Are stem cells a potential therapeutic tool in coeliac disease?

Despite the growing understanding of its pathogenesis, the treatment of coeliac disease is still based on a lifelong gluten-free diet that, although efficacious, is troublesome for affected patients, and a definitive cure is still an unmet need. In this regard, the development of new chemical- and biological-derived agents has often resulted in unsatisfactory effects when tested in vivo, probably because of their ability to target only a single pathway, whilst the immunological cascade responsible for tissue injury is complex and redundant. The advent of cellular therapies, mainly based on the use of stem cells, is an emerging area of interest since it has the advantage of a multi-target strategy. Both haematopoietic and mesenchymal stem cells have been employed in the treatment of refractory patients suffering from autoimmune diseases, with promising results. However, the lack of immunogenicity makes mesenchymal stem cells more suitable than their haematopoietic counterpart, since their transplantation may be performed in the absence of a myeloablative conditioning regimen. In addition, mesenchymal stem cells have been shown to harbour strong modulatory effects on almost all cells involved in immune response, together with a potent regenerative action. It is therefore conceivable that over the next few years their therapeutic use will increase as their biological interactions with injured tissues become clearer.

Fetal mesenchymal stromal cells from cryopreserved human chorionic villi: cytogenetic and molecular analysis of genome stability in long-term cultures.

BACKGROUND AIMS: First-trimester chorionic villi (CV) are an attractive source of human mesenchymal stromal cells (hMSC) for possible applications in cellular therapy and regenerative medicine. Human MSC from CV were monitored for genetic stability in long-term cultures. METHODS: We set up a good manufacturing practice cryopreservation procedure for small amounts of native CV samples. After isolation, hMSC were in vitro cultured and analyzed for biological end points. Genome stability at different passages of expansion was explored by karyotype, genome-wide array-comparative genomic hybridization and microsatellite genotyping. RESULTS: Growth curve analysis revealed a high proliferative potential of CV-derived cells. Immunophenotyping showed expression of typical MSC markers and absence of hematopoietic markers. Analysis of multilineage potential demonstrated efficient differentiation into adipocytes, osteocytes, chondrocytes and induction of neuro-glial commitment. In angiogenic experiments, differentiation in endothelial cells was detected by in vitro Matrigel assay after vascular endothelial growth factor stimulation. Data obtained from karyotyping, array-comparative genomic hybridization and microsatellite genotyping comparing early with late DNA passages did not show any genomic variation at least up to passage 10. Aneuploid clones appeared in four of 14 cases at latest passages, immediately before culture growth arrest. CONCLUSIONS: Our findings indicate that hCV-MSC are genetically stable in long-term cultures at least up to passage 10 and that it is possible to achieve clinically relevant amounts of hCV-MSC even after few stages of expansion. Genome abnormalities at higher passages can occasionally occur and are always associated with spontaneous growth arrest. Under these circumstances, hCV-MSC could be suitable for therapeutic purposes.

Correction of beta-thalassemia major by gene transfer in haematopoietic progenitors of pediatric patients.

Beta-thalassemia is a common monogenic disorder due to mutations in the beta-globin gene and gene therapy, based on autologous transplantation of genetically corrected haematopoietic stem cells (HSCs), holds the promise to treat patients lacking a compatible bone marrow (BM) donor. We recently showed correction of murine beta-thalassemia by gene transfer in HSCs with the GLOBE lentiviral vector (LV), expressing a transcriptionally regulated human beta-globin gene. Here, we report successful correction of thalassemia major in human cells, by studying a large cohort of pediatric patients of diverse ethnic origin, carriers of different mutations and all candidates to BM transplantation. Extensive characterization of BM-derived CD34(+) cells before and following gene transfer shows the achievement of high frequency of transduction, restoration of haemoglobin A synthesis, rescue from apoptosis and correction of ineffective erythropoiesis. The procedure does not significantly affect the differentiating potential and the relative proportion of haematopoietic progenitors. Analysis of vector integrations shows preferential targeting of transcriptionally active regions, without bias for cancer-related genes. Overall, these results provide a solid rationale for a future clinical translation.