Adoptive cellular immunotherapy with CD19-specific T cells

Background: No effective therapeutic modalities exist for the treatment of relapsed high risk acute lymphoblastic leukemia (ALL). Adoptive cellular immunotherapy by transfusion of polyclonal donor lymphocytes is not always effective and is limited by cellular cross-reactivity with normal tissues, leading to development of clinical graft-versus-host disease (GVHD). Method: To develop an immunotherapeutic strategy for targeted elimination of residual leukemic blasts, human T cells were gene-modified to express CD19-specific chimeric receptors. Results: Gene-modified T cells specifically lyse CD19-expressing lymphatic blast cells, however, they show a limited proliferative response to stimulation with CD19. Integration of the signal transduction domain of the costimulatory molecule CD28 enhances the proliferative properties of the gene-modified T cells. Conclusions: Adoptive transfer of gene-modified virus-specific T cells may provide a useful strategy for prevention and early treatment of ALL relapses following allogeneic stem cell transplantation.