Location: Dairy and Functional Foods ResearchTitle: High density recombinant AAV particles are competent vectors for in vivo transduction Author
|Wang, Qizhao - Temple University|
|Wu, Zhongren - Temple University|
|Pokiniewski, Katie - Temple University|
|Valencia, C. - Children'S Hospital - Cincinnati, Ohio|
|Wang, Hairong - Temple University|
|Wei, Hongying - Temple University|
|Zhuang, Zhenjing - Temple University|
|Wunder, Stephanie - Temple University|
|Chin, Mario P. - Temple University|
|Xu, Ruian - School Of Biomedical Sciences, Huaqiao University|
|Diao, Yong - School Of Biomedical Sciences, Huaqiao University|
|Dong, Biao - School Of Biomedical Sciences, Huaqiao University|
|Xiao, Weidong - Temple University|
Submitted to: Human Gene Therapy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2016
Publication Date: 8/22/2016
Citation: Wang, Q., Firrman, J., Wu, Z., Pokiniewski, K.A., Valencia, C.A., Wang, H., Wei, H., Zhuang, Z., Liu, L.S., Wunder, S.L., Chin, M.S., Xu, R., Diao, Y., Dong, B., Xiao, W. 2016. High density recombinant AAV particles are competent vectors for in vivo transduction. Human Gene Therapy. doi: 10.1089/hum.2016.055. PMID: 27550145.
Interpretive Summary: Gene therapy is a way to treat disease by delivering a gene into a human cell. There has been success in the field of gene therapy using an Adeno-Associated Virus, a small, non-toxic virus used as a vehicle to deliver the gene into the cell. However, making Adeno-Associated Virus is a difficult and complicated process. In the end product there are two types of viruses found, one that is the correct density (rAAVRD) and one that has a high density (rAAVHD), or a heavier weight per viral particle. Typically, the viruses with a high density are not used and discarded. In this study, the functional properties of both regular and high density Adeno-associated viruses were compared. We found that the amount of DNA in each type of virus was the same, however, the high density viruses had less protein and a smaller size. Viruses that have a high density were also less effective when tested in cells, however, both types of viruses performed the same in mice. For the first time, our results demonstrate that both densities of Adeno-Associated virus are equally effective in an animal model, and therefore should be considered for use in human gene therapy.
Technical Abstract: Recombinant adeno-associated viral (rAAV) vectors have recently achieved clinical successes in human gene therapy. However, the commonly observed heavier particles found in AAV preparations have traditionally been ignored due to its low in vitro infectivity. In this study, we systemically compared the biological and transduction profiles of regular and high density rAAV (rAAVRD and rAAVHD) vectors. Interestingly, rAAVHD particles showed a higher DNA/protein ratio than that of rAAVRD as both rAAVRD and rAAVHD exhibited similar DNA contents while rAAVHD capsids consist of fewer VP1 and/or VP2 proteins. Dynamic light scattering and transmission electron microscopy data revealed that the diameter of rAAVHD was 5 to approximately 7% smaller than rAAVRD. Their ratio in a vector preparation varies depending on vector genome size. In vitro, rAAVHD was 2 to approximately 4-fold less efficient in transduction as compared to rAAVRD. Surprisingly, the transduction performance of rAAVHD and rAAVRD was similar in vivo. Further investigation showed that rAAVRD and rAAVHD reacted similarly to AAV neutralizing antibodies, which suggested the surface epitope of rAAVRD and rAAVHD remained the same. In summary, we have demonstrated that rAAVRD and rAAVHD are equally competent for in vivo transduction despite their difference in vitro. The use of rAAVHD vectors in human gene therapy should be further evaluated.