| 1. |
- Mold, Jeff E., et al.
(författare)
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Divergent clonal differentiation trajectories establish CD8(+) memory T cell heterogeneity during acute viral infections in humans
- 2021
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Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 35:8
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Tidskriftsartikel (refereegranskat)abstract
- The CD8(+) T cell response to an antigen is composed of many T cell clones with unique T cell receptors, together forming a heterogeneous repertoire of effector and memory cells. How individual T cell clones contribute to this heterogeneity throughout immune responses remains largely unknown. In this study, we longitudinally track human CD8(+) T cell clones expanding in response to yellow fever virus (YFV) vaccination at the single-cell level. We observed a drop in clonal diversity in blood from the acute to memory phase, suggesting that clonal selection shapes the circulating memory repertoire. Clones in the memory phase display biased differentiation trajectories along a gradient from stem cell to terminally differentiated effector memory fates. In secondary responses, YFV- and influenza-specific CD8(+) T cell clones are poised to recapitulate skewed differentiation trajectories. Collectively, we show that the sum of distinct clonal phenotypes results in the multifaceted human T cell response to acute viral infections.
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| 2. |
- Alekseenko, Alisa, et al.
(författare)
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Direct detection of SARS-CoV-2 using non-commercial RT-LAMP reagents on heat-inactivated samples
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- RT-LAMP detection of SARS-CoV-2 has been shown to be a valuable approach to scale up COVID-19 diagnostics and thus contribute to limiting the spread of the disease. Here we present the optimization of highly cost-effective in-house produced enzymes, and we benchmark their performance against commercial alternatives. We explore the compatibility between multiple DNA polymerases with high strand-displacement activity and thermostable reverse transcriptases required for RT-LAMP. We optimize reaction conditions and demonstrate their applicability using both synthetic RNA and clinical patient samples. Finally, we validate the optimized RT-LAMP assay for the detection of SARS-CoV-2 in unextracted heat-inactivated nasopharyngeal samples from 184 patients. We anticipate that optimized and affordable reagents for RT-LAMP will facilitate the expansion of SARS-CoV-2 testing globally, especially in sites and settings where the need for large scale testing cannot be met by commercial alternatives.
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| 3. |
- de Sousa, Nuno Rufino, et al.
(författare)
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Detection and isolation of airborne SARS-CoV-2 in a hospital setting
- 2022
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Ingår i: Indoor Air. - : John Wiley & Sons. - 0905-6947 .- 1600-0668. ; 32:3
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Tidskriftsartikel (refereegranskat)abstract
- Transmission mechanisms for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are incompletely understood. In particular, aerosol transmission remains unclear, with viral detection in air and demonstration of its infection potential being actively investigated. To this end, we employed a novel electrostatic collector to sample air from rooms occupied by COVID-19 patients in a major Swedish hospital. Electrostatic air sampling in conjunction with extraction-free, reverse-transcriptase polymerase chain reaction (hid-RT-PCR) enabled detection of SARS-CoV-2 in air from patient rooms (9/22; 41%) and adjoining anterooms (10/22; 45%). Detection with hid-RT-PCR was concomitant with viral RNA presence on the surface of exhaust ventilation channels in patients and anterooms more than 2 m from the COVID-19 patient. Importantly, it was possible to detect active SARS-CoV-2 particles from room air, with a total of 496 plaque-forming units (PFUs) being isolated, establishing the presence of infectious, airborne SARS-CoV-2 in rooms occupied by COVID-19 patients. Our results support circulation of SARS-CoV-2 via aerosols and urge the revision of existing infection control frameworks to include airborne transmission.
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| 4. |
- Lagerström, Malin C., et al.
(författare)
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VGLUT2-Dependent Sensory Neurons in the TRPV1 Population Regulate Pain and Itch
- 2010
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Ingår i: Neuron. - : Elsevier BV. - 0896-6273 .- 1097-4199. ; 68:3, s. 529-542
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Tidskriftsartikel (refereegranskat)abstract
- The natural response to itch sensation is to scratch, which relieves the itch through an unknown mechanism. Interaction between pain and itch has been frequently demonstrated, and the selectivity hypothesis of itch, based on data from electrophysiological and behavioral experiments, postulates the existence of primary pain afferents capable of repressing itch. Here, we demonstrate that deletion of vesicular glutamate transporter (VGLUT) 2 in a subpopulation of neurons partly overlapping with the vanilloid receptor (TRPV1) primary afferents resulted in a dramatic increase in itch behavior accompanied by a reduced responsiveness to thermal pain. The increased itch behavior was reduced by administration of antihistaminergic drugs and by genetic deletion of the gastrin-releasing peptide receptor, demonstrating a dependence on VGLUT2 to maintain normal levels of both histaminergic and nonhistaminergic itch. This study establishes that VGLUT2 is a major player in TRPV1 thermal nociception and also serves to regulate a normal itch response.
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| 5. |
- Larsson, Anton J M, et al.
(författare)
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X-chromosome upregulation is driven by increased burst frequency
- 2019
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Ingår i: Nature Structural & Molecular Biology. - Stockholm : Karolinska Institutet, Dept of Medical Biochemistry and Biophysics. - 1545-9993 .- 1545-9985.
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Tidskriftsartikel (refereegranskat)abstract
- Ohno's hypothesis postulates that X-chromosome upregulation rectifies X-dose imbalance relative to autosomal genes, present in two active copies per cell. Here we dissected X-upregulation into kinetics of transcription, inferred from allele-specific single-cell RNA-sequencing (scRNAseq) data from somatic mouse cells. We confirmed increased X-chromosome expression in female and male somatic cells, and remarkably found that the X-chromosome achieved upregulation by elevated burst frequencies. By monitoring differentiating female embryonic stem cells, we found that elevated burst frequency established on the active X-chromosome as X-inactivation occurred on the other allele. This provides mechanistic insights into X-chromosome upregulation.
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| 6. |
- Mondal, Tanmoy, 1981, et al.
(författare)
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MEG3 long noncoding RNA regulates the TGF-β pathway genes through formation of RNA–DNA triplex structures
- 2015
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Long noncoding RNAs (lncRNAs) regulate gene expression by association with chromatin, but how they target chromatin remains poorly understood. We have used chromatin RNA immunoprecipitation-coupled high-throughput sequencing to identify 276 lncRNAs enriched in repressive chromatin from breast cancer cells. Using one of the chromatin-interacting lncRNAs, MEG3, we explore the mechanisms by which lncRNAs target chromatin. Here we show that MEG3 and EZH2 share common target genes, including the TGF-β pathway genes. Genome-wide mapping of MEG3 binding sites reveals that MEG3 modulates the activity of TGF-β genes by binding to distal regulatory elements. MEG3 binding sites have GA-rich sequences, which guide MEG3 to the chromatin through RNA–DNA triplex formation. We have found that RNA–DNA triplex structures are widespread and are present over the MEG3 binding sites associated with the TGF-β pathway genes. Our findings suggest that RNA–DNA triplex formation could be a general characteristic of target gene recognition by the chromatin-interacting lncRNAs.
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| 7. |
- Radomska, Katarzyna J., et al.
(författare)
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RNA-binding protein QKI regulates Glial fibrillary acidic protein expression in human astrocytes
- 2013
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 22:7, s. 1373-1382
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Tidskriftsartikel (refereegranskat)abstract
- Linkage, association and expression studies previously pointed to the human QKI, KH domain containing, RNA-binding (QKI) as a candidate gene for schizophrenia. Functional studies of the mouse orthologue Qk focused mainly on its role in oligodendrocyte development and myelination, while its function in astroglia remained unexplored. Here, we show that QKI is highly expressed in human primary astrocytes and that its splice forms encode proteins targeting different subcellular localizations. Uncovering the role of QKI in astrocytes is of interest in light of growing evidence implicating astrocyte dysfunction in the pathogenesis of several disorders of the central nervous system. We selectively silenced QKI splice variants in human primary astrocytes and used RNA sequencing to identify differential expression and splice variant composition at the genome-wide level. We found that an mRNA expression of Glial fibrillary acidic protein (GFAP), encoding a major component of astrocyte intermediate filaments, was down-regulated after QKI7 splice variant silencing. Moreover, we identified a potential QKI-binding site within the 3 untranslated region of human GFAP. This sequence was not conserved between mice and humans, raising the possibility that GFAP is a target for QKI in humans but not rodents. Haloperidol treatment of primary astrocytes resulted in coordinated increases in QKI7 and GFAP expression. Taken together, our results provide the first link between QKI and GFAP, two genes with alterations previously observed independently in schizophrenic patients. Our findings for QKI, together with its well-known role in myelination, suggest that QKI is a hub regulator of glia function in humans.
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| 8. |
- Reinius, Björn, et al.
(författare)
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A new mouse line based on the Gpr101 promoter drives expression of Cre in medium spiny neurons of the striatum.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- A novel transgenic mouse that expresses the Cre recombinase in striatal medium spiny neurons was generated. To create the line, we have used the promoter of the X-linked gene Gpr101 and a Bacterial Artificial Chromosome recombineering strategy. When the Gpr101-Cre mouse was bred to the tdTomato Ai14 [1] reporter line, we observed strong fluorescence in medium-size spiny neurons (MSNs) of the striatum. In addition, Gpr101-Cre was detected in hippocampal pyramidal neurons and sparse cerebellar purkinje cells. Interestingly, Gpr101-Cre expression in this mouse line differs from the endogenous Gpr101 gene expression, which is highest in amygdala and hypothalamus and not detected in striatum in adult mice, as shown by in situ hybridization. The tdTomato Ai14 reporter marks any cell lineages in which Gpr101-Cre has, at any time, been expressed. Our results show that the Gpr101-Cre gene construct had lost the original ability of the Gpr101 promotor to drive expression of the Gpr101 gene in the amygdala and the hypothalamus. Second, the Gpr101-Cre gene construct either acquired a novel capability to express in striatum, or more probably, Gpr101 is expressed transiently in striatum during development. In addition, a small subpopulation of astrocytes (GFAP positive cells) was labelled in several regions of the central nervous system, allowing for specific follow-up studies of these cells. We envision that the newly created Cre-line will contribute to numerous studies, particularly related to the development and differentiation of cellular networks in the brain.
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| 9. |
- Reinius, Björn, et al.
(författare)
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Abundance of female-biased and paucity of male-biased somatically expressed genes on the mouse X-chromosome.
- 2012
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Ingår i: BMC genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: Background: Empirical evaluations of sexually dimorphic expression of genes on the mammalian X-chromosome are needed to understand the evolutionary forces and the gene-regulatory mechanisms controlling this chromosome. We performed a large-scale sex-bias expression analysis of genes on the X-chromosome in six different somatic tissues from mouse. Results: Our results show that the mouse X-chromosome is enriched with female-biased genes and depleted of male-biased genes. This suggests that feminisation as well as de-masculinisation of the X-chromosome has occurred in terms of gene expression in non-reproductive tissues. Several mechanisms may be responsible for the control of female-biased expression on chromosome X, and escape from X-inactivation is a main candidate. We confirmed escape in case of Tmem29 using RNA-FISH analysis. In addition, we identified novel female-biased non-coding transcripts located in the same female-biased cluster as the well-known coding X-inactivation escapee Kdm5c, likely transcribed from the transition-region between active and silenced domains. We also found that previously known escapees only partially explained the overrepresentation of female-biased X-genes, particularly for tissue-specific female-biased genes. Therefore, the gene set we have identified contains tissue-specific escapees and/or genes controlled by other sexually skewed regulatory mechanisms. Analysis of gene age showed that evolutionarily old X-genes (>100 myr, preceding the radiation of placental mammals) are more frequently female-biased than younger genes. Conclusion: Altogether, our results have implications for understanding both gene regulation and gene evolution of mammalian X-chromosomes, and suggest that the final result in terms of the X-gene composition (masculinisation versus feminisation) is a compromise between different evolutionary forces acting on reproductive and somatic tissues.
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| 10. |
- Reinius, Björn, et al.
(författare)
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An evolutionarily conserved sexual signature in the primate brain
- 2008
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Ingår i: PLoS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 4:e1000100
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Tidskriftsartikel (refereegranskat)abstract
- The question of a potential biological sexual signature in the human brain is a heavily disputed subject. In order to provide further insight into this issue, we used an evolutionary approach to identify genes with sex differences in brain expression level among primates. We reasoned that expression patterns important to uphold key male and female characteristics may be conserved during evolution. We selected cortex for our studies because this specific brain region is responsible for many higher behavioral functions. We compared gene expression profiles in the occipital cortex of male and female humans (Homo sapiens, a great ape) and cynomolgus macaques (Macaca fascicularis, an old world monkey), two catarrhine species that show abundant morphological sexual dimorphism, as well as in common marmosets ( Callithrix Jacchus, a new world monkey) which are relatively sexually monomorphic. We identified hundreds of genes with sex-biased expression patterns in humans and macaques, while fewer than ten were differentially expressed between the sexes in marmosets. In primates, a general rule is that many of the morphological and behavioral sexual dimorphisms seen in polygamous species, such as macaques, are typically less pronounced in monogamous species such as the marmosets. Our observations suggest that this correlation may also be reflected in the extent of sex-biased gene expression in the brain. We identified 85 genes with common sex-biased expression, in both human and macaque and 2 genes, X inactivation-specific transcript (XIST) and Heat shock factor binding protein 1 ( HSBP1), that were consistently sex-biased in the female direction in human, macaque, and marmoset. These observations imply a conserved signature of sexual gene expression dimorphism in cortex of primates. Further, we found that the coding region of female-biased genes is more evolutionarily constrained compared to the coding region of both male-biased and non sex-biased brain expressed genes. We found genes with conserved sexual gene expression dimorphism in the occipital cortex of humans, cynomolgus macaques, and common marmosets. Genes within sexual expression profiles may underlie important functional differences between the sexes, with possible importance during primate evolution.
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