU5F1, SOX2 and NANOG. Expression of the marsupial pluripotency factor POU5F3, a paralogue of OCT4/POU5F1, is significantly reduced in association with the transition from pluripotency to multipotency. Devil iMSCs readily differentiate along the adipogenic, osteogenic and chondrogenic pathways in vitro, confirming their trilineage differentiation potential. Importantly, in vitro teratoma assays confirmed their multipotency, rather than pluripotency, since the iMSCs only formed derivatives of the mesodermal germ layer. Devil iMSCs show a tropism towards medium conditioned by devil facial tumour cells and express a range of immunomodulatory and anti-inflammatory factors. Therefore, devil iMSCs will be a valuable tool for further studies on marsupial biology and may facilitate the development of an MSC-based treatment strategy against Devil Facial Tumour Disease.