SAHA联合低剂量硼替佐米分离GVHD与GVL效应的协同作用及其免疫机制

Allogeneic bone marrow transplantation (allo-BMT) can induce graft-versus-leukemia (GVL) responses, which are crucial for the cure of hematological malignancies. Graft-versus-host disease (GVHD) which is a major complication in BMT, and GVL are both closely related to donor graft T cells; and up-regulating GVL responses while separating GVHD is one of the research highlights in the field of BMT. The applicant first discovered the unique value and shortcomings of proteasome inhibitor bortezomib in separating GVL and GVHD, and demonstrated that transplantation of donor T cells that release interferon-gamma (IFNγ) but do not express interferon-gamma receptor (IFNγR) are able to effectively reduce the pathological damage of GVHD while preserving GVL responses, which confirmed that IFNγR signal pathway is a key target of separation of GVL and GVHD. Suberoylanilide hydroxamic acid (SAHA, vorinostat) is a novel kind of molecular-targeted drug that inhibits histone deacetylases, and studies indicated that its mechanism of action is correlated with the inhibition of IFNγR signal pathway. In this proposal we hypothesize that SAHA and low-dose bortezomib exert a synergistic effect on separating GVL and GVHD. We are going to continue the investigations on the platform of related mouse BMT models to study the synergistic effect of the combination of SAHA and bortezomib on GVL and GVHD, and reveal the immune mechanism of separating GVL and GVHD, so as to provide theoretical evidence for improvement of BMT treatment strategies.

异基因骨髓移植具有移植物抗白血病（GVL）效应，对治愈恶性血液病至关重要。GVL和移植并发症-移植物抗宿主病（GVHD）均与供者T细胞相关联；上调GVL效应并分离GVHD，是本领域的研究热点。申请人最早发现蛋白酶体抑制剂硼替佐米在分离GVL与GVHD中的独特价值与不足；也曾报道移植不表达γ-干扰素受体（IFNγR）、但能正常释放γ-干扰素（IFNγ）的供者T细胞，可有效减轻GVHD，同时保留GVL效应，证实了IFNγR信号通路是分离GVL与GVHD的一个关键靶点。SAHA是一种抑制组蛋白去乙酰化酶的新型分子靶向药物，其作用机制被认为与阻断IFNγR信号通路相关联。申请人假设SAHA与低剂量硼替佐米两药合用对分离GVL/GVHD有协同调控作用，拟继续以相关小鼠移植模型为平台，探究上述二药合用对GVL/GVHD的影响，揭示其分离GVL/GVHD的免疫机制，为优化骨髓移植治疗策略提供理论依据。

移植物抗宿主病（GVHD）是异基因造血干细胞移植（allo-HSCT）的主要并发症，临床上经典的免疫抑制治疗，虽然可以减少急性GVHD的发生、减轻GVHD的严重程度，也同时减弱了移植物抗白血病（graft versus leukemia，GVL）效应，增加了白血病复发的风险。本课题申请人在国家自然科学基金资助下,取得了如下主要研究进展和重要实验结果：.（1）硼替佐米单药在移植后持续应用，受者血清细胞因子（IL-2,IL-5,IL-6,IL-10,GM-CSF,IFN-gamma）和趋化因子(CCL2,CXCL1,MIP-2,TNF-alpha,VEGF)水平显著上升。（2）组蛋白去乙酰化酶抑制剂SAHA 联合低剂量硼替佐米对抑制同种异基因反应 T淋巴细胞增殖有协同作用。（3）SAHA联合低浓度硼替佐米对SP2/0小鼠骨髓瘤细胞，RPMI8226/R5人骨髓瘤细胞，NCI-H929人骨髓瘤细胞 和K562人白血病细胞凋亡有协同促进作用。（4）SAHA治疗后，非侵袭性荷瘤小鼠外周血循环中的骨髓瘤细胞消失，侵袭性荷瘤小鼠瘤体生长速度缓慢，小鼠生存期延长。SAHA显著抑制了小鼠骨髓瘤细胞增殖，其抑制效应与诱导骨髓瘤细胞周期阻滞及凋亡相关联，而其机制与SAHA能够上调Caspase3和p53蛋白表达水平有关。（5）西达本胺是中国原创的比SAHA更新一代组蛋白去乙酰化酶抑制剂，西达苯胺联合地西他滨对抑制髓系白血病细胞增殖有协同作用；西达苯胺能够促进组蛋白H3K18乙酰化；西达苯胺联合地西他滨诱导髓系白血病细胞周期阻滞在G0/G1期；西达苯胺增强地西他滨对髓系白血病细胞的凋亡诱导作用；西达苯胺和地西他滨单独或联合使用均可促进线粒体膜电位下降。（6）在真实世界的造血干细胞移植体系，我们从供者和受者多角度证明了白血病干细胞的克隆性演化; 证实了微环境对急性白血病发生发展的影响；证明初诊急性白血病患者筛查SET-NUP214融合基因有利于白血病患者的早期识别。我们还发现， D-Dimer/FIB 比值和FDP/FIB比值对高危急性早幼粒白血病患者血栓及出血并发症的鉴别诊断与预测具有重大意义。本课题核心结果和关联结果发表SCI文章5篇，中文核心期刊文章5篇，培养博士生2名，硕士生7名。