Immune-mediated bone marrow failure in C57BL/6 mice

• We developed a new model of immune-mediated bone marrow failure in C57BL/6 mice
• Irradiation dose and specific donor-recipient combination are critical to model development
• Bone marrow of model animals displayed clonal T-cell expansion and T-cell Fas ligand upregulation
• Inflammatory cytokine interferon γ and tumor necrosis factor α were increased
• Mice carrying germline Fas deletion had bone marrow destruction significantly attenuated

We established a model of immune-mediated bone marrow (BM) failure in C57BL/6 (B6) mice with 6.5 G total-body irradiation followed by the infusion of 4-10 × 106 lymph node (LN) cells/recipient from Friend leukemia virus B/N (FVB) donors. Forty-three percent of animals succumbed, with surviving animals showing marked declines in blood neutrophils, red blood cells, platelets and total BM cells at 8 to 14 days following LN cell infusion. Lowering the total-body irradiation dose to 5 G or altering the LN source from FVB to BALB/cBy donors failed to produce BM destruction. Affected animals showed significant expansion and activation of CD8 T lymphocytes in both the blood and BM; cytotoxic T cells had elevated Fas ligand expression and were oligoclonal, mainly displaying Vβ7 and Vβ17 T cell receptors. There were significant increases in blood plasma interferon γ and tissue necrosis factor α in affected animals. Chemokine ligands CCL3, CCL4, CCL5, CCL20, CXCL2, and CXCL5 and hematopoietic growth factors G-CSF, M-CSF, GM-CSF, VEGF were also elevated. In B6 mice carrying a Fas gene mutation, BM failure was attenuated when they were infused with FVB LN cells. Our model establishes a useful platform to define the roles of individual genes and their products in immune-mediated BM failure.