RNAi沉默HMGA1基因对肝癌细胞凋亡和细胞周期的影响

目的:筛选HMGA1基因沉默稳定转染肝癌细胞株,检测沉默后肿瘤细胞凋亡、周期和增殖的变化。方法:靶向HMGA1的RNAi载体转染肝癌细胞,G418筛选得到稳定转染细胞株并鉴定;MTT法和FACS检测细胞增殖、凋亡及细胞周期。结果:成功建立基因沉默HMGA1稳定细胞株;HMGA1基因沉默后,细胞凋亡百分率(29.46±3.04%)明显高于质粒对照组和空白对照组(1.96±0.76%和2.04±0.70%,P<0.01);G0-G1期细胞百分率(75.21±2.35%)明显高于质粒对照组和空白对照组(37.98±3.02%和39.23±3.63%,P<0.01),G2-S期(24.79±2.35%)显著低于质粒对照组和空白对照组(62.03±3.01%和60.77±3.63%,P<0.01);MTT检测显示,HMGA1沉默细胞增殖与质粒对照组和空白对照组相比显著降低(P<0.01或0.05)。结论:基因沉默HMGA1可促进肿瘤细胞凋亡,抑制细胞增殖。     

桔皮素对人肝癌细胞株SMMC-7721抑制作用的初步研究

目的：探讨桔皮素对人肝癌细胞株SMMC-7721的抑制作用。方法：采用四唑盐（MTT）比色法观察不同浓度桔皮素对人肝癌细胞株SMMC-7721细胞增殖的影响,计算半数抑制浓度IC50;绘制细胞株SMMC-7721的生长曲线观察桔皮素对其增殖的影响。结果：MTT结果显示不同浓度的桔皮素对SMMC-7721的生长均有一定的抑制作用,同一时间,各浓度组与对照组相比均有统计学差异（P〈0．05）;桔皮素浓度为0．24—30μg·mL。时,对SMMC-7721细胞在药物处理72小时后抑制率为3．85％～93．59％,且72小时的IG50为14．69—21．11μg·mL^-1。生长曲线结果提示,桔皮素对SMMC-7721细胞的抑制作用呈明显时效和量效关系。结论：桔皮素能抑制人肝癌细胞株SMMC-7721的增殖。     

重组腺病毒介导的人AWP1基因转移对人源肝癌细胞增殖的影响

目的以重组腺病毒作为AWP1（associated with PRK1）的转基因载体,研究AWP1对人肝癌细胞增殖的影响,为进一步研究AWP1基因功能提供依据。方法重组腺病毒质粒pAd-flag-AWP1转染293细胞进行重组腺病毒的包装和扩增,并进行PCR鉴定。用空病毒Ad-Null和重组腺病毒Ad-flag-AWP1分别感染人源肝癌细胞SMMC-7721,并于感染后24 h、72 h、第5天和第7天收集细胞计数,绘制细胞生长曲线,计算细胞倍增时间。结果重组腺病毒Ad-flag-AWP1能够感染SMMC-7721细胞;依据细胞生长曲线计算的SMMC-7721细胞倍增时间分别为：SMMC-7721细胞约为5 d;而Ad-Null感染后其生长被抑制,倍增时间约为6 d;Ad-flag-AWP1感染后,其倍增时间约为3 d。结论重组flag-AWP1腺病毒转染SMMC-7721细胞过表达的AWP1蛋白可能具有促进人肝癌细胞生长的作用。     

hPOT1基因过表达对HeLa细胞细胞周期和凋亡的影响

目的观察人POT1(protection of telomeres1)基因过表达对HeLa细胞细胞周期和细胞凋亡的影响。方法利用本课题组构建的hPOTl基因真核表达重组质粒pcDNA3-hPOT1,经脂质体介导瞬时转染HeLa细胞;通过RT-PCR和EMSA法(电泳迁移率改变分析)检测外源基因的表达效果,流式细胞术分析细胞周期,Hoechst33342荧光染色检测细胞凋亡。结果pcDNA3-hPOT1重组质粒转染HeLa细胞48h后,mRNA和蛋白质分析表明,外源性hPOT1基因能在HeLa细胞中有效表达,HeLa细胞阻滞于细胞周期s期,而对凋亡无明显影响。结论hPOT1基因可能参与了高等真核细胞细胞周期调控过程,但与细胞凋亡无密切关系。     

Foxp3在小鼠1型糖尿病模型中的表达情况研究

目的:研究Foxp3在小鼠1型糖尿病模型中的表达情况,并探讨其在1型糖尿病发病机制中的作用.方法:利用链脲佐菌素(STZ)致诱小鼠1型糖尿病模型,半定量RT-PCR检测脾脏Foxp3 mRNA的表达,Western blot法检测脾脏Scurfin蛋白的表达,流式细胞术检测CD4+CD25+Treg细胞亚群比例.结果:模型组Foxp3 mRNA及其蛋白产物Scurfin的表达短期内上升,约在7天左右开始下降,到30天左右低于对照组(P＜0.05).7天内,CD4+CD25+Treg细胞亚群比例在模型组与对照组大致相等,而7天后,其比例在模型组逐渐下降(P＜0.05).结论:Foxp3的表达异常,使CD4+CD25+Treg细胞亚群比例下降,以致不能抑制效应性CD4+T细胞的增殖对胰岛的破坏,此机制参与了1型糖尿病的发生.     

Regulatory T cell-like activity of Foxp3+ adult T cell leukemia cells

Adult T cell leukemia (ATL) is an aggressive neoplastic disease, in which a quarter of the patients develop opportunistic infections due to cellular immunodeficiency. However, the underlying mechanism responsible for the immunosuppression has remained unclear. Recent studies have demonstrated that the leukemia cells from a subset of patients with ATL express Foxp3, a specific marker for CD25+CD4+ regulatory T (Treg) cells, which regulate the immune response by suppressing CD4+ T cell functions. However, whether there is a functional resemblance between ATL cells that have Foxp3 expression and Treg cells is still unknown. In this report, we confirmed the high expression of Foxp3 in leukemia cells from 5 of 12 ATL patients and demonstrated that ATL cells from 3 patients suppressed the proliferation of CD4+ T cells. Similarly, one of six HTLV-I-infected cell lines showed both high Foxp3 expression and suppressive activity. Like Treg cells, the suppression induced by the ATL cells from two patients and the HTLV-infected cell line appeared to be mediated by a cell-cell contact-dependent mechanism. Nevertheless, among the ATL cells that strongly expressed Foxp3, those from two of the five patients showed no apparent suppressive activity. Furthermore, retroviral transfection of Foxp3 did not confer any suppressive function on low Foxp3-expressing HTLV-I-infected cell lines. These results indicate that Foxp3 may be essential but is not sufficient for the Treg-cell-like suppressive activity of ATL cells and HTLV-I-infected cell lines.     

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。     

褪黑素对小鼠CD4~+ T细胞增殖及Foxp3启动子活性的影响

目的探讨褪黑素(melatonin,MLT)对小鼠CD4+T细胞增殖及Foxp3(Forkhead box P3)启动子活性的影响,进一步丰富神经内分泌免疫网络学说。方法免疫磁珠分选小鼠脾CD4+T细胞,CCK-8法检测褪黑素对其增殖活性的影响;构建、筛选及鉴定Foxp3核心和全长启动子重组载体,并且电转染入小鼠CD4+T细胞,加以不同淋巴细胞刺激因子和褪黑素干预,用双荧光素酶报告基因法检测Foxp3启动子的活性变化。结果与空白对照组相比,从10-5mol浓度的MLT开始对CD4+T细胞有毒性作用,并呈剂量依赖性。10-6mol MLT对CD4+T细胞的增殖活性无影响。3种淋巴细胞刺激因子(佛波酯PMA+离子霉素ionomycin;植物血凝素PHA;T细胞抗原受体TCR)刺激和(或)褪黑素干预虽然使小鼠Foxp3核心或全长启动子活性有所上调,但与空白对照差异无统计学意义(P0.05)。结论不同浓度褪黑素对小鼠CD4+T细胞增殖活性产生不同影响;褪黑素未显著增强小鼠Foxp3启动子活性。     

RNAi blocks DYT1 mutant torsinA inclusions in neurons

Early onset generalized dystonia is a dominantly inherited movement disorder caused by neuronal dysfunction without an apparent loss of neurons. The same single mutation (GAG deletion) causes most cases and results in loss of a glutamic acid (E) in the carboxy terminal region of torsinA (Delta302/303). To model the neuronal involvement, adult rat primary sensory dorsal root ganglion neurons in culture were infected with lentivirus vectors expressing human wild-type or mutant torsinA. Expression of the mutant protein resulted in formation of torsinA-positive perinuclear inclusions. When the cells were co-infected with lentivirus vectors expressing the mutant torsinA message and a shRNA selectively targeting this message, inclusion formation was blocked. Vector-delivered siRNAs have the potential to decrease the adverse effects of this mutant protein in neurons without affecting wild-type protein.     

Foxp3基因与自身免疫性疾病

自身免疫性疾病系由于机体免疫系统失衡,产生针对自身组织的免疫应答并导致自身组织、器官损害的一类疾病.调节性T淋巴细胞(Regulatory T cell,Treg )具有免疫应答低下和免疫抑制特性,在维持机体免疫耐受和免疫应答稳态方面具有非常重要的作用,Treg的异常与多种自身免疫性疾病有关[1].Foxp3特异性表达于CD4 CD25 Treg细胞,与其发育、成熟以及抑制功能关系密切.本文拟就Foxp3基因的研究进展及与多种自身免疫性疾病的关系作一综述.     

中国HIV-1感染者CD4+CD25+Foxp3+调节性T细胞与疾病进展相关性研究

目的对中国HIV-1感染者CD4~ CD25~ Foxp3~ 调节性T细胞水平及与疾病进展相关性进行研究,探讨CD4~ CD25~ Foxp3~ 调节性T细胞在HIV-1疾病进程中发挥的作用。方法选取35名HIV-1感染者及14名健康对照,应用流式细胞仪胞内染色技术在单细胞水平检测CD~ CD25~ Foxp3~ 调节性T细胞表达及淋巴细胞活化、凋亡水平。结果中国HIV-1感染者CD4~ CD25~ Foxp3~ T细胞水平与CD4~ T细胞显著负相关(r=-0.544,P=0.001),与病毒载量明显正相关(r=0.484,P= 0.026),与CD4~ T细胞凋亡(CD95表达)水平明显正相关(r=0.431,P=0.011)。艾滋病人CD4~ CD25~ Foxp3~ T细胞水平明显高于无症状HIV感染者(P<0.05),与健康人相比差异无统计学意义。艾滋病人CD4~ 、CD8~ T细胞凋亡水平明显高于无症状HIV感染者及健康人(P<0.05),艾滋病人及无症状HIV感染者CD4~ 、CD8~ T细胞活化明显高于健康人(P<0.05)。结论中国HIV-1感染者CD4~ CD25~ Foxp3~ 调节性T细胞水平与疾病进展明显相关。     

5-Aza-CdR抑制HepG2细胞DLK1基因表达及细胞生长

目的 探讨去甲基化药物5-氮杂-2’-脱氧胞苷(5-Aza-CdR)对DLK1基因及肝癌细胞系HepG2增殖、侵袭的影响.方法 不同浓度的5-Aza-CdR及PBS作用HepG2细胞后,RT-PCR、Western blot检测DLK1基因及蛋白的表达水平;MTT、Transwell和流式细胞术检测HepG2细胞的生长、侵袭力及细胞周期的变化.结果 HepG2细胞经5-Aza-CdR处理后,DLK1 mRNA、蛋白表达量降低;MTT试验显示细胞生长速度依5-Aza-CdR浓度出现不同程度减慢;流式结果表明G1期细胞减少,S期细胞增加,出现S期阻滞;Transwell证实侵袭能力显著降低(P＜0.05).结论 去甲基化药物5-Aza-CdR能有效地抑制DLK1基因的表达,从而抑制肿瘤细胞HepG2生长、增殖、侵袭能力.     

脱落酸抑制人肝癌细胞增殖

目的探讨脱落酸抑制SMMC-7721人肝癌细胞增殖作用的机制。方法免疫细胞化学检测P53、Ki-67、Cyclin D1蛋白表达;RT-PCR检测P53和端粒酶mRNA表达。结果经脱落酸(ABA)、环六亚甲基二乙酰胺(HMBA)和ABA HMBA作用后细胞内mtP53、Cyclin D1、Ki-67及细胞内mt P53、hTERT mRNA表达水平均明显降低(P<0.05)。结论ABA抑制SMMC-7721人肝癌细胞增殖,其作用机制可能是调控细胞周期,降低mtP53、Ki-67、Cyclin D1蛋白及mtP53,hTERT mRNA表达。     

Role of Foxp3-positive regulatory T cells during infection

Surviving an infection requires the generation of an immune response that controls the invading pathogen while limiting collateral damage to self tissues that may result from an exuberant immune response. Various populations of regulatory cells, including Foxp3+ Treg, have been shown to play a central role in the establishment of these controlled immune responses. In this review, I discuss current hypotheses and points of polemic associated with the origin, mode of action and antigen specificity of Foxp3+ Treg during infection.     

KLRG1 impairs regulatory T‐cell competitive fitness in the gut

Immune homeostasis requires the tight, tissue‐specific control of the different CD4⁺ Foxp3⁺ regulatory T (Treg) cell populations. The cadherin‐binding inhibitory receptor killer cell lectin‐like receptor G1 (KLRG1) is expressed by a subpopulation of Treg cells with GATA3⁺ effector phenotype. Although such Treg cells are important for the immune balance, especially in the gut, the role of KLRG1 in Treg cells has not been assessed. Using KLRG1 knockout mice, we found that KLRG1 deficiency does not affect Treg cell frequencies in spleen, mesenteric lymph nodes or intestine, or frequencies of GATA3⁺ Treg cells in the gut. KLRG1‐deficient Treg cells were also protective in a T‐cell transfer model of colitis. Hence, KLRG1 is not essential for the development or activity of the general Treg cell population. We then checked the effects of KLRG1 on Treg cell activation. In line with KLRG1's reported inhibitory activity, in vitro KLRG1 cross‐linking dampened the Treg cell T‐cell receptor response. Consistently, lack of KLRG1 on Treg cells conferred on them a competitive advantage in the gut, but not in lymphoid organs. Hence, although absence of KLRG1 is not enough to increase intestinal Treg cells in KLRG1 knockout mice, KLRG1 ligation reduces T‐cell receptor signals and the competitive fitness of individual Treg cells in the intestine.     

转录因子Foxp3在肺癌细胞的表达及其意义

目的研究转录因子Foxp3在肺癌细胞中的表达及其对肿瘤免疫的影响。方法用常规RT-PCR检测Foxp3在肺癌细胞系中的表达,进一步用Western blot验证其蛋白水平的表达;将表达Foxp3的肿瘤细胞及用Foxp3 siRNA沉默后的肿瘤细胞分别与CD4+CD25-T细胞共培养,CFSE评价免疫效应细胞增殖情况。结果 Foxp3在肺癌细胞系中出现表达;肺癌细胞与CD4+T细胞进行共培养,可显著抑制共培养体系中CD4+T细胞增殖;肺癌细胞Foxp3表达沉默后,可显著改善共培养体系中肺癌细胞对CD4+T细胞增殖的抑制作用。结论在肺细胞癌细胞系发现Foxp3的表达,肺癌细胞Foxp3的表达参与对肿瘤特异性T细胞增殖的抑制。     

Diversification and senescence of Foxp3+ regulatory T cells during experimental autoimmune encephalomyelitis

The fate of Foxp3⁺ regulatory T (Treg) cells responding during autoimmunity is not well defined. We observed a marked elevation in KLRG1⁺ (where KLRG1 stands for killer cell lectin‐like receptor G1) CNS‐infiltrating Treg cells in experimental autoimmune encephalomyelitis (EAE), and assessed their origin and properties. KLRG1⁺ Treg cells showed increased activation marker expression, Foxp3 and CD25 levels, and more rapid cell cycling than KLRG1^? cells. KLRG1^? Treg cells converted into KLRG1⁺ cells and this was increased in autoimmune inflammation. Conversion was unidirectional; KLRG1⁺ Treg cells did not revert to a KLRG1^? state. KLRG1⁺ but notKLRG1^?Treg cells survived poorly, indicative of terminal differentiation. This was associated with diminished BCL2 and increased apoptosis of isolated cells. KLRG1 was also upregulated on iTreg cells after transfer and EAE induction or on iTreg cells developing spontaneously during EAE. KLRG1⁺ Treg cells produced more IL‐10 and had altered effector cytokine production compared with their KLRG1^? counterparts. Despite their differences, KLRG1⁺ and KLRG1^? Treg cells proved similarly potent in suppressing EAE. KLRG1⁺ and KLRG1^? populations were phenotypically heterogeneous, with the extent and pattern of activation marker expression dependent both on cellular location and inflammation. Our results support an extensive diversification of Treg cells during EAE, and associate KLRG1 with altered Treg‐cell function and senescence.     

小鼠Foxp3基因慢病毒载体构建及其在DC2.4细胞的表达

目的:构建小鼠Foxp3基因的慢病毒载体,体外感染树突状细胞DC2.4,制备Foxp3+DC细胞,为进一步研究其免疫调节作用奠定基础。方法:将小鼠Foxp3基因克隆到慢病毒pGC-FU载体,通过PCR和测序鉴定获得连接正确的克隆。将鉴定后的重组表达质粒pGC-FU-Foxp3与pHelper1.0质粒和pHelper2.0质粒共转染293T细胞,制备携带Foxp3基因的慢病毒Lentivirus-Foxp3。Lentivirus-Foxp3感染体外培养的DC细胞,流式细胞术(FCM)检测感染后的DC细胞Foxp3表达。结果:构建的慢病毒载体pGC-FU-Foxp3经PCR鉴定和测序正确,包装慢病毒Lentivirus-Foxp3滴度为2×108TU/mL。慢病毒Lentivirus-Foxp3感染DC2.4细胞后Foxp3表达明显增加。结论:成功构建了小鼠Foxp3基因的慢病毒表达载体,慢病毒Lentivirus-Foxp3能有效感染DC细胞。