| 1. |
- Li, Hongzhe, et al.
(författare)
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Identification of phenotypically, functionally, and anatomically distinct stromal niche populations in human bone marrow based on single-cell RNA sequencing
- 2023
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Ingår i: eLife. - : eLife Sciences Publications, Ltd. - 2050-084X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Hematopoiesis is regulated by the bone marrow (BM) stroma. However, cellular identities and functions of the different BM stromal elements in humans remain poorly defined. Based on single-cell RNA sequencing (scRNAseq), we systematically characterized the human non-hematopoietic BM stromal compartment and we investigated stromal cell regulation principles based on the RNA velocity analysis using scVelo and studied the interactions between the human BM stromal cells and hematopoietic cells based on ligand-receptor (LR) expression using CellPhoneDB. scRNAseq led to the identification of six transcriptionally and functionally distinct stromal cell populations. Stromal cell differentiation hierarchy was recapitulated based on RNA velocity analysis and in vitro proliferation capacities and differentiation potentials. Potential key factors that might govern the transition from stem and progenitor cells to fate-committed cells were identified. In situ localization analysis demonstrated that different stromal cells were localized in different niches in the bone marrow. In silico cell-cell communication analysis further predicted that different stromal cell types might regulate hematopoiesis through distinct mechanisms. These findings provide the basis for a comprehensive understanding of the cellular complexity of the human BM microenvironment and the intricate stroma-hematopoiesis crosstalk mechanisms, thus refining our current view on human hematopoietic niche organization.
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| 2. |
- Rosa, Fábio F, et al.
(författare)
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Single-cell transcriptional profiling informs efficient reprogramming of human somatic cells to cross-presenting dendritic cells
- 2022
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Ingår i: Science Immunology. - : American Association for the Advancement of Science (AAAS). - 2470-9468. ; 7:69, s. 1-18
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 conventional dendritic cells (cDC1s) are rare immune cells critical for the induction of antigen-specific cytotoxic CD8+ T cells, although the genetic program driving human cDC1 specification remains largely unexplored. We previously identified PU.1, IRF8, and BATF3 transcription factors as sufficient to induce cDC1 fate in mouse fibroblasts, but reprogramming of human somatic cells was limited by low efficiency. Here, we investigated single-cell transcriptional dynamics during human cDC1 reprogramming. Human induced cDC1s (hiDC1s) generated from embryonic fibroblasts gradually acquired a global cDC1 transcriptional profile and expressed antigen presentation signatures, whereas other DC subsets were not induced at the single-cell level during the reprogramming process. We extracted gene modules associated with successful reprogramming and identified inflammatory signaling and the cDC1-inducing transcription factor network as key drivers of the process. Combining IFN-γ, IFN-β, and TNF-α with constitutive expression of cDC1-inducing transcription factors led to improvement of reprogramming efficiency by 190-fold. hiDC1s engulfed dead cells, secreted inflammatory cytokines, and performed antigen cross-presentation, key cDC1 functions. This approach allowed efficient hiDC1 generation from adult fibroblasts and mesenchymal stromal cells. Mechanistically, PU.1 showed dominant and independent chromatin targeting at early phases of reprogramming, recruiting IRF8 and BATF3 to shared binding sites. The cooperative binding at open enhancers and promoters led to silencing of fibroblast genes and activation of a cDC1 program. These findings provide mechanistic insights into human cDC1 specification and reprogramming and represent a platform for generating patient-tailored cDC1s, a long-sought DC subset for vaccination strategies in cancer immunotherapy.
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| 3. |
- Ahlstrand, Erik, 1974-, et al.
(författare)
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Highly Reduced Survival in Essential Thrombocythemia and Polycythemia Vera Patients with Vascular Complications during Follow-up
- 2020
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Ingår i: European Journal of Haematology. - : Munksgaard Forlag. - 0902-4441 .- 1600-0609. ; 104:3, s. 271-278
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To explore the relative importance of risk factors, treatments and blood counts for the occurrence of vascular complications and their impact on life expectancy in Essential Thrombocythemia (ET) and Polycythemia Vera (PV).METHODS: Nested case-control study within the Swedish MPN registry. From a cohort of 922 ET patients and 763 PV patients, 71 ET and 81 PV cases with vascular complications were compared to matched controls.RESULTS: Incidence of vascular complications were 2.0 and 3.4 events per 100 patient-years in ET and PV, respectively. At diagnosis, no significant risk factor differences were observed between cases and controls in neither of the diseases. At the time of vascular event, ET complication cases did not differ significantly from controls but in PV, cases had significantly higher WBCs and were to a lesser extent treated with antithrombotic and cytoreductive therapy. Life expectancy was significantly decreased in both ET and PV cases compared to controls.CONCLUSIONS: The risk of vascular complications is high in both ET and PV and these complications have a considerable impact on life expectancy. The protective effect of antithrombotic and cytoreductive therapy for vascular complications in PV underscores the importance of avoiding undertreatment.
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| 4. |
- Ahrens, Norbert, et al.
(författare)
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Mesenchymal stem cell content of human vertebral bone marrow
- 2004
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Ingår i: Transplantation. - 1534-6080. ; 78:6, s. 925-929
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Tidskriftsartikel (refereegranskat)abstract
- Mesenchymal stem cells (MSCs) are capable of down-regulating alloimmune responses and promoting the engraftment of hematopoietic stem cells. MSCs may therefore be suitable for improving donor-specific tolerance induction in solid-organ transplantation. Cells from cadaveric vertebral bone marrow (V-BM), aspirated iliac crest-BM, and peripheral blood progenitor cells were compared. Cells were characterized by flow cytometry and colony assays. MSCs generated from V-BM were assayed for differentiation capacity and immunomodulatory function. A median 5.7 x 10(8) nucleated cells (NCs) were recovered per vertebral body. The mesenchymal progenitor, colony-forming unit-fibroblast, frequency in V-BM (11.6/10(5) NC, range: 6.0-20.0) was considerably higher than in iliac crest-BM (1.4/10(5) NC, range: 0.4-2.6) and peripheral blood progenitor cells (not detectable). MSC generated from V-BM had the typical MSC phenotype (CD105(pos)CD73(pos)CD45(neg)CD34(neg)), displayed multilineage differentiation potential, and suppressed alloreactivity in mixed lymphocyte reactions. V-BM may be an excellent source for MSC cotransplantation approaches.
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| 5. |
- Bexell, Daniel, et al.
(författare)
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Bone Marrow Multipotent Mesenchymal Stroma Cells Act as Pericyte-like Migratory Vehicles in Experimental Gliomas.
- 2009
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Ingår i: Molecular Therapy. - : Elsevier BV. - 1525-0024 .- 1525-0016. ; 2008:Nov 4., s. 183-190
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Tidskriftsartikel (refereegranskat)abstract
- Bone marrow-derived multipotent mesenchymal stroma cells (MSCs) have emerged as cellular vectors for gene therapy of solid cancers. We implanted enhanced green fluorescent protein-expressing rat MSCs directly into rat malignant gliomas to address their migratory capacity, phenotype, and effects on tumor neovascularization and animal survival. A single intratumoral injection of MSCs infiltrated the majority of invasive glioma extensions (72 +/- 14%) and a substantial fraction of distant tumor microsatellites (32 +/- 6%). MSC migration was highly specific for tumor tissue. Grafted MSCs integrated into tumor vessel walls and expressed pericyte markers alpha-smooth muscle actin, neuron-glia 2, and platelet-derived growth factor receptor-beta but not endothelial cell markers. The pericyte marker expression profile and perivascular location of grafted MSCs indicate that these cells act as pericytes within tumors. MSC grafting did not influence tumor microvessel density or survival of tumor-bearing animals. The antiangiogenic drug Sunitinib markedly reduced the numbers of grafted MSCs migrating within tumors. We found no MSCs within gliomas following intravenous (i.v.) injections. Thus, MSCs should be administered by intratumoral implantations rather than by i.v. injections. Intratumorally grafted pericyte-like MSCs might represent a particularly well-suited vector system for delivering molecules to affect tumor angiogenesis and for targeting cancer stem cells within the perivascular niche.Molecular Therapy (2008); doi:10.1038/mt.2008.229.
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| 6. |
- Bexell, Daniel, et al.
(författare)
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Rat Multipotent Mesenchymal Stromal Cells Lack Long-Distance Tropism to 3 Different Rat Glioma Models
- 2012
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Ingår i: Neurosurgery. - 0148-396X. ; 70:3, s. 731-739
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Viral gene therapy of malignant brain tumors has been restricted by the limited vector distribution within the tumors. Multipotent mesenchymal stromal cells (MSCs) and other precursor cells have shown tropism for gliomas, and these cells are currently being explored as potential vehicles for gene delivery in glioma gene therapy. OBJECTIVE: To investigate MSC migration in detail after intratumoral and extratumoral implantation through syngeneic and orthotopic glioma models. METHODS: Adult rat bone marrow-derived MSCs were transduced to express enhanced green fluorescent protein and implanted either directly into or at a distance from rat gliomas. RESULTS: We found no evidence of long-distance MSC migration through the intact striatum toward syngeneic D74(RG2), N32, and N29 gliomas in the ipsilateral hemisphere or across the corpus callosum to gliomas located in the contralateral hemisphere. After intratumoral injection, MSCs migrated extensively, specifically within N32 gliomas. The MSCs did not proliferate within tumors, suggesting a low risk of malignant transformation of in vivo grafted cell vectors. Using a model for surgical glioma resection, we found that intratumorally grafted MSCs migrate efficiently within glioma remnants after partial surgical resection. CONCLUSION: The findings point to limitations for the use of MSCs as vectors in glioma gene therapy, although intratumoral MSC implantation provides a dense and tumor-specific vector distribution.
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| 7. |
- Bexell, Daniel, et al.
(författare)
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Toward Brain Tumor Gene Therapy Using Multipotent Mesenchymal Stromal Cell Vectors.
- 2010
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Ingår i: Molecular Therapy. - : Elsevier BV. - 1525-0024 .- 1525-0016. ; May 4, s. 1067-1075
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Tidskriftsartikel (refereegranskat)abstract
- Gene therapy of solid cancers has been severely restricted by the limited distribution of vectors within tumors. However, cellular vectors have emerged as an effective migratory system for gene delivery to invasive cancers. Implanted and injected multipotent mesenchymal stromal cells (MSCs) have shown tropism for several types of primary tumors and metastases. This capacity of MSCs forms the basis for their use as a gene vector system in neoplasms. Here, we review the tumor-directed migratory potential of MSCs, mechanisms of the migration, and the choice of therapeutic transgenes, with a focus on malignant gliomas as a model system for invasive and highly vascularized tumors. We examine recent findings demonstrating that MSCs share many characteristics with pericytes and that implanted MSCs localize primarily to perivascular niches within tumors, which might have therapeutic implications. The use of MSC vectors in cancer gene therapy raises concerns, however, including a possible MSC contribution to tumor stroma and vasculature, MSC-mediated antitumor immune suppression, and the potential malignant transformation of cultured MSCs. Nonetheless, we highlight the novel prospects of MSC-based tumor therapy, which appears to be a promising approach.
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| 8. |
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| 9. |
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| 10. |
- Brune, Jan Claas, et al.
(författare)
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Mesenchymal stromal cells from primary osteosarcoma are non-malignant and strikingly similar to their bone marrow counterparts.
- 2011
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 129, s. 319-330
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Tidskriftsartikel (refereegranskat)abstract
- Mesenchymal stromal cells (MSC) are multipotent cells that can be isolated from a number of human tissues. In cancer, MSC have been implicated with tumor growth, invasion, metastasis, drug resistance and were even suggested as possible tumor-initiating cells in osteosarcoma (OS). However, MSC from OS and their possible tumor origin have not yet been thoroughly investigated. Therefore, primary OS mesenchymal progenitors and OS-derived MSC were studied. OS samples contained very high frequencies of mesenchymal progenitor cells as measured by the CFU-F assay (median: 1,117 colonies per 10(5) cells, range: 133 - 3,000, n=6). This is considerably higher compared to other human tissues such as normal bone marrow (1.3 ± 0.2 colonies per 10(5) cells, n=8). OS-derived MSC (OS-MSC) showed normal MSC morphology and expressed the typical MSC surface marker profile (CD105/CD73/CD90/CD44/HLA-classI/CD166 positive, CD45/CD34/CD14/CD19/HLA-DR/CD31 negative). Furthermore, all OS-MSC samples could be differentiated into the osteogenic lineage, and all but one sample into adipocytes and chondrocytes. Genetic analysis of OS-MSC as well as OS-derived spheres showed no tumor-related chromosomal aberrations. OS-MSC expression of markers related to tumor-associated fibroblasts (fibroblast surface protein, alpha-smooth muscle actin, vimentin) was comparable to bone marrow MSC and OS-MSC growth was considerably affected by tyrosine kinase inhibitors. Taken together, our results demonstrate that normal, non-malignant mesenchymal stroma cells are isolated from OS when MSC culture techniques are applied. OS-MSC represent a major constituent of the tumor microenvironment, and they share many properties with bone marrow-derived MSC. © 2010 UICC.
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