Abstract：
BACKGROUND: Myeloid-derived suppressor cells (MDSCs) negatively modulate immune activity. Prior investigations have shown much promise in using MDSCs-assisted immunotherapy for organ transplantation patients. Additionally, owing to its immunosuppressive activity, MDSCs can also be used to manage immune-associated disorders.
METHODS: Granulocyte-macrophage colony-stimulating factor (GM-CSF) was employed to stimulate myeloid progenitor cell differentiation. Triptolide (PG490) was introduced toward the later phases of in vitro MDSCs induction. Lastly, real-time PCR (RT-PCR) and flow cytometry were used to assess transcript expression and cell phenotype, and a mouse skin transplantation model was established to evaluate the MDSCs-mediated immune suppression in vivo.
RESULTS: Co-stimulation with PG490 and GM-CSF potently induced myeloid-derived monocytes to form MDSCs, with remarkable immune-suppressive activity. The underlying mechanism involved downregulation of T cell proliferation, activation, enhancement of inflammatory cytokine release, as well as T cell conversion to Treg cells. PG490 strongly enhanced iNOS expression in MDSCs, and iNOS inhibition successfully reversed the immune-suppression. The PG490- and GM-CSF-induced MDSCs substantially extended survival duration of murine skin grafts, thereby validating their strong immune-suppressive activity in vivo.
CONCLUSIONS: Herein, we presented a new approach involving MDSCs-based immunosuppression in vitro. PG490 and GM-CSF co-treatment strongly induced immuno-suppressive activity in MDSCs both in vitro and in vivo. Our findings highlight the promise of applying MDSCs-based therapy in clinical organ transplantation treatment.
METHODS: Granulocyte-macrophage colony-stimulating factor (GM-CSF) was employed to stimulate myeloid progenitor cell differentiation. Triptolide (PG490) was introduced toward the later phases of in vitro MDSCs induction. Lastly, real-time PCR (RT-PCR) and flow cytometry were used to assess transcript expression and cell phenotype, and a mouse skin transplantation model was established to evaluate the MDSCs-mediated immune suppression in vivo.
RESULTS: Co-stimulation with PG490 and GM-CSF potently induced myeloid-derived monocytes to form MDSCs, with remarkable immune-suppressive activity. The underlying mechanism involved downregulation of T cell proliferation, activation, enhancement of inflammatory cytokine release, as well as T cell conversion to Treg cells. PG490 strongly enhanced iNOS expression in MDSCs, and iNOS inhibition successfully reversed the immune-suppression. The PG490- and GM-CSF-induced MDSCs substantially extended survival duration of murine skin grafts, thereby validating their strong immune-suppressive activity in vivo.
CONCLUSIONS: Herein, we presented a new approach involving MDSCs-based immunosuppression in vitro. PG490 and GM-CSF co-treatment strongly induced immuno-suppressive activity in MDSCs both in vitro and in vivo. Our findings highlight the promise of applying MDSCs-based therapy in clinical organ transplantation treatment.
摘要：
背景：髓系来源的抑制细胞（MDSC）负调节免疫活性。先前的研究显示，在器官移植患者使用MDSC辅助免疫疗法方面有很大的希望。此外,由于其免疫抑制活性，MDSC还可用于管理免疫相关病症。
方法：使用粒细胞-巨噬细胞集落刺激因子（GM-CSF）刺激骨髓祖细胞分化。将雷公藤甲素(PG490)引入体外MDSC诱导的后期阶段。最后,实时PCR（RT-PCR）和流式细胞术用于评估转录本表达和细胞表型，建立小鼠皮肤移植模型,评价MDSCs介导的体内免疫抑制作用。
结果：PG490和GM-CSF共刺激可有效诱导髓源性单核细胞形成MDSCs，具有显著的免疫抑制活性。潜在的机制涉及T细胞增殖的下调，激活,炎性细胞因子释放的增强，以及T细胞转化为Treg细胞。PG490强烈增强MDSCs中iNOS的表达，和iNOS抑制成功逆转了免疫抑制。PG490和GM-CSF诱导的MDSCs显著延长小鼠皮肤移植物的存活时间,从而验证其在体内的强免疫抑制活性。
结论：此处，我们提出了一种基于MDSCs的体外免疫抑制新方法.PG490和GM-CSF共同处理在体外和体内都强烈诱导了MDSC中的免疫抑制活性。我们的发现强调了在临床器官移植治疗中应用基于MDSCs的治疗的前景。
方法：使用粒细胞-巨噬细胞集落刺激因子（GM-CSF）刺激骨髓祖细胞分化。将雷公藤甲素(PG490)引入体外MDSC诱导的后期阶段。最后,实时PCR（RT-PCR）和流式细胞术用于评估转录本表达和细胞表型，建立小鼠皮肤移植模型,评价MDSCs介导的体内免疫抑制作用。
结果：PG490和GM-CSF共刺激可有效诱导髓源性单核细胞形成MDSCs，具有显著的免疫抑制活性。潜在的机制涉及T细胞增殖的下调，激活,炎性细胞因子释放的增强，以及T细胞转化为Treg细胞。PG490强烈增强MDSCs中iNOS的表达，和iNOS抑制成功逆转了免疫抑制。PG490和GM-CSF诱导的MDSCs显著延长小鼠皮肤移植物的存活时间,从而验证其在体内的强免疫抑制活性。
结论：此处，我们提出了一种基于MDSCs的体外免疫抑制新方法.PG490和GM-CSF共同处理在体外和体内都强烈诱导了MDSC中的免疫抑制活性。我们的发现强调了在临床器官移植治疗中应用基于MDSCs的治疗的前景。
