[HTML][HTML] Integration profile and safety of an adenovirus hybrid-vector utilizing hyperactive sleeping beauty transposase for somatic integration

W Zhang, M Muck-Hausl, J Wang, C Sun, M Gebbing… - PloS one, 2013 - journals.plos.org
W Zhang, M Muck-Hausl, J Wang, C Sun, M Gebbing, C Miskey, Z Ivics, Z Izsvak, A Ehrhardt
PloS one, 2013journals.plos.org
We recently developed adenovirus/transposase hybrid-vectors utilizing the previously
described hyperactive Sleeping Beauty (SB) transposase HSB5 for somatic integration and
we could show stabilized transgene expression in mice and a canine model for hemophilia
B. However, the safety profile of these hybrid-vectors with respect to vector dose and
genotoxicity remains to be investigated. Herein, we evaluated this hybrid-vector system in
C57Bl/6 mice with escalating vector dose settings. We found that in all mice which received …
We recently developed adenovirus/transposase hybrid-vectors utilizing the previously described hyperactive Sleeping Beauty (SB) transposase HSB5 for somatic integration and we could show stabilized transgene expression in mice and a canine model for hemophilia B. However, the safety profile of these hybrid-vectors with respect to vector dose and genotoxicity remains to be investigated. Herein, we evaluated this hybrid-vector system in C57Bl/6 mice with escalating vector dose settings. We found that in all mice which received the hyperactive SB transposase, transgene expression levels were stabilized in a dose-dependent manner and that the highest vector dose was accompanied by fatalities in mice. To analyze potential genotoxic side-effects due to somatic integration into host chromosomes, we performed a genome-wide integration site analysis using linker-mediated PCR (LM-PCR) and linear amplification-mediated PCR (LAM-PCR). Analysis of genomic DNA samples obtained from HSB5 treated female and male mice revealed a total of 1327 unique transposition events. Overall the chromosomal distribution pattern was close-to-random and we observed a random integration profile with respect to integration into gene and non-gene areas. Notably, when using the LM-PCR protocol, 27 extra-chromosomal integration events were identified, most likely caused by transposon excision and subsequent transposition into the delivered adenoviral vector genome. In total, this study provides a careful evaluation of the safety profile of adenovirus/Sleeping Beauty transposase hybrid-vectors. The obtained information will be useful when designing future preclinical studies utilizing hybrid-vectors in small and large animal models.
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