6533b871fe1ef96bd12d1a98

RESEARCH PRODUCT

Human CD8+ memory and EBV-specific T cells show low alloreactivity in vitro and in CD34+ stem cell–engrafted NOD/SCID/IL-2Rγcnull mice

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Current strategies in cellular immunotherapy of cancer and viral infections include the adoptive transfer of T cell receptor (TCR) and chimeric antigen receptor engineered T cells. When using transient RNA expression systems in clinical studies, multiple infusions with receptor-redirected T cells appear necessary. However, in allogeneic hematopoietic stem-cell transplantation, repeated transfer of donor-derived T cells increases the risk of alloreactive graft-versus-host disease. We investigated naive-derived (T N ), memory-derived (T M ), and Epstein Barr virus-specific (T EBV ) CD8 + T cell subsets for alloreactivity upon redirection with RNA encoding a cytomegalovirus-specific model TCR. We observed that alloreactivity to human leukocyte antigen (HLA)-mismatched hematopoietic cells developed at much stronger levels in T N compared with T M or T EBV populations in cytokine-release and cytotoxicity assays. Cytomegalovirus-specific effector function was higher in TCR-transfected T EBV and T M over T N cells. To measure alloreactivity in vivo, we reconstituted NOD/SCID/IL-2Rγc null mice with human CD34 + stem cells and adoptively transferred them with CD8 + T cell subsets previously stimulated against cells of the HLA-mismatched stem-cell donor. T N cells showed a significant ability to eliminate CD34-derived hematopoietic cells, which was not found with T M and T EBV cells. This reduced alloreactive potential along with strong effector function upon receptor RNA engineering makes CD8 + memory and EBV-specific T cells advantageous tools in adoptive immunotherapy after allogeneic transplantation.