Dataset Information

Integration-specific In Vitro Evaluation of Lentivirally Transduced Rhesus CD34(+) Cells Correlates With In Vivo Vector Copy Number.

ABSTRACT: Hematopoietic stem cell (HSC) gene therapy using integrating vectors has a potential leukemogenic risk due to insertional mutagenesis. To reduce this risk, a limitation of ?2 average vector copy number (VCN) per cell is generally accepted. We developed an assay for VCN among transduced CD34(+) cells that reliably predicts in vivo VCN in 16 rhesus recipients of CD34(+) cells transduced with a green fluorescent protein (GFP) (or yellow fluorescent protein (YFP))-encoding lentiviral vector. Using GFP (or YFP)-specific probe/primers by real-time PCR, VCN among transduced CD34(+) cells had no correlation with VCN among granulocytes or lymphocytes in vivo assayed 6 months post-transplantation. This was a likely result of residual plasmids present in the vector preparation. We then designed self-inactivating long terminal repeat (SIN-LTR)-specific probe/primers, which detect only integrated provirus. Evaluation with SIN-LTR probe/primers resulted in a positive correlation of VCN among transduced CD34(+) cells with granulocytes and lymphocytes in vivo. The transduced CD34(+) cells had higher VCN (25.1?±?5.6) as compared with granulocytes (2.8?±?1) and lymphocytes (2.4?±?0.7). In summary, an integrated provirus-specific real-time PCR system demonstrated nine- to tenfold higher VCN in transduced CD34(+) cells in vitro, as compared with VCN in vivo. Therefore, the restriction of ?2 VCN before infusion might unnecessarily limit gene transfer efficacy.Molecular Therapy-Nucleic Acids (2013) 2, e122; doi:10.1038/mtna.2013.49; published online 17 September 2013.

SUBMITTER: Uchida N

PROVIDER: S-EPMC4098567 | biostudies-literature | 2013 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Integration-specific In Vitro Evaluation of Lentivirally Transduced Rhesus CD34(+) Cells Correlates With In Vivo Vector Copy Number.

Uchida Naoya N Evans Molly E ME Hsieh Matthew M MM Bonifacino Aylin C AC Krouse Allen E AE Metzger Mark E ME Sellers Stephanie E SE Dunbar Cynthia E CE Donahue Robert E RE Tisdale John F JF

Molecular therapy. Nucleic acids 20130917

Hematopoietic stem cell (HSC) gene therapy using integrating vectors has a potential leukemogenic risk due to insertional mutagenesis. To reduce this risk, a limitation of ≤2 average vector copy number (VCN) per cell is generally accepted. We developed an assay for VCN among transduced CD34(+) cells that reliably predicts in vivo VCN in 16 rhesus recipients of CD34(+) cells transduced with a green fluorescent protein (GFP) (or yellow fluorescent protein (YFP))-encoding lentiviral vector. Using G ...[more]

PMID: 24045711

Similar Datasets

Project description:The occurrence of clonal perturbations and leukemia in patients transplanted with retrovirally-transduced autologous hematopoietic stem and progenitor cells (HSPCs) has stimulated extensive investigation, demonstrating that proviral insertions perturb adjacent proto-oncogene expression. Although enhancer-deleted lentiviruses are less likely to result in insertional oncogenesis, there is evidence that they may perturb transcript splicing, and one patient with a benign clonal expansion of lentivirally-transduced HPSC has been reported. The rhesus macaque model provides an opportunity for informative long-term analysis to ask whether transduction impacts on long-term HSPC properties. We utilized two techniques to examine whether lentivirally-transduced HSPCs from eight rhesus macaques transplanted 1-13.5 years previously are perturbed at a population level, comparing telomere length as a measure of replicative history and gene expression profile of vector positive versus vector negative cells. There were no differences in telomere lengths between sorted GFP+ and GFP- blood cells, suggesting that lentiviral transduction did not globally disrupt replicative patterns. Bone marrow GFP+ and GFP- CD34+ cells showed no differences in gene expression using unsupervised and principal component analysis. These studies did not uncover any global long-term perturbation of proliferation, differentiation, or other important functional parameters of transduced HSPCs in the rhesus macaque model. CD34+ hematopoietic stem and progenitor cells were purified from bone marrow aspirates obtained from 4 rhesus macaques 3-9 years following transplantation with lentivirally-transduced autologous hematopoietic stem and progenitor cells. All lentiviral vectors contained the GFP marker gene. The CD34+ cells from each animal were sorted via flow cytometry into GFP+ and GFP- fractions, and RNA from these cells was used for Affymetrix gene expression analysis as detailed below. There were two samples, GFP+ and GFP-, from each of 4 animals.

Dataset Information

Integration-specific In Vitro Evaluation of Lentivirally Transduced Rhesus CD34(+) Cells Correlates With In Vivo Vector Copy Number.

Publications

Integration-specific In Vitro Evaluation of Lentivirally Transduced Rhesus CD34(+) Cells Correlates With In Vivo Vector Copy Number.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets