@phdthesis{Hollmann2017,
  author    = {Hollmann, Claudia Beate},
  title     = {Einfluss der sauren Sphingomyelinase auf anti-virale T-Zellantworten im Masernvirus-Infektionsmodell},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-153807},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2017},
  abstract  = {Die saure Sphingomyelinase (Asm), ein Enzym des Sphingolipidmetabolismus, spaltet Sphingomyelin zu Ceramid und Phosopocholin. Aktiviert wird die Asm unter anderem durch Stimulation des CD28 Rezeptors. CD28 Signale werden auch f{\"u}r die Aktivierung von konventionellen T-Zellen (Tconv) und f{\"u}r die Kostimulation ben{\"o}tigt und sind essentiell f{\"u}r die Differenzierung von regulatorischen T-Zellen (Treg) im Thymus und deren Erhalt in der Peripherie. Wir konnten zeigen, dass sich Tconv und Treg Zellen hinsichtlich der Asm unterscheiden. Treg haben eine h{\"o}here "basale" Asm Aktivit{\"a}t, widergespiegelt im h{\"o}heren Ceramidgehalt und haben eine niedrigere Lipidordnung als Tconv Zellen. Die Abwesenheit der Asm in defizienten M{\"a}usen bewirkt einen relativen Anstieg der Treg-Frequenz innerhalb der CD4+ T-Zellen. Außerdem f{\"u}hrt die Asm-Defizienz in Treg Zellen zu einer erh{\"o}hten Umsatzrate des immunsupprimierenden Molek{\"u}ls CTLA-4 und zu einer verst{\"a}rkten Suppressivit{\"a}t von Treg Zellen aus Asm-/- M{\"a}usen gegen{\"u}ber Wildtyp Zellen. Ein Anstieg in der Treg-Frequenz, {\"a}quivalent zur genetischen Defizienz, kann auch durch Inhibition der Asm, d. h. durch Wirkstoffe wie Amitriptylin und Desipramin erreicht werden. Es konnte gezeigt werden, dass die Inhibitorbehandlung die absolute Anzahl der Tconv Zellen selektiv verringert, da Treg Zellen gegen{\"u}ber dem Asm Inhibitor-induzierten Zelltod resistenter sind. Mechanistisch erkl{\"a}rbar sind die Unterschiede gegen{\"u}ber den proapoptotischen Inhibitoreffekten zwischen Tconv und Treg Zellen dadurch, dass Treg Zellen durch die Anwesenheit von IL-2 gesch{\"u}tzt sind. In Abwesenheit von IL-2 sterben die Treg Zellen ebenfalls. Die gezielte Ver{\"a}nderung des Verh{\"a}ltnisses von Treg zu Tconv durch den Einsatz von Asm-inhibitorischen Medikamenten kann hilfreich bei der therapeutischen Behandlung von inflammatorischen- und Autoimmunerkrankungen sein. Inwiefern die Asm f{\"u}r die Funktion von T-Zellen in der anti-viralen Immunantwort entscheidend ist, wurde im Masernvirus-Infektionsmodell n{\"a}her untersucht. In Asm-/- M{\"a}usen und Amitriptylin-behandelten M{\"a}usen konnte gezeigt werden, dass in Abwesenheit der Asm die Kontrolle der Masernvirusinfektion verschlechtert ist. Treg sind auch hier von entscheidender Bedeutung, da die Asm-abh{\"a}ngige, verst{\"a}rkte Masernvirusinfektion bei Fehlen der Asm nur in Gegenwart von Treg auftritt. In der akuten Phase gibt es in Asm-/- M{\"a}usen weniger masernvirusspezifische T-Zellen und dadurch eine verringerte Beseitigung der Viruslast. In der chronischen Phase ist die Anzahl masernvirusspezifischer T-Zellen zwischen WT und Asm-/- M{\"a}usen vergleichbar. In Letzteren ist allerdings die Anzahl und Frequenz von T-Zellen im Gehirn infizierter M{\"a}use noch deutlich erh{\"o}ht, was die verst{\"a}rkte Maserninfektion widerspiegelt. Zusammenfassend zeigt sich, dass die Asm die Funktion von Treg moduliert und einen Einfluss auf das Verh{\"a}ltnis von Tconv und Treg zueinander hat. Im Masernvirus-Infektionsmodell kann die Ver{\"a}nderung des Tconv zu Treg Verh{\"a}ltnisses in Abwesenheit der Asm urs{\"a}chlich f{\"u}r die verringerte Viruskontrolle sein. Die Asm Inhibitor-induzierte Treg-Aktivierung und die Beeinflussung des Treg zu Tconv Verh{\"a}ltnisses k{\"o}nnen wiederum f{\"u}r therapeutische Zwecke genutzt werden, wie beispielsweise bei Multipler Sklerose und Rheumatoider Arthritis.},
  subject      = {saure Sphingomyelinase},
  language  = {de}
}
@phdthesis{Gschmack2017,
  author    = {Gschmack, Eva Maria},
  title     = {Anti-Gehirn-Autoantik{\"o}rper und deren Bedeutung bei Morbus Parkinson},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149348},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2017},
  abstract  = {Hintergrund: Die der Pathogenese von Morbus Parkinson (PD, Parkinson's disease) zugrunde liegenden Mechanismen sind bis heute nur unvollst{\"a}ndig verstanden. Insbesondere ist unklar, durch welche urs{\"a}chlichen Faktoren Parkinson ausgel{\"o}st wird. Bei der HIV-Infektion treten bei vielen Patienten neurologische St{\"o}rungen auf (HIV-Associated Neurological Disorders, HAND), die in der klinischen Symptomatik und der Lokalisation der betroffenen Gehirnareale dem Morbus Parkinson {\"a}hneln. M{\"o}glicherweise k{\"o}nnte eine Fehlregulation der Immunantwort eine Rolle als Ausl{\"o}ser beider Erkrankungen spielen. In dieser Arbeit wurde die Autoimmunantwort von PD- und HAND-Patienten und gesunden Kontrollen gegen verschiedene Gehirnhomogenate untersucht, die w{\"a}hrend der Parkinsonerkrankung in unterschiedlichem Ausmaß gesch{\"a}digt werden. Das Autoimmun-Signal wurde quantifiziert und prominente Autoantigene wurden identifiziert. Methoden: In dieser Arbeit wurde ein Western-Blot-basiertes Verfahren zum Nachweis von Autoantik{\"o}rpern gegen Gehirngewebe entwickelt. Dieses Verfahren wurde nach Optimierung mit Plasmaproben von gesunden Kontrollen, PD-Patienten und Patienten mit HIV-Infektion insbesondere an einer Gruppe von 40 Parkinson-Patienten (Durchschnittsalter 65 Jahre, 45 \% weiblich) und 40 alters- und geschlechtsgemachten Kontrollen (Durchschnittsalter 62 Jahre, 50 \% weiblich) angewendet und die humorale Autoimmunit{\"a}t gegen verschiedene Gehirnareale untersucht. Dazu wurden die verschiedenen Areale (dorsaler Motornucleus des Glossopharynx- und Vagusnervs (dm), Substantia nigra (SN), anteromedialer temporaler Mesocortex (MC), high order sensorische Assoziations- und pr{\"a}frontale Felder (HC), first oder sensorische Assoziations- und pr{\"a}motorische Felder, prim{\"a}re sensorische und motorische Felder (FC)) von post-mortem Gehirnen homogenisiert, auf SDS-Gradienten-Gelen elektrophoretisch aufgetrennt und auf Nitrocellulose geblottet. Die Membranen wurden mit den Plasmen inkubiert und gebundene Autoantik{\"o}rper immunologisch detektiert. Die Signale wurden qualitativ und quantitativ ausgewertet. Mit Hilfe einer zweidimensionalen Elektrophorese und anschließender Immunf{\"a}rbung wurden prominente Autoantigene durch Massenspektroskopie identifiziert. Ergebnisse: Mit dem in dieser Arbeit entwickelten Assay l{\"a}sst sich die humorale Autoimmunantwort gegen Gehirngewebe semiquantitativ bestimmen. In allen untersuchten Proben konnten verschiedene Autoantik{\"o}rper gegen unterschiedliche Antigene nachgewiesen werden. Der Gesamt-IgG-Gehalt der Plasmen unterscheidet sich weder zwischen PD-Patienten und gesunden Kontrollen, noch zwischen M{\"a}nnern und Frauen signifikant. Weibliche PD-Patienten zeigen signifikant st{\"a}rkere Signale gegen dm als m{\"a}nnliche (p = 0.02, Mann-Whitney-U-Test), der wiederum in jedem Patienten - unabh{\"a}ngig vom Geschlecht - von den untersuchten Hirnarealen signifikant st{\"a}rker autoimmunologisch erkannt wird, als die {\"u}brigen Hirnareale (p < 0.0001, Friedman-ANOVA). In jedem Hirnareal wurden drei Banden besonders h{\"a}ufig erkannt (45, 40 und 37 kDa), jede davon am st{\"a}rksten im dm (p < 0.0001, Friedman-ANOVA). Die Einzelanalysen der Signalintensit{\"a}ten zeigt, dass PD-Patienten signifikant weniger Autoreaktivit{\"a}t gegen die 45 kDa-Bande in der SN (p = 0.056), im MC (p = 0.0277) und im FC (p = 0.0188) zeigen, als Kontrollen. Weitere Analysen zeigen, dass m{\"a}nnliche PD-Patienten hochsignifikant weniger das 45 kDa-Protein im SN (p < 0.0001), MC (p = 0.0042) und FC (p = 0.0088) erkennen als Kontrollen, wohingegen bei den weiblichen Kontroll- und PD-Plasmen kein Unterschied festzustellen war. Ein weiteres Protein bei 160 kDa wird signifikant unterschiedlich stark in allen Gehirnarealen erkannt (p < 0.0001, Friedman-ANOVA), wobei die st{\"a}rkste Immunreaktivit{\"a}t gegen FC besteht. Basierend auf dem Nachweis der 45 kDa-Bande aus der SN ergibt sich eine Odds Ratio f{\"u}r das Merkmal Parkinson von 3.38 (CI 1.11 - 10.30). Bei M{\"a}nnern ist diese Odds Ratio sogar 53.12 (CI 2.79 - 1012), bei Frauen 0.44 (CI 0.09 - 2.09). Die Sensitivit{\"a}t dieses Tests liegt bei M{\"a}nnern bei 1 (CI 0.84 - 1), die Spezifit{\"a}t bei 4.41 (0.31 - 0.78). Die negativ pr{\"a}diktiven Werte liegen in allen Gruppen {\"u}ber 99.15 \%. Die Identifizierung der Proteine mittels Massenspektroskopie ergab, dass es sich bei den 37 - 45 kDa Banden um Isoformen oder posttranslational modifizierte Formen des GFAP (glial fibrillary acidic protein), einem Bestandteil von Neurofilamenten v.a. in Astrozyten handelt. Außerdem wurde Fructose-Bisphosphate Aldolase A und Aspartat-Aminotransferase (mitochondriale Isoform 1 Vorl{\"a}ufer), beides Proteine des Kohlenhydrat-Stoffwechsels und der Glykolyse, als weitere Proteine mit ebenfalls 45 kDa identifiziert. Bei dem identifizierten Protein mit dem Molekulargewicht von 160 kDa handelt es sich wahrscheinlich um Dihydropyrimidinase-related protein 2, wie GFAP ebenfalls bei der Bildung des Zytoskeletts beteiligt. Diskussion: Autoantik{\"o}rper gegen Gehirnantigene sind ein physiologisches Ph{\"a}nomen, das unabh{\"a}ngig von dem Vorliegen einer neurologischen Erkrankung besteht. Gehirnareale, die bei Parkinson besonders stark gesch{\"a}digt werden, werden von dieser humoralen Autoimmunantwort besonders stark erkannt. Eine vor{\"u}bergehende Permeabilisierung der Blut-Hirn-Schranke durch Infektion oder Trauma k{\"o}nnte den Zutritt der Autoantik{\"o}rper zum Gehirn erlauben und so autoreaktive Prozesse in Gang setzen und zum Untergang dopaminerger Neuronen f{\"u}hren. Bei den identifizierten Proteinen handelt es sich um grundlegende Bestandteile eukaryotischer Zellen, was die Hypothese eines Art Beseitigungsmechanismus der Autoantik{\"o}rper und damit die Aufgabe der Aufrechterhaltung der Hom{\"o}ostase darstellen k{\"o}nnte. Bei m{\"a}nnlichen PD Patienten wird die 45 kDa Bande signifikant weniger stark von Auto-IgGs erkannt; dieser Mechanismus k{\"o}nnte somit in den m{\"a}nnlichen PD-Patienten vermindert sein. Als Folge w{\"a}re die Ablagerung von Zelltr{\"u}mmern im Gehirn vorstellbar, die dann auch langfristig eine Angriffsfl{\"a}che f{\"u}r Autoimmunprozesse mit dem Verlust dopaminerger Neuronen bieten k{\"o}nnte.},
  subject      = {Parkinson-Krankheit},
  language  = {de}
}
@article{KleinHesslingMuhammadKleinetal.2017,
  author    = {Klein-Hessling, Stefan and Muhammad, Khalid and Klein, Matthias and Pusch, Tobias and Rudolf, Ronald and Fl{\"o}ter, Jessica and Qureischi, Musga and Beilhack, Andreas and Vaeth, Martin and Kummerow, Carsten and Backes, Christian and Schoppmeyer, Rouven and Hahn, Ulrike and Hoth, Markus and Bopp, Tobias and Berberich-Siebelt, Friederike and Patra, Amiya and Avots, Andris and M{\"u}ller, Nora and Schulze, Almut and Serfling, Edgar},
  title     = {NFATc1 controls the cytotoxicity of CD8\(^{+}\) T cells},
  series = {Nature Communications},
  volume    = {8},
  journal   = {Nature Communications},
  number    = {511},
  doi       = {10.1038/s41467-017-00612-6},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170353},
  year      = {2017},
  abstract  = {Cytotoxic T lymphocytes are effector CD8\(^{+}\) T cells that eradicate infected and malignant cells. Here we show that the transcription factor NFATc1 controls the cytotoxicity of mouse cytotoxic T lymphocytes. Activation of Nfatc1\(^{-/-}\) cytotoxic T lymphocytes showed a defective cytoskeleton organization and recruitment of cytosolic organelles to immunological synapses. These cells have reduced cytotoxicity against tumor cells, and mice with NFATc1-deficient T cells are defective in controlling Listeria infection. Transcriptome analysis shows diminished RNA levels of numerous genes in Nfatc1\(^{-/-}\) CD8\(^{+}\) T cells, including Tbx21, Gzmb and genes encoding cytokines and chemokines, and genes controlling glycolysis. Nfatc1\(^{-/-}\), but not Nfatc2\(^{-/-}\) CD8\(^{+}\) T cells have an impaired metabolic switch to glycolysis, which can be restored by IL-2. Genome-wide ChIP-seq shows that NFATc1 binds many genes that control cytotoxic T lymphocyte activity. Together these data indicate that NFATc1 is an important regulator of cytotoxic T lymphocyte effector functions.},
  language  = {en}
}
@article{WylerMenegattiFrankeetal.2017,
  author    = {Wyler, Emanuel and Menegatti, Jennifer and Franke, Vedran and Kocks, Christine and Boltengagen, Anastasiya and Hennig, Thomas and Theil, Kathrin and Rutkowski, Andrzej and Ferrai, Carmelo and Baer, Laura and Kermas, Lisa and Friedel, Caroline and Rajewsky, Nikolaus and Akalin, Altuna and D{\"o}lken, Lars and Gr{\"a}sser, Friedrich and Landthaler, Markus},
  title     = {Widespread activation of antisense transcription of the host genome during herpes simplex virus 1 infection},
  series = {Genome Biology},
  volume    = {18},
  journal   = {Genome Biology},
  doi       = {10.1186/s13059-017-1329-5},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173381},
  year      = {2017},
  abstract  = {Background Herpesviruses can infect a wide range of animal species. Herpes simplex virus 1 (HSV-1) is one of the eight herpesviruses that can infect humans and is prevalent worldwide. Herpesviruses have evolved multiple ways to adapt the infected cells to their needs, but knowledge about these transcriptional and post-transcriptional modifications is sparse. Results Here, we show that HSV-1 induces the expression of about 1000 antisense transcripts from the human host cell genome. A subset of these is also activated by the closely related varicella zoster virus. Antisense transcripts originate either at gene promoters or within the gene body, and they show different susceptibility to the inhibition of early and immediate early viral gene expression. Overexpression of the major viral transcription factor ICP4 is sufficient to turn on a subset of antisense transcripts. Histone marks around transcription start sites of HSV-1-induced and constitutively transcribed antisense transcripts are highly similar, indicating that the genetic loci are already poised to transcribe these novel RNAs. Furthermore, an antisense transcript overlapping with the BBC3 gene (also known as PUMA) transcriptionally silences this potent inducer of apoptosis in cis. Conclusions We show for the first time that a virus induces widespread antisense transcription of the host cell genome. We provide evidence that HSV-1 uses this to downregulate a strong inducer of apoptosis. Our findings open new perspectives on global and specific alterations of host cell transcription by viruses.},
  language  = {en}
}
@article{KuznetsovAlmuzzainiKritikouetal.2017,
  author    = {Kuznetsov, Nikolai V. and Almuzzaini, Bader and Kritikou, Joanna S. and Baptista, Marisa A. P. and Oliveira, Mariana M. S. and Keszei, Marton and Snapper, Scott B. and Percipalle, Piergiorgio and Westerberg, Lisa S.},
  title     = {Nuclear Wiskott-Aldrich syndrome protein co-regulates T cell factor 1-mediated transcription in T cells},
  series = {Genome Medicine},
  volume    = {9},
  journal   = {Genome Medicine},
  doi       = {10.1186/s13073-017-0481-6},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173486},
  year      = {2017},
  abstract  = {Background The Wiskott-Aldrich syndrome protein (WASp) family of actin-nucleating factors are present in the cytoplasm and in the nucleus. The role of nuclear WASp for T cell development remains incompletely defined. Methods We performed WASp chromatin immunoprecipitation and deep sequencing (ChIP-seq) in thymocytes and spleen CD4\(^+\) T cells. Results WASp was enriched at genic and intergenic regions and associated with the transcription start sites of protein-coding genes. Thymocytes and spleen CD4\(^+\) T cells showed 15 common WASp-interacting genes, including the gene encoding T cell factor (TCF)12. WASp KO thymocytes had reduced nuclear TCF12 whereas thymocytes expressing constitutively active WASp\(^{L272P}\) and WASp\(^{I296T}\) had increased nuclear TCF12, suggesting that regulated WASp activity controlled nuclear TCF12. We identify a putative DNA element enriched in WASp ChIP-seq samples identical to a TCF1-binding site and we show that WASp directly interacted with TCF1 in the nucleus. Conclusions These data place nuclear WASp in proximity with TCF1 and TCF12, essential factors for T cell development.},
  language  = {en}
}
@article{UriWernerLuehderetal.2017,
  author    = {Uri, Anna and Werner, Sandra and L{\"u}hder, Fred and H{\"u}nig, Thomas and Kerkau, Thomas and Beyersdorf, Niklas},
  title     = {Protection of mice from acute graft-versus-host disease requires CD28 co-stimulation on donor CD4\(^{+}\) Foxp3\(^{+}\) regulatory T Cells},
  series = {Frontiers in Immunology},
  volume    = {8},
  journal   = {Frontiers in Immunology},
  number    = {721},
  doi       = {10.3389/fimmu.2017.00721},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158469},
  year      = {2017},
  abstract  = {Acute graft-versus-host disease (aGvHD) is a major cause of morbidity and mortality after allogeneic hematopoietic stem cell plus T cell transplantation (allo-HSCT). In this study, we investigated the requirement for CD28 co-stimulation of donor CD4\(^{+}\) conventional (CD4\(^{+}\)CD25\(^{-}\)Foxp3\(^{-}\), Tconv) and regulatory (CD4\(^{+}\)CD25\(^{+}\)Foxp3\(^{+}\), Treg) T cells in aGvHD using tamoxifen-inducible CD28 knockout (iCD28KO) or wild-type (wt) littermates as donors of CD4\(^{+}\) Tconv and Treg. In the highly inflammatory C57BL/6 into BALB/c allo-HSCT transplantation model, CD28 depletion on donor CD4\(^{+}\) Tconv reduced clinical signs of aGvHD, but did not significantly prolong survival of the recipient mice. Selective depletion of CD28 on donor Treg did not abrogate protection of recipient mice from aGvHD until about day 20 after allo-HSCT. Later, however, the pool of CD28-depleted Treg drastically declined as compared to wt Treg. Consequently, only wt, but not CD28-deficient, Treg were able to continuously suppress aGvHD and induce long-term survival of the recipient mice. To our knowledge, this is the first study that specifically evaluates the impact of CD28 expression on donor Treg in aGvHD. Moreover, the delayed kinetics of aGvHD lethality after transplantation of iCD28KO Treg provides a novel animal model for similar disease courses found in patients after allo-HSCT.},
  language  = {en}
}
@article{HellmannLotherWursteretal.2017,
  author    = {Hellmann, Anna-Maria and Lother, Jasmin and Wurster, Sebastian and Lutz, Manfred B. and Schmitt, Anna Lena and Morton, Charles Oliver and Eyrich, Matthias and Czakai, Kristin and Einsele, Hermann and Loeffler, Juergen},
  title     = {Human and Murine Innate Immune Cell Populations Display Common and Distinct Response Patterns during Their In Vitro Interaction with the Pathogenic Mold Aspergillus fumigatus},
  series = {Frontiers in Immunology},
  volume    = {8},
  journal   = {Frontiers in Immunology},
  number    = {1716},
  doi       = {10.3389/fimmu.2017.01716},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169926},
  year      = {2017},
  abstract  = {Aspergillus fumigatus is the main cause of invasive fungal infections occurring almost exclusively in immunocompromised patients. An improved understanding of the initial innate immune response is key to the development of better diagnostic tools and new treatment options. Mice are commonly used to study immune defense mechanisms during the infection of the mammalian host with A. fumigatus. However, little is known about functional differences between the human and murine immune response against this fungal pathogen. Thus, we performed a comparative functional analysis of human and murine dendritic cells (DCs), macrophages, and polymorphonuclear cells (PMNs) using standardized and reproducible working conditions, laboratory protocols, and readout assays. A. fumigatus did not provoke identical responses in murine and human immune cells but rather initiated relatively specific responses. While human DCs showed a significantly stronger upregulation of their maturation markers and major histocompatibility complex molecules and phagocytosed A. fumigatus more efficiently compared to their murine counterparts, murine PMNs and macrophages exhibited a significantly stronger release of reactive oxygen species after exposure to A. fumigatus. For all studied cell types, human and murine samples differed in their cytokine response to conidia or germ tubes of A. fumigatus. Furthermore, Dectin-1 showed inverse expression patterns on human and murine DCs after fungal stimulation. These specific differences should be carefully considered and highlight potential limitations in the transferability of murine host-pathogen interaction studies.},
  language  = {en}
}
@phdthesis{Kuen2017,
  author    = {Kuen, Janina},
  title     = {Influence of 3D tumor cell/fibroblast co-culture on monocyte differentiation and tumor progression in pancreatic cancer},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-156226},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2017},
  abstract  = {Pancreatic cancer (PC) remains one of the most challenging solid tumors to treat with a high unmet medical need as patients poorly respond to standard-of-care-therapies. Prominent desmoplastic reaction involving cancer-associated fibroblasts (CAFs) and the immune cells in the tumor microenvironment (TME) and their cross-talk play a significant role in tumor immune escape and progression. To identify the key cellular mechanisms induce an immunosuppressive tumor microenvironment, we established 3D co-culture model with pancreatic cancer cells, CAFs, monocyte as well as T cells. Using this model, we analysed the influence of tumor cells and fibroblasts on monocytes and their immune suppressive phenotype. Phenotypic characterization of the monocytes after 3D co-culture with tumor/fibroblast spheroids was performed by analysing the expression of defined cell surface markers and soluble factors. Functionality of these monocytes and their ability to influence T cell phenotype and proliferation was investigated. 3D co-culture of monocytes with pancreatic cancer cells and fibroblasts induced the production of immunosuppressive cytokines which are known to promote polarization of M2 like macrophages and myeloid derived suppressive cells (MDSCs). These co-culture spheroid polarized monocyte derived macrophages (MDMs) were poorly differentiated and had an M2 phenotype. The immunosuppressive function of these co-culture spheroids polarized MDMs was demonstrated by their ability to inhibit autologous CD4+ and CD8+ T cell activation and proliferation in vitro, which we could partially reverse by 3D co-culture spheroid treatment with therapeutic molecules that are able to re-activate spheroid polarized MDMs or block immune suppressive factors such as Arginase-I. In conclusion, we generated a physiologically relevant 3D co-culture model, which can be used as a promising tool to study complex cell-cell interactions between different cell types within the tumor microenvironment and to support drug screening and development. In future, research focused on better understanding of resistance mechanisms to existing cancer immunotherapies will help to develop new therapeutic strategies in order to combat cancer.},
  subject      = {monocyte},
  language  = {en}
}
@article{MoschallDenkErkelenzetal.2017,
  author    = {Moschall, Rebecca and Denk, Sarah and Erkelenz, Steffen and Schenk, Christian and Schaal, Heiner and Bodem, Jochen},
  title     = {A purine-rich element in foamy virus pol regulates env splicing and gag/pol expression},
  series = {Retrovirology},
  volume    = {14},
  journal   = {Retrovirology},
  number    = {10},
  doi       = {10.1186/s12977-017-0337-6},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-157614},
  year      = {2017},
  abstract  = {Background: The foamy viral genome encodes four central purine-rich elements localized in the integrase-coding region of pol. Previously, we have shown that the first two of these RNA elements (A and B) are required for protease dimerization and activation. The D element functions as internal polypurine tract during reverse transcription. Peters et al., described the third element (C) as essential for gag expression suggesting that it might serve as an RNA export element for the unspliced genomic transcript. Results: Here, we analysed env splicing and demonstrate that the described C element composed of three GAA repeats known to bind SR proteins regulates env splicing, thus balancing the amount of gag/pol mRNAs. Deletion of the C element effectively promotes a splice site switch from a newly identified env splice acceptor to the intrinsically strong downstream localised env 3′ splice acceptor permitting complete splicing of almost all LTR derived transcripts. We provide evidence that repression of this env splice acceptor is a prerequisite for gag expression. This repression is achieved by the C element, resulting in impaired branch point recognition and SF1/mBBP binding. Separating the branch point from the overlapping purine-rich C element, by insertion of only 20 nucleotides, liberated repression and fully restored splicing to the intrinsically strong env 3′ splice site. This indicated that the cis-acting element might repress splicing by blocking the recognition of essential splice site signals. Conclusions: The foamy viral purine-rich C element regulates splicing by suppressing the branch point recognition of the strongest env splice acceptor. It is essential for the formation of unspliced gag and singly spliced pol transcripts.},
  language  = {en}
}
@article{BergfeldDasariWerneretal.2017,
  author    = {Bergfeld, Arne and Dasari, Prasad and Werner, Sandra and Hughes, Timothy R. and Song, Wen-Chao and Hortschansky, Peter and Brakhage, Axel A. and H{\"u}nig, Thomas and Zipfel, Peter F. and Beyersdorf, Niklas},
  title     = {Direct binding of the pH-regulated Protein 1 (Pra1) from Candida albicans inhibits cytokine secretion by mouse CD4\(^{+}\) T cells},
  series = {Frontiers in Microbiology},
  volume    = {8},
  journal   = {Frontiers in Microbiology},
  number    = {844},
  doi       = {10.3389/fmicb.2017.00844},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158274},
  year      = {2017},
  abstract  = {Opportunistic infections with the saprophytic yeast Candida albicans are a major cause of morbidity in immunocompromised patients. While the interaction of cells and molecules of innate immunity with C. albicans has been studied to great depth, comparatively little is known about the modulation of adaptive immunity by C. albicans. In particular, direct interaction of proteins secreted by C. albicans with CD4\(^{+}\) T cells has not been studied in detail. In a first screening approach, we identified the pH-regulated antigen 1 (Pra1) as a molecule capable of directly binding to mouse CD4\(^{+}\) T cells in vitro. Binding of Pra1 to the T cell surface was enhanced by extracellular Zn\(^{2+}\) ions which Pra1 is known to scavenge from the host in order to supply the fungus with Zn\(^{2+}\). In vitro stimulation assays using highly purified mouse CD4\(^{+}\) T cells showed that Pra1 increased proliferation of CD4\(^{+}\) T cells in the presence of plate-bound anti-CD3 monoclonal antibody. In contrast, secretion of effector cytokines such as IFNγ and TNF by CD4\(^{+}\) T cells upon anti-CD3/ anti-CD28 mAb as well as cognate antigen stimulation was reduced in the presence of Pra1. By secreting Pra1 C. albicans, thus, directly modulates and partially controls CD4\(^{+}\) T cell responses as shown in our in vitro assays.},
  language  = {en}
}
@article{LutzStroblSchuleretal.2017,
  author    = {Lutz, Manfred B. and Strobl, Herbert and Schuler, Gerold and Romani, Nikolaus},
  title     = {GM-CSF monocyte-derived cells and Langerhans cells as part of the dendritic cell family},
  series = {Frontiers in Immunology},
  volume    = {8},
  journal   = {Frontiers in Immunology},
  number    = {1388},
  doi       = {10.3389/fimmu.2017.01388},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158730},
  year      = {2017},
  abstract  = {Dendritic cells (DCs) and macrophages (Mph) share many characteristics as components of the innate immune system. The criteria to classify the multitude of subsets within the mononuclear phagocyte system are currently phenotype, ontogeny, transcription patterns, epigenetic adaptations, and function. More recently, ontogenetic, transcriptional, and proteomic research approaches uncovered major developmental differences between Flt3L-dependent conventional DCs as compared with Mphs and monocyte-derived DCs (MoDCs), the latter mainly generated in vitro from murine bone marrow-derived DCs (BM-DCs) or human CD14\(^{+}\) peripheral blood monocytes. Conversely, in vitro GM-CSF-dependent monocyte-derived Mphs largely resemble MoDCs whereas tissue-resident Mphs show a common embryonic origin from yolk sac and fetal liver with Langerhans cells (LCs). The novel ontogenetic findings opened discussions on the terminology of DCs versus Mphs. Here, we bring forward arguments to facilitate definitions of BM-DCs, MoDCs, and LCs. We propose a group model of terminology for all DC subsets that attempts to encompass both ontogeny and function.},
  language  = {en}
}
@article{DoehlerSchneiderEckertetal.2017,
  author    = {D{\"o}hler, Anja and Schneider, Theresa and Eckert, Ina and Ribechini, Eliana and Andreas, Nico and Riemann, Marc and Reizis, Boris and Weih, Falk and Lutz, Manfred B.},
  title     = {RelB\(^{+}\) Steady-State Migratory Dendritic Cells Control the Peripheral Pool of the Natural Foxp3\(^{+}\) Regulatory T Cells},
  series = {Frontiers in Immunology},
  volume    = {8},
  journal   = {Frontiers in Immunology},
  number    = {726},
  doi       = {10.3389/fimmu.2017.00726},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158121},
  year      = {2017},
  abstract  = {Thymus-derived natural Foxp3\(^{+}\) CD4\(^{+}\) regulatory T cells (nTregs) play a key role in maintaining immune tolerance and preventing autoimmune disease. Several studies indicate that dendritic cells (DCs) are critically involved in the maintenance and proliferation of nTregs. However, the mechanisms how DCs manage to keep the peripheral pool at constant levels remain poorly understood. Here, we describe that the NF-κB/Rel family transcription factor RelB controls the frequencies of steady-state migratory DCs (ssmDCs) in peripheral lymph nodes and their numbers control peripheral nTreg homeostasis. DC-specific RelB depletion was investigated in CD11c-Cre × RelB\(^{fl/fl}\) mice (RelB\(^{DCko}\)), which showed normal frequencies of resident DCs in lymph nodes and spleen while the subsets of CD103\(^{-}\) Langerin\(^{-}\) dermal DCs (dDCs) and Langerhans cells but not CD103\(^{+}\) Langerin\(^{+}\) dDC of the ssmDCs in skin-draining lymph nodes were increased. Enhanced frequencies and proliferation rates were also observed for nTregs and a small population of CD4\(^{+}\) CD44\(^{high}\) CD25\(^{low}\) memory-like T cells (Tml). Interestingly, only the Tml but not DCs showed an increase in IL-2-producing capacity in lymph nodes of RelB\(^{DCko}\) mice. Blocking of IL-2 in vivo reduced the frequency of nTregs but increased the Tml frequencies, followed by a recovery of nTregs. Taken together, by employing RelB\(^{DCko}\) mice with increased frequencies of ssmDCs our data indicate a critical role for specific ssmDC subsets for the peripheral nTreg and IL-2\(^{+}\) Tml frequencies during homeostasis.},
  language  = {en}
}
@article{SilvaVilchesPletinckxLohnertetal.2017,
  author    = {Silva-Vilches, Cinthia and Pletinckx, Katrien and Lohnert, Miriam and Pavlovic, Vladimir and Ashour, Diyaaeldin and John, Vini and Vendelova, Emilia and Kneitz, Susanne and Zhou, Jie and Chen, Rena and Reinheckel, Thomas and Mueller, Thomas D. and Bodem, Jochen and Lutz, Manfred B.},
  title     = {Low doses of cholera toxin and its mediator cAMP induce CTLA-2 secretion by dendritic cells to enhance regulatory T cell conversion},
  series = {PLoS ONE},
  volume    = {12},
  journal   = {PLoS ONE},
  number    = {7},
  doi       = {10.1371/journal.pone.0178114},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158244},
  pages     = {e0178114},
  year      = {2017},
  abstract  = {Immature or semi-mature dendritic cells (DCs) represent tolerogenic maturation stages that can convert naive T cells into Foxp3\(^{+}\) induced regulatory T cells (iTreg). Here we found that murine bone marrow-derived DCs (BM-DCs) treated with cholera toxin (CT) matured by up-regulating MHC-II and costimulatory molecules using either high or low doses of CT (CT\(^{hi}\), CT\(^{lo}\)) or with cAMP, a known mediator CT signals. However, all three conditions also induced mRNA of both isoforms of the tolerogenic molecule cytotoxic T lymphocyte antigen 2 (CTLA-2α and CTLA-2β). Only DCs matured under CT\(^{hi}\) conditions secreted IL-1β, IL-6 and IL-23 leading to the instruction of Th17 cell polarization. In contrast, CT\(^{lo}\)- or cAMP-DCs resembled semi-mature DCs and enhanced TGF-β-dependent Foxp3\(^{+}\) iTreg conversion. iTreg conversion could be reduced using siRNA blocking of CTLA-2 and reversely, addition of recombinant CTLA-2α increased iTreg conversion in vitro. Injection of CT\(^{lo}\)- or cAMP-DCs exerted MOG peptide-specific protective effects in experimental autoimmune encephalomyelitis (EAE) by inducing Foxp3\(^{+}\) Tregs and reducing Th17 responses. Together, we identified CTLA-2 production by DCs as a novel tolerogenic mediator of TGF-β-mediated iTreg induction in vitro and in vivo. The CT-induced and cAMP-mediated up-regulation of CTLA-2 also may point to a novel immune evasion mechanism of Vibrio cholerae.},
  language  = {en}
}
@article{CollenburgBeyersdorfWieseetal.2017,
  author    = {Collenburg, Lena and Beyersdorf, Niklas and Wiese, Teresa and Arenz, Christoph and Saied, Essa M. and Becker-Flegler, Katrin Anne and Schneider-Schaulies, Sibylle and Avota, Elita},
  title     = {The activity of the neutral sphingomyelinase is important in T cell recruitment and directional migration},
  series = {Frontiers in Immunology},
  volume    = {8},
  journal   = {Frontiers in Immunology},
  number    = {1007},
  doi       = {10.3389/fimmu.2017.01007},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158944},
  year      = {2017},
  abstract  = {Breakdown of sphingomyelin as catalyzed by the activity of sphingomyelinases profoundly affects biophysical properties of cellular membranes which is particularly important with regard to compartmentalization of surface receptors and their signaling relay. As it is activated both upon TCR ligation and co-stimulation in a spatiotemporally controlled manner, the neutral sphingomyelinase (NSM) has proven to be important in T cell activation, where it appears to play a particularly important role in cytoskeletal reorganization and cell polarization. Because these are important parameters in directional T cell migration and motility in tissues, we analyzed the role of the NSM in these processes. Pharmacological inhibition of NSM interfered with early lymph node homing of T cells in vivo indicating that the enzyme impacts on endothelial adhesion, transendothelial migration, sensing of chemokine gradients or, at a cellular level, acquisition of a polarized phenotype. NSM inhibition reduced adhesion of T cells to TNF-α/IFN-γ activated, but not resting endothelial cells, most likely via inhibiting high-affinity LFA-1 clustering. NSM activity proved to be highly important in directional T cell motility in response to SDF1-α, indicating that their ability to sense and translate chemokine gradients might be NSM dependent. In fact, pharmacological or genetic NSM ablation interfered with T cell polarization both at an overall morphological level and redistribution of CXCR4 and pERM proteins on endothelial cells or fibronectin, as well as with F-actin polymerization in response to SDF1-α stimulation, indicating that efficient directional perception and signaling relay depend on NSM activity. Altogether, these data support a central role of the NSM in T cell recruitment and migration both under homeostatic and inflamed conditions by regulating polarized redistribution of receptors and their coupling to the cytoskeleton.},
  language  = {en}
}
@article{ArmbrusterKriegWeissenbergeretal.2017,
  author    = {Armbruster, Nicole and Krieg, Jennifer and Weißenberger, Manuel and Scheller, Carsten and Steinert, Andre F.},
  title     = {Rescued Chondrogenesis of Mesenchymal Stem Cells under Interleukin 1 Challenge by Foamyviral Interleukin 1 Receptor Antagonist Gene Transfer},
  series = {Frontiers in Pharmacology},
  volume    = {8},
  journal   = {Frontiers in Pharmacology},
  number    = {255},
  doi       = {10.3389/fphar.2017.00255},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170919},
  year      = {2017},
  abstract  = {Background: Mesenchymal stem cells (MSCs) and their chondrogenic differentiation have been extensively investigated in vitro as MSCs provide an attractive source besides chondrocytes for cartilage repair therapies. Here we established prototype foamyviral vectors (FVV) that are derived from apathogenic parent viruses and are characterized by a broad host range and a favorable integration pattern into the cellular genome. As the inflammatory cytokine interleukin 1 beta (IL1β) is frequently present in diseased joints, the protective effects of FVV expressing the human interleukin 1 receptor antagonist protein (IL1RA) were studied in an established in vitro model (aggregate culture system) of chondrogenesis in the presence of IL1β. Materials and Methods: We generated different recombinant FVVs encoding enhanced green fluorescent protein (EGFP) or IL1RA and examined their transduction efficiencies and transgene expression profiles using different cell lines and human primary MSCs derived from bone marrow-aspirates. Transgene expression was evaluated by fluorescence microscopy (EGFP), flow cytometry (EGFP), and ELISA (IL1RA). For evaluation of the functionality of the IL1RA transgene to block the inhibitory effects of IL1β on chondrogenesis of primary MSCs and an immortalized MSC cell line (TERT4 cells), the cells were maintained following transduction as aggregate cultures in standard chondrogenic media in the presence or absence of IL1β. After 3 weeks of culture, pellets were harvested and analyzed by histology and immunohistochemistry for chondrogenic phenotypes. Results: The different FVV efficiently transduced cell lines as well as primary MSCs, thereby reaching high transgene expression levels in 6-well plates with levels of around 100 ng/ml IL1RA. MSC aggregate cultures which were maintained in chondrogenic media without IL1β supplementation revealed a chondrogenic phenotype by means of strong positive staining for collagen type II and matrix proteoglycan (Alcian blue). Addition of IL1β was inhibitory to chondrogenesis in untreated control pellets. In contrast, foamyviral mediated IL1RA expression rescued the chondrogenesis in pellets cultured in the presence of IL1β. Transduced MSC pellets reached thereby very high IL1RA transgene expression levels with a peak of 1087 ng/ml after day 7, followed by a decrease to 194 ng/ml after day 21, while IL1RA concentrations of controls were permanently below 200 pg/ml. Conclusion: Our results indicate that FVV are capable of efficient gene transfer to MSCs, while reaching IL1RA transgene expression levels, that were able to efficiently block the impacts of IL1β in vitro. FVV merit further investigation as a means to study the potential as a gene transfer tool for MSC based therapies for cartilage repair.},
  language  = {en}
}
@article{HalderAbdelfatahJoetal.2017,
  author    = {Halder, Luke D. and Abdelfatah, Mahmoud A. and Jo, Emeraldo A. H. and Jacobsen, Ilse D. and Westermann, Martin and Beyersdorf, Niklas and Lorkowski, Stefan and Zipfel, Peter F. and Skerka, Christine},
  title     = {Factor H binds to extracellular DNA traps released from human blood monocytes in response to Candida albicans},
  series = {Frontiers in Immunology},
  volume    = {7},
  journal   = {Frontiers in Immunology},
  doi       = {10.3389/fimmu.2016.00671},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-181127},
  year      = {2017},
  abstract  = {Upon systemic infection with human pathogenic yeast Candida albicans (C. albicans), human monocytes and polymorph nuclear neutrophilic granulocytes are the first immune cells to respond and come into contact with C. albicans. Monocytes exert immediate candidacidal activity and inhibit germination, mediate phagocytosis, and kill fungal cells. Here, we show that human monocytes spontaneously respond to C. albicans cells via phagocytosis, decondensation of nuclear DNA, and release of this decondensed DNA in the form of extracellular traps (called monocytic extracellular traps: MoETs). Both subtypes of monocytes (CD14\(^{++}\)CD16\(^-\)/CD14\(^+\)CD16\(^+\)) formed MoETs within the first hours upon contact with C. albicans. MoETs were characterized by the presence of citrullinated histone, myeloperoxidase, lactoferrin, and elastase. MoETs were also formed in response to Staphylococcus aureus and Escherichia coli, indicating a general reaction of monocytes to infectious microbes. MoET induction differs from extracellular trap formation in macrophages as MoETs are not triggered by simvastatin, an inhibitor of cholesterol synthesis and inducer of extracellular traps in macrophages. Extracellular traps from both monocytes and neutrophils activate complement and C3b is deposited. However, factor H (FH) binds via C3b to the extracellular DNA, mediates cofactor activity, and inhibits the induction of the inflammatory cytokine interleukin-1 beta in monocytes. Altogether, the results show that human monocytes release extracellular DNA traps in response to C. albicans and that these traps finally bind FH via C3b to presumably support clearance without further inflammation.},
  language  = {en}
}