人树突状细胞SOCS1基因RNA干扰慢病毒载体的构建及鉴定

目的构建人树突状细胞（hDCs）信号传导通路抑制因子1（SOCS1）基因RNA干扰（RNAi）慢病毒载体。方法根据人树突状细胞SOCS1基因（NM-0037）,筛选出一个靶序列,设计并合成包含正反义靶序列的互补单链寡核苷酸,与经BamH和Xho酶切后的慢病毒载体质粒pRNA-Lenti-增强型绿色荧光蛋白（EGFP）（含U6启动子和EGFP）连接产生pRNA-Lenti-SOCS1-EGFP慢病毒重组质粒,与慢病毒包装混合物共转染293T细胞,包装产生慢病毒,收集病毒上清,采取系列稀释法测定慢病毒滴度。然后转染hDCs,通过荧光显微镜观察细胞转染情况,利用荧光实时定量PCR和Westernblot检测干扰组、阴性对照组、空白对照组SOCS1的表达情况。结果将目的序列成功连接到载体上,并经测序分析证实载体构建成功。荧光实时定量PCR及Westernblot检测显示慢病毒重组质粒感染hDCs后,与空白对照组及阴性对照组比较,siRNA组mRNA和SOCS1蛋白的表达量显著降低,差异均有统计学意义（P〈0.05）。结论构建的pRNA-Lenti-SOCS1-EGFP慢病毒载体可有效地抑制hDCs的SOCS1的表达,为进一步研究DCs增强抗肿瘤免疫应答效应奠定基础。     

肿瘤微环境中IL-10限制SOCS1基因沉默的树突状细胞疫苗的抗肿瘤作用

目的观察SOCS1基因沉默的DC疫苗对荷黑素瘤小鼠的抗肿瘤作用及肿瘤微环境中IL-10对该DC疫苗抗瘤作用的影响。方法从小鼠股骨分离骨髓细胞,GM-CSF和IL-4联合诱导DCs分化,然后感染携带沉默SOCS1基因的Len-SOCS1-shRNA慢病毒;用TRP2抗原肽负载沉默SOCS1的DC细胞制备DC疫苗,LPS诱导成熟,流式细胞仪分析DC细胞表面MHCⅡ和CD86的表达,real-time PCR分析该DC细胞的SOCS1、IL-10和IL-12p40表达。用B16细胞或降低IL-10基因表达的B16(B16-IL-10-/-)制备荷瘤小鼠模型,瘤内注射DC疫苗(3×106/只),观察肿瘤生长和荷瘤小鼠生存期。采用不连续梯度离心法分离肿瘤浸润淋巴细胞,流式细胞仪观察CD8+T细胞的分布;并采用微量细胞毒的方法分析CTL活性。结果 Len-SOCS1-shRNA慢病毒感染DC后,可使SOCS1表达下调80%;下调SOCS1表达的DC细胞MHCⅡ和CD86表达有增加趋势,但与对照组DC相比无明显差异;下调SOCS1表达可降低DC细胞的IL-10表达,提高IL-12p40的表达。沉默SOCS1的DC疫苗对B16荷瘤小鼠的生存率没有明显影响,但可显著提高B16-IL-10-/-荷瘤小鼠的生存率(P<0.05)。下调SOCS1表达的DC疫苗不仅可提高B16-IL-10-/-荷瘤小鼠肿瘤浸润CD8+T淋巴细胞数,还可促进CD8+T细胞IFN-γ的分泌及CTL活性。结论沉默SOCS1可提高DC疫苗的活性,但肿瘤微环境的IL-10依然是限制该DC疫苗有效发挥抗瘤作用的因素。     

纳米粒子-siRNA复合物抑制脐血树突状细胞SOCS1基因表达的实验研究

目的:构建复合纳米粒子载体,传递siRNA序列,抑制脐血树突状细胞SOCS1基因表达.方法:构建PEI包覆的以SiO2和Fe3O4为主要成分的复合纳米粒子载体,以LipofectamineTM2000为对照,琼脂糖凝胶电泳检测纳米粒子-siRNA的结合效率;荧光显微镜和流式细胞术检测纳米粒子-SOCS1-siRNA序列被细胞摄入的效率;Western blot检测纳米粒子-siRNA复合物转染脐血树突状细胞后对SOCS1基因表达的抑制.MTT法检测纳米粒子-SOCS1-siRNA处理的脐血DCs对肿瘤细胞的杀伤活性.结果:纳米粒子可以高效结合siRNA序列,纳米粒子-SOCS1-siRNA序列可被脐血树突状细胞摄取,但是单独的纳米粒子抑制SOCS1基因表达效率比较低,在外加磁场的作用下,基因沉默作用显著增强,抗肿瘤作用也相应提高.结论:纳米粒子载体传递siRNA安全性好,效率高,可以高效沉默脐血树突状细胞SOCS1基因表达,能为设计更有效的以树突状细胞为基础的抗肿瘤疫苗提供新思路和实验依据.     

树突状细胞激活的CTLs在裸鼠体内外诱导抗喉癌作用

目的探讨树突状细胞(Dendritic cells,DCs)激活的细胞毒性T细胞(eytotoxic T lymphocytes,CTLs)在裸鼠体内外能否诱导抗喉癌免疫。方法用细胞因子从健康人外周血诱导DCs,MTT法检测DCs激活的CTLs在体外对喉癌细胞的作用。将裸鼠接种CTLs,1w后用喉癌细胞攻击,观察成瘤潜伏期、成瘤率、瘤重量及瘤体积。结果用细胞因子能从健康人外周血诱导大量DCs,该DCs激活的CTLs在体外对喉癌细胞产生了高效而特异的抑制及杀伤作用(P<0.01)。在裸鼠体内,负载抗原的DCs激活的CTLs有免疫保护作用,其成瘤率减低(84%,P<0.01),潜伏期延长(14±2d,P<0.01),瘤重及瘤体积均显著降低(0.47±0.10g,12.64±3.98mm~3,P<0.01)。结论DCs激活的CTLs能在裸鼠体内外诱导高效的抗喉癌作用。     

SOCS及其免疫学作用研究进展

SOCS蛋白是细胞因子信号通路重要的抑制剂,最近的研究表明SOCS蛋白是天然免疫和获得性免疫系统中关键的生理性调节剂,它们可以调节树突状细胞的激活和T细胞的发育和分化等活动,并且在免疫性疾病中发挥重要的作用。     

热处理淋巴瘤细胞增强树突状细胞介导的抗瘤效应研究

目的:探讨淋巴瘤细胞热处理后作为抗原,冲击树突状细胞而引发的抗淋巴瘤免疫效应。方法:用健康人外周血分离出单核细胞,体外培养树突状细胞(Dendritic cells,DCs),将淋巴瘤细胞株热处理(42℃,2小时)培养24小时后负载于DCs,在流式细胞仪上检测DCs的免疫表型变化;负载抗原后的DCs与淋巴细胞混合反应,以MTT法评价细胞毒性及在流式细胞仪上检测淋巴细胞的免疫表型;ELISPOT法检测细胞内因子IFNγ-的释放。结果:在两实验组中,DCs负载了热处理的淋巴瘤抗原后,细胞表面的共刺激分子和MHCⅡ类分子表达水平较对照组明显增加(P0.05),而两组之间差别无显著性(P0.05);经热处理的肿瘤细胞负载于DCs后,与淋巴细胞混合后IFNγ-的释放量明显增加;混合淋巴细胞反应后,细胞毒性实验(MTT法)和流式细胞仪检测结果均显示两实验组的杀瘤作用强于对照组(P0.05),两组之间无显著差别(P0.05)。结论:用热处理的淋巴瘤细胞作为肿瘤抗原冲击DC,能够增强抗淋巴瘤效应。     

RelB shRNA慢病毒感染小鼠骨髓树突状细胞的免疫学效应

背景：沉默树突状细胞发育成熟的关键基因核因子кB/RelB可构建新型致耐受树突状细胞？ 目的：探讨RelB shRNA转染小鼠骨髓树突细胞的生物免疫学功能的影响。 方法：利用重组粒细胞-巨噬细胞集落刺激因子和重组白细胞介素4联合诱导小鼠骨髓树突状细胞;慢病毒载体将RelB shRNA转染致小鼠骨髓树突细胞后,分为未成熟树突状细胞、脂多糖刺激成熟、RelB基因沉默及脂多糖刺激RelB沉默的4组树突状细胞进行观察。 结果：体外培养第 6 天脂多糖刺激组细胞表面可见大量细长的类似树枝的突起,其他3组细胞形态特征相似,呈圆形、皱缩状态,这3组细胞表面MHC-II类分子、CD86和CD40分子表达水平相当,但低于脂多糖刺激组;3组混合淋巴细胞反应中刺激T细胞增殖能力差异无显著性意义(P > 0.05),但均较脂多糖刺激组显著降低(P < 0.01);RelB基因沉默的树突状细胞分泌Th1细胞因子γ-干扰素和白细胞介素2的能力较低,分泌Th2白细胞介素10和白细胞介素4的能力较高(P < 0.01),Th1/Th2细胞因子的比例与未成熟树突状细胞类似。说明RelB shRNA经慢病毒转染骨髓源性树突状细胞后,在细胞形态、表面分子表达、免疫学功能等方面均具有与未成熟树突状细胞相似的特点,且不能被脂多糖刺激成熟。     

SOCS1基因沉默增强DC疫苗对肺癌动物模型的治疗效果

尽管树突状细胞(dendritic cell,DC)是机体内最有效的抗原提呈细胞(antigen presenting cell,APC),但由于逃逸机制的存在,基于DC的肿瘤疫苗效果并不如人意。因此,采用一定方法增强DC提呈抗原的能力是提高疫苗效能的关键。本研究中,采用RNA干扰技术(RNA interference,RNAi),沉默DC中细胞因子信号转导抑制因子1(suppressor of cyto- kine signaling 1,SOCS1)的表达,使之提呈抗原的能力显著提高,从而有效激发针对肿瘤的特异免疫应答,疫苗的治疗效果得以明显增强。     

SOCS3与中枢神经再生的研究进展

细胞因子信号转导抑制因子（suppressors of cytokine signaling,SOCS）家族是一类对细胞因子信号通路具有负反馈调节作用的蛋白分子,参与多种细胞因子、生长因子和激素的信号调节。细胞因子对中枢神经系统中的各种生物效应具有广泛多样的调节作用,SOCS家族的许多成员（比如SOCS1,SOCS2和SOCS3等）在发育时期和成年脑内均有表达。近来发现,SOCS3在中枢神经再生中有重要作用。     

IL-12基因修饰DC中SOCS1基因沉默对体外诱导特异性CTL的影响

利用重组腺病毒载体pAd CMV/V5-DEST-IL-12转染小鼠骨髓来源的树突状细胞(IL-12/DC),探讨SOCS1基因沉默IL-12/DC在体外诱导细胞毒性T淋巴细胞(CTL)的效能,及其免疫杀伤肺癌细胞株LLC的能力。采用重组腺病毒介导IL-12基因和SOCS1SiRNA基因共同修饰C57BL/6小鼠骨髓来源的DC,经反复冻融法提取LLC抗原,致敏基因修饰的DC;用ELISA法检测各组DC分泌IL-12和IL-10的水平,及各组DC刺激后的T细胞分泌IFN-γ的水平;MTT法检测DC刺激同源小鼠T细胞的增殖能力,微量细胞毒法检测CTL的活性并收集刺激后的T细胞,流式细胞术分析CD8+/CD4+比例和CD4+CD25+Treg的水平;统计学分析各组间的差异。SOCS1SiRNA和IL-12基因共同修饰能有效下调DC中SOCS1蛋白的表达并上调IL-12蛋白的表达;IL-12的分泌水平也明显高于SOCS1SiRNA或IL-12单基因转染组;基因共同修饰的DC表型更加成熟,能明显促进CTL的增殖和活化,减少Treg的生成;CTL分泌高水平的IFN-γ,产生对LLC特异性的细胞免疫。     

Silencing of ZnT-1 expression enhances heavy metal influx and toxicity

ZnT-1 reduces intracellular zinc accumulation and confers resistance against cadmium toxicity by a mechanism which is still unresolved. A functional link between the L-type calcium channels (LTCC) and ZnT-1 has been suggested, indicating that ZnT-1 may regulate ion permeation through this pathway. In the present study, immunohistochemical analysis revealed a striking overlap of the expression pattern of LTCC and ZnT-1 in cardiac tissue and brain. Using siRNA to silence ZnT-1 expression, we then assessed the role of ZnT-1 in regulating cation permeation through the L-type Ca²⁺ channels in cells that are vulnerable to heavy metal permeation. Transfection of cortical neurons with ZnT-1 siRNA resulted in about 70% reduction of ZnT-1 expression and increased Ca²⁺ influx via LTCC by approximately fourfold. Moreover, ZnT-1 siRNA transfected neurons showed ∼30% increase in synaptic release, monitored using the FM1-43 dye. An increased cation influx rate, through the LTCC, was also recorded for Zn²⁺ and Cd²⁺ in cells treated with the ZnT-1 siRNA. Furthermore, Cd²⁺-induced neuronal death increased by approximately twofold after transfection with ZnT-1 siRNA. In addition, ZnT-1 siRNA transfection of the ovarian granulosa cell line, POGRS1, resulted in a twofold increase in Cd²⁺ influx rate via the LTCC. Finally, a robust nimodipine-sensitive Cd²⁺ influx was observed using a low extracellular Cd²⁺ concentration (5 μM) in neurons and testicular slice cultures, attesting to the relevance of the LTCC pathway to heavy metal toxicity. Taken together, our results indicate that endogenously-expressed ZnT-1, by modulating LTCC, has a dual role: regulating calcium influx, and attenuating Cd²⁺ and Zn²⁺ permeation and toxicity in neurons and other cell types.     

Silencing of TMSG1 enhances metastasis capacity by targeting V-ATPase in breast cancer

TMSG1, as a novel tumor metastasis suppressor gene, has been demonstrated to closely relate to the metastasis and drug-resistant of breast cancer. However, its molecular mechanism is still unclear. In this study, we explored the effect of small interference RNA (siRNA) targeting TMSG1 on the invasion of human breast carcinoma cell line MCF-7 and its molecular mechanisms associated with the extracellular pH. qRT-PCR and Western blot analysis revealed dramatic reduction of the levels of TMSG1 mRNA and protein after transfection of siRNA in MCF-7 cells. Cell migration and invasion were obviously increased by TMSG1 siRNA treatment. The activity of vacuolar ATPase (V-ATPase) and MMP-2 was significantly increased in MCF-7 cells transfected with the TMSG1 siRNA compared with the controls. Furthermore, acidic intracellular environment significantly increased the MMP-2 activity and the capacity of cell migration and invasion. In conclusion, silencing of TMSG1 increased V-ATPase activity, decreased extracellular pH and in turn the activation of secreted MMP-2, which ultimately promoted metastasis capacity of breast cancer cell.     

Regulation of innate immunity by suppressor of cytokine signaling (SOCS) proteins

Innate immunity represents the first line of defense against invading pathogens. Toll-like receptors (TLRs) are important for activation of innate immunity. Moreover, cytokines mediate communication of cells and are necessary to mount an appropriately regulated immune response. However, activation of innate immunity has to be tightly controlled to avoid overshooting immune reactions. Suppressor of cytokine signaling (SOCS) proteins have been identified as inducible feedback inhibitors of cytokine receptors and have been shown to be of crucial importance for the limitation of inflammatory responses. In this review, we describe the role of SOCS proteins in macrophages and dendritic cells (DCs). Based on our own findings, we show that SOCS proteins are directly induced by stimulation of TLRs. However, SOCS proteins do not interfere with direct TLR signaling, but avoid overshooting activation by regulating paracrine IFN-beta signaling. In addition, SOCS proteins in macrophages and DCs regulate the sensitivity towards IFN-gamma and GM-CSF, thereby modulating anti-microbial activity of macrophages and differentiation of DCs. We discuss that SOCS induction can also be used by microbes to evade immune defense, and this is exemplified by the parasite Toxoplasma gondii which induces SOCS1 to inhibit IFN-gamma-mediated macrophage activation. Taken together, the findings indicate that SOCS proteins play an important role in the balanced activation of innate immunity during infectious encounter.     

细胞因子信号转导抑制因子1和3在脓毒症小鼠脾脏中表达量的变化

目的探讨细胞因子信号转导抑制因子-1和3（SOCS1和SOCS3）的含量在脓毒症小鼠脾脏中的变化情况以及可能的作用机制。方法采用盲肠结扎并穿刺术（CLP）制作脓毒症模型,提取脾脏组织的RNA及蛋白质,采用RT-PCR测定组织中SOCS1和SOCS3 mRNA的相对含量,用免疫印迹方法测定组织中SOCS1和SOCS3相对蛋白含量,用SPSS统计软件测定上述指标之间的变化关系。结果脓毒症手术后SOCS1在脾脏中仅检测到基因表达,随时间逐渐上升,并一直保持高位;SOCS3在脾脏内的基因表达和蛋白表达在术后2h迅速升高,至12h达峰值（P〈0.05）;统计分析发现SOCS1和SOCS3的基因表达呈明显正相关性（P〈0.05）。结论 CLP导致的脓毒症可以诱导SOCS1和SOCS3在脾脏中表达增多,提示SOCS1和SOCS3在脓毒症出现后的免疫变化中有重要作用,可能可利用它们对脓毒症进行干预,以改善脓毒症的预后。     

Immunization of RANTES expression plasmid with a DNA vaccine enhances HIV-1-specific immunity.

Cytokines play important roles in regulating immune response. This study evaluated the adjuvant effect of an expression plasmid encoding RANTES (regulated on activation normal T-cell expressed and secreted) chemokine on the immunity induced by a DNA vaccine. This vaccine consists of expression plasmids encoding the env and rev genes of human immunodeficiency virus type 1 (HIV-1). DNA vaccination with RANTES plasmid induced significantly higher titers of serum HIV-1-specific IgG and IgG2a antibodies than DNA vaccination alone on both intramuscular and intranasal immunization. This combination also increased HIV-1-specific cytotoxic T lymphocyte activity and delayed-type hypersensitivity. Intranasal immunization induced a higher titer of fecal secretory IgA antibody than intramuscular immunization. These results demonstrate that coadministration of RANTES plasmid dominantly induced HIV-1-specific cell-mediated immunity.