Transcription activator like effector (TALE)-directed piggyBac transposition in human cells

Nucleic Acids Res. 2013 Oct;41(19):9197-207. doi: 10.1093/nar/gkt677. Epub 2013 Aug 5.

Abstract

Insertional therapies have shown great potential for combating genetic disease and safer methods would undoubtedly broaden the variety of possible illness that can be treated. A major challenge that remains is reducing the risk of insertional mutagenesis due to random insertion by both viral and non-viral vectors. Targetable nucleases are capable of inducing double-stranded breaks to enhance homologous recombination for the introduction of transgenes at specific sequences. However, off-target DNA cleavages at unknown sites can lead to mutations that are difficult to detect. Alternatively, the piggyBac transposase is able perform all of the steps required for integration; therefore, cells confirmed to contain a single copy of a targeted transposon, for which its location is known, are likely to be devoid of aberrant genomic modifications. We aimed to retarget transposon insertions by comparing a series of novel hyperactive piggyBac constructs tethered to a custom transcription activator like effector DNA-binding domain designed to bind the first intron of the human CCR5 gene. Multiple targeting strategies were evaluated using combinations of both plasmid-DNA and transposase-protein relocalization to the target sequence. We demonstrated user-defined directed transposition to the CCR5 genomic safe harbor and isolated single-copy clones harboring targeted integrations.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • DNA Transposable Elements*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Gene Targeting*
  • HEK293 Cells
  • Humans
  • Receptors, CCR5 / genetics
  • Recombinant Fusion Proteins / metabolism
  • Transposases / genetics
  • Transposases / metabolism*

Substances

  • CCR5 protein, human
  • DNA Transposable Elements
  • DNA-Binding Proteins
  • Receptors, CCR5
  • Recombinant Fusion Proteins
  • Transposases