T cell-mediated immune surveillance is critical for cancer control, yet its role in bone marrow malignancies remains poorly understood. Here, we integrate TCR profiling, HLA immunopeptidomics, and functional screening to characterize tumor-reactive T cells in the bone marrow of patients with multiple myeloma (MM) and acute myeloid leukemia (AML). These cells are transcriptionally defined by a conserved effector program distinct from the exhausted phenotype of tumor-reactive T cells in solid cancers. Immunopeptidomic profiling reveals a partially shared antigen landscape enriched for noncanonical peptides driving convergent TCR responses. We develop TFiT (tumor-reactive features in T cells), a transcriptional classifier that identifies these cells and stratifies immunotherapy, but not chemotherapy, response across independent MM and AML cohorts, supporting its specificity for T cell-mediated tumor control. These findings reveal a latent but activatable anti-tumor T cell compartment in bone marrow malignancies and provide a framework for engaging endogenous immunity in MM and AML.
N. Kehl, T. Wagner, Simon Steiger et al.· Cancer Cell· 0 citations
Neoepitope-based therapies hold great promise for cancer immunotherapy because they target tumor-specific mutations and elicit potent anti-tumor T-cell responses. However, their clinical implementation remains limited by the complexity of neoepitope discovery and uncertainty regarding presentation by tumor cells. A potential alternative is the generation of immunogenic neoepitopes directly within cancer cells through programmable RNA editing. Here, we develop Short Precise-Encodable ADAR Recruiting (SPEAR) gRNAs that harness endogenous ADAR1 to direct precise adenosine-to-inosine (A-to-I) editing at selected transcript sites. Using these gRNAs, we demonstrate the generation of immunogenic neoepitopes through RNA editing at the transcript level, termed editopes. In a proof-of-concept model based on the melanoma antigen MART-1, SPEAR-mediated RNA editing restored antigen-specific T cell recognition and enabled tumor control in vivo. Finally, we developed a computational pipeline to identify candidate tumor-selective neoepitopes across multiple cancer types amenable to guided RNA editing. Our findings establish programmable RNA editing as a strategy for engineering immunogenic editopes and provide a framework for neoepitope-directed cancer immunotherapy.
R. Pecori, Beatrice Casati, Rona Merdler-Rabinowicz et al.· EMBO Journal· 0 citations