反义CD40RNA对EB病毒转化的B细胞CD40分子表达和增殖能力的影响

目的 :探讨瞬时表达的反义CD4 0RNA ,对EB病毒转化的健康人B细胞膜表面CD4 0分子表达和增殖能力的影响。方法 :应用T A克隆技术和亚克隆技术 ,构建人反义CD4 0RNA的真核表达载体pcDNA3/CD4 0 ,并以其转染本室建立的EB病毒转化的健康人B细胞。应用流式细胞仪 (FACS) ,检测B细胞膜上CD4 0分子表达的变化。应用MTT比色法检测反义CD4 0RNA对B细胞增殖能力的影响。结果 :与转染空载体pcDNA3组相比 ,转染pcDNA3/CD4 0细胞上CD4 0分子的表达降低 (P<0 .0 1) ,其增殖能力明显降低 (P <0 .0 1)。结论 :反义CD4 0RNA技术 ,可作为有效的免疫调控手段。CD4 0基因本身在细胞的生长代谢中也起着重要作用     

反义DcR3 RNA转染诱导肝癌细胞凋亡的作用

目的研究DcR3反义mRNA在肝癌细胞凋亡中的作用。方法构建pVAXⅠ-as-DcR3反义表达载体，转染肝癌细胞，Western blot法观察DcR3蛋白合成有无降低，流式细胞术、TUNEL等方法观察凋亡变化。结果Western blot证实反义重组体可有效阻滞DcR3表达，同时转染了pVAXⅠ-as-DcR3的肝癌细胞凋亡较对照组增多。结论DcR3反义RNA可使肝癌细胞凋亡增多。     

CD40/CD40L交联在CD4+T细胞诱导肿瘤细胞凋亡中的机制研究

目的探讨CD40/CD40L交联在CIK细胞中CD4 T细胞(CD4 CIK)诱导肿瘤细胞凋亡中的作用机制.方法体外扩增CIK细胞并纯化CD4 T细胞亚群,AnnexinV染色法观察CD4 CIK诱导肿瘤细胞凋亡的作用;半定量PCR、流式细胞法及ELISA法比较CD4 CIK激活前后CD40L的表达变化;将转染质粒pIRES2-EGFP-sCD40L的CHO细胞(CHO-sCD40L)与乳腺癌细胞T47D共孵育,监测24小时后其表面分子Fas的表达变化及对Fas介导凋亡的敏感性.结果CD4 CIK细胞可诱导肿瘤细胞凋亡,凋亡率随孵育时间和效靶比的升高而增加,且肿瘤细胞表面分子Fas水平升高,可从1.98%±0.23%升高到31.62%±7.07%;CD4 CIK细胞被激活后,CD40L表达水平均较激活前明显增加;成功转染的CHO-sCD40L细胞与T47D共培养后,T47D表面分子Fas可被诱导升高,加入CH-11 24小时后可观察到明显T47D细胞的凋亡.结论CD4 CIK可能通过CD40/CD40L交联提升肿瘤细胞表面功能性Fas表达来诱导其凋亡.     

survivin反义寡核苷酸在体外诱导胰癌细胞凋亡

目的：探讨survivin反义核酸对胰腺癌细胞株Panc-1细胞凋亡的影响.方法：用脂质体瞬时转染法介导survivin反义核苷酸处理胰腺癌Panc-1细胞后,MTT试验测定转染细胞的相对存活率,RT-PCR检测survivin mRNA表达,琼脂糖凝胶电泳分析其对Panc-1细胞的凋亡诱导作用.结果：转染survivin反义核酸的Panc-1细胞增殖明显受抑制,与对照进行比较,具有显著性差异（P＜0.05）;经琼脂糖凝胶电泳,转染survivin反义核酸的Panc-1细胞可见到DNA梯形条带,而对照细胞未见到.结论：survivin反义核酸能够诱导Panc-1细胞凋亡.     

hTERT 基因反义核酸诱导卵巢癌细胞凋亡的研究

目的 在体外实验中，探讨hTERT反义核酸诱导卵巢癌细胞发生凋亡的可能性，揭示该凋亡发生与bcl-2和bax之间的关系。方法采用TUNEL染色法，定性、定量地研究hTERT反义核酸与卵巢癌细胞凋亡的关系；通过免疫组织化学法检测凋亡相关基因bcl-2和bax的表达。结果hTERT反义核酸在体外能诱导卵巢癌细胞发生凋亡。下调bcl-2的表达，增强bax的表达。结论诱导卵巢癌细胞发生凋亡是hTERT反义核酸抗卵巢癌作用的机制之一。hTERT反义核酸可能通过下调bcl-2的表达及增强bax的表达诱导卵巢癌细胞发生凋亡。     

CD40分子在树突状细胞中的信号转导通路

树突状细胞 (DC )作为体内功能最强的抗原提呈细胞 (APC ) ,是启动机体免疫应答的中心环节[1] 。未成熟DC定居在外周组织 ,具有极强的捕获抗原能力 ,通过多种方式捕获入侵的病原体、损伤或恶变的组织后迁移至淋巴结 ,将加工过的抗原以MHC 抗原肽的形式提呈给T细胞启动机体免疫应答。在此过程中 ,DC逐渐发育成熟 ,伴随着膜表面黏附分子表达的变化以及MHCII类分子和共刺激分子如CD4 0、OX4 0L、CD80、CD86表达的上调。然而 ,DC抗原提呈功能的完全成熟需要T细胞提供的共刺激信号 ,其中CD4 0相关的信号通路在此过程中发挥了重要作用     

反义RNA阻断Hep G2细胞FasL的表达及功能研究

应用分子克隆技术将人FasLcDNA片段反向插入逆转录病毒载体pLXSN ,构建重组质粒pL (hFasL AS )SN ,转染包装细胞PA317后获得FasL反义RNA重组逆转录病毒表达载体假病毒上清 ,经NIH3T3细胞检测其感染滴度后转染肝癌细胞株HepG2细胞并筛选建系 ,命名为HepG2 hFasL AS。半定量RT PCR检测显示HepG2 FasL AS细胞FasL的mRNA明显少于正常HepG2细胞 ;FACS检测显示HepG2 FasL AS细胞FasL的表达与HepG2细胞相比显著下降 ;同时 ,HepG2 FasL AS细胞导致HL 6 0细胞凋亡能力有所下降。表明人FasL反义RNA重组逆转录病毒表达载体能抑制转染细胞FasL的表达并下调其致凋亡功能     

Survivin反义寡核苷酸对骨肉瘤细胞凋亡的诱导效应

目的：利用骨肉瘤OS-732细胞,探讨survivin反义寡核苷酸（ASODN）对survivin基因表达的影响及其诱导肿瘤细胞凋亡的效应。方法:设计合成特异性靶向survivin的ASODN,以不同浓度和时间对OS-732细胞进行转染,并设空白、正义（SODN）对照组进行比较。采用RT-PCR、Westernblotting、免疫细胞化学技术检测各组OS-732细胞中survivinmRNA、蛋白表达状态,吖啶橙/溴化乙锭（AO/EB）染色法、流式细胞仪检测细胞凋亡水平和形态变化,MTT法检测细胞生长抑制情况,激酶活性测定法检测细胞中caspase-3活性程度。结果:转染ASODN各组OS-732细胞survivinmRNA和蛋白表达均明显弱于空白对照组、SODN组;细胞凋亡率（AI）显著增加,细胞生长相应受抑,caspase-3活性显著提高;上述效应在ASODN各组存在一定的时间浓度依赖性;而SODN各组与空白对照组间各项指标均无明显差异。结论:ASODN能够特异性下调OS-732细胞中survivin基因表达,激活凋亡效应蛋白酶caspase-3,在诱导肿瘤细胞凋亡、抑制增殖中发挥重要作用。     

用反义寡核苷酸阻断热休克蛋白70表达诱导卵巢癌细胞凋亡

目的 观察特异性热体克蛋白７０（ｈｅａｔ－ｓｈｏｃｋ ｐｒｏｔｅｉｎ,ＨＳＰ）反义寡核苷酸阻断卵巢癌细胞的ＨＳＰ７０表达,及其对卵巢癌细胞生长和增殖的影响。方法 用胎盘蓝拒染法计算卵巢癌细胞的生长抑制率。Ｇｉｅｎｓａ染色法从形态上了解凋亡的发生,用琼脂糖凝胶电脉进一步检测发生凋亡的特征性ＤＮＡ降解,流式细胞仪定量分析凋亡发生率及周期性异性。结果 用ＨＳＰ７０反义寡核苷酸处理的卵巢细胞表现有显的生长     

CD40L/CD40轴的生物学功能及其与疾病的关系研究进展

CD40L／CD40为体内免疫反应系统中一对重要的共刺激分子,参与机体的体液和细胞免疫反应。CD40L主要表达在CD4^＋T细胞、CD8^＋T细胞和B细胞,CD40主要表达于B细胞、活化的单核／巨噬细胞、树突状细胞（DC）、上皮细胞等。CD40L／CD40轴对B细胞的活化、增殖、细胞因子的分泌及免疫球蛋白的类别转换起到了非常重要的作用。CD40L／CIMO相互作用也对细胞毒性T细胞前体的活化,维持调节性T细胞的动态平衡及诱导辅助性T细胞的分化等方面起重要作用。CIMOL／CIMO轴还参与多种免疫相关疾病的致病过程,如自身免疫性疾病、肝炎等,且在抗肿瘤免疫中起到重要作用。多种动物模型的建立为探究疾病病因、研究CIMOL／CIMO轴在疾病发生过程中的作用提供了重要的平台。     

Regulation of B cell growth and differentiation via CD21 and CD40

Stimulation in vitro of murine splenic B cells by lipopolysaccharide, anti-ϰ Sepharose, anti-CD40 or allo-reactive T helper cells all up-regulated CD21 and CD23 surface expression. Neither anti-CD21 nor anti-CD23 antibodies induced B cell growth or differentiation when added in soluble form or coupled to Sepharose. However, anti-CD40-stimulated B cells showed increased proliferation in the presence of anti-CD21 antibodies coupled to Sepharose; co-stimulation via CD21 also induced differentiation to immunoglobulin secretion in a fraction of anti-CD40-stimulated B cells. Furthermore, anti-CD40 antibodies inhibited differentiation to immunoglobulin secretion induced by lipopolysaccharide and, hence, appears to be a dominant negative signal for B cell differentiation.     

CD40-CD40 ligand interactions stimulate B cell antigen processing

The interactions between B cell CD40 and T cell CD40 ligand (CD40L) have been shown recently to play an important role in T cell-dependent activation of B cells. Here, we show that the ligation of CD40 stimulates the processing of antigen by B cells. The activation of an antigen-specific T cell hybrid by B cells co-cultured with insect cells expressing recombinant CD40L or with a CD40-specific monoclonal antibody requires less antigen and fewer B cells compared to control cells. The augmentation was observed both for processing initiated by antigen binding to and cross-linking the surface immunoglobulin, and processing of antigen taken up by fluid-phase pinocytosis. CD40 appears to affect a step in the intracellular processing of antigen, as CD40 has no effect on the presentation of an antigenic peptide which does not require processing. In addition, the CD40-induced augmentation of processing is not attributable to the effect of CD40 ligation on the cell surface expression of B7, LFA-1 or CD23. CD40 ligation does not affect the biosynthesis of the class II E^k molecules, and although ligation of CD40 induces B cell proliferation, the augmentation of processing does not require proliferation. The ability of CD40 to stimulate B cell antigen processing has the potential to influence significantly the outcome of antigen-dependent T cell-B cell interactions.     

CD40 ligation decreases its protein half-life at the cell surface

CD40 is expressed on a variety of tumors; anti-CD40 agonists promote tumor cell apoptosis and subsequent tumor regression. Because the effectiveness of anti-CD40- agonists is dependent upon CD40 surface expression, the current study examined ligation-mediated changes in CD40 protein half-life (t(1/2))( )at the cell surface. This study utilized a CD40(+) epithelial cell line (9HTEo-), a CD40 null epithelial cell line (HT-29) engineered to express either wild-type (WT) or mutant (T254A, Q263A, E235A, Delta201) CD40, and the anti-CD40 antibody G28.5. Ligation of endogenous CD40 expressed on 9HTEo- cells decreased CD40 surface protein t(1/2 )from 13 to 4 h (p <0.05). Ligation of WT-, Q263A-, or T254A-CD40 expressed on engineered HT-29 cells decreased CD40 surface protein t(1/2) from an average of 8 to 4 h (p <0.05); T254A and Q263A contain mutated TNF receptor-associated factor (TRAF)2/3-binding sites. In contrast, ligation of E235A and Delta201-CD40 had no affect on its surface protein t(1/2) (p <0.05); E235A contains a mutated TRAF6-binding site while Delta201 lacks an intact cytoplasmic tail. These results suggest that anti-CD40 agonists decrease CD40 surface protein t(1/2) via a mechanism that involves TRAF6 but not TRAF2/3. The therapeutic implications for CD40-mediated tumor regression are discussed.     

CD40 ligand-positive CD8+ T cell clones allow B cell growth and differentiation

A fraction of activated CD8⁺ T cells expresses CD40 ligand (CD40L), a molecule that plays a key role in T cell-dependent B cell stimulation. CD8⁺ T cell clones were examined for CD40L expression and for their capacity to allow the growth and differentiation of B cells, upon activation with immobilized anti-CD3. According to CD40L expression, CD8⁺ clones could be grouped into three subsets. CD8⁺ T cell clones expressing high levels of CD40L (≥80% CD40L⁺ cells) were equivalent to CD4⁺ T cell clones with regard to induction of tonsil B cell proliferation and immunoglobulin (Ig) production, provided the combination of interleukin (IL)-2 and IL-10 was added to cultures. CD8⁺ T cell clones, with intermediate levels of CD40L expression (10 to 30% CD40L⁺ cells), also stimulated B cell proliferation and Ig secretion with IL-2 and IL-10. B cell responses induced by these CD8⁺ T cell clones were neutralized by blocking monoclonal antibodies specific for either CD40L or CD40. By contrast, CD40L^?? T cell clones (?5 % CD40L⁺ cells), only induced marginal B cell responses even with IL-2 and IL-10. All three clone types were able to activate B cells as shown by up-regulation of CD25, CD80 and CD86 expression. A neutralizing anti-CD40L antibody indicated that T cell-dependent B cell activation was only partly dependent on CD40-CD40L interaction. These CD40L^?? clones had no inhibitory effects on B cell proliferation induced by CD40L-expressing CD8⁺ T cell clones. Taken together, these results indicate that CD8⁺ T cells can induce B cell growth and differentiation in a CD40L-CD40-dependent fashion.     

CD40 ligand-independent B cell activation revealed by CD40 ligand-deficient T cell clones: evidence for distinct activation requirements for antibody formation and B cell proliferation

We report the capacity of CD40 ligand (CD40L)-negative T cell clones to activate human B cells. CD40L-negative T cells induce a level of B cell proliferation 10–20% of that seen with normal T cells. The signal provided by the negative clones is synergistic with that derived from a CD40L transfectant, and restores B cell proliferation to normal levels, showing that CD40L-negative T cell clones are not inherently inhibitory for B cells. Although their capacity to induce proliferation was much reduced, CD40L-negative T cell clones were still strong inducers of B cell differentiation to plasma cells. This differentiation to plasma cells was inhibited by a CD40L transfectant. The data are discussed with regard to the normal in vivo mechanism for maintaining B cell memory and memory antibody responses to T-dependent antigens.     

VEGF165反义RNA对人食管鳞癌细胞影响的实验研究

目的 :观察血管内皮生长因子16 5 (VEGF16 5 )反义RNA对人食管鳞癌细胞EC10 9的影响 ,探讨其治疗食管癌的可行性。方法 :采用亚克隆技术 ,构建并鉴定VEGF16 5 反义RNA的真核表达载体。以重组质粒转染人食管鳞癌细胞EC10 9后 ,将其接种于裸鼠皮下 ,分别利用原位杂交、激光共聚焦、图象分析及微血管计数等方法 ,观察转染前后EC10 9细胞的生物学性状和致瘤性。结果 :成功地构建了VEGF16 5 反义RNA的真核表达载体 ,并在EC10 9细胞中获得表达。转染细胞中VEGF16 5 的表达下降 75% ,其生物学性状不受外源基因表达的影响 ,但其在裸鼠皮下的致瘤性和和瘤组织中血管的生成明显下降。VEGF16 5 反义RNA转染组、空载体转染组和对照组中肿瘤的体积 ,分别为 (82 0± 112 .5)mm3 、(793 0± 10 3 5)mm3 和 (7850± 950 )mm3(P <0 .0 1) ;微血管的密度分别为 (8.5± 1.2 ) /mm2 、(44.3± 9.4) /mm2 和 (46.4± 12 .6) /mm2 (P <0 .0 1)。结论 :VEGF16 5反义RNA能够明显减少食管鳞癌细胞内VEGF16 5 的表达 ,具有抑制肿瘤生长和血管生成的作用 ,可望用于实体肿瘤的辅助治疗。     

The role of CD40 and CD154/CD40L in dendritic cells

In this review, we focus on the function of CD40–CD40L (CD154) interactions in the regulation of dendritic cell (DC)–T cell and DC–B cell crosstalk. In addition, we examine differences and similarities between the CD40 signaling pathway in DCs and other innate immune cell receptors, and how these pathways integrate DC functions. As research into DC vaccines and immunotherapies progresses, further understanding of CD40 and DC function will advance the applicability of DCs in immunotherapy for human diseases.