Low dose ruxolitinib plus cyclosporine to treat murine immune-mediated bone marrow failure

Background and methods: Ruxolitinib (RUX), a Jak1/2 inhibitor, has been reported to attenuate murine bone marrow failure recently. Its potential toxocicty of anemia and thrombocytopenia in human remains a concern. To minimize its potential toxoxicity, we tested therapeutic effectsof low dose ruxolitinib plus cyclosporine in murine model of immune-mediated bone marrow failure. Bone marrow CD8 and CD4 T cells were sorted from treated or untreated bone marrow failure mice. RNA-Seq and analysis was performed using SMART-Seq mRNA LP Kit (Takara) and the Illumina Novaseq6000, according to the Institute's protocols. Results: low dose of ruxolitinib plus cyclosporine improved pancytopenia and BM cellularity and decreased BM T cell infiltration in bone marrow failure mice. RNA sequencing demonstrated that low dose of ruxolitinib plus cyclosporine suppressed immune-related pathways in bone marrow infiltrated CD8 T cells and MHC-II expression in CD4 T cells compared with untreated mice. Conclusion: Our results demonstrate that low dose of ruxolitinib plus cyclosporine remains the efficacy in attenuation of disease and extending survival of immune-mediated bone marrow failure mice.