84 research outputs found

    Stem cell-derived porcine macrophages as a new platform for studying host-pathogen interactions

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    BACKGROUND: Infectious diseases of farmed and wild animals pose a recurrent threat to food security and human health. The macrophage, a key component of the innate immune system, is the first line of defence against many infectious agents and plays a major role in shaping the adaptive immune response. However, this phagocyte is a target and host for many pathogens. Understanding the molecular basis of interactions between macrophages and pathogens is therefore crucial for the development of effective strategies to combat important infectious diseases. RESULTS: We explored how porcine pluripotent stem cells (PSCs) can provide a limitless in vitro supply of genetically and experimentally tractable macrophages. Porcine PSC-derived macrophages (PSCdMs) exhibited molecular and functional characteristics of ex vivo primary macrophages and were productively infected by pig pathogens, including porcine reproductive and respiratory syndrome virus (PRRSV) and African swine fever virus (ASFV), two of the most economically important and devastating viruses in pig farming. Moreover, porcine PSCdMs were readily amenable to genetic modification by CRISPR/Cas9 gene editing applied either in parental stem cells or directly in the macrophages by lentiviral vector transduction. CONCLUSIONS: We show that porcine PSCdMs exhibit key macrophage characteristics, including infection by a range of commercially relevant pig pathogens. In addition, genetic engineering of PSCs and PSCdMs affords new opportunities for functional analysis of macrophage biology in an important livestock species. PSCs and differentiated derivatives should therefore represent a useful and ethical experimental platform to investigate the genetic and molecular basis of host-pathogen interactions in pigs, and also have wider applications in livestock. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12915-021-01217-8

    Comparative epigenetic analysis of tumour initiating cells and syngeneic EPSC-derived neural stem cells in glioblastoma

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    Epigenetic mechanisms which play an essential role in normal developmental processes, such as self-renewal and fate specification of neural stem cells (NSC) are also responsible for some of the changes in the glioblastoma (GBM) genome. Here we develop a strategy to compare the epigenetic and transcriptional make-up of primary GBM cells (GIC) with patient-matched expanded potential stem cell (EPSC)-derived NSC (iNSC). Using a comparative analysis of the transcriptome of syngeneic GIC/iNSC pairs, we identify a glycosaminoglycan (GAG)-mediated mechanism of recruitment of regulatory T cells (Tregs) in GBM. Integrated analysis of the transcriptome and DNA methylome of GBM cells identifies druggable target genes and patient-specific prediction of drug response in primary GIC cultures, which is validated in 3D and in vivo models. Taken together, we provide a proof of principle that this experimental pipeline has the potential to identify patient-specific disease mechanisms and druggable targets in GBM. The identification of patient-specific disease mechanisms and druggable targets is crucial for precision medicine in glioblastoma. Here, the authors show that comparing patients-matched glioma-initiating cells with neural stem cells enables the discovery of patient-specific mechanisms of disease and the identification of effective drug

    BCL11A interacts with SOX2 to control the expression of epigenetic regulators in lung squamous carcinoma.

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    Patients diagnosed with lung squamous cell carcinoma (LUSC) have limited targeted therapies. We report here the identification and characterisation of BCL11A, as a LUSC oncogene. Analysis of cancer genomics datasets revealed BCL11A to be upregulated in LUSC but not in lung adenocarcinoma (LUAD). Experimentally we demonstrate that non-physiological levels of BCL11A in vitro and in vivo promote squamous-like phenotypes, while its knockdown abolishes xenograft tumour formation. At the molecular level we found that BCL11A is transcriptionally regulated by SOX2 and is required for its oncogenic functions. Furthermore, we show that BCL11A and SOX2 regulate the expression of several transcription factors, including SETD8. We demonstrate that shRNA-mediated or pharmacological inhibition of SETD8 selectively inhibits LUSC growth. Collectively, our study indicates that BCL11A is integral to LUSC pathology and highlights the disruption of the BCL11A-SOX2 transcriptional programme as a novel candidate for drug development.Cancer Research UK (CRUK) - C47525/A1734

    BCL11B mutations in patients affected by a neurodevelopmental disorder with reduced type 2 innate lymphoid cells

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    The transcription factor BCL11B is essential for development of the nervous and the immune system, and Bcl11b deficiency results in structural brain defects, reduced learning capacity, and impaired immune cell development in mice. However, the precise role of BCL11B in humans is largely unexplored, except for a single patient with a BCL11B missense mutation, affected by multisystem anomalies and profound immune deficiency. Using massively parallel sequencing we identified 13 patients bearing heterozygous germline alterations in BCL11B. Notably, all of them are affected by global developmental delay with speech impairment and intellectual disability; however, none displayed overt clinical signs of immune deficiency. Six frameshift mutations, two nonsense mutations, one missense mutation, and two chromosomal rearrangements resulting in diminished BCL11B expression, arose de novo. A further frameshift mutation was transmitted from a similarly affected mother. Interestingly, the most severely affected patient harbours a missense mutation within a zinc-finger domain of BCL11B, probably affecting the DNA-binding structural interface, similar to the recently published patient. Furthermore, the most C-terminally located premature termination codon mutation fails to rescue the progenitor cell proliferation defect in hippocampal slice cultures from Bcl11b-deficient mice. Concerning the role of BCL11B in the immune system, extensive immune phenotyping of our patients revealed alterations in the T cell compartment and lack of peripheral type 2 innate lymphoid cells (ILC2s), consistent with the findings described in Bcl11b-deficient mice. Unsupervised analysis of 102 T lymphocyte subpopulations showed that the patients clearly cluster apart from healthy children, further supporting the common aetiology of the disorder. Taken together, we show here that mutations leading either to BCL11B haploinsufficiency or to a truncated BCL11B protein clinically cause a non-syndromic neurodevelopmental delay. In addition, we suggest that missense mutations affecting specific sites within zinc-finger domains might result in distinct and more severe clinical outcomes

    Quantitative evaluation of the immunodeficiency of a mouse strain by tumor engraftments

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    © 2015 Ye et al. Background: The mouse is an organism that is widely used as a mammalian model for studying human physiology or disease, and the development of immunodeficient mice has provided a valuable tool for basic and applied human disease research. Following the development of large-scale mouse knockout programs and genome-editing tools, it has become increasingly efficient to generate genetically modified mouse strains with immunodeficiency. However, due to the lack of a standardized system for evaluating the immuno-capacity that prevents tumor progression in mice, an objective choice of the appropriate immunodeficient mouse strains to be used for tumor engrafting experiments is difficult. Methods: In this study, we developed a tumor engraftment index (TEI) to quantify the immunodeficiency response to hematologic malignant cells and solid tumor cells of six immunodeficient mouse strains and C57BL/6 wild-type mouse (WT). Results: Mice with a more severely impaired immune system attained a higher TEI score. We then validated that the NOD-scid-IL2Rg-/- (NSI) mice, which had the highest TEI score, were more suitable for xenograft and allograft experiments using multiple functional assays. Conclusions: The TEI score was effectively able to reflect the immunodeficiency of a mouse strain.Link_to_subscribed_fulltex

    Internet-gestützte Nachsorge für Frauen mit schwerwiegender und chronischer Bulimia nervosa (IN@)

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    The imprinted region on chromosome 14q32 harbors several maternally or paternally expressed genes as well as two DMRs (differentially methylated regions), the IG-DMR and the MEG3-DMR, which both act as imprinting control centers. Genetic aberrations affecting the imprinted gene cluster in 14q32 result in distinct phenotypes, known as maternal or paternal uniparental disomy 14 phenotypes (upd(14)mat, upd(14)pat). In both syndromes, three types of molecular alterations have been reported: uniparental disomy 14, deletions and epimutations. In contrast to uniparental disomy and epimutations, deletions affecting regulatory elements in 14q32 are associated with a high-recurrence risk. Based on two single deletion cases a functional hierarchy of the IG-DMR as a regulator for the methylation of the MEG3-DMR has been proposed. We have identified two novel deletions of maternal origin spanning the MEG3-DMR, but not the IG-DMR in patients with upd(14)pat syndrome, one de novo deletion of 165 kb and another deletion of 5.8 kb in two siblings. The 5.8 kb deletion was inherited from the phenotypically normal mother, who carries the deletion in a mosaic state on her paternal chromosome 14. The methylation at both DMRs was investigated by quantitative next generation bisulfite sequencing and revealed normal methylation patterns at the IG-DMR in all patients with the exception of certain CpG dinucleotides. Thus, we could confirm that deletions of the MEG3-DMR does not generally influence the methylation pattern of the IG-DMR, which strengthens the hypothesis of a hierarchical structure and distinct functional properties of the two DMRs

    Polygenic in vivo validation of cancer mutations using transposons

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    The in vivo validation of cancer mutations and genes identified in cancer genomics is resource-intensive because of the low throughput of animal experiments. We describe a mouse model that allows multiple cancer mutations to be validated in each animal line. Animal lines are generated with multiple candidate cancer mutations using transposons. The candidate cancer genes are tagged and randomly expressed in somatic cells, allowing easy identification of the cancer genes involved in the generated tumours. This system presents a useful, generalised and efficient means for animal validation of cancer genes.Link_to_subscribed_fulltex

    Bcl11a controls Flt3 expression in early hematopoietic progenitors and is required for pDC development in vivo.

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    Bcl11a is a transcription factor known to regulate lymphoid and erythroid development. Recent bioinformatic analysis of global gene expression patterns has suggested a role for Bcl11a in the development of dendritic cell (DC) lineages. We tested this hypothesis by analyzing the development of DC and other lineages in Bcl11a (-/-) mice. We found that Bcl11a was required for expression of IL-7 receptor (IL-7R) and Flt3 in early hematopoietic progenitor cells. In addition, we found severely decreased numbers of plasmacytoid dendritic cells (pDCs) in Bcl11a (-/-) fetal livers and in the bone marrow of Bcl11a (-/-) fetal liver chimeras. Moreover, Bcl11a (-/-) cells showed severely impaired in vitro development of Flt3L-derived pDCs and classical DCs (cDCs). In contrast, we found normal in vitro development of DCs from Bcl11a (-/-) fetal liver cells treated with GM-CSF. These results suggest that the persistent cDC development observed in Bcl11a (-/-) fetal liver chimeras reflects derivation from a Bcl11a- and Flt3-independent pathway in vivo

    Mutant nucleophosmin and cooperating pathways drive leukemia initiation and progression in mice.

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    Acute myeloid leukemia (AML) is a molecularly diverse malignancy with a poor prognosis whose largest subgroup is characterized by somatic mutations in NPM1, which encodes nucleophosmin. These mutations, termed NPM1c, result in cytoplasmic dislocation of nucleophosmin and are associated with distinctive transcriptional signatures, yet their role in leukemogenesis remains obscure. Here we report that activation of a humanized Npm1c knock-in allele in mouse hemopoietic stem cells causes Hox gene overexpression, enhanced self renewal and expanded myelopoiesis. One third of mice developed delayed-onset AML, suggesting a requirement for cooperating mutations. We identified such mutations using a Sleeping Beauty transposon, which caused rapid-onset AML in 80% of mice with Npm1c, associated with mutually exclusive integrations in Csf2, Flt3 or Rasgrp1 in 55 of 70 leukemias. We also identified recurrent integrations in known and newly discovered leukemia genes including Nf1, Bach2, Dleu2 and Nup98. Our results provide new pathogenetic insights and identify possible therapeutic targets in NPM1c+ AML

    LIF-independent JAK signalling to chromatin in embryonic stem cells uncovered from an adult stem cell disease

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    Activating mutations in the tyrosine kinase Janus kinase 2 (JAK2) cause myeloproliferative neoplasms, clonal blood stem cell disorders with a propensity for leukaemic transformation. Leukaemia inhibitory factor (LIF) signalling through the JAK-signal transducer and activator of transcription (STAT) pathway enables self-renewal of embryonic stem (ES) cells. Here we show that mouse ES cells carrying the human JAK2V617F mutation were able to self-renew in chemically defined conditions without cytokines or small-molecule inhibitors, independently of JAK signalling through the STAT3 or phosphatidylinositol-3-OH kinase pathways. Phosphorylation of histone H3 tyrosine 41 (H3Y41) by JAK2 was recently shown to interfere with binding of heterochromatin protein 1α (HP1α). Levels of chromatin-bound HP1α were lower in JAK2V617F ES cells but increased following inhibition of JAK2, coincident with a global reduction in histone H3Y41 phosphorylation. JAK2 inhibition reduced levels of the pluripotency regulator Nanog, with a reduction in H3Y41 phosphorylation and concomitant increase in HP1à ± levels at the Nanog promoter. Furthermore, Nanog was required for factor independence of JAK2V617F ES cells. Taken together, these results uncover a previously unrecognized role for direct signalling to chromatin by JAK2 as an important mediator of ES cell self-renewal. © 2011 Macmillan Publishers Limited. All rights reserved.Link_to_subscribed_fulltex
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