Overview

• BCG reprograms hematopoietic stem and progenitor cells in the bone marrow to boost myeloid-driven innate immune responses against tumors.
• Single-cell sequencing of circulating progenitors from treated patients revealed gene expression changes that favor the development of more potent cancer-fighting myeloid cells.
• Mouse models confirmed that bladder-administered BCG migrates to the bone marrow, where live bacteria can be recovered, underpinning its systemic effects.
• Preclinical experiments showed that pairing BCG with checkpoint inhibitors achieved superior tumor shrinkage and extended survival compared to either therapy alone.
• Researchers suggest that harnessing this bone marrow reprogramming could enhance the effectiveness of immunotherapies across a range of cancer types.