Stabilized Production of Ribozymes, iRNA, mRNA and Other Gene Products
Wistar researchers have developed a novel method to stabilize introns that offers the potential for stable production of ribozymes, iRNA, mRNA and related gene products. Using the Wistar technology, stabilized intron compositions are prepared with a sequence from the LAT intron of the HSV-1 virus. Polynucleotide encoding sequences are then ligated into a stabilized intron, resulting in a 105 -fold increase in stability. Unlike typical introns that rapidly degrade within seconds after excision, these stabilized introns have a half life of 24 hours (Thomas et al. 2002. J. Virol., 76, 532-540). The increased stability has been demonstrated in several models, indicating that the method is neither cell type- nor species-specific and can be applied to both eukaryotic and yeast expression systems.
These methods and compositions are useful for:
- Stabilizing a gene transcript to permit enhanced expression, and increased production, of a recombinant gene product.
- Production of vectors and gene products for research reagents, markers of gene production, and diagnostic and therapeutic compositions.
- Markers for determining whether a gene of interest is being transcribed, particularly for identification of genes transcribed only in a selected stage of the cell cycle.
A Method of Delivering Genes to the Central Nervous System
One of the limitations of gene therapy has been the lack of methods to effectively deliver genes to the central nervous system. Herpes simplex virus (HSV) is a neurotropic virus that naturally establishes latent infections in the peripheral nervous system and the central nervous system of humans. Wistar researchers have developed a novel method for using neurotropic HSV to deliver genes of therapeutic value. Additionally, the Wistar technology promotes long-term expression of the therapeutic genes, which is necessary for treatment of a genetic defect.
The Wistar technology has several advantages over other methods of delivering genes to the central nervous system (CNS). First, no helper virus is needed, and second, long-term expression of the gene is achieved using a naturally-occurring viral promoter. This technology has been used successfully in vivo in a mouse model. In this study, the gene encoding §-glucorinodase was delivered to the CNS and long-term expression (over 4 months) of the gene product was obtained.