The role of human umbilical cord tissue-derived mesenchymal stromal cells (UCX ) in the treatment of inflammatory arthritis

Background ECBio has developed proprietary technology to consistently isolate, expand and cryopreserve a well-characterized population of stromal cells from human umbilical cord tissue (UCX cells). The technology has recently been optimized in order to become compliant with Advanced Medicine Therapeutic Products. In this work we report the immunosuppressive capacity of UCX cells for treating induced autoimmune inflammatory arthritis. Methods UCX cells were isolated using a proprietary method (PCT/IB2008/054067) that yields a well-defined number of cells using a precise proportion between tissue digestion enzyme activity units, tissue mass, digestion solution volume and void volume. The procedure includes three recovery steps to avoid non-conformities related to cell recovery. UCX surface markers were characterized by flow cytometry and UCX capacity to expand in vitro and to differentiate into adipocyte, chondrocyte and osteoblast-like cells was evaluated. Mixed Lymphocyte Reaction (MLR) assays were performed to evaluate the effect of UCX cells on T-cell activation and Treg conversion assays were also performed in vitro. Furthermore, UCX cells were administered in vivo in both a rat acute carrageenan-induced arthritis model and rat chronic adjuvant induced arthritis model for arthritic inflammation. UCX anti-inflammatory activity was then monitored over time. Results UCX cells stained positive for CD44, CD73, CD90 and CD105; and negative for CD14, CD19 CD31, CD34, CD45 and HLA-DR; and were capable to differentiate into adipocyte, chondrocyte and osteoblast-like cells. UCX cells were shown to repress T-cell activation and promote the expansion of Tregs better than bone marrow mesenchymal stem cells (BM-MSCs). Accordingly, xenogeneic UCX administration in an acute carrageenan-induced arthritis model showed that human UCX cells can reduce paw edema in vivo more efficiently than BM-MSCs. Finally, in a chronic adjuvant induced arthritis model, animals treated with intra-articular (i.a.) and intra-peritoneal (i.p.) infusions of UCX cells showed faster remission of local and systemic arthritic manifestations. Conclusion The results suggest that UCX cells may be an effective and promising new approach for treating both local and systemic manifestations of inflammatory arthritis.