Chimeric Ecotropic MLV Envelope Proteins that Carry EGF Receptor-Specific Ligands and the Pseudomonas Exotoxin A Translocation Domain to Target Gene Transfer to Human Cancer Cells

• Published in: Virology (New York, N.Y.) N.Y.), 2002-10, Vol.302 (2), p.333-341
• Main Authors: Erlwein, Otto, Wels, Winfried, Schnierle, Barbara S.
• Format: Article
• Language: English
• Subjects: ADP Ribose Transferases - chemistry; ADP Ribose Transferases - genetics; ADP Ribose Transferases - metabolism; Animals; Bacterial Toxins - chemistry; Bacterial Toxins - genetics; Bacterial Toxins - metabolism; Cell Line; ErbB Receptors - genetics; ErbB Receptors - metabolism; Exotoxins - chemistry; Exotoxins - genetics; Exotoxins - metabolism; Gene Targeting; Gene Transfer Techniques; Genetic Vectors; Humans; Ligands; Mice; Moloney murine leukemia virus - genetics; Moloney murine leukemia virus - metabolism; Pseudomonas aeruginosa Exotoxin A; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Transduction, Genetic; Tumor Cells, Cultured; Viral Envelope Proteins - genetics; Viral Envelope Proteins - metabolism; Virulence Factors - chemistry; Virulence Factors - genetics; Virulence Factors - metabolism
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1006/viro.2002.1517

Redirecting retroviral vector transduction simply by insertion of a ligand into the envelope (Env) protein has met with several obstacles. For example, virions targeted to epidermal growth factor receptor (EGFR), after receptor binding, rapidly traffic to the lysosomes, where they are degraded. Exotoxin A of Pseudomonas aeruginosa has the ability to translocate from endosomes to the cytoplasm by means of a translocation domain (TLD). We generated a series of chimeric Env proteins of Moloney murine leukemia virus containing EGFR ligands, where TLD was inserted into different regions. These chimeric proteins were successfully produced, if the translocation domain was not located at the immediate N-terminus of Env. The ability to transduce murine cells via the ecotropic receptor varied but correlated with the amount of Env proteins incorporated into the virions. Chimeric vector particles could bind to EGFR, demonstrating the functional exposure of the peptide ligand. However, transduction of human cells expressing EGFR but not the ecotropic receptor by virions carrying the chimeric protein was not observed.