| 1. |
- Bestas, Burcu, et al.
(författare)
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Splice-correcting oligonucleotides restore BTK function in X-linked agammaglobulinemia model
- 2014
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Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 124:9, s. 4067-4081
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Tidskriftsartikel (refereegranskat)abstract
- X-linked agammaglobulinemia (XLA) is an inherited immunodeficiency that results from mutations within the gene encoding Bruton's tyrosine kinase (BTK). Many XLA-associated mutations affect splicing of BTK pre-mRNA and severely impair B cell development. Here, we assessed the potential of antisense, splice-correcting oligonucleotides (SCOs) targeting mutated BTKtranscripts for treating XLA. Both the SCO structural design and chemical properties were optimized using 2'-O-methyl, locked nucleic acid, or phosphorodiamidate morpholino backbones. In order to have access to an animal model of XLA, we engineered a transgenic mouse that harbors a BAC with an authentic, mutated, splice-defective human BTK gene. BTK transgenic mice were bred onto a Btk knockout background to avoid interference of the orthologous mouse protein. Using this model, we determined that BTK-specific SCOs are able to correct aberrantly spliced BTK in B lymphocytes, including pro-B cells. Correction of BTK mRNA restored expression of functional protein, as shown both by enhanced lymphocyte survival and reestablished BTK activation upon B cell receptor stimulation. Furthermore, SCO treatment corrected splicing and restored BTK expression in primary cells from patients with XLA. Together, our data demonstrate that SCOs can restore BTK function and that BTK-targeting SCOs have potential as personalized medicine in patients with XLA.
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| 2. |
- Gupta, Dhanu, et al.
(författare)
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Amelioration of systemic inflammation via the display of two different decoy protein receptors on extracellular vesicles
- 2021
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Ingår i: Nature Biomedical Engineering. - Stockholm : Karolinska Institutet, Dept of Laboratory Medicine. - 2157-846X.
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Tidskriftsartikel (refereegranskat)abstract
- Extracellular vesicles (EVs) can be functionalized to display specific protein receptors on their surface. However, surface-display technology typically labels only a small fraction of the EV population. Here, we show that the joint display of two different therapeutically relevant protein receptors on EVs can be optimized by systematically screening EV-loading protein moieties. We used cytokine-binding domains derived from tumour necrosis factor receptor 1 (TNFR1) and interleukin-6 signal transducer (IL-6ST), which can act as decoy receptors for the pro-inflammatory cytokines tumour necrosis factor alpha (TNF-α) and IL-6, respectively. We found that the genetic engineering of EV-producing cells to express oligomerized exosomal sorting domains and the N-terminal fragment of syntenin (a cytosolic adaptor of the single transmembrane domain protein syndecan) increased the display efficiency and inhibitory activity of TNFR1 and IL-6ST and facilitated their joint display on EVs. In mouse models of systemic inflammation, neuroinflammation and intestinal inflammation, EVs displaying the cytokine decoys ameliorated the disease phenotypes with higher efficacy as compared with clinically approved biopharmaceutical agents targeting the TNF-α and IL-6 pathways.
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| 3. |
- Muthukrishnan, Uma, 1984-, et al.
(författare)
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The exosome membrane localization of histones is independent of DNA and upregulated in response to stress
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Extracellular histones contribute to many acute and chronic diseases but also populate the secretomes of healthy cells and biofluids. However, a secretory pathway for histones has not been described. Here we report that core and linker histones localize to multivesicular bodies and are secreted via exosomes. Histones are tightly associated with the exosome membrane, with N-terminal domains exposed, in a DNA-independent manner. Furthermore, rapid upregulation of exosomal histones occurs following heat stress, accompanied by enhanced vesicle secretion and a shift towards a population of smaller vesicles. Proteomic analyses identified the downregulation of endosomal sorting complex required for transport (ESCRT) complex as a possible mechanism underlying increased histone secretion.We show for the first time that membrane-associated histones are actively secreted from intact cells via the multivesicular body/exosomal pathway. We demonstrate a novel pathway for extracellular histone release that may have a role in both health and disease.
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| 4. |
- Nordin, Joel Z
(författare)
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Purification and biodistribution of extracellular vesicles
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Extracellular vesicles (EVs) are nano-sized vesicles that contain bioactive lipids, RNAs and proteins, which can be transferred to recipient cells. EVs are important for physiological as well as pathological processes, such as coagulation and immune homeostasis, aiding cancer metastasis and spread of infectious diseases. Owing to their relatively small size the purification of EVs is a challenge, hence we have established and optimised workflows consisting of ultrafiltration with subsequent size exclusion liquid chromatography (UFLC)( Paper I) and bind-elute combined with size exclusion (BE-SEC) columns (Paper III) for EV purification. UF-LC allowed for purification of biophysically intact EVs with better yield and purity compared to ultracentrifugation (UC), which is the gold standard purification method in the field. The biodistribution of UF-LC EVs was different compared to vesicles isolated using UC, despite having highly similar protein composition according to proteomics analysis. We found that UF-LC vesicles accumulated less in lung, possibly owing to their higher integrity. Indeed, fluorescence correlation spectroscopy and transmission electron microscopy indicated that the high gravitational forces in UC lead to aggregation and disruption of the vesicles. The BE-SEC method is a similar method to UF-LC, however protein impurities less than 700 kDa in size are bound in the interior of the beads, thus improving simple size-based exclusion. The BE-SEC method is scalable, produces samples with better purity than UC, displaying yields exceeding 70% and demonstrates a good reproducibility between samples. Moreover, vesicles purified by BE-SEC display the same EV surface markers as UC purified EVs, and CD63-eGFP positive vesicles are taken up in recipient cells to the same extent. In summary, the BE-SEC method is a reproducible and fast alternative to UF-LC for large media volumes. Reliable purification methods are important for the implementation of therapeutically active EVs, however knowledge regarding their eventual organotropism and biodistribution is equally important. Thus, in article II we evaluated the biodistribution of EVs specifically labeled with a near-infrared dye. The main sites of accumulation of exogenously injected EVs were liver, spleen and lungs. Biodistribution profile of EVs depended strongly on injection route, and to certain extent, on EV cell type source, as dendritic cell derived EVs exhibited a more pronounced uptake in spleen compared to the other cell sources tested. We further showed that small alterations of EV surface proteins could significantly affect biodistribution as well, since EVs equipped with a brain targeting peptide on their surface increased the uptake of targeted EVs in brain. This study highlights that the biodistribution of EVs follows other nano-sized particles with uptake mainly in liver. Administration route, cell source and a targeting peptide influence the distribution, however the overall distribution is unaltered with the highest signal originating from liver. To summarise, this thesis has resulted in improvements of the EV field by systematically enhancing EV isolation workflows to achieve greater sample purity and at the same time preserving EV biophysical characteristics. Furthermore, it has laid groundwork for studying in vivo effects of exogenous vesicles. Both these aspects are particularly important for understanding EV biology more clearly and with increased detail.
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| 5. |
- Nordin, Joel Z., et al.
(författare)
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Ultrafiltration with size-exclusion liquid chromatography for high yield isolation of extracellular vesicles preserving intact biophysical and functional properties
- 2015
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Ingår i: Nanomedicine. - : Elsevier BV. - 1549-9634 .- 1549-9642. ; 11:4, s. 879-883
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Tidskriftsartikel (refereegranskat)abstract
- Extracellular vesicles (EVs) are natural nanoparticles that mediate intercellular transfer of RNA and proteins and are of great medical interest; serving as novel biomarkers and potential therapeutic agents. However, there is little consensus on the most appropriate method to isolate high-yield and high-purity EVs from various biological fluids. Here, we describe a systematic comparison between two protocols for EV purification: ultrafiltration with subsequent liquid chromatography (UF-LC) and differential ultracentrifugation (UC). A significantly higher EV yield resulted from UF-LC as compared to UC, without affecting vesicle protein composition. Importantly, we provide novel evidence that, in contrast to UC-purified EVs, the biophysical properties of UF-LC-purified EVs are preserved, leading toadifferent in vivo biodistribution, with less accumulation in lungs. Finally, we show that UF-LC is scalable and adaptable for EV isolation from complex media types such as stem cell media, which is of huge significance for future clinical applications involving EVs.
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| 6. |
- Simonson, Oscar E., et al.
(författare)
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In Vivo Effects of Mesenchymal Stromal Cells in Two Patients With Severe Acute Respiratory Distress Syndrome
- 2015
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Ingår i: Stem Cells Translational Medicine. - : Oxford University Press (OUP). - 2157-6564 .- 2157-6580. ; 4:10, s. 1199-1213
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Tidskriftsartikel (refereegranskat)abstract
- Mesenchymal stromal cells (MSCs) have been investigated as a treatment for various inflammatory diseases because of their immunomodulatory and reparative properties. However, many basic questions concerning their mechanisms of action after systemic infusion remain unanswered. We performed a detailed analysis of the immunomodulatory properties and proteomic profile of MSCs systemically administered to two patients with severe refractory acute respiratory distress syndrome (ARDS) on a compassionate use basis and attempted to correlate these with in vivo anti-inflammatory actions. Both patients received 2 x 10(6) cells per kilogram, and each subsequently improved with resolution of respiratory, hemodynamic, and multiorgan failure. In parallel, a decrease was seen in multiple pulmonary and systemic markers of inflammation, including epithelial apoptosis, alveolar-capillary fluid leakage, and proinflammatory cytokines, microRNAs, and chemokines. In vitro studies of the MSCs demonstrated a broad anti-inflammatory capacity, including suppression of T-cell responses and induction of regulatory phenotypes in T cells, monocytes, and neutrophils. Some of these in vitro potency assessments correlated with, and were relevant to, the observed in vivo actions. These experiences highlight both the mechanistic information that can be gained from clinical experience and the value of correlating in vitro potency assessments with clinical effects. The findings also suggest, but do not prove, a beneficial effect of lung protective strategies using adoptively transferred MSCs in ARDS. Appropriate randomized clinical trials are required to further assess any potential clinical efficacy and investigate the effects on in vivo inflammation. STEM CELLS TRANSLATIONAL MEDICINE 2015;4:1199-1213
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| 7. |
- Sork, Helena, et al.
(författare)
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Heterogeneity and interplay of the extracellular vesicle small RNA transcriptome and proteome
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Extracellular vesicles (EVs) mediate cell-to-cell communication by delivering or displaying macromolecules to their recipient cells. While certain broad-spectrum EV effects reflect their protein cargo composition, others have been attributed to individual EV-loaded molecules such as specific miRNAs. In this work, we have investigated the contents of vesicular cargo using small RNA sequencing of cells and EVs from HEK293T, RD4, C2C12, Neuro2a and C17.2. The majority of RNA content in EVs (49-96%) corresponded to rRNA-, coding-and tRNA fragments, corroborating with our proteomic analysis of HEK293T and C2C12 EVs which showed an enrichment of ribosome and translation-related proteins. On the other hand, the overall proportion of vesicular small RNA was relatively low and variable (2-39%) and mostly comprised of miRNAs and sequences mapping to piRNA loci. Importantly, this is one of the few studies, which systematically links vesicular RNA and protein cargo of vesicles. Our data is particularly useful for future work in unravelling the biological mechanisms underlying vesicular RNA and protein sorting and serves as an important guide in developing EVs as carriers for RNA therapeutics.
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| 8. |
- Sork, Helena, et al.
(författare)
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Lipid-based Transfection Reagents Exhibit Cryo-induced Increase in Transfection Efficiency
- 2016
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Ingår i: Molecular Therapy Nucleic Acids. - : Elsevier BV. - 2162-2531. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- The advantages of lipid-based transfection reagents have permitted their widespread use in molecular biology and gene therapy. This study outlines the effect of cryo-manipulation of a cationic lipid-based formulation, Lipofectamine 2000, which, after being frozen and thawed, showed orders of magnitude higher plasmid delivery efficiency throughout eight different cell lines, without compromising cell viability. Increased transfection efficiency with the freeze-thawed reagent was also seen with 2'-O-methyl phosphorothioate oligonucleotide delivery and in a splice-correction assay. Most importantly, a log-scale improvement in gene delivery using the freeze-thawed reagent was seen in vivo. Using three different methods, we detected considerable differences in the polydispersity of the different nucleic acid complexes as well as observed a clear difference in their surface spreading and sedimentation, with the freeze-thawed ones displaying substantially higher rate of dispersion and deposition on the glass surface. This hitherto overlooked elevated potency of the freeze-thawed reagent facilitates the targeting of hard-to-transfect cells, accomplishes higher transfection rates, and decreases the overall amount of reagent needed for delivery. Additionally, as we also saw a slight increase in plasmid delivery using other freeze-thawed transfection reagents, we postulate that freeze-thawing might prove to be useful for an even wider variety of transfection reagents.
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