四例血友病B患者基因治疗的临床试验

报道了对四例血友病Ｂ患者基因治疗的临床试验，取自四例血友病Ｂ患者的自体皮肤成纤维细胞，通过反转录病毒介导的基因转移，能高效地分泌人凝血因子Ⅸ。用胶原包埋经遗传修饰的自体皮肤成纤维细胞，再移植到血友病Ｂ患者皮下。四例患者经治疗后，自发出血症状得到了减轻，血浆中凝血因子Ⅸ蛋白浓度和凝血活性明显地增加，其中两例患者增加较大，达到正常值的４％￣５％。另外两例患者体内的凝血因子Ⅸ和凝血活性也有不同程度的提高     

凝血因子Ⅸ基因剔除小鼠遗传稳定性及其临床表型研究

通过对凝血因子Ⅸ基因剔除小鼠遗传稳定性及其相应临床表型的研究,为以该动物模型为研究对象的血友病Ｂ基因治疗提供相应背景资料,遗传分析表明,该小鼠繁殖过程中无回复突变出现,亦未发现Ⅸ因子基因未敲除部分被转录的证据;血浆ＰＴ,ＫＰＴＴ和Ⅸ因子活性检定结果提示该小鼠符合人血友病Ｂ相应临床表征。     

国外期刊亮点

<正>发现一种RNA或可治疗血友病血友病是由于某些突变导致凝血蛋白因子VIII或IX的缺乏,从而使得身体无法止血。但是,那些能够让抗凝血蛋白失效的变异能够抵消与凝血蛋白因子缺乏相关的突变带来的影响。Akin Akinc等研究人员设计出名为ALN-AT3的干预治疗RNA并将其作用于抗凝血蛋白中的抗凝血酶,它能够抑制凝血酶这种重要的凝血蛋白。研究成果发表于5月的Nature Medicine上。     

人凝血因子Ⅸ的线性B细胞表位预测及鉴定

为预测并鉴定人凝血因子IX(FIX)的线性B细胞表位.通过IEDB数据库及Discovery Studio软件预测FIX的B表位和白喉毒素T结构域(DTT)的B表位,用所预测的FIX的B表位替换某预测的DTT的B表位形成DTT-表位融合蛋白.通过基因工程技术制备各重组蛋白,并免疫小鼠,通过ELISA和Western-blot检测抗血清效价和特异性,通过等温量热滴定技术(ITC)测定抗体的亲和力.预测到4个FIX的B表位.用重组蛋白FIX-2-DTT免疫的小鼠产生了识别完整FIX的抗体,该抗体具有良好的特异性,其结合常数KD为106 M-1.表明FIX-2(306 NAAINKY312)是FIX的B表位,用重组蛋白FIX-2-DTT免疫小鼠能够产生特异性识别FIX且亲和力温和的抗体.     

凝血因子IX的体外检测方法研究

凝血因子ＩＸ的检测是血友病Ｂ基因治疗研究中的重要工作，在实验室原有基础上，发现和完善了凝血因子ＩＸ在蛋白质水平上的检测系统，为基因治疗血友病Ｂ提供了更为直观可靠的依据。首先，建立了以鼠抗人ＦＩＸ单克隆抗体Ａ－７为一抗的检测活性ＦＩＸ蛋白量的ＥＬＩＳＡ法，为检测活性ＦＩＸ提供了快速简便的方法。其次，实现了用Ｗｅｓｔｅｒｎｂｌｏｔ法检测转染细胞培养液上清中ＦＩＸ，确证了体外培养的转有人ＦＩＸｃＤＮＡ细     

丹酚酸B促进人软骨细胞生长并上调β-连环蛋白和类细胞介素-1的表达

为探讨中药丹参的主要活性成份丹酚酸B对人软骨细胞系C28112细胞的增殖作用及其调节作用机制中相关因子的初步辨识采用MTS法检测丹酚酸B的对软骨细胞作用的有效浓度;吖碇橙荧光标记软骨细胞的DNA及RNA,观察细胞分裂及形态学改变;Western Blotting(WB)检测β-Catenin及新型软骨生长因子类细胞介素1的蛋白质表达。结果显示MTS法检测加入丹酚酸B后的所有剂量实验组与对照组比较吸光度值均有不同程度的增高,差异均有统计学意义(P<0.01);丹酚酸B实验组可见明显核分裂及较多的双核现象,细胞增生较活跃;半定量WB分析结果显示丹酚酸B实验组比对照组的类细胞介素1蛋白表达量显著升高,β-Catenin蛋白质表达量亦显上调趋势。表明丹酚酸B能促进人软骨细胞的增殖并上调了相关因子的表达。其作用机制可能与丹酚酸B作用于软骨细胞中Wnt信号调节通路,上调信号调节因子β-Catenin表达量,激活靶基因类细胞介素1的转录并促进其表达释放有关。     

不同重组慢病毒介导人凝血因子Ⅸ cDNA在血友病B小鼠中表达的影响

血友病B是凝血因子Ⅸ(hFⅨ)缺乏所导致的严重凝血功能障碍、X-连锁隐性遗传性疾病,在男性中的发病率为三万分之一．目前没有理想的治疗措施,而基因治疗可能是根治该病的安全、有效方法．该实验构建了ubiquitin—c和ABP(肝特异性)启动子指导hFⅨ表达的载体FUXW、FAXW,利用磷酸钙法共转染三质粒制备高滴度的重组慢病毒．将不同剂量的重组FUXW、FAXW病毒,分别用尾静脉液压法和静脉缓注法注射入血友病B小鼠体内,各治疗组小鼠血浆均可持续检测到hFⅨ抗原,最高峰值为45ng／mL,表达持续超过60d．结果表明：hFⅨ蛋白的表达与病毒的剂量成正相关,重组FAXW病毒的hFⅨ表达量高于重组FUXW病毒,而尾静脉液压组和静脉缓注组在表达量、表达时间上没有显著差异．     

重组人凝血因子Ⅶ在HEK293细胞中的瞬时表达

[目的]在HEK293细胞中表达人凝血因子Ⅶ(human coagulation factor,hFⅦ)蛋白。[方法]通过PCR分别扩增与hFⅦ羧基化有关的酶(γ-谷氨酰基羧化酶(GGCX)和维生素K环氧化物还原酶复合体亚单位1(VKORC1))基因序列,与hFⅦ基因片段构建真核表达载体p CAEVKORC1-GGCX-hFⅦ,利用脂质体将表达载体转入HEK293细胞,采用Western blotting和ELISA方法检测细胞上清中hFⅦ的表达水平,凝血因子Ⅶ检测试剂盒测定hFⅦ的促凝血活性。[结果]Western blotting检测细胞上清中含有hFⅦ蛋白,经ELISA检测表达量为12 mg/L,凝血因子Ⅶ检测试剂盒测定hFⅦ的促凝血相对比活性为612%。[结论]该表达载体成功在HEK293细胞中瞬时表达hFⅦ蛋白,为进一步深入研究hFⅦ的生物学特性奠定了基础。     

阻塞性黄疸患者血液高凝状态探讨

通过检测１５例ＯＪ患才充前及引流后第２、５、１０日血浆中抗凝物质蛋白Ｃ（ＰＣ），凝血因子ｖＷ因子及血小板颗粒膜蛋白（ＧＭＰ－１４０）的含量变化。     

第Ⅶ因子抑制物

<正> 在一名疑为支气管癌的66岁男病人身上发现了第Ⅶ因子抑制物的活性.初步研究表明部分凝血活酶时间(PTT)正常,凝血酶原时间(PT)延长,后者随培养而延长.在体内用50%的正常血浆以及在体内用2单位新鲜冰冻血浆均未校正PT,从而证实了抑制物的活性.特殊因子含量的测定除了Ⅶ因子为30%外,其余均在正常范围内.对于抗球蛋白的进一步研究提示抑制物来源于IgG.凝血因子抑制物的出现是罕见的.在这当中了解最多的是Ⅶ因子血发病,其发病率占这类疾病的8—14%,可能与频繁地输入外源性Ⅶ因子有关.凝血因子抑制物常继发于胶原性疾病,血清蛋白异常,淀粉样变性和输入血液制品后,而明显的原发性疾病较少.在此之前的英文文献中,还未曾记载有临床意义的Ⅶ因子抑制物.     

Expression of human clotting factor Ⅸ mediated by recom- binant lentiviral vector in cultured cells and hemophilia B mice

To explore the expression of human clotting factor Ⅸ (hFⅨ) cDNA in vitro and the feasibility of gene therapy for hemophilia B mice mediated by recombinant lentiviral vector, a recombinant hFⅨ lentiviral vector driven by ubiquitin-C promoter, FUXW, and by ABP liver specific promoter, FAXW, was constructed respectively. Recombinant lentivirus was harvested from 293T cells by calcium phosphate-mediated transient cotransfection of three plasmids (transgene vector, CMV腞8.2, VSV-G). hFⅨ expression was detected in supernatant of 293T, BHK and L-02 cells infected with FUXW virus, whereas higher expression of hFⅨ levels (630 ng/106 cells/48 h) was detected only in L-02 cells infected with FAXW virus. Serum hFⅨ antigen was detected in all hemophilia B mice treated with FAXW virus by tail vein injection, an efficiency level of hFⅨ was observed (45 ng/mL, approximately 1% of normal human levels), the expression lasted for more than 60 d. The results indicated that HIV-based lentiviral vectors offer a promising approach to the gene therapy of hemophilia B.     

Preparation of a recombinant adeno-associated viral vector with a mutation of human factor Ⅸ in large scale and its expression in vitro and in vivo

A series of adeno-associated viral vectors containing a mutation of human factor Ⅸ (hFⅨR338A) with different regulation elements were constructed and used to transduce cell lines. The plasmids and the stable transduction cell clones with high expression level of hFⅨR338A were obtained by selecting and optimizing, and then, the recombinant adeno-associated viral vector with hFⅨR338A was prepared via novel rHSV/AAV hybrid virus packaging system on a large scale, which contained the capsid protein genes. A method for producing rAAV-hFⅨR338A viral stocks on a large scale and higher titer was established, which can be used for industrial purpose. The titer of rAAV-hFⅨR338A was more than 1.25×10¹² particle/mL, and then, a mammalian cell line, C2C12 and the factor Ⅸ knock-out mice were transfected with the rAAV-hFⅨR338A in vitro and in vivo. The results show that the high-level expression of rAAV-hFⅨR338A was achieved in cell line and hemophilia B mice. It reached at (2551.32±92.14) ng·(10⁶ cells)^-1·(24 h)^-1 in C2C12 cell in vitro and had a peak concentration of 463.28 ng/mL in mice treated with rAAV-hFⅨR338A, which was as high as the expression of rAAV-hFⅨ-wt (2565.76±64.36) ng·(10⁶ cells)^-1·(24 h)^-1 in C2C12 and 453.92 ng/mL in the mice treated with rAAV-hFⅨ-wt) in vitro and in vivo, there is no any difference between two groups, but the clotting activity of hFⅨR338A is about 2.46 times higher than that of hFⅨ-wt. It was first reported that a mutation of human factor Ⅸ was used into gene therapy research for hemophilia B, meanwhile, a novel packaging system, rAAV/HSV was used for preparation of rAAV-hFⅨR338A on a large scale, which laid the foundation of industrial production for applying rAAV viral stocks to gene therapy clinical trial for hemophilia B mediated with rAAV-hFⅨ.     

Construction and expression of inverted configuration of retroviral vector containing intron 1 of hFIX

Intron was found to play an important role in improving gene expression. To improve the human factor IX(hFIX) expression level in hemophilia B gene therapy study, the retroviral vector containing intron 1 of hFIX gene was constructed in forwarded configuration, but the intron 1 was found spliced in virus particles by RT_PCR detection. So the inverted configuration vector G1NaPAi′IX was suggested and constructed on the basis of SNMBAIXm and transfected into PA317. Then C2C12 cells were transfected using the above virus supernatant and the G418_resistant clones were selected. PCR and RT_PCR detection found that intron 1 structure existed in C2C12 clones and retroviral particles. And the expression level of inverted vector was 3 times higher than that of forwarded vector. These results showed that the inverted configuration vector was in deed able to avoid splicing of intron 1 during the process of retroviral packaging and improved the expression level of hFIX protein.     

Distribution of factor VIII mRNA and antigen in human liver and other tissues

The cellular site of synthesis of factor VIII (FVIII:C; anti-haemophilic factor) has long been sought. Previous studies suggested the liver as a major site of synthesis, but extrahepatic sources such as spleen and lung have been implicated. Using an immunoradiometric assay (IRMA), we recently localized factor VIII antigen (FVIII:Ag, formerly FVIII:CAg), to whole perfused guinea pig liver and spleen, and to isolated hepatocytes, with lesser or trace amounts in other tissues. Using an immunohistological technique, Stel et al. detected FVIII:Ag in normal human liver sinusoidal endothelial cells, while Exner et al. detected FVIII:Ag by IRMA in extracts of human lymph nodes, lung, liver and spleen. The localization of antigen in tissues does not, however, distinguish sites of factor VIII synthesis from those of storage, and such experiments are subject to misinterpretation due to entrapment of plasma factor VIII in tissues. The recent cloning of the human factor VIII gene provides hybridization probes for the detection of factor VIII messenger RNA in cells, thus directly determining sites of synthesis. During complementary DNA cloning, we detected factor VIII mRNA in liver, and it has been localized by others in liver and placenta and in liver and kidney. In the present study, we detected factor VIII mRNA in isolated human hepatocytes, in spleen and in numerous tissues including lymph nodes and kidney, but not in white blood cells or cultured endothelial cells. We also found that the factor VIII, factor VII, factor IX and protein C antigens in liver are predominantly localized in hepatocytes, while very little von Willebrand factor antigen (vWF:Ag, formerly FVIIIR Ag) is detectable in this organ.     

DCN调控TGF-βRII高表达抑制HepG2细胞增殖分子机制研究

目的 探讨DCN通过TGF-β信号通路抑制肿瘤细胞增殖的分子机制.方法 应用质粒转染方法诱导HepG2细胞高表达核心蛋白聚糖,应用siRNA法抑制核心蛋白聚糖表达,应用Western blot法检测HepG细胞TGF-β信号通路相关因子表达,最终用MTT法检测细胞增殖.结果 DCN通过增高TGF-βRII的表达,引起TGF-βRI磷酸化程度增高,诱导p15蛋白表达增高,与对照组比较,差异具有统计学意义(P<0.05).结论 DCN最终抑制HepG2细胞的增殖;使用siRNA沉默TGF-βRII可减弱DCN对HepG2细胞增殖的抑制作用.     

Signalling through the MHC class II cytoplasmic domain is required for antigen presentation and induces B7 expression.

Class II major histocompatibility complex (MHC) molecules function as antigen-presenting elements as well as signal transducers on B lymphocytes. We previously reported that a B lymphoma cell transfectant, 5C2, expressing genetically engineered I-Ak molecules with truncated cytoplasmic domains was severely impaired in both antigen presentation and in anti-Ia-induced intracytoplasmic signalling. These two functions could be restored by preculturing 5C2 cells with cyclic AMP analogues. Here we demonstrate that impaired signal transduction by truncated class II molecules results in a deficiency in induction of the newly defined B-cell accessory molecule B7 (ref. 8), which can be reversed by restoration of B7 expression. These data imply that contact of the T-cell antigen receptor with MHC/antigen ligand results in signal transmission through the class II cytoplasmic domain. This signal, which can be mimicked by dibutyryl cAMP, induces expression of B7, resulting in effective antigen presentation. The fact that crosslinking of surface class II MHC also induces B7 expression on normal resting human B cells supports this contention.     

Human hepatitis B vaccine from recombinant yeast

The worldwide importance of human hepatitis B virus infection and the toll it takes in chronic liver disease, cirrhosis and hepatocarcinoma, make it imperative that a vaccine be developed for worldwide application. Human hepatitis B vaccines are presently prepared using hepatitis B surface antigen (HBsAg) that is purified from the plasma of human carriers of hepatitis B virus infection. The preparation of hepatitis B vaccine from a human source is restricted by the available supply of infected human plasma and by the need to apply stringent processes that purify the antigen and render it free of infectious hepatitis B virus and other possible living agents that might be present in the plasma. Joint efforts between our laboratories and those of Drs W. Rutter and B. Hall led to the preparation of vectors carrying the DNA sequence for HBsAg and antigen expression in the yeast Saccharomyces cerevisiae. Here we describe the development of hepatitis B vaccine of yeast cell origin. HBsAg of subtype adw was produced in recombinant yeast cell culture, and the purified antigen in alum formulation stimulated production of antibody in mice, grivet monkeys and chimpanzees. Vaccinated chimpanzees were totally protected when challenged intravenously with either homologous or heterologous subtype adr and ayw virus of human serum source. This is the first example of a vaccine produced from recombinant cells which is effective against a human viral infection.     

Haemophilia B caused by a point mutation in a donor splice junction of the human factor IX gene

Haemophilia B (Christmas disease) is an inherited, recessive, sex-linked, haemorrhagic condition caused by a defect in the intrinsic clotting factor IX. This disease occurs in males at a frequency of approximately 1 in 30,000. Patients differ in the severity of their clinical symptoms, and variation in the clotting activity and in the concentration of factor IX antigen in their plasma has been demonstrated. There is probably heterogeneity in the molecular defects of the factor IX gene causing the disease. Here we study a severely affected, antigen-negative patient, and show that the only significant sequence difference from the normal factor IX gene is a point mutation changing the obligatory GT to a TT within the donor splice junction of exon f. We infer that this change is the cause of the disease in this individual. In addition, we have used oligodeoxynucleotide probes specific for this mutation to demonstrate the feasibility of carrier detection and prenatal diagnosis for relatives of the patient.     

Human interleukin-2 promotes proliferation of activated B cells via surface receptors similar to those of activated T cells

Human interleukin-2 (IL-2) is a glycoprotein of relative molecular mass (Mr) 15,000, which is released by T lymphocytes on stimulation with antigen or mitogen and functions as a T-cell growth factor (TCGF) by inducing proliferation of activated T cells. It is generally accepted that resting or activated B cells do not respond directly to IL-2 but require for their proliferation other T-cell-derived lymphokines usually referred to as B-cell growth factors (BCGFs). Recently, however, a monoclonal antibody reacting with the IL-2 receptor molecules expressed by activated T cells (anti-Tac) was shown to react also with certain B tumour cells; in addition, murine B cells proliferate in response to pure human IL-2. We now show that recombinant IL-2, derived from Escherichia coli expressing the human gene, is able to promote strong proliferation of human B cells activated with protein-A-rich Staphylococcus aureus Cowans strain I. Moreover, we demonstrate that the anti-Tac antibody also reacts with S. aureus-activated normal B cells and inhibits sharply the proliferative response of such cells to IL-2. Finally, immunoprecipitation experiments reveal that anti-Tac defines similar molecules on activated T and B cells.