title: Proteasome inhibitors enhance bacteriophage lambda (lambda) mediated gene transfer in mammalian cells.
abstract: Bacteriophage lambda vectors can transfer their genomes into mammalian cells, resulting in expression of phage-encoded genes. However, this process is inefficient. Experiments were therefore conducted to delineate the rate limiting step(s) involved, using a phage vector that contains a mammalian luciferase reporter gene cassette. The efficiency of phage-mediated gene transfer in mammalian cells was quantitated, in the presence or absence of pharmacologic inhibitors of cell uptake and degradation pathways. Inhibitors of lysosomal proteases and proteasome inhibitors strongly enhanced phage-mediated luciferase expression, suggesting that these pathways contribute to the destruction of intracellular phage particles. In contrast, inhibition of endosome acidification had no effect on phage-mediated gene transfer, presumably because phage lambda is tolerant to extended exposure to low pH. These findings provide insights into the pathways by which phage vectors enter and transduce mammalian cells, and suggest that it may be possible to pharmacologically enhance the efficiency of phage-mediated gene transfer in mammalian cells. Finally, the data also suggest that the proteasome complex may serve as an innate defense mechanism that restricts the infection of mammalian cells by diverse viral agents.
authors.affiliation: Department of Microbiology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
authors.forename: Ketna
authors.initials: K
authors.lastname: Volcy
authors.forename: Stephen
authors.initials: S
authors.lastname: Dewhurst
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D010582:Bacteriophage lambda / Q000235:genetics*; D019556:COS Cells; D036022:Capsid Proteins / Q000235:genetics; D002460:Cell Line; D002522:Chlorocebus aethiops; D011992:Endosomes / Q000502:physiology / Q000821:virology; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D005822:Genetic Vectors; D006801:Humans; D008156:Luciferases / Q000235:genetics; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D061988:Proteasome Inhibitors; D014161:Transduction, Genetic
chemical_list: D036022:Capsid Proteins; D010446:Peptide Fragments; D061988:Proteasome Inhibitors; D008156:Luciferases