EMBL scientists have developed a new variant of the Sleeping Beauty transposase. It has dramatically improved biochemical features, including enhanced stability and intrinsic cell penetrating properties. This transposase can be used for genome engineering of stem cells and therapeutic T cells. As such it is extremely valuable for use in regenerative medicine and cancer immunotherapy. The underlying genome engineering procedures will in the future also reduce costs and improve the safety of genome modifications.<\/p>\n\n\n\n
The team, comprising researchers from the European Molecular Biology Laboratory, the Universit\u00e4tsklinikum W\u00fcrzburg<\/a> and the Paul-Ehrlich-Institut<\/a>, managed to design a new variant of the Sleeping Beauty transposase with dramatically improved biochemical properties, enabling the direct use of the transposase protein for genome modifications. \u201cThe protein we developed can be delivered into mammalian cells and remains fully functional, enabling efficient and stable genome modifications in target cells on demand,\u201d explains Orsolya Barabas, group leader at EMBL Heidelberg<\/a>.<\/p>\n\n\n\n The delivery and efficient genetic engineering can be used on different types of cells, including human stem cells and T lymphocytes. The latter can be genetically modified to produce an artificial chimeric antigen receptor (CAR) for use in cancer immunotherapy. The new type of Sleeping Beauty transposase developed by the researchers not only enables direct protein delivery, but also penetrates cells autonomously. The latter feature was not planned for the new variant and was only discovered when it was studied in action. This was a pleasant surprise, as it is the first of its kind with this characteristic. \u201cAll these features open new avenues for CAR-T cell production and other gene therapies,\u201d explains Irma Querques, PhD student at EMBL and a lead author of the paper. As such, this is a breakthrough compared to other existing variants of the Sleeping Beauty transposase.<\/p>\n\n\n\n The Sleeping Beauty transposon system consists of a transposase and a transposon to insert specific sequences of DNA into the genomes of animals.<\/p>\n\n\n A transposase is a protein that binds to the ends of a transposon \u2013 a DNA sequence that can change its position within a genome, sometimes creating or reversing mutations and altering the cell’s genetic identity \u2013 and catalyses its movement to another part of the genome.<\/p>\n <\/p><\/div>\n\n\n\n The transposase can be encoded either within the transposon or can be supplied by another source, in which case the transposon becomes a non-autonomous element. Non-autonomous transposons are most useful as genetic tools, because after insertion they cannot independently continue to excise and re-insert themselves. All of the DNA transposons identified in the human genome and other mammalian genomes are non-autonomous because, even though they contain transposase genes, these genes are non-functional and unable to generate a transposase that can mobilise the transposon.<\/p>\n\n\n\n <\/strong>The Sleeping Beauty transposase was resurrected from inactive copies in fish genomes by Zoltan Ivics<\/a> and his colleagues in 1997, creating the first transposon tool that worked efficiently in vertebrate cells. Since then it has been used for many applications in genetics, including gene therapy.<\/p>\n\n\nSleeping Beauty<\/h2>\n\n\n\n
What is a transposase?<\/h2>\n