Part:BBa_K1470003

Retro viral vectors provide an optimal gene delivery system. They are able to transport large DNA fragments and efficiently integrate them stable in the genome. However, high gene expression levels are often absent [1].
It is known that the Woodchuck Hepatitis Virus contains a regulatory RNA sequence, which promotes viral gene expression. When fused downstream to a gene, the Woodchuck Hepatitis Virus Posttranscriptional Regulatory Element (WPRE)creates a tertiary structure, which enhances the export of unspliced mRNA from the nucleus into the cytoplasm [2]. Klein et al. showed, that WPRE boosts gene expression level of enhanced green fluorescent protein (EGFP) or viral titres up to five times [3].

References

[1] ZUFFEREY, R., DONELLO, J.E., TRONO, D., HOPE, T.J.: Woodchuck Hepatitis Virus Posttranscriptional Regulatory Element Enhances Expression of Transgenes Delivered by Retroviral Vectors. J Virol. Apr 1999; 73(4): 2886–2892.
[2] POPA, I., HARRIS, M.E., DONELLO, J.E., HOPE, T.J.: CRM1-dependent function of a cis-acting RNA export element. Mol Cell Biol. 2002 Apr;22(7):2057-67.
[3] KLEINA, R., RUTTKOWSKIB, B., KNAPP, E., SALMONSA, B., GUENZBURG, W.H., HOHENADL, C.: WPRE-mediated enhancement of gene expression is promoter and cell line specific. Gene. 2006 May 10;372:153-61