IFNγ Drives Long-Term Bone Marrow Niche Dysfunction Following Doxorubicin-Based Chemotherapy

Cancer survivors experience long-term skeletal and hematopoietic complications that limit quality of life following chemotherapy (CTX), yet the mechanisms underlying these defects remain incompletely understood. Using a murine model of doxorubicin (DOX)-based leukemia induction therapy, we show that CTX induces inflammatory remodeling of the bone marrow (BM) niche. DOX treatment resulted in loss of arteriolar vasculature, blockade of mesenchymal stromal cell (MSC) differentiation, trabecular bone loss, and reduced niche capacity to maintain hematopoietic stem cells (HSCs). These defects were accompanied by aberrant immune activation within the BM, marked by increased interferon-γ (IFNγ) production by CD8⁺ T cells. Inhibition of IFNγ signaling partially restored arteriolar vessels and adipogenic differentiation. Moreover, combined IFNγ blockade and deferoxamine mesylate (DFM), which promotes vascular recovery, attenuated chemotherapy-associated skeletal damage. Consistent with these findings, paired BM samples collected at diagnosis and post-CTX from leukemia patients exhibited altered MSC lineage priming, upregulation of inflammatory pathways, and expansion of BM CD8⁺ memory T cells after treatment. Together, these findings implicate IFNγ-driven chronic inflammatory remodeling as a central mechanism of CTX-associated BM niche dysfunction and pinpoints inflammatory signaling as a potential target to preserve BM function and long-term tissue integrity.