Brain-death donors as an alternative source of human stromal mesenchymal cells for cell-based therapy

Abstract

Background & Aim In the last decades, human mesenchymal stromal cells (hMSC) have been widely investigated, due to their capacity to extensively proliferate in vitro while maintaining their differentiation potential into several mesodermal lineages. Besides, they have low immunogenicity, immunomodulatory effects, ability to migrate and graft at inflammation sites and secrete bioactive molecules. These properties are of great interest for applications in cell therapy and regenerative medicine and hMSCs are currently being evaluated in several clinical trials. Various sources of hMSCs have been studied, being bone marrow (BM) the most commonly used for autologous or allogeneic clinical applications. In the latter case, one of the difficulties is the scarce availability of living donors of BM. In contrast, the alternative use of deceased donors as an allogeneic source has been little explored. The aim of our study was to evaluate the relative potential of BM from brain-death donors (BDD) as a source of hMSCs for cell therapy, obtained from two different sites: femur (F) and iliac crest (IC). Methods, Results & Conclusion Adequate procedures were developed for BM collection and processing, as well as for in vitro culture, immunophenotyping and differentiation. Fourteen donor-matched BM samples (IC and F) were processed from seven deceased donors (Table 1). Our results show that it is possible to obtain viable hMSC from both sites. Although the total number of mononuclear cells (MNC) per gram of BM appears to be greater in the CI than in F, no statistically significant differences were observed between both sources. Neither the total content of fibroblastoid colony-forming units (CFU-F) per gram of BM nor the amount of CFU-F per MNC differ significantly. The comparative analysis of MSC yields showed that there were no significant differences in MSC obtained per gram of IC-BM or F-BM during the first three passages of cell culture. Furthermore, there were no statistical differences in cell doubling time and population duplications. Cultured cells from both sites exhibited the ability to adhere to plastic and express CD105, CD73, CD90 but not CD45, CD34, CD14 markers by flow cytometry analysis. Trilineage differentiation was also achieve, meeting the ISCT minimum criteria to define hMSC. These results show the feasibility to obtain hMSC from two sites in BDD, and underscores the potential of this new source as a suitable allogeneic source of hMSC for cell-based therapies.