Dokument: The global transcription factor reservoir in TLR9 activated pDCs and the role of BATF for development and function of pDCs
| Titel: | The global transcription factor reservoir in TLR9 activated pDCs and the role of BATF for development and function of pDCs | |||||||
| URL für Lesezeichen: | https://docserv.uni-duesseldorf.de/servlets/DocumentServlet?id=57949 | |||||||
| URN (NBN): | urn:nbn:de:hbz:061-20221130-101226-0 | |||||||
| Kollektion: | Dissertationen | |||||||
| Sprache: | Englisch | |||||||
| Dokumententyp: | Wissenschaftliche Abschlussarbeiten » Dissertation | |||||||
| Medientyp: | Text | |||||||
| Autor: | Mann-Nüttel, Ritu [Autor] | |||||||
| Dateien: |
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| Beitragende: | Dr. Scheu, Stefanie [Gutachter] Prof. Dr. Feldbrügge, Michael [Gutachter] | |||||||
| Dewey Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik » 570 Biowissenschaften; Biologie | |||||||
| Beschreibung: | This doctoral thesis is composed of two parts, one dealing with the transcription factor (TF) reservoir and chromatin landscape in activated plasmacytoid dendritic cells (pDCs), and the second one with the role of the TF BATF in pDC development and cell effector function. TFs control gene expression by direct binding to regulatory regions of target genes but also by impacting chromatin landscapes and thereby modulating DNA accessibility for other TFs. To date, the global TF reservoir in pDCs, a cell type with the unique capacity to produce unmatched amounts of type I interferons, has not been fully characterized. To fill this gap, we have performed a comprehensive analysis in naïve and TLR9-activated pDCs in a time course study covering early time points after stimulation (2h, 6h, 12h) integrating gene expression (RNA-Seq), chromatin landscape (ATAC-Seq) and Gene Ontology studies. We found that 70% of all described TFs are expressed in pDCs for at least one stimulation time point and that activation predominantly “turned on” the chromatin regions associated with TF genes. We hereby define the complete set of TLR9-regulated TFs in pDCs. Further, this study identifies the AP-1 family of TFs as potentially important but so far less well characterized regulators of pDC function.
In the second part of this doctoral thesis, we have evaluated the role of the TF BATF (basic leucine zipper ATF-like transcription factor) on pDC development and cell effector function. We found that BATF is highly expressed in type I IFN-producing pDCs (Bauer et al., 2016). Type I interferons are essential initiators of subsequent protective innate and adaptive immune responses to viruses, bacteria and other pathogens. Furthermore, these cytokines can play an ambivalent role in auto-immune diseases, which are often characterized by an excessive production of type I IFN in the body. While the necessity of BATF expression in lymphocytes such as T helper and T regulatory cell differentiation and B cell class switching has been well described, no biological role of BATF in pDCs has been shown so far. In analyzing Batf-/- vs WT mice we found increased type I IFN levels and numbers and frequencies of pDCs in Flt3-L treated in vitro bone marrow cultures in Batf deficiency. To unravel the underlying mechanism, we characterized the role of BATF (1) in regulating global gene expression using next generation sequencing, and (2) in modulating the chromatin landscape using ATAC-Seq in sorted Batf-/- and WT pDCs, and (3) regarding its genome wide direct DNA binding in pDCs using BATF ChIP-Seq. We found that BATF regulates type I IFN expression in pDCs indirectly via regulating the expression of the TF Zfp366, also known as DC-SCRIPT. Strikingly, BATF reduced pDC mediated LCMV infection control in an in vitro plaque assay. RNA-Seq and ChIP-Seq comparison revealed that expression of pDC lineage specific TFs such as E2-2 and Irf8 is significantly increased in naïve Batf-/- vs WT pDCs, and that BATF binds to promoter and enhancer regions of these genes, respectively. This suggests that BATF regulates pDC differentiation by controlling expression levels of pDC-lineage driving TFs. This impact of BATF on pDC development was found to be independent of signalling through the IFNAR. Lastly, global ATAC-Seq analysis showed that BATF acts as a pioneering TF which regulates chromatin accessibility of ~8,500 DNA regions, including around one third of all known TFs in pDCs. In summary, TLR9 activation of pDCs with CpG significantly altered the global TF reservoir and chromatin landscape of the cell. Further, we found that BATF is a dual negative regulator of type I IFN production and development of pDCs. Both CpG and BATF may be exploited for immunotherapeutic treatment to control infection and autoimmune disease. | |||||||
| Lizenz: |  Urheberrechtsschutz | |||||||
| Fachbereich / Einrichtung: | Mathematisch- Naturwissenschaftliche Fakultät » WE Biologie » Mikrobiologie | |||||||
| Dokument erstellt am: | 30.11.2022 | |||||||
| Dateien geändert am: | 30.11.2022 | |||||||
| Promotionsantrag am: | 23.07.2021 | |||||||
| Datum der Promotion: | 28.10.2021 |
