A novel potent strategy for gene delivery using a single peptide vector as a carrier

Centre de Recherches de Biochimie Macromoleculaire, UPR-1086 CNRS, 1919 Route de Mende, 34293 Montpellier Cedex 5, France.
Nucleic Acids Research (Impact Factor: 9.11). 10/1999; 27(17):3510-7. DOI: 10.1093/nar/27.17.3510
Source: PubMed


We have shown previously that a peptide, MPG, derived from the hydrophobic fusion peptide of HIV-1 gp41 and the hydrophilic nuclear localisation sequence of SV40 large T antigen, can be used as a powerful tool for the delivery of oligonucleotides into cultured cells. Now we extend the potential of MPG to the delivery of nucleic acids into cultured cells. In vitro, MPG interacts strongly with nucleic acids, most likely forming a peptide cage around them, which stabilises and protects them from degradation in cell culture media. MPG is non-cytotoxic, insensitive to serum and efficiently delivers plasmids into several different cell lines in only 1 h. Moreover, MPG enables complete expression of the gene products encoded by the plasmids it delivers into cultured cells. Finally, we have investigated the potential of MPG as an efficient delivery agent for gene therapy, by attempting to deliver antisense nucleic acids targeting an essential cell cycle gene. MPG efficiently delivered a plasmid expressing the full-length antisense cDNA of human cdc25C, which consequently successfully reduced cdc25C expression levels and promoted a block to cell cycle progression. Based on our results, we conclude that MPG is a potent delivery agent for the generalised delivery of nucleic acids as well as of oligonucleotides into cultured cells and believe that its contribution to the development of new gene therapy strategies could be of prime interest.

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    • "This suggests that pepM translocates bilayers in a receptor- or transporter-independent way, in tune with the ability of DENV C protein to deliver ssDNA at 4°C (Figures 3B,C). The divergent behavior of pepR and pepM suggests that the cationic domain favors non-covalent nucleic acid binding [26], [27], while the hydrophobic one may favors membrane interaction, perturbation and consequent translocation. It should be noted, however, that these domains cannot be simplistically assigned to the nucleic acid-binding and membrane-binding functionalities of DENV C protein, respectively, since both peptides have the ability to complex ssDNA and to interact with lipids [36], [52]. "
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    • "In the case of MPG complexation , no significant difference in silencing effect was seen at all molar ratios (Supplementary Fig. 5). It is possible that unstable complex formation (lanes 3 and 4, Fig. 1a) and degradation by nucleases [52] may have occurred. "
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    • "Such ''non-covalent'' transfection has generally been efficient for short nucleic acids such as siRNA and oligonucleotides, but not for plasmid DNA (pDNA) which needs to be condensed into compact particles, requiring higher density of positive charges in the vector than for complexing siRNA [4]. Only one CPP, MPG, has convincingly showed superior efficiency for pDNA compared to standard reagents such as Lipofectamine™ [5]. CPP-mediated transfection is mainly limited by endosomal entrapment [6] [7], but insufficient peptiplex stability also restricts successful delivery [8] [9] [10]. "
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