Use of herpes simplex virus type 1-based amplicon vector for delivery of small interfering RNA

Abstract

Silencing of gene expression by small interfering RNAs (siRNAs) is rapidly becoming a powerful tool for genetic analysis of mammalian cells. The use of DNA-based plasmid vectors to achieve transient and stable expression of siRNA has been developed to avoid the problems of double-stranded oligonucleotides transfection. These vectors direct the transcription of small hairpin RNAs (shRNAs) from a polymerase-III (H1 or U6)-RNA gene promoter. However, numerous disadvantages remain, including low transfection efficiency and difficulty in transfecting primary cells. To overcome some of these problems, the use of viral vectors for siRNA delivery has been described. Retroviral, adenoviral, adeno-associated and herpes viral shRNAs delivery systems have been successfully used to silence genes, in vitro and in vivo. The use of a herpes simplex virus type 1 (HSV-1)-based amplicon vector for siRNA delivery into mammalian cells, using human polyomavirus BK (BKV)-transformed cells as a model system is described. The results demonstrate the ability of amplicon vectors to inhibit the expression of BKV T-Ag and tumorigenicity of BKV-transformed cells. We show that the use of the amplicon vector is highly efficient for the delivery of siRNA molecules. The unique ability of these vectors to deliver multiple copies of siRNA may provide a useful tool in the development of novel anticancer therapy.

HSV as a vector in vaccine development and gene therapy

“…185 Of the wide range of prodrug activating enzymes tested for cancer therapy, 186,187 only a few have been delivered via HSV amplicon vectors. One of these is HSV TK, which converts nucleoside analogues, such as ganciclovir, into toxic analogues which incorporate into replicating DNA and lead to cell death.…”

RNA Interference Technologies and Therapeutics

“…Adeno-associated viruses have been used for the delivery of specific siRNAs targeting mutant ataxin-1 in a spinocerebellar ataxia-1 (SCA1) mouse model, showing that reduction of the expression of ataxin-1 could improve motor coordination and restore cerebellar morphology. [70] Sabbioni and co-workers [71] use herpes simplex virus type I (HSV-1)-based vectors for siRNA delivery into mammalian cells. Using human polyomavirus BK (BKV)-transformed cells as a model system, the ability of amplicon vectors to inhibit the expression of BKV-T-antigen has been demonstrated.…”

Pseudovirions as Vehicles for the Delivery of siRNA

“…Sabbioni et al (49) used shRNA-generating amplicon vectors to silence the expression of the large T antigen (T-Ag) in BK polyomavirus-transformed cells, thus neutralizing their tumorigenic properties and transformed phenotype. In addition to two GFP cassettes used to monitor transduction efficiency, the amplicon plasmid contained an oligonucleotide sequence under an H1 RNA polymerase III promoter that when expressed generates an shRNA designed to suppress T-ag (pA-shBKVT).…”