髓源性抑制细胞在肺癌中的研究进展

髓源性抑制细胞(Myeloid-derived suppressor cells,MDSCs)是一群来自骨髓不成熟的异质性细胞,表型及成分复杂,在肿瘤微环境中发挥免疫抑制功能,并主要抑制T细胞免疫应答.在肺癌的发生、发展过程中,多种异常表达的细胞因子促进MDSCs增殖与激活,MDSCs活化后参与形成抑制性肿瘤免疫微环境,从而促进肿瘤细胞生长.监测MDSCs的数量与功能变化对评估肺癌的预后有重要意义.一系列针对MDSCs的干预措施在肺癌治疗中获得了重大进展,也为肺部原发及转移瘤的预防带来了希望.     

骨髓源性抑制细胞在肿瘤免疫治疗中的研究进展及与肺癌预后的关系

免疫治疗是肺癌新兴治疗方法,其疗效受肿瘤免疫微环境（tumor immune microenvironment,TIME）影响。骨髓源性抑制细胞(myeloid-derived suppressor cells,MDSCs)是免疫微环境的主要免疫抑制细胞,在肿瘤的发生、发展、侵袭和转移过程中起关键作用。近年来,探索克服MDSCs的免疫抑制,从而增强抗肿瘤治疗疗效的研究已经成为研究热点。在这篇综述中,我们讨论了靶向MDSCs以及与ICI联合治疗的进展,并总结了MDSCs对肺癌患者预后的影响。     

髓样抑制细胞在肿瘤生物学中作用的研究进展

髓样抑制细胞(myeloid-derived suppressor cells,MDSCs)是存在于荷瘤小鼠及肿瘤患者体内、具有免疫抑制功能的细胞群。它由髓系来源的未分化成熟的具有异质性的细胞组成,其中包括树突状细胞、巨噬细胞和粒细胞等。肿瘤细胞分泌的各种因子能诱导MDSCs的产生、运动及活化。荷瘤小鼠来源的MDSCs主要表达CD11b+Gr1+,而肿瘤患者来源的MDSCs主要表达CD11b+CD14-。在荷瘤小鼠骨髓、脾脏和外周血及肿瘤患者的外周血中MDSCs水平升高。MDSCs通过抑制机体免疫功能和促进新生血管生成等机制参与肿瘤的生长及向远处转移。抑制体内MDSCs的功能和降低其数量有助于恢复机体识别、杀伤肿瘤细胞的能力,并提高药物疗效。本文对MDSCs在肿瘤领域的最新研究进展进行综述。     

骨髓间充质干细胞预防手术后肿瘤肺转移动物模型研究

背景与目的:近年来研究发现,肿瘤患者术后髓系抑制细胞(myeloid-derived suppressor cells,MDSCs)较术前升高,且其促肿瘤血管生成和肿瘤生长作用增强,骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)可抑制MDSCs活化与增殖.但围手术期MDSCs的变化与肿瘤术后转移的关系及BMSCs能否通过抑制MDSCs预防手术后肿瘤转移尚不清楚.该研究拟探讨围手术期MDSCs变化与手术后肿瘤转移的相关性及BMSCs对围手术期MDSCs和手术后肿瘤转移的影响.方法:C57BL/6小鼠经尾静脉注射LLC细胞后分为4组:对照组(C组)、麻醉组(A组)、麻醉后开腹组(AL组)及麻醉后开腹并肝叶切除组(ALH组).AL组小鼠手术后分为2组:术后无治疗组(AL1组)和术后给予同系BMSCs治疗组(ALB组).流式细胞术检测小鼠外周血单个核细胞(peripheral blood mononuclear cells,PBMCs)中Gr-1+CD11b+细胞的含量;第14天计数小鼠肺表面转移灶.小鼠骨髓细胞体外诱导MDSCs体系中加入BMSCs共培养的方法探讨BMSCs对MDSCs生成的影响.结果:与C、A组相比,AL和ALH组小鼠肺转移灶显著增多(P<0.01);且ALH组较AL组显著增多(P<0.05).手术后AL和ALH组小鼠PBMCs中Gr-1+CD11b+细胞与C、A组相比显著升高;与AL组比较,ALH组Gr-1+CD11b+细胞显著升高.第14天,AL及ALB组小鼠肺表面转移灶数量分别为38.00±9.57和6.54±1.49,差异有统计学意义(P<0.01).ALB组小鼠PBMCs中Gr-1+CD11b+细胞与AL1组相比明显降低.小鼠骨髓细胞体外诱导MDSCs体系中加入BMSCs可显著抑制MDSCs的活化和增殖.结论:手术应激诱导MDSCs并促肿瘤肺转移形成,BMSCs可以抑制MDSCs的生成进而抑制手术后肺转移形成.     

乳腺癌髓系来源抑制细胞中IDO表达与调节性T细胞相关性及其临床意义的研究

  目的  研究不同期别乳腺癌组织中CD33+髓系来源抑制细胞(MDSCs)和Foxp3+调节性T细胞(Tregs)的分布情况, 探讨MDSCs中吲哚胺2, 3-双加氧酶(IDO)表达与Tregs分布关系及其临床意义。   方法  收集天津医科大学附属肿瘤医院2005年1月至2007年1月手术患者的乳腺癌石蜡切片50例, 采用免疫组织化学单染方法对肿瘤局部CD33+MDSCs和Foxp3+Tregs分布和比例进行检测; 采用免疫组织化学双染方法检测肿瘤原位浸润MDSCs中IDO的表达情况; 分析MDSCs中IDO表达与Tregs分布、比例及其他临床病理资料之间的相关性。   结果  Foxp3+Tregs和CD33+MDSCs细胞在乳腺癌组织中呈散在性分布。MDSCs中IDO表达水平与腋窝淋巴结转移密切相关(P < 0.05)。Foxp3+Tregs高表达组中MDSCs中IDO表达水平显著高于Foxp3+Tregs低表达或不表达组(P < 0.05)。   结论  MDSCs中IDO过表达可能有利于Tregs的募集和乳腺癌的转移。      

MDSCs与肿瘤免疫逃逸

髓源抑制性细胞(myeloidderived suppressor cells, MDSCs)是一群异质性细胞,来源于骨髓祖细胞和未成熟髓细胞(immature myeloid cells, IMCs),是树突状细胞（dendritic cells, DCs）、巨噬细胞和（或）粒细胞的前体。在荷瘤小鼠的血液、脾脏和肿瘤组织及肿瘤患者的外周血和肿瘤组织存在大量MDSCs的扩增。MDSCs可以通过多种途径抑制机体的获得性和天然抗肿瘤免疫,使肿瘤细胞逃避机体的免疫监视和攻击,促进肿瘤发展。MDSCs首先从骨髓募集到外周,并在外周被激活后才能发挥抗肿瘤免疫抑制功能,肿瘤来源的慢性炎症相关的一系列因子在介导MDSCs的募集和活化中起关键作用。当前靶向MDSCs的抗肿瘤治疗取得了一定的进展,但MDSCs从发现到现在仅仅经历了10年左右的时间,该领域中许多的未知尚需要大量的基础和临床研究来阐明。本文主要介绍MDSCs的特征及其亚群、MDSCs的募集和活化、MDSCs介导免疫逃逸的机制及当前靶向MDSCs的抗肿瘤治疗策略,以期为从事该领域的研究工作者提供参考。     

乳腺癌患者髓系来源抑制性细胞的鉴定与免疫作用研究

目的:探讨乳腺癌患者体内一群髓系来源抑制性细胞(MDSCs)的表型特点及它对淋巴细胞的抑制作用.方法:收集20例乳腺癌患者外周血及肿瘤组织,10例体检正常健康者外周血,通过流式和免疫组织化学染色技术检测MDSCs的表型特点及比例.采用免疫磁珠技术分选乳腺癌患者肿瘤中的MDSCs,通过瑞氏染色观察细胞形态,分别利用MTT法、流式细胞术和ELISA法检测其对自体淋巴细胞增殖、凋亡和细胞因子分泌的影响.结果:流式细胞仪检测结果显示乳腺癌患者肿瘤组织及外周血中有一群具有髓系前体细胞形态的MDSCs,表面标志为CD45+ CD13+CD33+CD14-CD15-.实验结果显示肿瘤组织来源的MDSCs显著抑制自体淋巴细胞增殖,促进其调亡,并显著抑制其分泌IFN-γ,促进TGF-β、IL-10释放.结论:乳腺癌患者肿瘤组织中存在一群具有独特表型特点的MDSCs,不仅抑制自体淋巴细胞增殖和因子分泌,同时促进细胞凋亡.     

髓源性抑制细胞联合免疫检查点抑制剂抗肿瘤治疗的研究进展CSCD

免疫检查点抑制剂(ICI)可通过恢复T细胞对肿瘤细胞的识别和损伤功能来增强原有的抗肿瘤免疫应答。ICI已被批准用于黑色素瘤、非小细胞肺癌(NSCLC)和肾细胞癌等多种肿瘤的治疗。然而,许多患者对免疫治疗没有反应。其中部分原因是由髓源性抑制细胞(MDSCs)介导的。这种异质的未成熟骨髓细胞群可以强烈抑制T细胞和NK细胞的抗肿瘤活性并刺激调节性T细胞(Treg)产生免疫抑制,导致肿瘤进展。MDSCs可以促进患者对免疫检查点抑制的耐药。越来越多的证据表明MDSCs在肿瘤患者中的比例和免疫抑制功能可用于治疗反应的预测。本综述重点介绍了MDSCs在免疫检查点抑制中的作用,并提供了MDSCs与ICI靶向联合治疗的策略,以提高后者在肿瘤治疗中的疗效。     

髓源抑制性细胞与恶性肿瘤的研究进展

髓源抑制性细胞(myeloid derived suppressor cells,MDSCs)是一群异质性细胞,包括多种处于不同分化阶段的髓样细胞,如髓系祖细胞、未成熟的巨噬细胞、粒细胞、单核细胞、树突状细胞等。在荷瘤小鼠的血液、脾脏和肿瘤组织及肿瘤患者的外周血和肿瘤组织中存在大量MDSCs的扩增,与肿瘤的进展密切相关。恶性肿瘤来源的多种因子如粒细胞-巨噬细胞集落刺激因子（granulocyte-macrophage colony stimulating factor,GM-CSF）、白细胞介素（interleukin,IL）-6、S100钙结合蛋白A8/A9（S100 calcium binding protein A8/A9,S100A8/A9）等是导致MDSCs扩增的关键因素。MDSCs可通过抑制机体抗肿瘤免疫、上皮-间质转化(epithelial-mesenchymal transition,EMT）、侵袭、血管生成、转移前小生境形成等多种途径导致肿瘤发生发展。本文主要介绍MDSCs的亚群、功能、募集和活化机制,MDSCs作为预后标志物的价值以及当前靶向MDSCs的抗肿瘤治疗策略,以期加深对MDSCs与恶性肿瘤关系的认识。     

不同疾病状态ALL患者中MDSCs的分布差异及免疫抑制作用

目的 探讨髓系来源抑制细胞(myeloid-derived suppressor cells,MDSCs)在急性淋巴细胞白血病(acute lymphoblastic leukemia,ALL)不同疾病状态下的数量分布情况,并探讨其在介导ALL肿瘤免疫逃逸过程中的免疫抑制作用.方法 通过流式细胞术测定初发未治、治疗后缓解和复发难治ALL患者外周血单个核细胞中MDSCs细胞的比例,并采用定量PCR法检测Foxp3 mRNA的表达水平,以健康人外周血为对照组.分离不同疾病状态ALL患者的MDSCs细胞与健康人T淋巴细胞共培养,观察其抑制T淋巴细胞增殖的情况.结果 复发难治组外周血中的MDSCs数量所占比例高于初发未治组、缓解组以及对照组,而初发未治组又高于缓解组以及对照组(均P<0.05).Foxp3 mRNA水平在复发难治组中最高,其次为初发未治组.患者外周血中MDSCs与健康人T淋巴细胞共培养第5天和第7天时,初发未治组和复发难治组T细胞增殖水平均低于缓解组(均P<0.05).结论 初发和复发ALL患者中存在MDSCs数量扩增,且Foxp3 mRNA表达水平增高.MDSCs可能通过抑制正常T淋巴细胞增殖或诱导调节性T细胞产生介导肿瘤免疫逃逸,从而导致ALL的发生和复发.     

Mechanisms of immune suppression mediated by myeloid derived suppressor cell and the targeted therapy strategy

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells at different stages of maturation. MDSCs mediate the suppression of the anti-tumor immunity，and play a crucial role in cancer tolerance through suppressing the activity of T cells and natural killer cells ,inducing T-regs and involving the angiogenesis, and then contribute to the tumor development and metastasis. Promoting the differentiation of MDSCs, reducing its quantity and inhibiting its function by using various methods may contribute to the recovery of patients normal immune status, the tumor progression control, and improvement of the efficacy of other anti-neoplastic therapies. Therefore，possible novel therapeutic approaches targeted at MDSCs could be considered and developed rapidly now.     

The immunobiology of myeloid-derived suppressor cells in cancer

The tumor microenvironment is a complex and heterogeneous milieu in which multiple interactions occur between tumor and host cells. Immunosuppressive cells which are present in this microenvironment, such as regulatory T (Treg) cells and myeloid-derived suppressor cells (MDSCs), play an important role in tumor progression, via down-regulation of antitumor responses. MDSCs represent a heterogeneous group of cells originated from the myeloid lineage that are in the immature state. These cells markedly accumulate under pathologic conditions, such as cancer, infection, and inflammation, and use various mechanisms to inhibit both adaptive and innate immune responses. These immunosuppressive mechanisms include deprivation of T cells from essential amino acids, induction of oxidative stress, interference with viability and trafficking of T cells, induction of immunosuppressive cells, and finally polarizing immunity toward a tumor-promoting type 2 phenotype. In addition to suppression of antitumor immune responses, MDSCs can also enhance the tumor metastasis and angiogenesis. Previous studies have shown that increased frequency of MDSCs is related to the tumor progression. Moreover, various drugs that directly target these cells or reverse their suppressive activity can improve antitumor immune responses as well as increase the efficacy of immunotherapeutic intervention. In this review, we will first discuss on the immunobiology of MDSCs in an attempt to find the role of these cells in tumor progression and then discuss about therapeutic approaches to target these cells.     

心理应激对肿瘤微环境中免疫细胞影响的研究进展

肿瘤微环境(Tumor microenvironment,TME)在肿瘤的发生发展中发挥重要作用。应激状态下的人体通常会经历一些重要的生物效应,从而损害免疫系统,各种应激反应可以通过调节肿瘤微环境中的免疫细胞,例如自然杀伤细胞、树突状细胞、髓系来源抑制细胞(MDSCs)等,导致肿瘤进展。由于免疫细胞对人体的多项活动都起着重要的调节作用,并且其在肿瘤中的应用也具有十分重要的意义。本文就心理应激如何影响肿瘤微环境中的免疫细胞做一综述,旨在为肿瘤治疗提供新的思路。     

S-1 eliminates MDSCs and enhances the efficacy of PD-1 blockade via regulation of tumor-derived Bv8 and S100A8 in thoracic tumor

Myeloid-derived suppressor cells (MDSCs) have been known to play a pivotal role in the induction of immune tolerance, which limits the benefits of immune checkpoint inhibitors (ICIs). Recent studies revealed that several chemotherapeutic agents decreased tumor-infiltrating MDSCs. Therefore, combination therapy with cytotoxic chemotherapeutic agents and ICIs was approved for first-line treatment for lung cancer. However, the impact of chemotherapeutic agents on MDSCs and an optimal partner of ICIs has not been fully investigated in thoracic tumors, including lung cancer and malignant pleural mesothelioma. In the present study, we found that treatment with 5-FU and its oral formulation, S-1, suppressed tumor progression and inhibited the accumulation of MDSCs in thoracic tumor-bearing mice. Tumor-infiltrating T cells and dendritic cells were significantly expanded in S-1-treated mice. 5-FU suppressed the ability of tumor cells to recruit MDSCs, while it did not suppress the survival and differentiation of mouse MDSCs in vitro. We also revealed that 5-FU or S-1 significantly downregulated the expression of tumor-derived Bv8 and S100A8. The knockdown of Bv8 or S100A8 in tumor cells suppressed tumor growth and MDSC recruitment in vivo. Furthermore, in comparison with pemetrexed, administration of S-1 improved the synergistic therapeutic efficacy of anti-PD-1 antibodies with or without carboplatin. Our findings revealed a novel mechanism wherein S-1 primed a favorable tumor microenvironment to provide the rationale for combination therapy with S-1 and ICIs as the optimal therapy for thoracic cancer.     

髓系抑制性细胞与肿瘤

髓系抑制性细胞(MDSC)是一群髓系来源具有抑制功能的天然免疫细胞,在肿瘤进展中发挥负向免疫调控作用.MDSC具有强大的抑制功能及显著的异质性,通过多种机制调控固有免疫及适应性免疫系统,发挥促肿瘤作用,同时可通过非免疫机制促进肿瘤血管生成及肿瘤转移等.近年来对其分化、增殖、抑制功能等的研究日趋成熟,由此衍生的靶向针对MDSC的肿瘤免疫治疗研究将为肿瘤疫苗的增效及肿瘤的治疗等带来新的希望.     

髓源性抑制细胞——肿瘤免疫治疗的新靶点

髓源性抑制细胞(Myeloid-derived suppressor cells,MDSCs)是在病理情况下扩增的一种髓源性抑制细胞群,其特点是能负向调节机体的抗肿瘤免疫反应从而促进肿瘤的发生和发展.通过阻断MDSCs的免疫抑制通路来提高肿瘤免疫治疗的效果,是一个颇有前景的治疗策略.     

The bone marrow microenvironment enhances multiple myeloma progression by exosome-mediated activation of myeloid-derived suppressor cells

Exosomes, extracellular nanovesicles secreted by various cell types, modulate the bone marrow (BM) microenvironment by regulating angiogenesis, cytokine release, immune response, inflammation, and metastasis. Interactions between bone marrow stromal cells (BMSCs) and multiple myeloma (MM) cells play crucial roles in MM development. We previously reported that BMSC-derived exosomes directly promote MM cell growth, whereas the other possible mechanisms for supporting MM progression by these exosomes are still not clear. Here, we investigated the effect of BMSC-derived exosomes on the MM BM cells with specific emphasis on myeloid-derived suppressor cells (MDSCs). BMSC-derived exosomes were able to be taken up by MM MDSCs and induced their expansion in vitro. Moreover, these exosomes directly induced the survival of MDSCs through activating STAT3 and STAT1 pathways and increasing the anti-apoptotic proteins Bcl-xL and Mcl-1. Inhibition of these pathways blocked the enhancement of MDSC survival. Furthermore, these exosomes increased the nitric oxide release from MM MDSCs and enhanced their suppressive activity on T cells. Taken together, our results demonstrate that BMSC-derived exosomes activate MDSCs in the BM through STAT3 and STAT1 pathways, leading to increased immunosuppression which favors MM progression.