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- Anagandula, Mahesh
(author)
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Studies of Enterovirus Infection and Induction of Innate Immunity in Human Pancreatic Cells
- 2016
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Doctoral thesis (other academic/artistic)abstract
- Several epidemiological and clinical studies have indicated a possible role of Enterovirus (EV) infection in type 1 diabetes (T1D) development. However, the exact casual mechanism of these viruses in T1D development is not known. The aim of this thesis is to study various EVs that have been shown to differ in their immune phenotype, lytic ability, association with induction of islet autoantibodies, ability to replicate, cause islet disintegration and induce innate antiviral pathways in infected pancreatic cells in vitro. Furthermore, EV presence and pathogenic process in pancreatic tissue and isolated islets of T1D patients was also studied.Studies in this thesis for first time show the detection of EV RNA and protein in recent onset live T1D patients supporting the EV hypothesis in T1D development. Further all EV serotypes studied were able to replicate in islets, causing variable amount of islet disintegration ranging from extensive islet disintegration to not affecting islet morphology at all. However, one of the EV serotype replicated in only two out of seven donors infected, highlighting the importance of individual variation between donors. Further, this serotype impaired the insulin response to glucose stimulation without causing any visible islet disintegration, suggesting that this serotype might impaired the insulin response by inducing a functional block. Infection of human islets with the EV serotypes that are differentially associated with the development of islet autoantibodies showed the islet cell disintegration that is comparable with their degree of islet autoantibody seroconversion. Suggesting that the extent of the epidemic-associated islet autoantibody induction may depend on the ability of the viral serotypes to damage islet cells. Furthermore, one of the EV strains showed unique ability to infect and replicate both in endo and exocrine cells of the pancreas. EV replication in both endo and exocrine cells affected the genes involved in innate and antiviral pathways and induction of certain genes with important antiviral activity significantly varied between different donors. Suggesting that the same EV infection could result in different outcome in different individuals. Finally, we compared the results obtained by lytic and non lytic EV strains in vitro with the findings reported in fulminant and slowly progressing autoimmune T1D and found some similarities. In conclusion the results presented in this thesis further support the role of EV in T1D development and provide more insights regarding viral and host variation. This will improve our understanding of the possible causative mechanism by EV in T1D development.
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- Čančer, Matko, et al.
(author)
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Humanized Stem Cell Models of Pediatric Medulloblastoma Reveal an Oct4/mTOR Axis that Promotes Malignancy
- 2019
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In: Cell Stem Cell. - : CELL PRESS. - 1934-5909 .- 1875-9777. ; 25:6, s. 855-870
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Journal article (peer-reviewed)abstract
- Medulloblastoma (MB), the most frequent malignant childhood brain tumor, can arise from cellular malfunctions during hindbrain development. Here we generate humanized models for Sonic Hedgehog (SHH)-subgroup MB via MYCN overexpression in primary human hindbrain-derived neuroepithelial stem (hbNES) cells or iPSC-derived NES cells, which display a range of aggressive phenotypes upon xenografting. iPSC-derived NES tumors develop quickly with leptomeningeal dissemination, whereas hbNES-derived cells exhibit delayed tumor formation with less dissemination. Methylation and expression profiling show that tumors from both origins recapitulate hallmarks of infant SHH MB and reveal that mTOR activation, as a result of increased Oct4, promotes aggressiveness of human SHH tumors. Targeting mTOR decreases cell viability and prolongs survival, showing the utility of these varied models for dissecting mechanisms mediating tumor aggression and demonstrating the value of humanized models for a better understanding of pediatric cancers.
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- Enblad, Gunilla, et al.
(author)
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A Phase I/IIa Trial Using CD19-Targeted Third-Generation CAR T Cells for Lymphoma and Leukemia
- 2018
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In: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 24:24, s. 6185-6194
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Journal article (peer-reviewed)abstract
- Purpose: The chimeric antigen receptor (CAR) T-cell therapy has been effective for patients with CD19(+) B-cell malignancies. Most studies have investigated the second-generation CARs with either CD28 or 4-1BB costimulatory domains in the CAR receptor. Here, we describe the first clinical phase I/IIa trial using third-generation CAR T cells targeting CD19 to evaluate safety and efficacy.Patients and Methods: Fifteen patients with B-cell lymphoma or leukemia were treated with CAR T cells. The patients with lymphoma received chemotherapy during CAR manufacture and 11 of 15 were given low-dose cyclophosphamide and fludarabine conditioning prior to CAR infusion. Peripheral blood was sampled before and at multiple time points after CAR infusion to evaluate the persistence of CAR T cells and for immune profiling, using quantitative PCR, flow cytometry, and a proteomic array.Results: Treatment with third-generation CAR T cells was generally safe with 4 patients requiring hospitalization due to adverse reactions. Six of the 15 patients had initial complete responses [4/11 lymphoma and 2/4 acute lymphoblastic leukemia (ALL)], and 3 of the patients with lymphoma were in remission at 3 months. Two patients are still alive. Best predictor of response was a good immune status prior to CAR infusion with high IL12, DC-Lamp, Fas ligand, and TRAIL. Responding patients had low monocytic myeloid-derived suppressor cells (MDSCs; CD14(+)CD33(+)HLA(-)DR(-)) and low levels of IL6, IL8, NAP3, sPDL1, and sPDL2.Conclusions: Third-generation CARs may be efficient in patients with advanced B-cell lymphoproliferative malignancy with only modest toxicity. Immune profiling pre- and posttreatment can be used to find response biomarkers.
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- Fotaki, Grammatiki, 1988-
(author)
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Allogeneic dendritic cells as adjuvants in cancer immunotherapy
- 2019
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Doctoral thesis (other academic/artistic)abstract
- In recent years, immunotherapeutic approaches have achieved remarkable successes through checkpoint blockade antibodies, advances in the use of chimeric antigen receptor (CAR) T cells and new insights into the immunosuppressive role of the tumor microenvironment (TME). Through the advances, the role of cancer vaccines based on ex vivo manipulated autologous dendritic cells (DC) has been challenged. The main aim of DC-based vaccination is the induction of tumor-specific T-cell responses through presentation of tumor-associated antigens. However, this process has been found to be highly dependent on the ability of the injected vaccine-DCs to activate endogenous bystander DCs.In this work, we examined the feasibility of having an allogeneic source of vaccine-DCs (alloDCs), not for direct antigen-presentation to T cells but as an immune primer aiming to activate bystander DCs. In paper I, we treated alloDCs with a T helper cell type 1 (Th1)-promoting maturation cocktail alone or combined with a replication-deficient, infection-enhanced adenoviral vector (Ad5M) as a potential gene delivery vehicle. We found that mature pro-inflammatory alloDCs, either non-transduced or transduced, created a cytokine- and chemokine-enriched milieu in vitro, and promoted the activation of co-cultured immune cells, including cytolytic NK cells, from unrelated donors. The emerged milieu induced the maturation of bystander DCs, which cross-presented antigens from their environment to autologous antigen-specific T cells. In paper II, we found that alloDCs promoted the migration of murine immune cells both to the site of injection and to the draining lymph node. When Ad5M was used for the delivery of the melanoma-associated antigen gp100, we found that gp100-expressing alloDCs were able to control tumor growth through gp100-specific T-cell responses and alteration of the TME. In paper III, we found that co-administration of alloDCs with an adenoviral vector encoding for HPV-antigens is effective in controlling the growth of HPV-related tumors and this may depend on a cross-talk between alloDCs and NK cells which leads to further recruitment of immune cells into the TME. In paper IV, we observed that concomitant targeting of immune checkpoint receptors or co-stimulatory molecules results in synergistic therapeutic effects in a murine colorectal model.
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- Fotaki, Grammatiki, et al.
(author)
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Cancer vaccine based on a combination of an infection-enhanced adenoviral vector and pro-inflammatory allogeneic DCs leads to sustained antigen-specific immune responses in three melanoma models
- 2018
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In: Oncoimmunology. - 2162-4011 .- 2162-402X. ; 7:3
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Journal article (peer-reviewed)abstract
- Autologous patient-derived dendritic cells (DCs) modified ex vivo to present tumor-associated antigens (TAAs) are frequently used as cancer vaccines. However, apart from the stringent logistics in producing DCs on a patient basis, accumulating evidence indicate that ex vivo engineered DCs are poor in migration and in fact do not directly present TAA epitopes to naïve T cells in vivo. Instead, it is proposed that bystander host DCs take up material from vaccine-DCs, migrate and subsequently initiate antitumor T-cell responses. We used mouse models to examine the possibility of using pro-inflammatory allogeneic DCs (alloDCs) to activate host DCs and enable them to promote antigen-specific T-cell immunity. We found that alloDCs were able to initiate host DC activation and migration to draining lymph node leading to T-cell activation. The pro-inflammatory milieu created by alloDCs also led to recruitment of NK cells and neutrophils at the site of injection. Vaccination with alloDCs combined with Ad5M(gp100), an infection-enhanced adenovirus encoding the human melanoma-associated antigen gp100 resulted in generation of CD8+ T cells with a T-cell receptor (TCR) specific for the gp10025-33 epitope (gp100-TCR+). Ad5M(gp100)-alloDC vaccination in combination with transfer of gp100-specific pmel-1 T cells resulted in prolonged survival of B16-F10 melanoma-bearing mice and altered the composition of the tumor microenvironment (TME). We hereby propose that alloDCs together with TAA- or neoepitope-encoding Ad5M can become an “off-the-shelf” cancer vaccine, which can reverse the TME-induced immunosuppression and induce host cellular anti-tumor immune responses in patients without the need of a time-consuming preparation step of autologous DCs.
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