This project is focused on the development of gene therapy for Wiskott-Aldrich syndrome (WAS), a severe immunodeficiency disorder also characterized by a low platelet count and chronic eczema. Affected boys may also suffer from autoimmunity and/or develop a neoplasm. We have made the following advances which support the application of gene transfer into blood stem cells for treatment of WAS: 1) developed a novel, HIV1 based lentiviral vector system to facilitate gene transfer into stem cells;2) identified the envelope protein from Vesicular Stomatitis Virus (VSV-G) as providing the highest efficiency of gene transfer into repopulating cells;and 3) developed a methodology for deriving stable producer clones that will facilitate vector preparation for our planned clinical trial.
In Specific Aim 1, experiments are proposed to identify a lentiviral vector design that achieves normal expression of Wiskott-Aldrich syndrome protein (WASp) in hematopoietic cells and demonstrates therapeutic potential, in Sub-Aim 1.1, we will compare the levels of WASp expression achieved with various promoters to select one for use in our clinical trial. In a second exploratory sub-aim of Specific Aim 1, we will map and functionally characterize distant tissue specific regulatory elements that may influence WASp gene expression.
In Specific Aim 2, we will evaluate the safety of WASp clinical vector using 2 cellular assays that detect proto-oncogene activation. Vectors will be assayed for their potential to activate the LM02 proto-oncogene in Jurkat T-celis and also for their ability to induce myeloid immortalization of primary lineage depleted bone marrow cells.
In Specific Aim 3, we propose to evaluate lentiviral vector mediated WASp gene transfer in WAS patients. Clinical vector design will be determined by the functional studies proposed in Sub-Aim 1.1 as well as the cellular assays for protooncogene activation in Specific Aim 2. Eligible participants are those whose platelet count is <50,000/mm3 who have other significant clinical manifestations of WAS but lack a matched related or unrelated allogeneic stem cell donor. G-CSF mobilized peripheral blood stem cells will be transduced and returned to participants following myelosuppressive therapy with Busulfan. Safety and feasibility will be assessed within 2 months of infusion of transduced cells and the protocol amended if one or more stopping rules are met. Objective measures of efficacy include a progressive increase in the number of genetically modified cells, particulariy in the lymphoid lineages, an increase in platelet count to &50,000/mm3 and a return of IgM levels to normal by 1 year. Patients will be observed long-term for restoration of immune function and for any evidence of vector induced clonal dominance or neoplasia.
of this work is that it will advance the development of stem cell targeted gene therapy for WAS and in so doing offer a potential curative option other than stem cell transplantation. Our efforts to identify and define the functional relevance of elements that influence WASp gene expression will provide new insights into the regulation of this gene and may inform the development of future vectors for gene therapy of WAS.
|Zhao, Hui Fen; Abraham, Allistair; Kim, Yoon-Sang et al. (2017) Lentiviral Transfer of ?-Globin with Fusion Gene NUP98-HOXA10HD Expands Hematopoietic Stem Cells and Ameliorates Murine ?-Thalassemia. Mol Ther 25:593-605|
|De Ravin, Suk See; Wu, Xiaolin; Moir, Susan et al. (2016) Lentiviral hematopoietic stem cell gene therapy for X-linked severe combined immunodeficiency. Sci Transl Med 8:335ra57|
|Abraham, Allistair; Kim, Yoon-Sang; Zhao, Huifen et al. (2016) Increased Engraftment of Human Short Term Repopulating Hematopoietic Cells in NOD/SCID/IL2r?null Mice by Lentiviral Expression of NUP98-HOXA10HD. PLoS One 11:e0147059|
|Wielgosz, Matthew M; Kim, Yoon-Sang; Carney, Gael G et al. (2015) Generation of a lentiviral vector producer cell clone for human Wiskott-Aldrich syndrome gene therapy. Mol Ther Methods Clin Dev 2:14063|
|Pestina, Tamara I; Hargrove, Phillip W; Zhao, Huifen et al. (2015) Amelioration of murine sickle cell disease by nonablative conditioning and ?-globin gene-corrected bone marrow cells. Mol Ther Methods Clin Dev 2:15045|
|Zhou, Sheng; Bonner, Melissa A; Wang, Yong-Dong et al. (2015) Quantitative shearing linear amplification polymerase chain reaction: an improved method for quantifying lentiviral vector insertion sites in transplanted hematopoietic cell systems. Hum Gene Ther Methods 26:4-12|
|Urbinati, Fabrizia; Hargrove, Phillip W; Geiger, Sabine et al. (2015) Potentially therapeutic levels of anti-sickling globin gene expression following lentivirus-mediated gene transfer in sickle cell disease bone marrow CD34+ cells. Exp Hematol 43:346-351|
|Treanor, Louise M; Zhou, Sheng; Janke, Laura et al. (2014) Interleukin-7 receptor mutants initiate early T cell precursor leukemia in murine thymocyte progenitors with multipotent potential. J Exp Med 211:701-13|
|Griffith, Linda M; Cowan, Morton J; Notarangelo, Luigi D et al. (2014) Primary Immune Deficiency Treatment Consortium (PIDTC) report. J Allergy Clin Immunol 133:335-47|
|De Ravin, Suk See; Gray, John T; Throm, Robert E et al. (2014) False-positive HIV PCR test following ex vivo lentiviral gene transfer treatment of X-linked severe combined immunodeficiency vector. Mol Ther 22:244-245|
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