Biological Characteristics of Bone Marrow-Derived Mesenchymal Stem Cells From a Patient with β-Thalassemia.

Abstract 4579

Thalassemia syndromes are considered as a heterogeneous group of inherited anemias leading to decrease or loss of synthesis of one or more globin chain subunits of the adult hemoglobin tetramer (Hb A). Beta-thalassemia results from a decrease in β-chain production of hemoglobin relative to alpha-chain production. Hematopoietic stem cell transplantation from HLA-identical siblings is curative for thalassemia syndrome. Bone marrow (BM)-derived mesenchymal stem cells (MSCs) are primitive, undifferentiated cells which are capable of self-renewal, and differentiating morphologically and functionally into different cell lineages including adipocytes, chondrocytes, myocytes, astrocytes, tenocytes, and hepatocytes. There have been contrasting data on whether BM derived MSCs are altered in various hematological disorders including leukemia, multiple myeloma, and myelodysplastic syndrome as well as autoimmune disease. To date, functional characterization of MSCs has never been performed in thalassemia syndrome. In the present study, we isolated BM-derivied MSCs from a patient with β-thalassemia in order to compare phenotypic and functional characteristics to those from normal healthy donor. No differences were observed between MSCs from β-thalassemia and those from normal healthy donor in terms of morphology, phenotype, karyotype, multi-differentiation capacity. In mitogen-stimulated T cell proliferation assay and mixed lymphocyte reaction, MSCs from β-thalassemia strongly inhibited the proliferation of allogeneic T cells in association with reduced proportion of CD3⁺, CD4⁺ and CD8⁺ cells. Furthermore, the fraction of CD4⁺CD25⁺Foxp3⁺ cells (Treg cells) was increased under the culture with MSCs from β-thalassemia, suggesting that MSCs from β-thalassemia exerts normal immunomodulatory function. In addition, β-thalassemia-derived MSCs expressed hematopoietic cytokines and supported hematopoiesis which were comparable to those from normal BM-dereived MSCs. In summary, β-thalassemia-derived MSCs exhibited normal phenotype, karyotype as well as normal immunomodulatory function, and autologous MSCs from patients with β-thalassemia may be an attractive source of stem cell in terms of hematopoietic support as well as immunomodulatory activity.