Latent effector T cells mediate immunotherapy responses in the bone marrow microenvironment.

Latent effector T cells in the bone marrow predict immunotherapy response in multiple myeloma and AML with 80% accuracy.

• Why it matters: Understanding T cell roles in bone marrow cancers is crucial because their unique characteristics may influence treatment success, yet they are poorly characterized compared to solid tumors.
• What they did: The study used TCR profiling, HLA immunopeptidomics, and functional screening to identify tumor-reactive T cells in the bone marrow of 50 patients, developing TFiT, a transcriptional classifier to detect these cells.
• The result: The classifier predicts immunotherapy response with high specificity, revealing a dormant but activatable anti-tumor T cell population that could be targeted to improve treatment outcomes in MM and AML.