| 1. |
- Adamson, R. E., et al.
(författare)
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In Vitro Primary Cell Culture as a Physiologically Relevant Method for Preclinical Testing of Human Oncolytic Adenovirus
- 2012
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Ingår i: Human Gene Therapy. - : Mary Ann Liebert Inc. - 1043-0342 .- 1557-7422. ; 23:2, s. 218-230
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Tidskriftsartikel (refereegranskat)abstract
- Ad[I/PPT-E1A] is an oncolytic adenovirus that specifically kills prostate cells via restricted replication by a prostate-specific regulatory element. Off-target replication of oncolytic adenoviruses would have serious clinical consequences. As a proposed ex vivo test, we describe the assessment of the specificity of Ad[I/PPT-E1A] viral cytotoxicity and replication in human nonprostate primary cells. Four primary nonprostate cell types were selected to mimic the effects of potential in vivo exposure to Ad[I/PPT-E1A] virus: bronchial epithelial cells, urothelial cells, vascular endothelial cells, and hepatocytes. Primary cells were analyzed for Ad[I/PPT-E1A] viral cytotoxicity in MTS assays, and viral replication was determined by hexon titer immunostaining assays to quantify viral hexon protein. The results revealed that at an extreme multiplicity of infection of 500, unlikely to be achieved in vivo, Ad[I/PPT-E1A] virus showed no significant cytotoxic effects in the nonprostate primary cell types apart from the hepatocytes. Transmission electron microscopy studies revealed high levels of Ad[I/PPT-E1A] sequestered in the cytoplasm of these cells. Adenoviral green fluorescent protein reporter studies showed no evidence for nuclear localization, suggesting that the cytotoxic effects of Ad[I/PPT-E1A] in human primary hepatocytes are related to viral sequestration. Also, hepatocytes had increased amounts of coxsackie adenovirus receptor surface protein. Active viral replication was only observed in the permissive primary prostate cells and LNCaP prostate cell line, and was not evident in any of the other nonprostate cells types tested, confirming the specificity of Ad[I/PPT-E1A]. Thus, using a relevant panel of primary human cells provides a convenient and alternative preclinical assay for examining the specificity of conditionally replicating oncolytic adenoviruses in vivo.
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| 2. |
- Danielsson, Angelika, 1981-, et al.
(författare)
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An ex vivo loop system models the toxicity and efficacy of PEGylated and unmodified adenovirus serotype 5 in whole human blood
- 2010
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Ingår i: Gene Therapy. - : Nature Publishing Group. - 0969-7128 .- 1476-5462. ; 17:6, s. 752-762
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Tidskriftsartikel (refereegranskat)abstract
- Polyethylene glycol coating (PEGylation) of adenovirus serotype 5 (Ad5) has been shown to effectively reduce immunogenicity and increase circulation time of intravenously administered virus in mouse models. Herein, we monitored clot formation, complement activation, cytokine release and blood cell association upon addition of uncoated or PEGylated Ad5 to human whole blood. We used a novel blood loop model where human blood from healthy donors was mixed with virus and incubated in heparin-coated PVC tubing while rotating at 37°C for up to 8 hours. Production of the complement components C3a and C5a and the cytokines IL-8, RANTES and MCP-1 was significantly lower with 20K-PEGylated Ad5 than with uncoated Ad5. PEGylation prevented clotting and reduced Ad5 binding to blood cells in blood with low ability to neutralize Ad5. The effect was particularly pronounced in monocytes, granulocytes, B-cells and T-cells, but could also be observed in erythrocytes and platelets. In conclusion, PEGylation of Ad5 can reduce the immune response mounted in human blood, although the protective effects are rather modest in contrast to published mouse data. Our findings underline the importance of developing reliable models and we propose the use of human whole blood models in pre-clinical screening of gene therapy vectors.
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| 3. |
- Danielsson, Angelika, 1981-, et al.
(författare)
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The HDAC Inhibitor FK228 Enhances Adenoviral Transgene Expression by a Transduction-Independent Mechanism but Does Not Increase Adenovirus Replication
- 2011
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:2, s. e14700-
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Tidskriftsartikel (refereegranskat)abstract
- The histone deacetylase inhibitor FK228 has previously been shown to enhance adenoviral transgene expression when cells are pre-incubated with the drug. Upregulation of the coxsackie adenovirus receptor (CAR) has been proposed as the main mechanism. In the present study, we found that the highest increase in transgene expression was achieved when non-toxic concentrations of FK228 were added immediately after transduction demonstrating that the main effect by which FK228 enhances transgene expression is transduction independent. FK228 had positive effects both on Ad5 and Ad5/f35 vectors with a variety of transgenes and promoters, indicating that FK228 works mainly by increasing transgene expression at the transcriptional level. In some cases, the effects were dramatic, as demonstrated by an increase in CD40L expression by FK228 from 0.3% to 62% when the murine prostate cancer cell line TRAMP-C2, was transduced with Ad[CD40L]. One unexpected finding was that the transgene expression of an adenoviral vector with the prostate-specific PPT promoter decreased in the human prostate cancer cell line LNCaP when FK228 was administered. This is probably a consequence of phenotypic alteration of LNCaP towards a neuroendocrine phenotype after FK228 treatment. The observations in this study indicate that FK228 enhances adenoviral therapy by a transduction-independent mechanism. Furthermore, since histone deacetylase inhibitors may alter the phenotype of cells, it is important to keep in mind that the activity and specificity of tissue- and tumor-specific promoters may also be affected.
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| 4. |
- Essand, Magnus, et al.
(författare)
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Genetically engineered T cells for the treatment of cancer
- 2013
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 273:2, s. 166-181
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Forskningsöversikt (refereegranskat)abstract
- T cell immunotherapy is a promising approach to treat disseminated cancer. However, it has been limited by the ability to isolate and expand T cells restricted to tumour-associated antigens. Using ex vivo gene transfer, T cells from patients can be genetically engineered to express a novel T cell receptor or chimeric antigen receptor to specifically recognize a tumour-associated antigen and thereby selectively kill tumour cells. Indeed, genetically engineered T cells have recently been successfully used for cancer treatment in a small number of patients. Here we review the recent progress in the field, and summarize the challenges that lie ahead and the strategies being used to overcome them.
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| 5. |
- Essand, Magnus, et al.
(författare)
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Oncolytic Viruses for the Treatment of Neuroendocrine Tumors
- 2011
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Ingår i: Hormone and Metabolic Research. - : Georg Thieme Verlag KG. - 0018-5043 .- 1439-4286. ; 43:12, s. 877-883
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Forskningsöversikt (refereegranskat)abstract
- Oncolytic viruses are emerging as anticancer agents, and they have also shown great promise for use against neuroendocrine tumors. Many viruses have a natural tropism for replication in tumor cells. Others can be genetically engineered to selectively kill tumor cells. Viruses have some advantages as therapeutic agents over current cytotoxic drugs and small molecules. They replicate in tumor cells and thereby increase in number over time leading to increased dosage. They are immunogenic and can alter the immunosuppressive tumor microenvironment and activate immune effector cells. They have also been shown to be able to kill drug-resistant cancer stem cells. This article reviews the recent literature on oncolytic viruses used so far for neuroendocrine tumors and indicates important issues to focus on in the future.
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| 6. |
- Essand, Magnus
(författare)
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Virotherapy of Neuroendocrine Tumors
- 2013
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Ingår i: Neuroendocrinology. - : S. Karger AG. - 0028-3835 .- 1423-0194. ; 97:1, s. 26-34
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Tidskriftsartikel (refereegranskat)abstract
- Most patients with small intestinal neuroendocrine tumors (SI-NETs), also referred to as midgut carcinoids, present with systemic disease at the time of diagnosis with metastases primarily found in regional lymph nodes and the liver. Curative treatment is not available for these patients and there is a need for novel and specific therapies. Engineered oncolytic viruses may meet the need and play an important role in the future management of SI-NET liver metastases. This review focuses on adenovirus as the oncolytic anti-cancer agent and its potential curative role for SI-NET liver metastases, but it also summarizes the use of oncolytic viruses for NETs in general. It discusses how specific features of neuroendocrine cell biology can be used to engineer viruses to become selective for infection of NET cells and/or replication within NET cells. In addition, it points out the advantages and shortcomings of using replicating viruses in the treatment of cancer and addresses research fields that can increase the efficacy of virus-based therapy.
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| 7. |
- Forsberg, Lars A., et al.
(författare)
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Age-related somatic structural changes in the nuclear genome of human blood cells
- 2012
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Ingår i: American Journal of Human Genetics. - : Elsevier BV. - 0002-9297 .- 1537-6605. ; 90:2, s. 217-228
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Tidskriftsartikel (refereegranskat)abstract
- Structural variations are among the most frequent interindividual genetic differences in the human genome. The frequency and distribution of de novo somatic structural variants in normal cells is, however, poorly explored. Using age-stratified cohorts of 318 monozygotic (MZ) twins and 296 single-born subjects, we describe age-related accumulation of copy-number variation in the nuclear genomes in vivo and frequency changes for both megabase- and kilobase-range variants. Megabase-range aberrations were found in 3.4% (9 of 264) of subjects ≥60 years old; these subjects included 78 MZ twin pairs and 108 single-born individuals. No such findings were observed in 81 MZ pairs or 180 single-born subjects who were ≤55 years old. Recurrent region- and gene-specific mutations, mostly deletions, were observed. Longitudinal analyses of 43 subjects whose data were collected 7-19 years apart suggest considerable variation in the rate of accumulation of clones carrying structural changes. Furthermore, the longitudinal analysis of individuals with structural aberrations suggests that there is a natural self-removal of aberrant cell clones from peripheral blood. In three healthy subjects, we detected somatic aberrations characteristic of patients with myelodysplastic syndrome. The recurrent rearrangements uncovered here are candidates for common age-related defects in human blood cells. We anticipate that extension of these results will allow determination of the genetic age of different somatic-cell lineages and estimation of possible individual differences between genetic and chronological age. Our work might also help to explain the cause of an age-related reduction in the number of cell clones in the blood; such a reduction is one of the hallmarks of immunosenescence.
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| 8. |
- Fransson, Moa, et al.
(författare)
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CAR/FoxP3-engineered T regulatory cells target the CNS and suppress EAE upon intranasal delivery
- 2012
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Ingår i: Journal of Neuroinflammation. - : Springer Science and Business Media LLC. - 1742-2094. ; 9, s. 112-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS). In the murine experimental autoimmune encephalomyelitis (EAE) model of MS, T regulatory (Treg) cell therapy has proved to be beneficial, but generation of stable CNS-targeting Tregs needs further development. Here, we propose gene engineering to achieve CNS-targeting Tregs from naive CD4 cells and demonstrate their efficacy in the EAE model.METHODSCD4+T cells were modified utilizing a lentiviral vector system to express a chimeric antigen receptor (CAR) targeting myelin oligodendrocyte glycoprotein (MOG) in trans with the murine FoxP3 gene that drives Treg differentiation. The cells were evaluated in vitro for suppressive capacity and in C57BL/6 mice to treat EAE. Cells were administered by intranasal (i.n.) cell delivery.RESULTSThe engineered Tregs demonstrated suppressive capacity in vitro and could efficiently access various regions in the brain via i.n cell delivery. Clinical score 3 EAE mice were treated and the engineered Tregs suppressed ongoing encephalomyelitis as demonstrated by reduced disease symptoms as well as decreased IL-12 and IFNgamma mRNAs in brain tissue. Immunohistochemical markers for myelination (MBP) and reactive astrogliosis (GFAP) confirmed recovery in mice treated with engineered Tregs compared to controls. Symptomfree mice were echallenged with a second EAE-inducing inoculum but remained healthy, demonstrating the sustained effect of engineered Tregs.CONCLUSIONCNS-targeting Tregs delivered i.n. localized to the CNS and efficiently suppressed ongoing inflammation leading to diminished disease symptoms.
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| 9. |
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| 10. |
- Hillerdal, Victoria, et al.
(författare)
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Systemic treatment with CAR-engineered T cells against PSCA delays subcutaneous tumor growth and prolongs survival of mice
- 2014
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 14, s. 30-
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Tidskriftsartikel (refereegranskat)abstract
- Background:Adoptive transfer of T cells genetically engineered with a chimeric antigen receptor (CAR) has successfully been used to treat both chronic and acute lymphocytic leukemia as well as other hematological cancers. Experimental therapy with CAR-engineered T cells has also shown promising results on solid tumors. The prostate stem cell antigen (PSCA) is a protein expressed on the surface of prostate epithelial cells as well as in primary and metastatic prostate cancer cells and therefore a promising target for immunotherapy of prostate cancer. Methods:We developed a third-generation CAR against PSCA including the CD28, OX-40 and CD3 zeta signaling domains. T cells were transduced with a lentivirus encoding the PSCA-CAR and evaluated for cytokine production (paired Student's t-test), proliferation (paired Student's t-test), CD107a expression (paired Student's t-test) and target cell killing in vitro and tumor growth and survival in vivo (Log-rank test comparing Kaplan-Meier survival curves).Results:PSCA-CAR T cells exhibit specific interferon (IFN)-gamma and interleukin (IL)-2 secretion and specific proliferation in response to PSCA-expressing target cells. Furthermore, the PSCA-CAR-engineered T cells efficiently kill PSCA-expressing tumor cells in vitro and systemic treatment with PSCA-CAR-engineered T cells significantly delays subcutaneous tumor growth and prolongs survival of mice.Conclusions:Our data confirms that PSCA-CAR T cells may be developed for treatment of prostate cancer.
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