Adoptive Therapy with Allogeneic Cord Blood T Regulatory Cells Improves Transfusion Requirement in Bone Marrow Failure Syndromes

Background: An inflammatory bone marrow microenvironment with unchecked immune activation mediated by cytotoxic T cells and defective T regulatory cells contribute to acquired bone marrow failure (BMF) syndromes, including aplastic anemia (AA), myelofibrosis (MF) and hypoplastic myelodysplasia (MDS). Adoptive therapy with allogeneic cord blood (CB) T-regulatory (Treg) cells has shown safety in humans and clinical benefit in graft vs. host disease. Derived from CB, these Treg cells enjoy immune privilege, demonstrate high proliferative index, lack plasticity, and have been shown to consistently suppress inflammation. Therefore, we hypothesized that adoptive therapy with CB Tregs can be utilized as treatment for the inflammatory BMF disorders.