MINNEAPOLIS, MN, United States
MINNEAPOLIS, MN, United States

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Wang Y.,Iowa State University | Kaiser M.S.,Iowa State University | Larson J.D.,University of Minnesota | Larson J.D.,Discovery Genomics, Inc. | And 10 more authors.
Development | Year: 2010

Endothelial tubulogenesis is a crucial step in the formation of functional blood vessels during angiogenesis and vasculogenesis. Here, we use in vivo imaging of living zebrafish embryos expressing fluorescent fusion proteins of β-Actin, α-Catenin, and the ERM family member Moesin1 (Moesin a), to define a novel cord hollowing process that occurs during the initial stages of tubulogenesis in intersegmental vessels (ISVs) in the embryo. We show that the primary lumen elongates along cell junctions between at least two endothelial cells during embryonic angiogenesis. Moesin1-EGFP is enriched around structures that resemble intracellular vacuoles, which fuse with the luminal membrane during expansion of the primary lumen. Analysis of silent heart mutant embryos shows that initial lumen formation in the ISVs is not dependent on blood flow; however, stabilization of a newly formed lumen is dependent upon blood flow. Zebrafish moesin1 knockdown and cell transplantation experiments demonstrate that Moesin1 is required in the endothelial cells of the ISVs for in vivo lumen formation. Our analyses suggest that Moesin1 contributes to the maintenance of apical/basal cell polarity of the ISVs as defined by adherens junctions. Knockdown of the adherens junction protein Ve-cadherin disrupts formation of the apical membrane and lumen in a cell-autonomous manner. We suggest that Ve-cadherin and Moesin1 function to establish and maintain apical/basal polarity during multicellular lumen formation in the ISVs.


Wang B.,Minneapolis | Dileepan T.,Minneapolis | Briscoe S.,Minneapolis | Hyland K.A.,Discovery Genomics, Inc. | And 3 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2010

Recurrent group A Streptococcus (GAS) tonsillitis and associated autoimmune diseases indicate that the immune response to this organism can be ineffective and pathological. TGF-β1 is recognized as an essential signal for generation of regulatory T cells (Tregs) and T helper (Th) 17 cells. Here, the impact of TGF-β1 induction on the Tcell response in mouse nasal-associated lymphoid tissue (NALT) following intranasal (i.n.) infections is investigated. ELISA and TGF-β1-luciferase reporter assays indicated that persistent infection of mouse NALT with GAS sets the stage for TGF-β1 and IL-6 production, signals required for promotion of a Th17 immune response. As predicted, IL-17, the Th17 signature cytokine, was induced in a TGF-β1 signaling-dependent manner in single-cell suspensions of both human tonsils and NALT. Intracellular cytokine staining and flow cytometry demonstrated that CD4+ IL-17+ T cells are the dominant T cells induced in NALT by i.n. infections. Moreover, naive mice acquired the potential to clear GAS by adoptive transfer of CD4+ T cells from immunized IL-17A +/+ mice but not cells from IL-17A-/ - mice. These experiments link specific induction of TGF-β1 by a bacterial infection to an in vivo Th17 immune response and show that this cellular response is sufficient for protection against GAS. The association of a Th17 response with GAS infection reveals a potential mechanism for destructive autoimmune responses in humans.


Podetz-Pedersen K.M.,University of Minnesota | Bell J.B.,University of Minnesota | Steele T.W.J.,University of Minnesota | Steele T.W.J.,University of Marburg | And 7 more authors.
Human Gene Therapy | Year: 2010

Two methods of systemic gene delivery have been extensively explored, using the mouse as a model system: hydrodynamic delivery, wherein a DNA solution equivalent in volume to 10% of the mouse weight is injected intravenously in less than 10 sec, and condensation of DNA with polyethylenimine (PEI) for standard intravenous infusion. Our goal in this study was to evaluate quantitatively the kinetics of gene expression, using these two methods for delivery of Sleeping Beauty transposons. Transposons carrying a luciferase expression cassette were injected into mice either hydrodynamically or after condensation with PEI at a PEI nitrogen-to-DNA phosphate ratio of 7. Gene expression in the lungs and liver after hydrodynamic delivery resulted in exponential decay with a half-life of about 35-40 hr between days 1 and 14 postinjection. The decay kinetics of gene expression after PEI-mediated gene delivery were more complex; an initial decay rate of 6 hr was followed by a more gradual loss of activity. Consequently, the liver became the primary site of gene expression about 4 days after injection of PEI-DNA, and by 14 days expression in the liver was 10-fold higher than in the lung. Overall levels of gene expression 2 weeks postinjection were 100-to 1000-fold lower after PEI-mediated delivery compared with hydrodynamic injection. These results provide insight into the relative effectiveness and organ specificity of these two methods of nonviral gene delivery when coupled with the Sleeping Beauty transposon system. © Copyright 2010, Mary Ann Liebert, Inc.


Hyland K.A.,Discovery Genomics, Inc. | Olson E.R.,Discovery Genomics, Inc. | Mcivor R.S.,Discovery Genomics, Inc. | Mcivor R.S.,University of Minnesota
Human Gene Therapy | Year: 2015

The Sleeping Beauty (SB) transposon system can insert sequences into mammalian chromosomes, supporting long-term expression of both reporter and therapeutic genes. Hematopoietic progenitor cells (HPCs) are an ideal therapeutic gene transfer target as they are used in therapy for a variety of hematologic and metabolic conditions. As successful SB-mediated gene transfer into human CD34+ HPCs has been reported by several laboratories, we sought to extend these studies to the introduction of a therapeutic gene conferring resistance to methotrexate (MTX), potentially providing a chemoprotective effect after engraftment. SB-mediated transposition of hematopoietic progenitors, using a transposon encoding an L22Y variant dihydrofolate reductase fused to green fluorescent protein, conferred resistance to methotrexate and dipyridamole, a nucleoside transport inhibitor that tightens MTX selection conditions, as assessed by in vitro hematopoietic colony formation. Transposition of individual transgenes was confirmed by sequence analysis of transposon-chromosome junctions recovered by linear amplification-mediated PCR. These studies demonstrate the potential of SB-mediated transposition of HPCs for expression of drug resistance genes for selective and chemoprotective applications. © Mary Ann Liebert, Inc. 2015.


Grant
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 1.77M | Year: 2011

DESCRIPTION (provided by applicant): Sleeping Beauty (SB) is a transposon system that has been extensively shown to be capable of mediating integration of new gene sequences into the chromosomes of target cells and tissues. At Discovery Genomics, Inc. (DGI), we are working to develop the SB transposon system for human gene therapy, with hemophilia as our lead project. During initial Phase II SBIR studies, we demonstrated effective delivery of SB transposon DNA to the liver of dogs. Single or double ballooncatheters were used to achieve whole or partial occlusion of the liver followed by rapid, high volume retrograde infusion of DNA containing solution into the hepatic venous circulation. Results from these experiments (reporter gene expression was observedfor six weeks following infusion) place DGI at the forefront of non-viral gene therapy efforts targeting the liver in large animals. Based on these results and recent feedback from the Food and Drug Administration, in this Phase II competing renewal application we propose further preclinical studies to address issues of safety, scale-up to the size of humans, and efficacy in a large animal model of hemophilia. The Specific Aims are; (i) To develop double balloon catheters capable of delivering SB transposonDNA to the liver in humans and to test the safety and effectiveness of these catheters for DNA delivery in pigs as a large animal model of comparable size to human beings; (ii) To extend the duration of transgene expression after delivery of SB transposons to the liver of normal dogs, using DGI's unique canine secreted alkaline phosphatase (cSEAP) reporter system; (iii) To deliver SB transposons encoding canine clotting factor IX (cFIX) to the liver of cFIX deficient dogs, testing for long-term expressionof cFIX and improved clotting function as a large animal model for SB mediated gene therapy of hemophilia B. Results from these studies will provide necessary preclinical data for subsequent submission of an Investigational New Drug application with the FDA for treatment of hemophilia B using the SB transposon system, with subsequent growth and commercial development of Discovery Genomics, Inc. PUBLIC HEALTH RELEVANCE: In this grant application, studies are proposed to develop a new approach for treating hemophilia by non-viral gene therapy using an integrating DNA element (a transposon) called Sleeping Beauty. The experiments described in the proposal will establish conditions for delivery of Sleeping Beauty DNA in pigs as an animal model similar insize to humans, and in hemophilic dogs as a model for treatment of human hemophilia.


Grant
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 270.67K | Year: 2010

DESCRIPTION (provided by applicant): Primary immune deficiencies comprise a group of inherited genetic disorders caused by interruption of normal lymphoid development. These diseases are considered prime candidates for gene therapy by introduction of the missing gene into hematopoietic stem cells that can then differentiate into lymphoid cells, and thus restore immunity. X-linked severe combined immunodeficiency (X-SCID), caused by a mutation in the gene encoding the common ( chain gene ((c) of the receptors for IL-2, IL-4, IL-7, IL-9, IL-15, and IL-213, is one of the more common of the primary immunodeficiencies. Clinical gene therapy trials for X-SCID have focused on the use of retroviruses as an integrating viral vector for introduction of the (c gene, resulting in restoration of immunity in patients that have engrafted with transduced, autologous hematopoietic stem cells. However, serious adverse events have emerged in these clinical trials, namely a T-cell leukemia-like syndrome developing in 5 of 21 treated patients. Therefore, safer, alterative therapies are needed. At Discovery Genomics, Inc. (DGI), we are working on developing the Sleeping Beauty (SB) transposon system for gene therapy, including the targeting of hematopoietic stem cells for treatment of primary immunodeficiencies. The two-component SB system consists of a transposon (inverted repeats (IR's) flanking a therapeutic gene of interest) and a transposase that catalyzes excision of the transposon at the ends of the IRs and then integration into host cell chromosomal sequence. As a lead immunodeficiency, here we propose that X-SCID may be treatable without the use of a virus by combining the power of electroporation for introduction of DNA into cells, along with use of DGI's Sleeping Beauty transposon system to achieve integration and long-term (c gene expression. In this Phase I application, the overall goal is to establish conditions for SB-mediated gene therapy for X-SCID. In this regard, there are two key questions that will need to be addressed: (i) Will SB-mediated transposition of the (c gene allow functional correction of lymphoid cells? (ii) What is the effectiveness of SB-mediated (c gene insertion in the treatment of an animal model of X-SCID? There are two Specific Aims: Aim 1. Evaluate the effectiveness of Sleeping Beauty transposons for correction of (c chain deficiency in a lymphoblastoid cell line derived from an X-linked SCID patient. Aim 2. Evaluate Sleeping Beauty-mediated transposition and long term expression of (c gene in hematopoietic stem cells derived of X-SCID mice, as a model for SB-mediated gene therapy of X-SCID. Successful accomplishment of these goals will provide evidence for the effectiveness of the SB system to mediate non-viral gene transfer in murine hematopoietic stem cells (previously undemonstrated), as well as provide key preclinical data for the development of SB transposons for X-SCID as a lead primary immunodeficiency. PUBLIC HEALTH RELEVANCE: Results from these experiments will provide the technical basis for achieving transposon-mediated integration and long-term expression in hematopoietic stem cells, the cellular target inr gene therapy of primary immunodeficiencies. In addition, it will provide the basis for the development of the SB transposon system for treatment of other hematologic diseases.


Patent
Discovery Genomics, Inc. | Date: 2013-11-19

Materials and methods for treating a patient to express a therapeutic agent comprising administering a Kupffer cell-suppressing substance in combination with a vehicle for introducing, into the patient, an exogenous nucleic acid comprising a sequence for expression of the agent.


Grant
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 200.24K | Year: 2013

DESCRIPTION (provided by applicant): Pancreatic cancer represents the 10th most common cancer diagnosis, yet the 4th most common estimated cause of death. The only potential curative therapy for pancreatic cancer is surgical resection; however, few patients have tumors which can be respected. Pancreatic ductal adenocarcinoma, which represents 90% of pancreatic cancers, is particularly aggressive, since it rapidly metastasizes and often expresses several growth factors and signaling components that permit rapid growth. Alternative therapies are desperately needed, as there have been no recent medical advances for treatment of pancreatic adenocarcinoma. Immunotherapy by adoptive transfer of engineered T cells can mediate cancer regression and overcome evasivemechanisms by which tumors avoid immune responses. Chimeric antigen receptors (CAR) are engineered molecules that are a fusion of an antibody-derived antigen-binding motif and intracellular signaling domains, and can recognize tumor antigens independentlyof the major histocompatiblity complex, expression of which is often lost by tumor cells. At Discovery Genomics, Inc. (DGI), we are developing the Sleeping Beauty transposon system to generate T cells for autologous adoptive T cell therapy. Here we proposeto use the SB system for engineering T cells to express CAR recognizing ?V?6, an integrin that is highly expressed on pancreatic cancer cells. In addition, we will stably co-express a chimeric receptor (4??), consisting of a fusion of the IL-4 receptor ?extracellular domain and the endodomain of the common ?- receptor, which is a component of both IL-2 and IL-15 receptors. Expression of the 4?? receptor by anti-??V?6 T cells will allow selective expansion of CAR positive cells. Binding of interleukin-4 tothe 4?? receptor will activate a proliferative signal, thus stimulating the T cells to divide. The engineered T cells will be immunophenotypically characterized by flow cytometry. Antitumor cytotoxic activity will be assessed in vitro by measuring cytokine secretion and degranulation after exposure of engineered T cells to ?V?6 positive pancreatic cancer cells and the ability of CAR-expressing T cells to lyse ?V?6 positive pancreatic cancer cells. Results from these experiments will provide an assessment of the effectiveness of SB-engineered T cells in killing pancreatic cancer cells. Subsequent studies in animal models of pancreatic cancer will lead to a clinical trial for the treatment of pancreatic adenocarcinoma by administering human T-cells genetically engineered ex vivo using the Sleeping Beauty transposon system. PUBLIC HEALTH RELEVANCE PUBLIC HEALTH RELEVANCE: In this grant application, studies are proposed to develop a new approach for treating pancreatic cancer by non-viral gene therapyusing an integrating DNA element (a transposon) called Sleeping Beauty . The experiments described in the proposal will establish conditions to genetically engineer lymphocytes as a cellular therapy to kill pancreatic cancer cells.


Grant
Agency: Department of Health and Human Services | Branch: National Institutes of Health | Program: SBIR | Phase: Phase I | Award Amount: 224.48K | Year: 2015

DESCRIPTION provided by applicant Mucopolysaccharidosis type I MPS I is an autosomal recessive storage disease caused by the absence of L iduronidase IDUA resulting in systemic accumulation of glycosaminoglycan GAG storage materials hepatosplenomegaly skeletal dysplasias cardiopulmonary obstruction progressive neurologic impairment and death by age MPS I is currently treated by enzyme replacement therapy and by allogeneic hematopoietic stem cell transplantation but these treatments are extraordinarily expensive and do not fully address the skeletal cardiac and neurologic manifestations of the disease Here we propose an entirely novel approach to the treatment of MPS I Immusoft Corp is developing genetically engineered autologous human B cells for production of therapeutic proteins upon infusion into patients Discovery Genomics Inc DGI focuses on clinical development of the Sleeping Beauty SB transposon system for integrative gene transfer and expression Here we propose to combine Immusoftandapos s novel B cell expression platform with DGIandapos s advanced DNA mediated cellular genetic engineering technology for the purpose of expressing human IDUA from B cells in vivo as an approach to achieve systemic expression of IDUA as a treatment for MPS I This collaborative project is further strengthened by the extensive experience of DGIandapos s investigative team and colleagues at the University of Minnesota in the conduct of preclinical studies and clinical trials of new treatments for lysosomal storage diseases in particular MPS I For this Phase I study the Specific Aims are i Sleeping Beauty mediated human iduronidase gene transfer and expression in primary human B cells cultured in vitro B cells will be isolated from human blood and expanded in culture using Immusoftandapos s Immune System Programming technology Early in the expansion process cells will be collected and nucleofected with SB transposon DNA encoding human IDUA along with a plasmid encoding SB transposase to mediate integration into host B cell chromosomes ii These cells will then be infused into immunodeficient NOD SCID IDUA deficient mice evaluating recipient animals for engraftment expression and distribution of IDUA activity and correction of metabolic and neurologic disease Results from these studies will be directly applicable to the development of a clinical protocol for treatment of human MPS I by infusion of B cells genetically engineered using the SB transposon system PUBLIC HEALTH RELEVANCE Lysosomal storage disorders are a rare group of inherited diseases in which patients suffer from skeletal abnormalities heart and breathing problems mental retardation and death While some of these diseases can be treated by protein therapy or by bone marrow transplantation these treatments are expensive and incompletely effective It is envisioned in this grant application that one way to treat these diseases would be to restore the missing gene in patientsandapos white blood cells as a way of providing the missing protein and restoring function in the different organs


PubMed | University of Minnesota, Mayo Medical School and Discovery Genomics, Inc.
Type: | Journal: Molecular therapy. Nucleic acids | Year: 2016

The Sleeping Beauty (SB) transposon system has been shown to enable long-term gene expression by integrating new sequences into host cell chromosomes. We found that the recently reported SB100x hyperactive transposase conferred a surprisingly high level of long-term expression after hydrodynamic delivery of luciferase-encoding reporter transposons in the mouse. We conducted dose-ranging studies to determine the effect of varying the amount of SB100x transposase-encoding plasmid (pCMV-SB100x) at a set dose of luciferase transposon and of varying the amount of transposon-encoding DNA at a set dose of pCMV-SB100x in hydrodynamically injected mice. Animals were immunosuppressed using cyclophosphamide in order to prevent an antiluciferase immune response. At a set dose of transposon DNA (25 g), we observed a broad range of pCMV-SB100x doses (0.1-2.5 g) conferring optimal levels of long-term expression (>10(11) photons/second/cm(2)). At a fixed dose of 0.5 g of pCMV-SB100x, maximal long-term luciferase expression (>10(10) photons/second/cm(2)) was achieved at a transposon dose of 5-125 g. We also found that in the linear range of transposon doses (100ng), co-delivering the CMV-SB100x sequence on the same plasmid was less effective in achieving long-term expression than delivery on separate plasmids. These results show marked flexibility in the doses of SB transposon plus pCMV-SB100x that achieve maximal SB-mediated gene transfer efficiency and long-term gene expression after hydrodynamic DNA delivery to mouse liver.

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