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Manuela Wissler

Bio: Manuela Wissler is an academic researcher from University of Freiburg. The author has contributed to research in topics: Severe combined immunodeficiency & Genetic enhancement. The author has an hindex of 13, co-authored 21 publications receiving 4811 citations. Previous affiliations of Manuela Wissler include National Institutes of Health & University of Washington.

Papers
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Journal ArticleDOI
17 Oct 2003-Science
TL;DR: Retrovirus vector insertion can trigger deregulated premalignant cell proliferation with unexpected frequency, most likely driven by retrovirus enhancer activity on the LMO2 gene promoter.
Abstract: We have previously shown correction of X-linked severe combined immunodeficiency [SCID-X1, also known as gamma chain (gamma(c)) deficiency] in 9 out of 10 patients by retrovirus-mediated gamma(c) gene transfer into autologous CD34 bone marrow cells. However, almost 3 years after gene therapy, uncontrolled exponential clonal proliferation of mature T cells (with gammadelta+ or alphabeta+ T cell receptors) has occurred in the two youngest patients. Both patients' clones showed retrovirus vector integration in proximity to the LMO2 proto-oncogene promoter, leading to aberrant transcription and expression of LMO2. Thus, retrovirus vector insertion can trigger deregulated premalignant cell proliferation with unexpected frequency, most likely driven by retrovirus enhancer activity on the LMO2 gene promoter.

3,514 citations

Journal ArticleDOI
TL;DR: The results obtained from a large-scale mapping of retroviral integration sites isolated from cells of 9 patients with X-linked SCID (SCID-X1) treated with a retrovirus-based gene therapy protocol help to elucidate the relationship between vector insertion and long-term in vivo selection of transduced cells in human patients with SCID- X1.
Abstract: Recent reports have challenged the notion that retroviruses and retroviral vectors integrate randomly into the host genome. These reports pointed to a strong bias toward integration in and near gene coding regions and, for gammaretroviral vectors, around transcription start sites. Here, we report the results obtained from a large-scale mapping of 572 retroviral integration sites (RISs) isolated from cells of 9 patients with X-linked SCID (SCID-X1) treated with a retrovirus-based gene therapy protocol. Our data showed that two-thirds of insertions occurred in or very near to genes, of which more than half were highly expressed in CD34+ progenitor cells. Strikingly, one-fourth of all integrations were clustered as common integration sites (CISs). The highly significant incidence of CISs in circulating T cells and the nature of their locations indicate that insertion in many gene loci has an influence on cell engraftment, survival, and proliferation. Beyond the observed cases of insertional mutagenesis in 3 patients, these data help to elucidate the relationship between vector insertion and long-term in vivo selection of transduced cells in human patients with SCID-X1.

256 citations

Journal ArticleDOI
15 Oct 2002-Blood
TL;DR: This study provides direct molecular evidence for a polyclonal, multilineage, and sustained contribution of individual stem cells to primate hematopoiesis and demonstrates the derivation of circulating peripheral blood cells from individual stem cell clones.

238 citations

Journal ArticleDOI
TL;DR: The divergence of RIS target frequency between transduced progenitor cells and post-thymic T lymphocytes indicates that vector integration influences cell survival, engraftment, or proliferation.
Abstract: We treated 10 children with X-linked SCID (SCID-X1) using gammaretrovirus-mediated gene transfer. Those with sufficient follow-up were found to have recovered substantial immunity in the absence of any serious adverse events up to 5 years after treatment. To determine the influence of vector integration on lymphoid reconstitution, we compared retroviral integration sites (RISs) from peripheral blood CD3+ T lymphocytes of 5 patients taken between 9 and 30 months after transplantation with transduced CD34+ progenitor cells derived from 1 further patient and 1 healthy donor. Integration occurred preferentially in gene regions on either side of transcription start sites, was clustered, and correlated with the expression level in CD34+ progenitors during transduction. In contrast to those in CD34+ cells, RISs recovered from engrafted CD3+ T cells were significantly overrepresented within or near genes encoding proteins with kinase or transferase activity or involved in phosphorus metabolism. Although gross patterns of gene expression were unchanged in transduced cells, the divergence of RIS target frequency between transduced progenitor cells and post-thymic T lymphocytes indicates that vector integration influences cell survival, engraftment, or proliferation.

203 citations

Journal ArticleDOI
TL;DR: EpTS/LM-PCR enables studies of retro- and lentiviral integration, viral vector tracking in gene therapy, insertional mutagenesis, transgene integration, and direct genomic sequencing that until now have been difficult or impossible to perform.
Abstract: By identifying the sequence of retro- and lentiviral integration sites in peripheral blood leukocytes, the clonal composition and fate of genetically modified hematopoietic progenitor and stem cells could be mapped in vitro and in vivo. Previously available methods have been limited to the analysis of mono- or oligoclonal integration sites present in high copy numbers. Here, we perform characterization of multiple rare retroviral and lentiviral integration sites in highly complex DNA samples. The reliability of this method results from nontarget DNA removal via magnetic extension primer tag selection (EPTS) preceding solid-phase ligation-mediated PCR. EPTS/LM-PCR allowed the simultaneous direct genomic sequencing of multiple proviral LTR-flanking sequences of retro- and lentiviral vectors even if only 1 per 100 to 1000 cells contained the provirus. A primer walking "around" the integration locus demonstrated the adaptability of EPTS/LM-PCR to study unknown flanking DNA regions unrelated to proviruses. The technique is fast, inexpensive, and sensitive in minimal samples. It enables studies of retro- and lentiviral integration, viral vector tracking in gene therapy, insertional mutagenesis, transgene integration, and direct genomic sequencing that until now have been difficult or impossible to perform.

168 citations


Cited by
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Journal ArticleDOI
17 Oct 2003-Science
TL;DR: Retrovirus vector insertion can trigger deregulated premalignant cell proliferation with unexpected frequency, most likely driven by retrovirus enhancer activity on the LMO2 gene promoter.
Abstract: We have previously shown correction of X-linked severe combined immunodeficiency [SCID-X1, also known as gamma chain (gamma(c)) deficiency] in 9 out of 10 patients by retrovirus-mediated gamma(c) gene transfer into autologous CD34 bone marrow cells. However, almost 3 years after gene therapy, uncontrolled exponential clonal proliferation of mature T cells (with gammadelta+ or alphabeta+ T cell receptors) has occurred in the two youngest patients. Both patients' clones showed retrovirus vector integration in proximity to the LMO2 proto-oncogene promoter, leading to aberrant transcription and expression of LMO2. Thus, retrovirus vector insertion can trigger deregulated premalignant cell proliferation with unexpected frequency, most likely driven by retrovirus enhancer activity on the LMO2 gene promoter.

3,514 citations

Journal ArticleDOI
TL;DR: Advances in nanoparticle design that overcome heterogeneous barriers to delivery are discussed, arguing that intelligent nanoparticles design can improve efficacy in general delivery applications while enabling tailored designs for precision applications, thereby ultimately improving patient outcome overall.
Abstract: In recent years, the development of nanoparticles has expanded into a broad range of clinical applications. Nanoparticles have been developed to overcome the limitations of free therapeutics and navigate biological barriers - systemic, microenvironmental and cellular - that are heterogeneous across patient populations and diseases. Overcoming this patient heterogeneity has also been accomplished through precision therapeutics, in which personalized interventions have enhanced therapeutic efficacy. However, nanoparticle development continues to focus on optimizing delivery platforms with a one-size-fits-all solution. As lipid-based, polymeric and inorganic nanoparticles are engineered in increasingly specified ways, they can begin to be optimized for drug delivery in a more personalized manner, entering the era of precision medicine. In this Review, we discuss advanced nanoparticle designs utilized in both non-personalized and precision applications that could be applied to improve precision therapies. We focus on advances in nanoparticle design that overcome heterogeneous barriers to delivery, arguing that intelligent nanoparticle design can improve efficacy in general delivery applications while enabling tailored designs for precision applications, thereby ultimately improving patient outcome overall.

2,179 citations

Journal ArticleDOI
29 Aug 2008-Science
TL;DR: Induced pluripotent stem cells are generated from an 82-year-old woman diagnosed with a familial form of amyotrophic lateral sclerosis and were successfully directed to differentiate into motor neurons, the cell type destroyed in ALS.
Abstract: The generation of pluripotent stem cells from an individual patient would enable the large-scale production of the cell types affected by that patient's disease. These cells could in turn be used for disease modeling, drug discovery, and eventually autologous cell replacement therapies. Although recent studies have demonstrated the reprogramming of human fibroblasts to a pluripotent state, it remains unclear whether these induced pluripotent stem (iPS) cells can be produced directly from elderly patients with chronic disease. We have generated iPS cells from an 82-year-old woman diagnosed with a familial form of amyotrophic lateral sclerosis (ALS). These patient-specific iPS cells possess properties of embryonic stem cells and were successfully directed to differentiate into motor neurons, the cell type destroyed in ALS.

1,980 citations

Journal ArticleDOI
TL;DR: The sustained correction of X-linked severe combined immunodeficiency disease by ex vivo, retrovirally mediated transfer of the γc gene into CD34+ cells in four of five patients with the disease has been reported.
Abstract: To the Editor: We recently reported (April 18 issue)1 the sustained correction of X-linked severe combined immunodeficiency disease by ex vivo, retrovirally mediated transfer of the γc gene into CD34+ cells in four of five patients with the disease. These results have since been confirmed in four additional patients with typical X-linked severe combined immunodeficiency. Of the first four successfully treated patients, three continue to do well up to 3.6 years after gene therapy, whereas a serious adverse event occurred in the fourth patient. At a routine checkup 30 months after gene therapy, lymphocytosis consisting of a monoclonal population . . .

1,869 citations

Journal ArticleDOI
12 Mar 2004-Science
TL;DR: Mobile elements within genomes have driven genome evolution in diverse ways and are becoming useful tools for learning more about genome evolution and gene function.
Abstract: Mobile elements within genomes have driven genome evolution in diverse ways. Particularly in plants and mammals, retrotransposons have accumulated to constitute a large fraction of the genome and have shaped both genes and the entire genome. Although the host can often control their numbers, massive expansions of retrotransposons have been tolerated during evolution. Now mobile elements are becoming useful tools for learning more about genome evolution and gene function.

1,797 citations