Retroviral Delivery of the Ecdysone‐Regulatable Gene Expression System

Abstract

We describe a set of Moloney Murine Leukemia Virus (MoMLV)-based replication-defective retroviral vectors for delivery of the ecdysone-inducible system into mammalian cells. The vector pFB-ERV contains a tricistronic CMV expression cassette from which the ecdysone receptor proteins RXR and VgEcR are expressed, with the neo-resistance marker expressed as the third open reading frame (ORF). The inducible vector pCFB-EGSH contains an ecdysone-inducible expression cassette inserted between the viral LTRs in the antisense orientation relative to that for the viral promoter. Potential interference from the proviral 5' LTR is obviated due to a SIN deletion in the 3' LTR. When used together, induction ratios of over 1000-fold were achieved in NIH3T3 cells using firefly luciferase as a reporter.

Effective Drug Therapies from Functional, Macromolecular Building Blocks with a Biomimetic Design

“…Although, viral vectors are currently by far the most efficient means of DNA delivery, [9] limitations are associated with immunogenicity, toxicity, restricted targeting of specific cells types and cost of production. [10] The ability to attach the carrier after protein cloning, expression and purification would afford methods to use recombinant proteins and peptides. Furthermore, tremendous opportunities are envisioned in the development of methodologies for immunogenic agents for viral diseases.…”

Gene Therapy Progress and Prospects: Development of improved lentiviral and retroviral vectors – design, biosafety, and production

“…Recently, a codon-optimized tetracycline trans-activator has reduced the 'leakiness' in different cell types, 31,32 and the use of ecdysone regulated promoters with MuLV and HIV vectors has been described. 33,34 Long-term tissue or cell specific expression can be facilitated by the choice of promoters. For example, liver expression with the human phosphoglycerate kinase (hPGK) or albumin promoters offer advantages over the commonly used cytomegalovirus (CMV) promoter.…”