髓源性抑制细胞在骨髓增生异常综合征中的研究进展

骨髓增生异常综合征(MDS)以造血细胞发育异常和无效造血为特征,骨髓造血微环境内髓源性抑制细胞(MDSC)的异常扩增和激活可能是重要原因。MDSC细胞扩增与激活导致自然杀伤细胞、CD8+T细胞功能低下与耗竭,并募集炎症细胞及因子,导致MDS患者遗传异常的进一步积累,致使MDS疾病进展。肿瘤环境炎症因子的积累诱导程序性死亡受体1(PD-1)在造血干、祖细胞上的表达和MDSC细胞程序性死亡受体配体1(PD-L1)过表达,PD-1/PD-L1的相互作用导致MDS造血祖细胞的凋亡和无效造血。靶向MDSC的试验及临床研究证实,纠正或逆转MDS免疫失调的骨髓微环境是恢复有效造血功能的治疗策略。     

髓源性抑制细胞在肿瘤发生发展中的作用

髓源性抑制细胞(myeloid-derived suppressor cells,MDSCs)是一组异质细胞,在肿瘤相关免疫抑制中起关键作用.MDSCs通过免疫抑制作用,使肿瘤逃避免疫监控.肿瘤组织中MDSCs的浸润与患者预后不良及治疗的抵抗密切相关.MDSCs在转移中发挥重要作用,但MDSCs在远处器官建立转移前微环...     

髓源抑制性细胞的功能及其逆转策略

髓源抑制性细胞（myeloid-derived suppressor cell,MDSC）是在骨髓中产生的一群具有高度异质性的免疫抑制细胞, 在 肿瘤等病理状态下大量聚集,是促进肿瘤进展、降低患者对传统治疗反应性的关键因素。近年来,免疫检查点阻断剂和基因工程 T细胞过继回输治疗延长了许多晚期恶性肿瘤患者的生存期,但上述免疫疗法在肺癌、结直肠癌等实体瘤中有效率仅为 15%~40%,这与实体瘤免疫抑制微环境密切相关。MDSC在肿瘤微环境中聚集,通过抑制T细胞或NK细胞增殖及功能减弱宿主 抗肿瘤免疫反应,是患者对免疫治疗耐受的关键机制。因此,明确MDSC聚集及功能特征是探索提高免疫治疗效果的重要研究 方向。本文将系统阐述MDSC的产生、聚集及其免疫抑制功能的调控机制,概述目前靶向MDSC治疗的最新研究进展。     

CARD9 prevents lung cancer development by suppressing the expansion of myeloid-derived suppressor cells and IDO production

Caspase recruitment domain-containing protein 9 (CARD9) is an adaptor protein and highly expressed in myeloid cells. Our previous study demonstrates a critical protective effect of CARD9 in the development of colitis-associated colon cancer. Nevertheless, the effect of CARD9 in lung cancer remains unclear. Here, using a mouse Lewis lung cancer model, we found the tumor burden of CARD9^−/− mice was much heavier than that in wild-type (WT) mice. More myeloid-derived suppressor cells (MDSCs) were accumulated and less cytotoxicity T lymphocyte was found in tumor tissues of CARD9^−/− mice, compared to WT mice. Depleting MDSCs using anti-Gr1 antibody can significantly decrease tumor burden in CARD9^−/− mice. Furthermore, the noncanonical nuclear factor-kappaB (NF-κB) pathway was activated in CARD9^−/− mice-derived MDSCs. Deficiency of CARD9 enhanced expression of indoleamine 2,3-dioxygenase (IDO) in MDSCs via noncanonical NF-κB pathway. Moreover, correlations between CARD9 expressions and MDSCs relative genes (IDO, iNOS-2 and arginase 1 [ARG-1]) were further confirmed in tumor tissues from lung cancer patients. Taken together, we showed a CARD9-NF-κB-IDO pathway in MDSCs which can inhibit the suppressive function of MDSCs and prevent lung cancer development.     

髓系来源的抑制性细胞在小鼠H22原位种植性肝癌中的表达及其意义

目的:比较小鼠H22原位种植性肝癌模型中髓系来源的抑制性细胞（MDSCs）和调节性T细胞（Tregs）的表达,确定主要的免疫抑制性细胞。并探讨主要免疫抑制性细胞在小鼠H22原位种植性肝癌模型中的意义。方法:建立小鼠H22原位种植性肝癌模型,用流式细胞术的方法比较外周血、脾脏、肿瘤组织中MDSCs、Tregs的比例。分析MDSCs与CD4+T细胞、CD8+T细胞、NK细胞、NKT细胞的相关性。通过脾脏切除的方法下调MDSCs的表达,观察对肿瘤存活的影响。结果:MDSCs的比例无论在外周血、脾脏还是肿瘤组织中都显著高于Tregs。MDSCs的比例与CD4+T细胞、CD8+T细胞、NK细胞、NKT细胞呈负相关。下调MDSCs的比例可以显著延长小鼠存活期。结论:小鼠H22原位种植性肝癌中主要的免疫抑制性细胞是MDSCs。MDSCs的高表达预示着不良的小鼠存活期。     

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.     

Normal human monocytes exposed to glioma cells acquire myeloid-derived suppressor cell-like properties

Glioblastoma patients are immunosuppressed, yet glioblastomas are highly infiltrated by monocytes/macrophages. Myeloid-derived suppressor cells (MDSC; immunosuppressive myeloid cells including monocytes) have been identified in other cancers and correlate with tumor burden. We hypothesized that glioblastoma exposure causes normal monocytes to assume an MDSC-like phenotype and that MDSC are increased in glioblastoma patients. Healthy donor human CD14⁺ monocytes were cultured with human glioblastoma cell lines. Controls were cultured alone or with normal human astrocytes. After 48 hours, glioblastoma-conditioned monocytes (GCM) were purified using magnetic beads. GCM cytokine and costimulatory molecular expression, phagocytic ability, and ability to induce apoptosis in activated lymphocytes were assessed. The frequency of MDSC was assessed by flow cytometry in glioma patients'' blood and in GCM in vitro. As predicted, GCM have immunosuppressive, MDSC-like features, including reduced CD14 (but not CD11b) expression, increased immunosuppressive interleukin-10, transforming growth factor-β, and B7-H1 expression, decreased phagocytic ability, and increased ability to induce apoptosis in activated lymphocytes. Direct contact between monocytes and glioblastoma cells is necessary for complete induction of these effects. In keeping with our hypothesis, glioblastoma patients have increased circulating MDSC compared with normal donors and MDSC are increased in glioma-conditioned monocytes in vitro. To our knowledge, this has not been reported previously. Although further study is needed to directly characterize their origin and function in glioblastoma patients, these results suggest that MDSC may be an important contributor to systemic immunosuppression and can be modeled in vitro by GCM.     

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.     

Elevated endoplasmic reticulum stress reinforced immunosuppression in the tumor microenvironment via myeloid-derived suppressor cells

The role of endoplasmic reticulum (ER) stress in cancer has been studied in detail, and ER stress is known to increase tumor cell apoptosis, and thus, reduce tumor growth. However, in our study, persistent ER stress induced by multiple administrations of low-dose thapsigargin (Tg) accelerated tumor growth in mice. Tg-mediated ER stress increased the generation of Ly6G⁺CD11b⁺ myeloid cells, but did not alter anti-tumor effector T cells. 4-Phenylbutyric acid (4-PBA), a chemical chaperone widely used as an ER stress reducer, attenuated Tg-induced myeloid-derived suppressor cell (MDSC) expansion and tumor growth. Tg-mediated ER stress enhanced the immunosuppressive capacity of tumor-infiltrating MDSCs by increasing expression of ARG1, iNOS, and NOX2, although splenic MDSCs were not affected. Consistent with these results, 4-PBA restored the anti-tumor immune response by regulating inflammatory cytokines such as TNF-α and CXCL1/KC, and activated tumor-infiltrating CD8⁺ T cells that were inhibited by Tg-mediated ER stress. These results suggest that significant ER stress in a tumor-bearing host might induce tumor growth mediated by enhancement of MDSC-mediated suppression. Therefore, ER stress reducers such as 4-PBA could restore anti-tumor immunity by inhibiting suppressive MDSCs that are exacerbated by ER stress.     

靶向髓系抑制性细胞抗肿瘤治疗策略研究进展

 髓系抑制性细胞（MDSC）来源于骨髓祖细胞和未成熟的髓细胞（IMC）,在荷瘤小鼠及肿瘤患者的骨髓、脾脏、外周血大量扩增,并募集到肿瘤组织。MDSC高表达精氨酸酶1（ARG1）、一氧化氮合酶（iNOS）、活性氧族（ROS）、过氧亚硝酸盐等介质,通过细胞接触依赖或非依赖方式诱导效应T细胞失能,或诱导调节性T细胞（Treg）等机制,抑制机体的抗肿瘤免疫功能。因此,靶向MDSC抗肿瘤策略成为研究热点,也取得了一定进展,现就当前靶向MDSC抗肿瘤免疫治疗策略及相关机制的研究进展做一简要介绍,为从事该领域的研究者提供参考。     

髓样来源抑制性细胞的研究进展

髓样来源的抑制性细胞(myeloid-derived suppressor cells,MDSC)是一群具有免疫抑制功能细胞的统称,通常认为它们是正常单核/巨噬细胞、DC细胞、粒细胞等处于分化的未成熟阶段,且可以分为单个核和分叶核两类。肿瘤模型小鼠中,单个核类MDSC典型的标记性分子是CD11b和Ly-6C,而分叶核类MDSC的典型标记分子是CD11b和Ly-6G;在肿瘤患者中,MDSC同时表达CD11和CD33等分子而不表达人白细胞抗原DR。MDSC由肿瘤微环境诱导产生,肿瘤产生过程中其在淋巴器官、血液以及病变部位聚集;针对不同的免疫细胞群,其通过分泌抑制性因子、接触性抑制以及诱导产生其他抑制性细胞等各种方式发挥免疫抑制作用,进而抑制天然免疫和适应性免疫。目前发现,MDSC抑制功能可以通过抗原特异性和抗原非特异性两种方式发挥作用,这是由其所处的局部微环境以及诱发其产生的肿瘤的性质来决定的。目前研究比较多的是其对NK细胞和T细胞的抑制作用,认为其主要可以通过产生精氨酸酶-1(arginase-1)、活性氧族(reactive oxygen species,ROS)以及抑制性的表面分子来实现对免疫系统的抑制作用,在肿瘤的生长以及转移过程中发挥重要的作用。     

乳腺癌患者肿瘤组织中髓源抑制性细胞的临床意义

目的：研究乳腺癌患者肿瘤组织中髓源抑制性细胞（myeloid-derived suppressor cells, MDSCs）与乳腺癌临床病理特征的关系。方法：收集天津肿瘤医院2009年2月至2009年12月间35例乳腺癌根治术的手术切除组织标本,制成单细胞悬液;流式细胞术检测其中MDSCs（Lin-CD33+CD13+CD14-CD15-）比例,免疫组化法检测同一肿瘤组织中ER、PR、Her-2表达;分析MDSCs比例与患者临床病理特征的关系。结果：乳腺癌患者肿瘤组织中MDSCs比例与临床分期、淋巴结转移有关,Ⅲ期患者MDSCs比例\[（11.70±7.85）%\]高于Ⅰ/Ⅱ期患者\[（5.32±4.59）%\],发生3个以上淋巴结转移患者的MDSCs比例\[（10.97±7.87）%\]高于3个以下（含3个）淋巴结转移的患者\[（5.86±5.26）%\]（P<0.05）。未观察到MDSCs比例高低与患者年龄、病理类型、肿瘤直径、组织学分级,以及ER、PR、Her-2表达有关（P>0.05）。结论：乳腺癌患者肿瘤组织中MDSCs比例与患者临床分期、淋巴结转移有关,MDSCs增多可能是乳腺癌患者发生免疫抑制的重要原因之一。     

NEDD9 promotes cancer stemness by recruiting myeloid-derived suppressor cells via CXCL8 in esophageal squamous cell carcinoma

Objective:Esophageal squamous cell carcinoma (ESCC) has high morbidity and mortality rates worldwide. Cancer stem cells (CSCs) may cause tumor initiation, metastasis, and recurrence and are also responsible for chemotherapy and radiotherapy failures. Myeloid-derived suppressor cells (MDSCs), in contrast, are known to be involved in mediating immunosuppression. Here, we aimed to investigate the mechanisms of interaction of CSCs and MDSCs in the tumor microenvironment.Methods:ESCC tissues and cell lines were evaluated. Neural precursor cell expressed, developmentally downregulated 9 (NEDD9) was knocked down and overexpressed by lentiviral transfection. Quantitative PCR, Western blot, immunohistochemistry, cell invasion, flow cytometry, cell sorting, multiplex chemokine profiling, and tumor growth analyses were performed.Results:Microarray analysis revealed 10 upregulated genes in esophageal CSCs. Only NEDD9 was upregulated in CSCs using the sphere-forming method. NEDD9 expression was correlated with tumor invasion (P = 0.0218), differentiation (P = 0.0153), and poor prognosis (P = 0.0373). Additionally, NEDD9 was required to maintain the stem-like phenotype. Screening of chemokine expression in ESCC cells with NEDD9 overexpression and knockdown showed that NEDD9 regulated C-X-C motif chemokine ligand 8 (CXCL8) expression via the ERK pathway. CXCL8 mediated the recruitment of MDSCs induced by NEDD9 in vitro and in vivo. MDSCs promoted the stemness of ESCC cells through NEDD9 via the Notch pathway.Conclusions:As a marker of ESCC, NEDD9 maintained the stemness of ESCC cells and regulated CXCL8 through the ERK pathway to recruit MDSCs into the tumor, suggesting NEDD9 as a therapeutic target and novel prognostic marker for ESCC.     

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。     

髓源抑制性细胞在结直肠癌中的研究进展

结直肠癌在临床较为常见,占消化道肿瘤的5％～8％,老年人较为多发,随着我国社会生活水平的逐步提高和生活节奏的加快,结直肠癌发病率也呈现上升趋势.髓源抑制性细胞是一群来源于骨髓的幼稚细胞,具有很强的免疫抑制作用,是引起肿瘤细胞免疫逃逸的重要细胞群.本文综述髓源抑制性细胞对结直肠癌发生发展的影响以及靶向髓源抑制性细胞治疗结直肠癌的研究进展,并对其进行分析与展望.     

靶向肿瘤干细胞治疗肿瘤

具有独特的分子表达、表面标志物、干性相关信号通路和代谢模式等方面特征的肿瘤干细胞(cancer stem cell,CSC)因其具有高致瘤、高转移、高治疗抵抗能力,可能是多种类型恶性肿瘤生长、转移、治疗抵抗的关键因素,也是肿瘤发生和复发的重要根源.正常干细胞在产生了第一个致癌突变之后将逐步发展成为癌前干细胞和CSC,随...     

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.     

水飞蓟素通过调控骨髓来源的抑制性细胞抗肺癌机制的实验研究

目的:研究水飞蓟素通过调控骨髓来源的抑制性细胞（MDSC）的抗肺癌机制。方法:我们在C57/BL6小鼠上构建了路易斯（Lewis）肺癌细胞转移瘤模型,灌胃给予不同浓度(25、50 mg/kg,每天一次)的水飞蓟素。测量小鼠肿瘤体积及体重变化。用免疫组化方法检测Lewis肺癌细胞肿瘤增殖相关指标增殖细胞核抗原（PCNA）的表达。通过TUNEL染色检测肺癌细胞的凋亡情况。通过免疫组化检测组织中CD8+ T细胞浸润及功能。通过流式细胞术检测CD11b+Gr-1+的MDSC百分比。通过Q-PCR检测肿瘤组织中Arg-1、iNOS2及MMP9的表达。结果:25和50 mg/kg的水飞蓟素剂量依赖地抑制肿瘤生长,诱导肿瘤细胞凋亡。水飞蓟素增加了CD8+ T细胞浸润;减少了肿瘤组织中MDSC的比例,肿瘤组织中Arg-1、iNOS2 及MMP9（MDSC功能相关） mRNA表达的减少也证实了MDSC功能的减弱。结论:水飞蓟素抑制了MDSC,促进CD8+ T细胞浸润及功能,抑制模型中肿瘤生长,为水飞蓟素治疗肺癌提供了依据。