Inhibition of the synthesis of proteins needed for Epstein-Barr virus replication by antisense RNA against the zta gene

Antisense RNA complementary to the Epstein-Barr virus (EBV) Zta gene, an immediate-early gene encoding a transactivator, was applied to inhibit EBV protein synthesis during its lytic cycle. A DNA fragment containing the Zta gene sequence was inserted into an expression vector, pMAMneo, in a sense and antisense direction under a dexamethasone-inducible murine mammary tumor virus LTR promoter, resulting in the construction of plasmids pZ(+) and pZ(–), respectively. Synthesis of Zta protein was reduced in pZ(–)-transfected cells upon dexamethasone induction. Because D-form early antigen and DNA polymerase are essential for viral DNA replication, the contents of these two viral proteins were examined. Amounts of the two lytic proteins were observed to be significantly repressed in pZ(–)-transfected cells. In contrast, both proteins were normally expressed in the sense plasmid pZ(+) or cells transfected with vector alone. Above results demonstrate that Zta antisense RNA can reduce the production of Zta protein and the other lytic proteins, possibly resulting in the inhibition of EBV replication.     

The structure and role of RNA polymerases in Plasmodium

During the past few years the characterization of several Plasmodium falciparum RNA polymerase subunits has revealed potentially significant differences between the corresponding subunits of the host and parasite enzymes(1-3). The largest subunits of P. falciparum RNA polymerase II and III contain enlarged variable domains that separate conserved domains in these subunits. The partially characterized beta and beta '-like subunits of an organellar P. falciparum RNA polymerase also appear to be distinct from the host RNA polymerases. In this review David Bzik discusses the structure and role of RNA polymerases in Plasmodium.     

Inhibition of expression of human immunodeficiency virus-1 in vitro by antibody-targeted liposomes containing antisense RNA to the env region.

Previous studies revealed that antisense oligodeoxynucleotides to specific regions of the human immunodeficiency virus-1 (HIV-1) are potent inhibitors of replication of HIV-1 in vitro (Zamecnik, P. C., Goodchild, J., Taguchi, Y., and Sarin, P. S. (1986) Proc. Natl. Acad. Sci. U. S. A. 83, 4143-4146). We now report that antisense RNA, synthesized in vitro using T7 and SP6 RNA polymerase, displayed an anti-HIV-1 effect in the HTLV-IIIB/H9 system in vitro. Treatment of HIV-1-infected H9 cells with viral env region antisense RNA encapsulated in liposomes targeted by antibodies specific for the T cell receptor molecule CD3 almost completely inhibited HIV-1 production. The viral env segment covered a part of exon II of HIV-1 tat gene. No anti-HIV activity could be detected with similarly targeted liposome-encapsulated sense env RNA or with pol RNA synthesized in either the sense or antisense orientations, or with env region antisense RNA free in solution, or encapsulated in liposomes in the absence of the targeting antibody. A semiquantitative evaluation revealed that 4000-7000 RNA molecules became cell-bound in targeted liposomes; the half-life of the intracellularly present hybridizable antisense env RNA was approximately 12 h. Western blots showed that antisense env RNA suppressed tat gene expression by approximately 90% and gp160 production by 100%. These data were confirmed by immunoprecipitation studies. Northern blots (using an env probe) demonstrated the existence of all major HIV RNA species (9.3-, 4.3-, and 2.0-kb mRNA) in HIV-infected cells treated with antisense env RNA although at a reduced level. We conclude that the antisense env RNA inhibited viral protein production at the translational level.     

反义RNA在基因治疗中的应用

由于反义RNA作为封闭基因表达的有效手段具有特异性强、安全性高、操作简单、靶基因范围广等特点,已被广泛应用于基因治疗肿瘤和病毒相关疾病的研究,反义RNA治疗肿瘤可以通过抑制癌基因的表达、封闭融合癌基因、抑制肿瘤细胞的耐药性、调节细胞因子的表达量等途径;反义RNA治疗病毒相关疾病多集中在艾滋病上,其手段主要是反义封闭TAR。反义RNA作为基因治疗的新途径具有良好的前景,但在设计上和应用上还存在一些急待解决的问题。     

反义RNA技术在花色育种中的应用

反义RNA技术是用反义RNA链去抑制靶基因的活性,从而达到对目的基因调控的一项分子生物学技术.该项技术应用于观赏植物的花色育种已有16年的历史并且取得了一定的成就.到目前为止,已经利用该技术对14种花卉花色形成过程中的3大类基因进行了正义和反义导入,获得了花色改变的转基因植株.本文简要回顾了反义RNA技术的产生与发展,并在介绍花色形成的分子生物学的基础上,综述了国际园艺育种中利用反义RNA技术调控花色基因表达的研究进展,以期为花色改良的分子育种提供参考资料.     

反义RNA 技术在花色育种中的应用

反义RNA技术是用反义RNA链去抑制靶基因的活性, 从而达到对目的基因调控的一项分子生物学技术。该项技术应用于观赏植物的花色育种已有16年的历史并且取得了一定的成就。到目前为止, 已经利用该技术对14种花卉花色形成过程中的3大类基因进行了正义和反义导入, 获得了花色改变的转基因植株。本文简要回顾了反义RNA技术的产生与发展, 并在介绍花色形成的分子生物学的基础上, 综述 了国际园艺育种中利用反义RNA技术调控花色基因表达的研究进展, 以期为花色改良的分子育种提供参考资料。