SOCS1 protects acute myeloid leukemia against allogeneic T cell-mediated cytotoxicity.

Despite the curative potential of allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia (AML), its efficacy is limited by intrinsic resistance of cancer cells to donor-derived T-cell cytotoxicity. Using a genome-wide CRISPR screen, we identified the SOCS1-JAK1-STAT1 pathway as a mediator of AML susceptibility to T cells. SOCS1 knockdown in AML cells sensitized them to killing by allogeneic T cells, whereas SOCS1 overexpression in AML cells induced resistance to T-cell anti-leukemic activity. Mechanistically, SOCS1 protected AML cells from T-cell killing by antagonizing IFNγ-JAK1-induced ICAM-1 expression. Furthermore, primary AML cells with lower SOCS1 expression correlated with better overall survival in patients, especially those with a lower exhausted CD8+ T-cell score. Thus, this study reveals SOCS1 and its downstream mediators as a potential targetable pathway to enhance T cell-based immunotherapy for AML.