DNA transposon-based gene vehicles - scenes from an evolutionary drive

Abstract

DNA transposons are primitive genetic elements which have colonized living organisms from plants to bacteria and mammals. Through evolution such parasitic elements have shaped their host genomes by replicating and relocating between chromosomal loci in processes catalyzed by the transposase proteins encoded by the elements themselves. DNA transposable elements are constantly adapting to life in the genome, and self-suppressive regulation as well as defensive host mechanisms may assist in buffering ‘cut-and-paste’ DNA mobilization until accumulating mutations will eventually restrict events of transposition. With the reconstructed Sleeping Beauty DNA transposon as a powerful engine, a growing list of transposable elements with activity in human cells have moved into biomedical experimentation and preclinical therapy as versatile vehicles for delivery and genomic insertion of transgenes. In this review, we aim to link the mechanisms that drive transposon evolution with the realities and potential challenges we are facing when adapting DNA transposons for gene transfer. We argue that DNA transposon-derived vectors may carry inherent, and potentially limiting, traits of their mother elements. By understanding in detail the evolutionary journey of transposons, from host colonization to element multiplication and inactivation, we may better exploit the potential of distinct transposable elements. Hence, parallel efforts to investigate and develop distinct, but potent, transposon-based vector systems will benefit the broad applications of gene transfer. Insight and clever optimization have shaped new DNA transposon vectors, which recently debuted in the first DNA transposon-based clinical trial. Learning from an evolutionary drive may help us create gene vehicles that are safer, more efficient, and less prone for suppression and inactivation.

Non Viral Vectors in Gene Therapy- An Overview

“…Presently researchers are concentrating more on developing cell penetrating peptides, nano shell, sleeping beauty transposon, conjugated polymers, and biological vectors to be effective in non-viral gene transfer as compare to viral vectors [33][34][35][36][37] Apart from above mentioned SPION (super paramagnetic nano particle), mitochondria targeting strategies {mitochondria leader peptide (MLP), mitochondria targeting sequence (MTS) +DNA, liposome based carrier (Dequalinium) DQAsomes} are also under present review of developing into potential gene transfer agent [38].…”

Transpo-mAb display: Transposition-mediated B cell display and functional screening of full-length IgG antibody libraries

“…16 It would be interesting to determine whether our technology can be transferred to other widely established cell lines such as Chinese hamster ovary (CHO) or HEK293T, and to investigate the extent to which different host cell lines would be beneficial in terms of the library sizes that could be generated and screened, the ratio of membrane-bound vs. secreted IgG that could be achieved with these non-B cell lines, and finally how the properties of the isolated antibodies compare with antibodies isolated from the B cell host cell line employed here. Importantly, PiggyBac seems to be active in a wide range of mammalian cell lines, 45,52,53 and thus could in principle be applied to other cell systems of choice.…”

Delivering the Goods for Genome Engineering and Editing

“…Notably, these first studies also showed that transposition was totally blocked when the transposase was expressed at high levels. 50 It is still not clear whether this phenomenon, referred to as overproduction inhibition (described in 15 ), in the mouse reflects restricted transposon mobility or toxicity in transfected hepatocytes. In accordance, however, we found that the transposase expression level had to be carefully tuned by use of an appropriate promoter when transposon and transposase gene were delivered on a single plasmid, leading to correction of hemophilia B in a preclinical mouse model.…”