Engager T cells: a new class of antigen-specific T cells that redirect bystander T cells.

Adoptive immunotherapy with antigen-specific T cells has shown promise for the treatment of malignancies. However, infused T cells are unable to redirect resident T cells, limiting potential benefit. While the infusion of bispecific T-cell engagers can redirect resident T cells to tumors, these molecules have a short half-life, and do not self amplify. To overcome these limitations, we generated T cells expressing a secretable T-cell engager specific for CD3 and EphA2, an antigen expressed on a broad range of human tumors (EphA2-ENG T cells). EphA2-ENG T cells were activated and recognized tumor cells in an antigen-dependent manner, redirected bystander T cells to tumor cells, and had potent antitumor activity in glioma and lung cancer severe combined immunodeficiency (SCID) xenograft models associated with a significant survival benefit. This new class of tumor-specific T cells, with the unique ability to redirect bystander T cells, may be a promising alternative to current immunotherapies for cancer.