Allogeneic Immunotherapy of Hematological Malignancies Using Regulatory T-cell Selective Depletion

Since the discovery that Treg suppress anti-tumor immune responses, inhibiting their function has become a major challenge for the development of efficient immunotherapy for cancer. In humans, we previously reported the positive results of a first clinical trial using Treg depletion for anti-tumor response amplification in the field of allogeneic hematopoietic stem cell transplantation (HSCT). The present project aims at developing this anti-tumor immunotherapeutic strategy in the same setting, i.e. donor lymphocyte infusion (DLI) for relapsing hematological malignancies after HSCT, using a new selection marker: CD127. The choice of this new strategy is supported by our results of a retrospective clinical study and pre-clinical data. Using human cells, this studies demonstrated, in vitro and in vivo in animal murine models, that Treg depletion through CD127 positive selection is much more efficient to improve allogeneic immune responses of donor T-cells as compared to the previous strategy using the CD25 marker.