TY - JOUR A1 - Hennig, Thomas A1 - Djakovic, Lara A1 - Dölken, Lars A1 - Whisnant, Adam W. T1 - A Review of the Multipronged Attack of Herpes Simplex Virus 1 on the Host Transcriptional Machinery JF - Viruses N2 - During lytic infection, herpes simplex virus (HSV) 1 induces a rapid shutoff of host RNA synthesis while redirecting transcriptional machinery to viral genes. In addition to being a major human pathogen, there is burgeoning clinical interest in HSV as a vector in gene delivery and oncolytic therapies, necessitating research into transcriptional control. This review summarizes the array of impacts that HSV has on RNA Polymerase (Pol) II, which transcribes all mRNA in infected cells. We discuss alterations in Pol II holoenzymes, post-translational modifications, and how viral proteins regulate specific activities such as promoter-proximal pausing, splicing, histone repositioning, and termination with respect to host genes. Recent technological innovations that have reshaped our understanding of previous observations are summarized in detail, along with specific research directions and technical considerations for future studies. KW - herpes simplex virus KW - RNA polymerase II KW - transcription KW - host shutoff KW - promoter-proximal pausing KW - C-terminal domain KW - polyadenylation KW - splicing Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-246165 SN - 1999-4915 VL - 13 IS - 9 ER - TY - JOUR A1 - Moschall, Rebecca A1 - Denk, Sarah A1 - Erkelenz, Steffen A1 - Schenk, Christian A1 - Schaal, Heiner A1 - Bodem, Jochen T1 - A purine-rich element in foamy virus pol regulates env splicing and gag/pol expression JF - Retrovirology N2 - 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. KW - splice regulation KW - foamy viruses KW - branch point KW - purine-rich element KW - RNA export Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-157614 VL - 14 IS - 10 ER - TY - THES A1 - Haack, Stephanie T1 - A novel mouse model for systemic cytokine release upon treatment with a superagonistic anti-CD28 antibody T1 - Ein neues Mausmodell zur Untersuchung der Zytokinfreisetzung nach Behandlung mit einem superagonistischen anti-CD28 Antikörper N2 - The adaptive immune system is known to provide highly specific and effective immunity against a broad variety of pathogens due to different effector cells. The most prominent are CD4+ T-cells which differentiate after activation into distinct subsets of effector and memory cells, amongst others T helper 1 (Th1) cells. We have recently shown that mouse as well as human Th1 cells depend on T cell receptor (TCR) signals concomitant with CD28 costimulation in order to secrete interferon  (IFN) which is considered as their main effector function. Moreover, there is a class of anti-CD28 monoclonal antibodies that is able to induce T cell (re-)activation without concomitant TCR ligation. These so-called CD28-superagonists (CD28-SA) have been shown to preferentially activate and expand CD4+ Foxp3+ regulatory T (Treg) cells and thereby efficaciously conferring protection e.g. against autoimmune responses in rodents and non-human primates. Considering this beneficial effect, CD28-SA were thought to be of great impact for immunotherapeutic approaches and a humanized CD28-SA was subjected to clinical testing starting with a first-in-man trial in London in 2006. Unexpectedly, the volunteers experienced life-threatening side effects due to a cytokine release syndrome (CRS) that was unpredicted by the preclinical studies prior to the trial. Retrospectively, CD4+ memory T cells within the tissues were identified as source of pro-inflammatory cytokines released upon CD28-SA administration. This was not predicted by the preclinical testing indicating a need for more reliable and predictive animal models. Whether mouse CD4+ T cells are generally irresponsive to CD28-SA stimulation or rather the lack of a bona fide memory T cell compartment in cleanly housed specific-pathogen-free (SPF) mice is the reason why the rodent models failed to predict the risk for a CRS remained unclear. To provide SPF mice with a true pool of memory/effector T cells, we transferred in vitro differentiated TCR-transgenic OT-II Th1 cells into untreated recipient mice. Given that Treg cells suppress T cell activation after CD28- SA injection in vivo, recipients were either Treg-competent or Treg-deficient, wild type or DEREG mice, respectively. Subsequent CD28-SA administration resulted in induction of systemic pro-inflammatory cytokine release, dominated by IFN, that was observed to be much more pronounced and robust in Treg-deficient recipients. Employing a newly established in vitro system mirroring the in vivo responses to CD28-SA stimulation of Th1 cells revealed that antigen-presenting cells (APCs) amplify CD28-SAinduced IFN release by Th1 cells due to CD40/CD40L-interactions. Thus, these data are the first to show that mouse Th1 cells are indeed sensitive to CD28-SA stimulation in vivo and in vitro responding with strong IFN release accompanied by secretion of further pro-inflammatory cytokines, which is compatible with a CRS. In conclusion, this study will facilitate preclinical testing of immunomodulatory agents providing a mouse model constituting more “human-like” conditions allowing a higher degree of reliability and translationability. N2 - Das adaptive Immunsystem ermöglicht mittels hocheffektiver, antigen-spezifischer Mechanismen und unterschiedlicher Effektorzellen den Schutz vor einer nahezu unbegrenzten Vielfalt von Pathogenen. Die Hauptakteure stellen hierbei CD4+ T-Zellen dar, welche nach Aktivierung distinkte Effektorpopulationen, unter anderem Th1 Zellen, bilden. Wir zeigten kürzlich, dass sowohl für Maus- als auch humane Th1-Zellen CD28-Kostimulation mit zeitgleicher T-Zellrezeptor (TZR)-Aktivierung essentiell für die Sekretion von Interferon  (IFN), deren Haupteffektorfunktion, ist. Allerdings sind monoklonale anti-CD28 Anti-körper bekannt, die auch ohne TZR-Signal T-Zellen aktivieren können. Diese sogenannten CD28 Supera-gonisten (CD28-SA) aktivieren und expandieren vorrangig CD4+ Foxp3+ regulatorische T-Zellen (Treg) und vermitteln wirksamen Schutz vor z.B. Autoimmunreaktionen in Nagern und Primaten. Um diesen erfolgversprechenden Effekt für immuntherapeutische Ansätze nutzen zu können, wurde 2006 in Lon-don eine erste klinische Erprobung eines humanisierten CD28-SA begonnen. Unerwarteterweise zeigten sich bei den Probanden lebensbedrohliche Nebenwirkungen, die Ausdruck eines Zytokin-Ausschüttungs-Syndroms (Cytokine Release Syndrome, CRS) waren, welches durch die vorangegangenen präklinischen Studien nicht vorhersagbar war. Rückblickend konnte die Sekretion pro-inflammatorischer Zytokine auf CD4+ Gedächtnis-T-Zellen im Gewebe zurückgeführt werden, die so auf die Gabe des CD28-SA reagier-ten. Die unvorhersehbare Reaktion im Menschen zeigt deutlich, dass verlässlichere und prädiktivere Tiermodelle unverzichtbar sind. Ob Maus CD4+-T-Zellen möglicherweise nicht durch CD28-SA stimulier-bar sind oder dieser fehlgeleiteten Einschätzung über das mögliche Risiko eines CRS eher das Fehlen eines echten CD4+ Gedächtnis-T-Zellen-Kompartiments in sauber gehaltenen spezifischen-Pathogen-freien (SPF) Mäusen zugrunde liegt, ist bisher ungeklärt. Um in SPF-Mäusen ein Gedächtnis-T-Zell-Kompartiment zu etablieren, wurden in vitro-differenzierte Th1 Zellen, die TZR-transgenen OT-II-Mäusen entstammen, in unbehandelte Empfängermäuse transferiert. Da bekannt ist, dass Treg-Zellen die Aktivierung von T-Zellen nach Anwendung von CD28-SA in vivo supprimieren, wurden Treg-kompetente (wildtypische) oder -defiziente (DEREG) Empfänger verwendet. Die anschließend erfolgte Injektion von CD28-SA löste die systemische Sekretion pro-inflammatorischer Zytokine aus, wobei eine stark erhöhter IFN-Konzentration im Serum zu beobachten war, welche deutlich ausgeprägter und robuster bei den Treg-defizienten Empfängern ausfiel. Ein neu etabliertes in vitro-System, welches die in vivo Antwort der Th1-Zellen auf CD28-SA-Stimulation widerspiegelt, identifizierte Antigen-präsentierende Zellen (APZs) als essentiellen Faktor für die erhöhte IFN-Sekretion der Th1-Zellen nach CD28-SA-Stimulation in Abhängigkeit von CD40/CD40L-Interaktionen. Zusammenfassend zeigt diese Thesis zum ersten Mal, dass Maus Th1 Zellen sowohl in vivo als auch in vitro durch CD28 SA stimulierbar sind, wodurch eine starke IFN-Sekretion induziert wird, die von der gesteigerten Ausschüttung anderer pro-inflammatorischer Zytokine begleitet wird und in Abwesenheit von Treg einem CRS gleicht. Folglich kann diese Erkenntnis die präklinische Forschung bei der Erprobung neuer immuntherapeutischer Ansät-ze durch ein neues Mausmodell voranbringen, das dem menschlichen erfahreneren Immunsystem mehr als bisherige Modelle entspricht und somit verlässlichere Vorhersagen erlaubt und eine verbesserte Übertragbarkeit von Maus zu Mensch ermöglicht. KW - CD28 KW - CD28-SA KW - cytokine release syndrome Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-237757 ER - TY - JOUR A1 - Merget, Benjamin A1 - Wolf, Matthias T1 - A molecular phylogeny of Hypnales (Bryophyta) inferred from ITS2 sequence-structure data N2 - Background: Hypnales comprise over 50% of all pleurocarpous mosses. They provide a young radiation complicating phylogenetic analyses. To resolve the hypnalean phylogeny, it is necessary to use a phylogenetic marker providing highly variable features to resolve species on the one hand and conserved features enabling a backbone analysis on the other. Therefore we used highly variable internal transcribed spacer 2 (ITS2) sequences and conserved secondary structures, as deposited with the ITS2 Database, simultaneously. Findings: We built an accurate and in parts robustly resolved large scale phylogeny for 1,634 currently available hypnalean ITS2 sequence-structure pairs. Conclusions: Profile Neighbor-Joining revealed a possible hypnalean backbone, indicating that most of the hypnalean taxa classified as different moss families are polyphyletic assemblages awaiting taxonomic changes. KW - Moose KW - Hypnales KW - Bryophyta Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-67997 ER - TY - JOUR A1 - Herrmann, Thomas A1 - Karunakaran, Mohindar Murugesh A1 - Fichtner, Alina Suzann T1 - A glance over the fence: Using phylogeny and species comparison for a better understanding of antigen recognition by human γδ T‐cells JF - Immunological Reviews N2 - Both, jawless and jawed vertebrates possess three lymphocyte lineages defined by highly diverse antigen receptors: Two T‐cell‐ and one B‐cell‐like lineage. In both phylogenetic groups, the theoretically possible number of individual antigen receptor specificities can even outnumber that of lymphocytes of a whole organism. Despite fundamental differences in structure and genetics of these antigen receptors, convergent evolution led to functional similarities between the lineages. Jawed vertebrates possess αβ and γδ T‐cells defined by eponymous αβ and γδ T‐cell antigen receptors (TCRs). “Conventional” αβ T‐cells recognize complexes of Major Histocompatibility Complex (MHC) class I and II molecules and peptides. Non‐conventional T‐cells, which can be αβ or γδ T‐cells, recognize a large variety of ligands and differ strongly in phenotype and function between species and within an organism. This review describes similarities and differences of non‐conventional T‐cells of various species and discusses ligands and functions of their TCRs. A special focus is laid on Vγ9Vδ2 T‐cells whose TCRs act as sensors for phosphorylated isoprenoid metabolites, so‐called phosphoantigens (PAg), associated with microbial infections or altered host metabolism in cancer or after drug treatment. We discuss the role of butyrophilin (BTN)3A and BTN2A1 in PAg‐sensing and how species comparison can help in a better understanding of this human Vγ9Vδ2 T‐cell subset. KW - antigen presentation KW - BTN2 KW - BTN3 KW - butyrophilin KW - evolution KW - γδ TCR Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218373 VL - 298 IS - 1 SP - 218 EP - 236 ER - TY - JOUR A1 - Karunakaran, Mohindar M. A1 - Subramanian, Hariharan A1 - Jin, Yiming A1 - Mohammed, Fiyaz A1 - Kimmel, Brigitte A1 - Juraske, Claudia A1 - Starick, Lisa A1 - Nöhren, Anna A1 - Länder, Nora A1 - Willcox, Carrie R. A1 - Singh, Rohit A1 - Schamel, Wolfgang W. A1 - Nikolaev, Viacheslav O. A1 - Kunzmann, Volker A1 - Wiemer, Andrew J. A1 - Willcox, Benjamin E. A1 - Herrmann, Thomas T1 - A distinct topology of BTN3A IgV and B30.2 domains controlled by juxtamembrane regions favors optimal human γδ T cell phosphoantigen sensing JF - Nature Communications N2 - Butyrophilin (BTN)–3A and BTN2A1 molecules control the activation of human Vγ9Vδ2 T cells during T cell receptor (TCR)-mediated sensing of phosphoantigens (PAg) derived from microbes and tumors. However, the molecular rules governing PAg sensing remain largely unknown. Here, we establish three mechanistic principles of PAg-mediated γδ T cell activation. First, in humans, following PAg binding to the intracellular BTN3A1-B30.2 domain, Vγ9Vδ2 TCR triggering involves the extracellular V-domain of BTN3A2/BTN3A3. Moreover, the localization of both protein domains on different chains of the BTN3A homo-or heteromers is essential for efficient PAg-mediated activation. Second, the formation of BTN3A homo-or heteromers, which differ in intracellular trafficking and conformation, is controlled by molecular interactions between the juxtamembrane regions of the BTN3A chains. Finally, the ability of PAg not simply to bind BTN3A-B30.2, but to promote its subsequent interaction with the BTN2A1-B30.2 domain, is essential for T-cell activation. Defining these determinants of cooperation and the division of labor in BTN proteins improves our understanding of PAg sensing and elucidates a mode of action that may apply to other BTN family members. KW - gammadelta T cells KW - immunosurveillance Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-358179 VL - 14 ER - TY - JOUR A1 - Sivarajan, Rinu A1 - Oberwinkler, Heike A1 - Roll, Valeria A1 - König, Eva-Maria A1 - Steinke, Maria A1 - Bodem, Jochen T1 - A defined anthocyanin mixture sourced from bilberry and black currant inhibits Measles virus and various herpesviruses JF - BMC Complementary Medicine and Therapies N2 - Background Anthocyanin-containing plant extracts and carotenoids, such as astaxanthin, have been well-known for their antiviral and anti-inflammatory activity, respectively. We hypothesised that a mixture of Ribes nigrum L. (Grossulariaceae) (common name black currant (BC)) and Vaccinium myrtillus L. (Ericaceae) (common name bilberry (BL)) extracts (BC/BL) with standardised anthocyanin content as well as single plant extracts interfered with the replication of Measles virus and Herpesviruses in vitro. Methods We treated cell cultures with BC/BL or defined single plant extracts, purified anthocyanins and astaxanthin in different concentrations and subsequently infected the cultures with the Measles virus (wild-type or vaccine strain Edmonston), Herpesvirus 1 or 8, or murine Cytomegalovirus. Then, we analysed the number of infected cells and viral infectivity and compared the data to non-treated controls. Results The BC/BL extract inhibited wild-type Measles virus replication, syncytia formation and cell-to-cell spread. This suppression was dependent on the wild-type virus-receptor-interaction since the Measles vaccine strain was unaffected by BC/BL treatment. Furthermore, the evidence was provided that the delphinidin-3-rutinoside chloride, a component of BC/BL, and purified astaxanthin, were effective anti-Measles virus compounds. Human Herpesvirus 1 and murine Cytomegalovirus replication was inhibited by BC/BL, single bilberry or black currant extracts, and the BC/BL component delphinidin-3-glucoside chloride. Additionally, we observed that BC/BL seemed to act synergistically with aciclovir. Moreover, BC/BL, the single bilberry and black currant extracts, and the BC/BL components delphinidin-3-glucoside chloride, cyanidin-3-glucoside, delphinidin-3-rutinoside chloride, and petunidin-3-galactoside inhibited human Herpesvirus 8 replication. Conclusions Our data indicate that Measles viruses and Herpesviruses are differentially susceptible to a specific BC/BL mixture, single plant extracts, purified anthocyanins and astaxanthin. These compounds might be used in the prevention of viral diseases and in addition to direct-acting antivirals, such as aciclovir. KW - anthocyanin KW - astaxanthin KW - bilberry KW - black currant KW - herpesvirus KW - measels virus Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-301423 VL - 22 ER - TY - JOUR A1 - Kühlhorn, Franziska A1 - Rath, Matthias A1 - Schmoeckel, Katrin A1 - Cziupka, Katharina A1 - Nguyen, Huu Hung A1 - Hildebrandt, Petra A1 - Hünig, Thomas A1 - Sparwasser, Tim A1 - Huehn, Jochen A1 - Pötschke, Christian A1 - Bröker, Barbara M. T1 - \(Foxp3^+\) Regulatory T Cells Are Required for Recovery from Severe Sepsis JF - PLoS ONE N2 - The role of regulatory T cells (Tregs) in bacterial sepsis remains controversial because antibody-mediated depletion experiments gave conflicting results. We employed DEREG mice (DEpletion of REGulatory T cells) and a caecal ligation and puncture model to elucidate the role of \(CD4^+Foxp3^+\) Tregs in sepsis. In DEREG mice natural Tregs can be visualized easily and selectively depleted by diphtheria toxin because the animals express the diphtheria toxin receptor and enhanced green fluorescent protein as a fusion protein under the control of the foxp3 locus. We confirmed rapid Treg-activation and an increased ratio of Tregs to Teffs in sepsis. Nevertheless, 24 h after sepsis induction, Treg-depleted and control mice showed equally strong inflammation, immune cell immigration into the peritoneum and bacterial dissemination. During the first 36 h of disease survival was not influenced by Treg-depletion. Later, however, only Treg-competent animals recovered from the insult. We conclude that the suppressive capacity of Tregs is not sufficient to control overwhelming inflammation and early mortality, but is a prerequisite for the recovery from severe sepsis. KW - CD4(+)CD25(+) KW - toll-like receptors KW - TGF-BETA KW - mediated suppression KW - polymicrobial sepsis KW - improves survival KW - adoptive transfer KW - infected mice KW - in-vivo KW - CD4(+) Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130940 VL - 8 IS - 5 ER - TY - JOUR A1 - Klotz, Barbara A1 - Mentrup, Birgit A1 - Regensburger, Martina A1 - Zeck, Sabine A1 - Schneidereit, Jutta A1 - Schupp, Nicole A1 - Linden, Christian A1 - Merz, Cornelia A1 - Ebert, Regina A1 - Jakob, Franz T1 - 1,25-Dihydroxyvitamin D3 Treatment Delays Cellular Aging in Human Mesenchymal Stem Cells while Maintaining Their Multipotent Capacity JF - PLoS ONE N2 - 1,25-dihydroxyvitamin D3 (1,25D3) was reported to induce premature organismal aging in fibroblast growth factor-23 (Fgf23) and klotho deficient mice, which is of main interest as 1,25D3 supplementation of its precursor cholecalciferol is used in basic osteoporosis treatment. We wanted to know if 1,25D3 is able to modulate aging processes on a cellular level in human mesenchymal stem cells (hMSC). Effects of 100 nM 1,25D3 on hMSC were analyzed by cell proliferation and apoptosis assay, beta-galactosidase staining, VDR and surface marker immunocytochemistry, RT-PCR of 1,25D3-responsive, quiescence-and replicative senescence-associated genes. 1,25D3 treatment significantly inhibited hMSC proliferation and apoptosis after 72 h and delayed the development of replicative senescence in long-term cultures according to beta-galactosidase staining and P16 expression. Cell morphology changed from a fibroblast like appearance to broad and rounded shapes. Long term treatment did not induce lineage commitment in terms of osteogenic pathways but maintained their clonogenic capacity, their surface marker characteristics (expression of CD73, CD90, CD105) and their multipotency to develop towards the chondrogenic, adipogenic and osteogenic pathways. In conclusion, 1,25D3 delays replicative senescence in primary hMSC while the pro-aging effects seen in mouse models might mainly be due to elevated systemic phosphate levels, which propagate organismal aging. KW - perspectives KW - bone marrow KW - mutant mice KW - oxidative stress KW - transcription factors KW - vitamin-D-receptor KW - differentiation KW - tissue KW - 2',7'-dichlorofluorescin KW - homeostasis Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-133392 VL - 7 IS - 1 ER -