Allogeneic T lymphocytes with potential immune reconstitution activity. Donor T lymphocytes are transduced with a retroviral vector (BPZ-1001) encoding the inducible suicide gene caspase 9 (iCasp9) and linked to a drug binding domain. Donor T-cell therapy may help control transplant-related infections following allogeneic hematopoietic stem cell transplantation. However, the addition of donor T cells can lead to graft-versus-host disease (GVHD). In the event that GVHD begins to develop, the chemical homodimerizer AP1903 can be administered, which binds to the drug binding domain and induces caspase 9 expression. This activates apoptosis in the T cells causing GVHD.