after the second round of selection and reached levels above 80% after the third round. The percentage of γ-globin-expressing cells was approximately 7-to 10-fold higher in erythroid Ter119 + cells versus nonerythroid Ter119cells in peripheral blood and bone marrow (Figure 1D). We used HPLC to measure the level of γ-globin protein in comparison with the adult mouse α-and β-globin chains (Figure 1E and Supplemental Figure 1; supplemental material available online with this article; https://doi.org/10.1172/ JCI122836DS1). At week 18, these levels reached 10%-15% of adult mouse α-globin and β-major globin and approximately 25% of mouse β-minor globin. This was confirmed on the mRNA level by quantitative reverse transcription PCR (RT-qPCR), where human γ-globin mRNA was approximately 13% of mouse β-major mRNA (Figure 1F). To further demonstrate that primitive, long-term repopulating HSCs were transduced, we transplanted lineagedepleted (Lin-) bone marrow cells from in vivo-transduced/ selected mice into irradiated C57BL/6 mice. Engraftment levels analyzed in peripheral blood, bone marrow, and spleen were greater than 95% and stable over an observation period of 20 weeks (Supplemental Figure 2, A and B). Human γ-globin levels (compared with mouse α-globin) were similar in ("primary") in vivo-transduced mice (analyzed at week 18 after transduction) and secondary recipients analyzed at weeks 14 and 20 after transplantation (Supplemental Figure 2C). The in vivo HSPC transduction/selection approach does not change the SB100X-mediated random transgene integration pattern and does not alter hematopoiesis. We previously showed that in vivo transduction with the hybrid transposon/SB100X HDAd5/35++ system resulted in random transgene integration in HSPCs (6). To evaluate the effect of O 6 BG/BCNU in in vivo selection, we analyzed transgene integration in bone marrow Lincells at the end of the study, i.e., at week 20 in secondary recipients. Linear amplification-mediated PCR (LAM-PCR) followed by deep sequencing showed a random distribution pattern of integration sites in the mouse genome (Figure 2A). Data pooled from 5 mice demonstrated 2.23% integration into exons, 31.58% into introns, 65.17% into intergenic regions, and 1.04% into untranslated regions (Figure 2B). The level of randomness of integration was 99% without preferential integration in any given window of the whole mouse genome (Figure 2C). This indicates that in vivo selection and further expansion of cells in secondary recipients did not result in the emergence of dominant integration sites (Figure 2D). We measured, by qPCR, on average two γ-globin cDNA copies per bone marrow cell in a population containing both transduced and nontransduced cells. We then quantified the integrated transgene copy number on a single-cell level. To do this, we plated bone marrow Lincells from week 18 mice in methylcellulose, isolated individual progenitor colonies, and performed qPCR on genomic DNA. In transgene-positive colonies (n = 113), 86.7% of colonies had 2 or 3 integrated co...

We generated an integrating, CD46-targeted, helper-dependent adenovirus HDAd5/35++ vector system for hematopoietic stem cell (HSC) gene therapy. The ∼12-kb transgene cassette included a β-globin locus control region (LCR)/promoter driven human γ-globin gene and an elongation factor alpha-1 (EF1α)-mgmtP140K expression cassette, which allows for drug-controlled increase of γ-globin-expressing erythrocytes. We transduced bone marrow lineage-depleted cells from human CD46-transgenic mice and transplanted them into lethally irradiated recipients. The percentage of γ-globin-positive cells in peripheral blood erythrocytes in primary and secondary transplant recipients was stable and greater than 90%. The γ-globin level was 10%–20% of adult mouse globin. Transgene integration, mediated by a hyperactive Sleeping Beauty SB100x transposase, was random, without a preference for genes. A second set of studies was performed with peripheral blood CD34+ cells from mobilized donors. 10 weeks after transplantation of transduced cells, human cells were harvested from the bone marrow and differentiated ex vivo into erythroid cells. Erythroid cells expressed γ-globin at a level of 20% of adult α-globin. Our studies suggest that HDAd35++ vectors allow for efficient transduction of long-term repopulating HSCs and high-level, almost pancellular γ-globin expression in erythrocytes. Furthermore, our HDAd5/35++ vectors have a larger insert capacity and a safer integration pattern than currently used lentivirus vectors.

A systematic workflow consisting of comparative genomics, metabolic pathways analysis and additional drug prioritization parameters identified 264 proteins of Vibrio cholerae which were predicted to be absent in Homo sapiens. Among these, 40 proteins were identified as essential proteins that could serve as potential drug and vaccine targets. Additional prioritization parameters characterized 11 proteins as vaccine candidates while druggability of each of the identified proteins as evaluated by the Drug Bank database which prioritized 16 proteins suitable for drug targets. As a case study, we built a homology model of one of the potential drug targets, MurA ligase, using MODELLER (9v12) software. The model has been further explored for in silico docking with inhibitors having druggability potential from the Drug Bank database. Results from this study could facilitate selecting V. cholerae proteins for drug design and vaccine production pipelines in future.

Background Type 3 von Willebrand disease (VWD) is characterized by complete absence of von Willebrand factor (VWF). Current therapy is limited to treatment with exogenous VWF/FVIII products, which only provide a short-term solution. Gene therapy offers the potential for a long-term treatment for VWD. Objectives To develop an integrative Sleeping Beauty (SB) transposon-mediated VWF gene transfer approach in a preclinical mouse model of severe VWD. Methods We established a robust platform for sustained transgene murine VWF (mVWF) expression in the liver of Vwf mice by combining a liver-specific promoter with a sandwich transposon design and the SB100X transposase via hydrodynamic gene delivery. Results The sandwich SB transposon was suitable to deliver the full-length mVWF cDNA (8.4 kb) and supported supra-physiological expression that remained stable for up to 1.5 years after gene transfer. The sandwich vector stayed episomal (~60 weeks) or integrated in the host genome, respectively, in the absence or presence of the transposase. Transgene integration was confirmed using carbon tetrachloride-induced liver regeneration. Analysis of integration sites by high-throughput analysis revealed random integration of the sandwich vector. Although the SB vector supported long-term expression of supra-physiological VWF levels, the bleeding phenotype was not corrected in all mice. Long-term expression of VWF by hepatocytes resulted in relatively reduced amounts of high-molecular-weight multimers, potentially limiting its hemostatic efficacy. Conclusions Although this integrative platform for VWF gene transfer is an important milestone of VWD gene therapy, cell type-specific targeting is yet to be achieved.

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