Efficacy of JAK 1/2 inhibition in murine immune bone marrow failure

Background and methods: Ruxolitinib (RUX) is a Jak inhibitor that is used in the treatment of intermediate or high risk myelofibrosis and resistant forms of polycythemia vera and graft-vs-host disease due to its efficacy of reducing inflammatory cytokines and markers of inflammation. We tested its potential therapeutic effects in murine models of immune-mediated bone marrow failure. RNA-Seq and analysis was performed using NEBNext Ultra™ II RNA Library Prep Kit for Illumina and Illumina Novaseq6000, according to the Institute's protocols. Results: As both prophylaxis and therapy, Ruxolitinib improved pancytopenia and BM cellularity and decreased BM T cell infiltration in bone marrow failure mice. RNA sequencing demonstrated that Ruxolitinib suppressed expression of inflammtory genes in bone marrow infiltrated CD8 T cells compared with untreated mice. Conclusion: Our results demonstrate that Ruxolitinib is highly effective in attenuation of disease and extending survival of immune-mediated bone marrow failure mice. We compared transcriptomes of CD8 T cells in the bone marrow failure mice treated with and without Ruxolitinib, and described differentially expressed genes of these cells. CD8+ T cells were isolated from bone marrow cells of Ruxolitinib-treated and control BMF mice using CD8 microbeads (Miltenyi Biotec, Auburn, CA). To get enough cells for RNA extraction, CD8+ T cells from every 2-3 mice in the same group were pooled together, we obtained 3 pools/group. Total RNA was isolated using the RNeasy Mini kit (Qiagen, Valencia, CA), according to the manufacturer's instructions.