髓源性抑制细胞在肿瘤免疫中的作用

近来研究发现,一类被称为髓源性抑制细胞(Myeloid-derived suppressor cells,MDSCs)的细胞群,参与了肿瘤的免疫逃逸、免疫耐受、免疫抑制等病理过程,促进肿瘤的发生和生长。这群细胞主要分布在血液、脾、淋巴结、骨髓及肿瘤微环境等部位,通过复杂的分子途径,对机体的抗肿瘤免疫起抑制作用。本文就MDSCs在这方面作用的研究进展作一综述。     

髓源性抑制细胞研究进展

髓源性抑制细胞(myeloid-derived suppressor cells, MDSCs)是一群表型异常、具有免疫抑制功能的髓系来源细胞。在进展期肿瘤、败血症、慢性感染等病理环境中,MDSCs大量扩增并通过多种途径抑制T淋巴细胞等免疫细胞的增殖、活化和迁移,MDSCs的数量与疾病进程和患者转归密切相关。通过单细胞测序、质谱流式等新技术,研究人员发现MDSCs和正常髓系细胞在表型标记分子、基因表达、能量代谢和调控通路上存在明显差异。特别是在肿瘤领域,MDSCs靶向治疗研究也取得了丰硕的成果。本文以MDSCs研究里程碑为起点,以MDSCs靶向治疗机制及其在感染性疾病中的作用为重点,对MDSCs新近研究成果进行综述。     

重要食药用菌多糖降血糖分子机制研究进展

目前以糖尿病为代表的糖代谢紊乱疾病愈演愈烈,严重危害人体健康.食药用菌多糖因其具有良好的调节糖代谢作用而被关注,但其调节糖代谢的作用机制并未被很好地综述.本文从关键基因、蛋白、信号通路等方面综述了食药用菌活性多糖的降血糖机制,包括抑制蛋白酪氨酸磷酸酶1B(Protein Tyrosine Phosphatase-1B,...     

肿瘤发生过程中髓源性抑制细胞能量代谢的特点

髓源性抑制细胞(myeloid-derived suppressor cells, MDSCs)作为免疫调节细胞,在肿瘤发生和发展中起重要作用。糖代谢参与MDSCs功能的调节,但是,对于肿瘤进程中MDSCs代谢水平的变化,相关报道甚少。基于此,本研究利用小鼠肿瘤模型,采用流式细胞术先后分析肿瘤发生中MDSCs的丰度、周期及线粒体质量,利用ELISA试剂盒检测MDSCs乙酰辅酶A的含量,并在2-脱氧-D-葡萄糖(2-deoxy-D-glucose, 2-DG)改变糖代谢水平之后检测线粒体质量和细胞凋亡。结果发现:肿瘤发生中MDSCs的丰度明显增加,进入分裂期的细胞数增多;肿瘤状态下MDSCs乙酰辅酶A的含量增加,线粒体质量显著增加; 2-DG处理后,肿瘤条件下MDSCs的线粒体质量恢复至正常水平且细胞凋亡减少。以上结果表明,在肿瘤发生过程中, MDSCs主要依赖氧化磷酸化代谢获取能量,改变其糖代谢水平可能导致细胞功能变化。     

髓源性抑制细胞对炎症性肠病的免疫调节作用及靶向免疫治疗研究

髓源性抑制细胞(myeloid-derived suppressor cells, MDSCs)是机体在缺氧、炎症、感染和癌症等病理条件下,髓系细胞分化受阻的一组异质性未成熟细胞,具有强大的免疫抑制功能。在小鼠和人类中研究表明,MDSCs在炎症肠病(inflammatory bowel disease, IBD)中激活和扩增,通过抑制炎症反应改善IBD的疾病进展,或通过促炎反应加速IBD的发生、发展。因此,了解MDSCs的生物学特性及其在IBD肠道炎症微环境中的调节作用,对靶向MDSCs的免疫治疗至关重要。现就MDSCs在IBD炎症条件下的不同生理作用,包括其促炎或免疫抑制作用以及目前基于MDSCs的免疫治疗策略作一概述,旨在为临床更全面的靶向MDSCs免疫治疗提供理论依据。     

现代提取分离技术在食药用菌多糖分离纯化中的应用

详细综述了超声波法,酶解法,超滤法,透析法,色谱法等现代提取分离技术在食药用菌多糖分离纯化中的应用,简单阐述了各种技术的优缺点,并对其应用前景作了简要探讨。     

髓系抑制细胞在1型糖尿病患者中作用的研究

髓系抑制细胞(myeloid-derived suppressor cells, MDSC)是来源于髓系的一类未成熟细胞群,初期对肿瘤的研究中发现,这类细胞具有抑制免疫应答,并促进炎性细胞因子及趋化因子分泌的作用,近年来对这类细胞在治疗自身免疫性疾病等方面的作用进行了研究。发现MDSC具有治疗自身免疫性疾病的功效;但也有研究显示,MDSC不仅无治疗效果,甚至还会起到相反的作用,这可能与其促炎因子过度分泌或诱导辅助性T细胞17(T helper cell, Th17)分化有关。1型糖尿病(type 1 diabetes, T1D)是一种常见的自身免疫性疾病,如何有效治疗该疾病一直是内分泌研究领域的热点。现就MDSC的来源、功能及其在T1D中的作用进行阐述,旨在为T1D的治疗提供新思路。     

灵芝多糖GLP 抑制小鼠骨肉瘤细胞S-180 在体内生长的作用机制

目的:探讨灵芝多糖成分(GLP)抑制肿瘤的作用机制。方法:在小鼠右腋皮下接种1×106TC-1细胞后7天后,用100mg/kg、200mg/kg和400mg/kg 3种剂量给小鼠口服灌胃给药20天,然后观察肿瘤的重量,并用ELISA检测小鼠血清中IL-2、IL-6和TNF-alpha,用流式细胞仪检测其外周血中CD4+和CD8+。结果:100mg/kg、200mg/kg和400mg/kg 3种剂量给小鼠口服灌胃给药20天,与对照组比较,抑瘤率分别可以达到53%、59%和58%,P<0.05;小鼠外周血血清中的IL-2从1.27ng/mL提高到了2.88ng/mL,P<0.05;TNF-α从1.05ng/mL提高到了1.82ng/mL,P<0.05;而IL-6则没有明显的变化。CD4+细胞水平升高(从54.80%提高到了58.27%),但差异无统计学意义(P>0.05);CD8+细胞明显增多(从24.15%提高到了45.36%),差异有统计学意义(P<0.05)。结论:GLP有明显抑瘤作用,但抑瘤作用与GLP剂量不存在依赖关系。GLP对肿瘤细胞生长的抑制是通过提高小鼠的细胞免疫能力来实现,而并非直接杀伤肿瘤细胞。     

食药用真菌多糖对肿瘤免疫逃逸调节作用机制研究进展

食药用真菌多糖是食药用真菌的主要天然生物活性成分,可以从多层次、多靶点调节机体的免疫功能,被认为是一种天然免疫调节剂.此前食药用真菌多糖抗肿瘤机制研究集中在提升机体的免疫力达到抑制肿瘤的目的 ,但近年的研究表明它可以调节肿瘤微环境,恢复机体对肿瘤以及肿瘤微环境的监视能力,提升机体对肿瘤微环境的特异性免疫应答能力,进而达...     

NKT细胞在抗肿瘤免疫中的作用及其机制

NKT细胞是免疫细胞中一类具有NK细胞特定标志的T细胞亚群,经活化,既可直接作为抗肿瘤效应细胞发挥杀伤作用,又能通过激活其他免疫效应细胞,如NK细胞,间接实现抗肿瘤作用。NKT细胞在抗肿瘤免疫、获得性免疫应答及免疫调节中起着重要作用。     

Contribution of myeloid-derived suppressor cells to tumor-induced immune suppression, angiogenesis, invasion and metastasis

Growing evidence suggests that myeloid-derived suppressor cells (MDSCs), which have been named "immature myeloid cells" or "myeloid suppressor cells" (MSCs), play a critical role during the progression of cancer in tumor-bearing mice and cancer patients. As their name implies, these cells are derived from bone marrow and have a tremendous potential to suppress immune responses. Recent studies indicated that these cells also have a crucial role in tumor progression. MDSCs can directly incorporate into tumor endothelium.They secret many pro-angiogenic factors as well. In addition, they play an essential role in cancer invasion and metastasis through inducing the production of matrix metalloproteinases (MMPs), chemoattractants and creating a pre-metastatic environment. Increasing evidence supports the idea that cancer stem cells (CSCs) are responsible for tumorigenesis, resistance to therapies, invasion and metastasis.Here, we hypothesize that CSCs may "hijack" MDSCs for use as alternative niche cells, leading to the maintenance of stemness and enhanced chemo- and radio-therapy resistance. The countermeasure that directly targets to MDSCs may be useful for against angiogenesis and preventing cancer from invasion and metastasis. Therefore, the study of MDSCs is important to understand tumor progression and to enhance the therapeutic efficacy against cancer.     

蓝藻多糖的食药特性和应用研究进展

蓝藻是地球上最重要的初级生产者之一,也是重要的生物资源。有些蓝藻在我国具有悠久的食用历史,比如发状念珠藻。蓝藻能合成多种生物活性物质,具有抑菌、抗氧化、抗肿瘤、抗炎症、抗病毒和免疫调节等功能,并在食品、医药、农业、环保和化妆品领域具有广泛的应用。多糖是蓝藻最主要的代谢产物之一,它本身结构复杂、性质多样,决定了其具有多样化的功能。本文对蓝藻多糖的制备过程、生物活性以及应用研究的进展进行综述,以期更好地开发和利用其食药用价值。     

A novel role of hematopoietic CCL5 in promoting triple-negative mammary tumor progression by regulating generation of myeloid-derived suppressor cells

CCL5 is a member of the CC chemokine family expressed in a wide array of immune and non-immune cells in response to stress signals. CCL5 expression correlates with advanced human breast cancer. However, its functional significance and mode of action have not been established. Here, we show that CCL5-deficient mice are resistant to highly aggressive, triple-negative mammary tumor growth. Hematopoietic CCL5 is dominant in this phenotype. The absence of hematopoietic CCL5 causes aberrant generation of CD11b⁺/Gr-1⁺, myeloid-derived suppressor cells (MDSCs) in the bone marrow in response to tumor growth by accumulating Ly6C^hi and Ly6G⁺ MDSCs with impaired capacity to suppress cytotoxicity of CD8⁺ T cells. These properties of CCL5 are observed in both orthotopic and spontaneous mammary tumors. Antibody-mediated systemic blockade of CCL5 inhibits tumor progression and enhances the efficacy of therapeutic vaccination against non-immunogenic tumors. CCL5 also helps maintain the immunosuppressive capacity of human MDSCs. Our study uncovers a novel, chemokine-independent activity of the hematopoietically derived CCL5 that promotes mammary tumor progression via generating MDSCs in the bone marrow in cooperation with tumor-derived colony-stimulating factors. The study sheds considerable light on the interplay between the hematopoietic compartment and tumor niche. Because of the apparent dispensable nature of this molecule in normal physiology, CCL5 may represent an excellent therapeutic target in immunotherapy for breast cancer as well as a broad range of solid tumors that have significant amounts of MDSC infiltration.     

Comparing the frequency of CD33+ pSTAT3+ myeloid-derived suppressor cells and IL-17+ lymphocytes in patients with prostate cancer and benign prostatic hyperplasia

Prostate cancer (PCa) is one of the most epidemic types of cancer in men. The tumor microenvironment (TME) of PCa is involved in the emergence of immunosuppressive factors such as myeloid-derived suppressor cells (MDSC), which regulate the immune system by several mechanisms, including interleukin (IL)-10 production. On the other hand, IL-17⁺ helper T cells (Th17) induce MDSCs and chronic inflammation in TME by producing IL-17. This study demonstrated that the frequency of CD33⁺ pSTAT3⁺ MDSC and IL-17⁺ lymphocyte as well as IL-10 messenger RNA (mRNA) expression were significantly higher in the PCa patients than in the benign prostatic hyperplasia (BPH) group. Moreover, there was no significant relationship between the frequency of CD33⁺ pSTAT3⁺ MDSC, and IL-17⁺ lymphocyte with Gleason scores in the PCa group. We suggested that the higher frequency of CD33⁺ pSTAT3⁺ MDSC and IL-17⁺ lymphocyte and the more frequent expression of IL-10 mRNA in PCa patients may play roles in tumor progression from BPH to PCa.     

Functional changes in myeloid-derived suppressor cells (MDSCs) during tumor growth: FKBP51 contributes to the regulation of the immunosuppressive function of MDSCs

Myeloid-derived suppressor cells (MDSCs) are increased by tumor-derived factors and suppress anti-tumor immunity. MDSCs obtained at a late time point after tumor injection had stronger suppressive activity than MDSCs obtained at an early time point, as measured by T cell proliferation assays. To find factors in MDSCs that change during tumor growth, we analyzed gene expression profiles from MDSCs at different time points after tumor injection. We found that immune response-related genes were downregulated but protumor function-related genes were upregulated in both monocytic MDSCs (Mo-MDSCs) and polymorphonuclear granulocytic MDSCs (PMN-MDSCs) at the late time point. Among differentially expressed genes, FK506 binding protein 51 (FKBP51), which is a member of the immunophilin protein family and plays a role in immunoregulation, was increased in the Mo-MDSCs and PMN-MDSCs isolated from the late time points. Experiments using small interfering RNA and a chemical inhibitor of FKBP51 revealed that FKBP51 contributes to the regulation of the suppressive function of MDSCs by increasing inducible NO synthase, arginase-1, and reactive oxygen species levels and enhancing NF-κB activity. Collectively, our data suggest that FKBP51 is a novel molecule that can be targeted to regulate the immunosuppressive function of MDSCs.     

Regulation of arginase I activity and expression by both PD-1 and CTLA-4 on the myeloid-derived suppressor cells

An elevated number of Gr-1⁺CD11b⁺ myeloid-derived suppression cells (MDSCs) has been described in mice and human bearing tumor and associated with immune suppression. Arginase I production by MDSCs in the tumor environment may be a central mechanism for immunosuppression and tumor evasion. In this study and before, we found that Gr-1⁺CD11b⁺ MDSCs from ascites and spleen of mice bearing ovarian 18D carcinoma express a high level of PD-1, CTLA-4, B7-H1 and CD80 while other co-stimulatory molecules, namely CD40, B7-DC and CD86 are not detected. Further studies showed that PD-1 and CTLA-4 on the Gr-1⁺CD11b⁺ MDSCs regulated the activity and expression of arginase I. The blockage and silencing of PD-1, CTLA-4 or both PD-1 and CTLA4 molecules could significantly reduce arginase I activity and expression induced with tumor-associated factor. Similar results were also observed while their ligands B7-H1 and/or CD80 were blocked or silenced. Furthermore, CD80 deficiency also decreased the arginase I expression and activity. Antibody blockade or silencing of PD-1, CTLA-4 or both reduced the suppressive potential of PD-1+CTLA-4+MDSCs. Blockade of PD-1, CTLA-4 or both also slowed tumor growth and improved the survival rate of tumor-bearing mice. Thus, there may exist a coinhibitory and costimulatory molecules-based immuno-regulating wet among MDSCs. This research was supported by Nankai University grant, NSFC grant “30771967”, “985” grant,The Ministry of Science and Technology grant “2006AA020502”“06C26211200695”, Tianjin Grant “07JCZDJC03300” and “06ZHCXSH04800”.     

Role of leaf extracts of some medicinal plants in the management of fungal diseases of okra (Abelmoschus esculentus (L.) Moench)

In order to manage the fungal pathogens in okra, seeds of variety Arka Anamika were subjected to soaking treatment with the aqueous leaf extracts of Coleus aromaticus, Adathoda vesica, Vitex negundo, Solanum nigrum, Leucas aspera, Ocimum sanctum and Catharanthus roseus. Among the extracts used, C. aromaticus, V. negundo extracts were found superior in reducing the incidence of mycoflora. These leaf extract treatments also resulted in increased seed germination and vigour of the seedlings. Both in green-house and field conditions also these extracts were proved their efficient in the enhancement of biomass, number of leaves, number of seeds per fruit, seed density and ascorbic acid content in the raw fruits.     

长白山区野生食药兼用菌资源调查研究

调查吉林省长白山地区野生食药兼用菌资源,介绍几种具有开发潜力的野生食药兼用菌形态特性、生态习性、食疗保健价值。指出长白山野生食药兼用菌的开发具有广阔前景。