|WANG, QIZHAO - School Of Biomedical Sciences, Huaqiao University|
|DONG, BIAO - Temple University|
|POKINIEWSKI, KATIE - Temple University|
|WU, ZHONGREN - Temple University|
|CHIN, MARIO P.S. - School Of Biomedical Sciences, Huaqiao University|
|CHEN, XIONGWEN - Temple University|
|XU, RUIAN - School Of Biomedical Sciences, Huaqiao University|
|DIAO, YONG - School Of Biomedical Sciences, Huaqiao University|
|XIAO, WEIDONG - Temple University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/2/2016
Publication Date: 5/4/2016
Citation: Wang, Q., Dong, B., Pokiniewski, K., Firrman, J., Wu, Z., Chin, M., Chen, X., Liu, L.S., Xu, R., Diao, Y., Xiao, W. 2016. Syngeneic AAV pseudo-vectors potentiates full vector transduction. Meeting Abstract. 19(5):11.
Technical Abstract: An excessive amount of empty capsids are generated during regular AAV vector production process. These pseudo-vectors often remain in final vectors used for animal studies or clinical trials. The potential effects of these pseudo-vectors on AAV transduction have been a major concern. In the current study, we systemically examined how the AAV pseudo-vectors interact with the full AAV vectors in the transduction processes. Three different types of AAV pseudo-vectors were used: syngeneic AAV pseudo-vector (sAAV, purified from the full AAV vector preparation with the same reporter gene), null AAV pseudo-vector (nAAV, produced by using AAV packaging plasmid and adenoviral helper plasmid), and allogeneic AAV pseudo-vector (aAAV, purified from the AAV vector preparation with a genome different to reporter gene). All three AAV2 pseudo-vectors exhibited inhibition effects on full AAV2 vectors particle transduction in a dose dependent manner in vitro. AAV2 pseudo-vectors not only inhibited full AAV2 vector transduction but also decreased gene expression from full AAV8 vectors. However, sAAV2 pseudo-vectors exhibited less inhibition effects on the transduction efficiency of full AAV2 or AAV8 vectors compared with nAAV2 or aAAV2 pseudo-vectors in vitro. In contrast, all three kinds of AAV8 pseudo-vectors did not show such inhibition effects on full AAV8 and AAV2 vectors in vitro or in vivo. Moreover, the sAAV8 pseudo-vector enhanced its full AAV8 vector transduction while nAAV8 and aAAV8 pseudo-vector did not have similar effects. Nine fold sAAV8 pseudo-vectors increased AAV8-TTR-hF8-X5 transduction by 2~5-fold in two different hemophilia A mouse models as measured the coagulation activity of factor VIII by aPTT assays and antigen levels by ELISA. Further characterization showed that sAAV8 and aAAV8 pseudo-vectors contain DNAs of varying sizes. In general, these DNAs still have AAV ITR sequences and partial vector genomes near ITRs. It is likely that such partial genome could anneal to the full AAV genomes and facilitate the second strand DNA synthesis thus increasing full AAV transduction.