Browsing by Author "Sadat, Mohammed A."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    From bench to bedside: preclinical evaluation of a self-inactivating gammaretroviral vector for the gene therapy of X-linked chronic granulomatous disease
    (Mary Ann Liebert, 2013-06) Stein, Stefan; Scholz, Simone; Schwäble, Joachim; Sadat, Mohammed A.; Modlich, Ute; Schultze-Strasser, Stephan; Diaz, Margarita; Chen-Wichmann, Linping; Müller-Kuller, Uta; Brendel, Christian; Fronza, Raffaele; Kaufmann, Kerstin B.; Naundorf, Sonja; Pech, Nancy K.; Travers, Jeffrey B.; Matute, Juan D.; Presson, Robert G.; Sandusky, George E.; Kunkel, Hana; Rudolf, Eva; Dillmann, Adelina; von Kalle, Christof; Kühlcke, Klaus; Baum, Christopher; Schambach, Axel; Dinauer, Mary C.; Schmidt, Manfred; Grez, Manuel; Pediatrics, School of Medicine
    Chronic granulomatous disease (CGD) is a primary immunodeficiency characterized by impaired antimicrobial activity in phagocytic cells. As a monogenic disease affecting the hematopoietic system, CGD is amenable to gene therapy. Indeed in a phase I/II clinical trial, we demonstrated a transient resolution of bacterial and fungal infections. However, the therapeutic benefit was compromised by the occurrence of clonal dominance and malignant transformation demanding alternative vectors with equal efficacy but safety-improved features. In this work we have developed and tested a self-inactivating (SIN) gammaretroviral vector (SINfes.gp91s) containing a codon-optimized transgene (gp91(phox)) under the transcriptional control of a myeloid promoter for the gene therapy of the X-linked form of CGD (X-CGD). Gene-corrected cells protected X-CGD mice from Aspergillus fumigatus challenge at low vector copy numbers. Moreover, the SINfes.gp91s vector generates substantial amounts of superoxide in human cells transplanted into immunodeficient mice. In vitro genotoxicity assays and longitudinal high-throughput integration site analysis in transplanted mice comprising primary and secondary animals for 11 months revealed a safe integration site profile with no signs of clonal dominance.
  • Thumbnail Image
    Item
    Real-Time PCR: An Effective Tool for Measuring Transduction Efficiency in Human Hematopoietic Progenitor Cells
    (Elsevier, 2004-12-04) Villella, Anthony D.; Yao, Jing; Getty, Robert R.; Juliar, Beth E.; Yiannoutsos, Constantin; Hartwell, Jennifer R.; Cai, Shanbao; Sadat, Mohammed A.; Cornetta, Kenneth; Williams, David A.; Pollok, Karen E.; Medical and Molecular Genetics, School of Medicine
    Accurate measurement of gene transfer into hematopoietic progenitor cells is an essential prerequisite for assessing the utility of gene therapy approaches designed to correct hematologic defects. We developed a reliable method to measure transduction efficiency at the level of the progenitor cell with real-time polymerase chain reaction (PCR) analysis of individual progenitor-derived colonies. We hypothesized that this method would demonstrate better sensitivity and specificity than are currently achievable with conventional PCR. An oncoretroviral vector containing the enhanced green fluorescent protein was used to transduce human CD34+ cells derived from bone marrow or granulocyte-colony-stimulating factor-mobilized peripheral blood. Progenitor assays were set up and colonies plucked after visualization by fluorescence microscopy. By analyzing microscopically identified fluorescent samples and nontransduced samples, we calculated an overall sensitivity and specificity of 90.2 and 95.0%, respectively. Real-time PCR had higher specificity and sensitivity than conventional PCR as analyzed by generalized linear models (P = 0.002 and P = 0.019, respectively). In conclusion, we found real-time PCR to have superior sensitivity and specificity compared to conventional PCR in determining transduction efficiency of hematopoietic progenitor cells.