@phdthesis{Beyersdorf2004, author = {Beyersdorf, Niklas}, title = {Ph{\"a}notyp und Funktion KLRG1-exprimierender Lymphozyten der Maus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-17550}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2004}, abstract = {Die Reifung, Differenzierung und Funktion von Lymphozyten wird maßgeblich von aktivierenden und inhibitorischen Zelloberfl{\"a}chenrezeptoren reguliert. "Killer cell Lectin-like receptor G1" (KLRG1) ist ein Typ-II-Transmembranprotein, dessen Expression auf Subpopulationen von T-Lymphozyten und Nat{\"u}rlichen Killerzellen beschr{\"a}nkt ist. Die vorliegende Arbeit hatte zum Ziel, die differentielle Expression und m{\"o}gliche Funktion von KLRG1 auf diesen Zellen im Maussystem zu charakterisieren. Mit Hilfe zellbiologischer Untersuchungsmethoden konnte gezeigt werden, dass die KLRG1-Expressionsfrequenz mit dem Reifegrad der Zellen korreliert. Fr{\"u}here Beobachtungen, wonach KLRG1 durch Erkennung eigener Klasse-I-Molek{\"u}le des Haupthistokompatibilit{\"a}tskomplexes (MHC) {\"u}ber inhibitorische Rezeptoren der Ly49-Familie induziert wird, konnten auf klassische Klasse-I-Molek{\"u}le und neue Ly49-Familienmitglieder ausgeweitet werden. Ferner belegen Daten dieser Arbeit, dass reife NK-Zellen die KLRG1-Expressionsfrequenz in verschiedenen lymphoiden Organen dem Klasse-I-Niveau der umgebenden Zellen anpassen k{\"o}nnen und dass T- und B-Lymphozyten m{\"o}glicherweise eine zentrale Rolle hierbei spielen. Somit stellt KLRG1 einen NK-Zellrezeptor dar, dessen Expression durch Ly49-Rezeptorengagement dynamisch reguliert wird. Es ist m{\"o}glich, dass KLRG1 kompensatorische (ko-)inhibitorische Eigenschaften besitzt, die f{\"u}r die Aufrechterhaltung der Selbsttoleranz von NK-Zellen von Bedeutung sind. Unter den CD8-T-Zellen identifiziert ein polyklonales abT-Zellrezeptorrepertoire und die Expression von CD8 als ab-Heterodimer den 2-3\%igen Anteil an KLRG1+ Zellen als konventionelle T-Zellen thymischen Ursprungs. Umfangreiche ph{\"a}notypische und funktionelle Analysen ergaben, dass KLRG1-exprimierende CD8-Zellen sich aus ca. 20\% proinflammatorischer Effektorzellen und ca. 80\% Ged{\"a}chtniszellen zusammensetzen. Aufgrund von Daten der Arbeitsgruppe Pircher scheint das Zellteilungsverm{\"o}gen letzterer ausgesch{\"o}pft zu sein. Demzufolge markiert KLRG1 eine neue Subpopulation von CD8-T-Zellen, der sowohl Effektorzellen, als auch "replikativ seneszente" Ged{\"a}chtniszellen angeh{\"o}ren. Abschließende Untersuchungen ergaben, dass KLRG1 interessanterweise auch von 1-2\% der CD4+ T-Zellen exprimiert wird und dass die KLRG1+ CD4-T-Zellen zum Großteil CD25 koexprimieren. Funktionelle Anschlußexperimente zeigten, dass es sich bei diesen Zellen um regulatorische T-Zellen handelt. Zusammenfassend kennzeichnet KLRG1-Expression eine Subpopulationen von NK-Zellen, die k{\"o}rpereigene Zellen {\"u}ber Klasse-I erkennen k{\"o}nnen, eine Untergruppe von Effektor- und seneszenten CD8-T-Zellen sowie neuartige regulatorische CD4-T-Zellen.}, language = {de} } @article{BeyersdorfWernerWolfetal.2011, author = {Beyersdorf, Niklas and Werner, Sandra and Wolf, Nelli and Herrmann, Thomas and Kerkau, Thomas}, title = {Characterization of a New Mouse Model for Peripheral T Cell Lymphoma in Humans}, series = {PLoS One}, volume = {6}, journal = {PLoS One}, number = {12}, doi = {10.1371/journal.pone.0028546}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-137946}, pages = {e28546}, year = {2011}, abstract = {Peripheral T cell lymphomas (PTCLs) are associated with a poor prognosis due to often advanced disease at the time of diagnosis and due to a lack of efficient therapeutic options. Therefore, appropriate animal models of PTCL are vital to improve clinical management of this disease. Here, we describe a monoclonal CD8\(^+\) CD4\(^-\) αβ T cell receptor Vβ2\(^+\) CD28\(^+\) T cell lymphoma line, termed T8-28. T8-28 cells were isolated from an un-manipulated adult BALB/c mouse housed under standard pathogen-free conditions. T8-28 cells induced terminal malignancy upon adoptive transfer into syngeneic BALB/c mice. Despite intracellular expression of the cytotoxic T cell differentiation marker granzyme B, T8-28 cells appeared to be defective with respect to cytotoxic activity as read-out in vitro. Among the protocols tested, only addition of interleukin 2 in vitro could partially compensate for the in vivo micro-milieu in promoting growth of the T8-28 lymphoma cells.}, language = {en} } @article{BoivinBeyersdorfPalmetal.2015, author = {Boivin, Val{\´e}rie and Beyersdorf, Niklas and Palm, Dieter and Nikolaev, Viacheslav O. and Schlipp, Angela and M{\"u}ller, Justus and Schmidt, Doris and Kocoski, Vladimir and Kerkau, Thomas and H{\"u}nig, Thomas and Ertl, Georg and Lohse, Martin J. and Jahns, Roland}, title = {Novel Receptor-Derived Cyclopeptides to Treat Heart Failure Caused by \(Anti-β_1-Adrenoceptor\) Antibodies in a Human-Analogous Rat Model}, series = {PLoS One}, volume = {10}, journal = {PLoS One}, number = {2}, doi = {10.1371/journal.pone.0117589}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126028}, pages = {e0117589}, year = {2015}, abstract = {Despite recent therapeutic advances the prognosis of heart failure remains poor. Recent research suggests that heart failure is a heterogeneous syndrome and that many patients have stimulating auto-antibodies directed against the second extracellular loop of the \(β_1\) adrenergic receptor \((β_1EC2)\). In a human-analogous rat model such antibodies cause myocyte damage and heart failure. Here we used this model to test a novel antibody-directed strategy aiming to prevent and/or treat antibody-induced cardiomyopathy. To generate heart failure, we immunised n = 76/114 rats with a fusion protein containing the human β1EC2 (amino-acids 195-225) every 4 weeks; n = 38/114 rats were control-injected with 0.9\% NaCl. Intravenous application of a novel cyclic peptide mimicking \(β_1EC2\) (\(β_1EC2-CP\), 1.0 mg/kg every 4 weeks) or administration of the \(β_1-blocker\) bisoprolol (15 mg/kg/day orally) was initiated either 6 weeks (cardiac function still normal, prevention-study, n = 24 (16 treated vs. 8 untreated)) or 8.5 months after the 1st immunisation (onset of cardiomyopathy, therapy-study, n = 52 (40 treated vs. 12 untreated)); n = 8/52 rats from the therapy-study received \(β_1EC2-CP/bisoprolol\) co-treatment. We found that \(β_1EC2-CP\) prevented and (alone or as add-on drug) treated antibody-induced cardiac damage in the rat, and that its efficacy was superior to mono-treatment with bisoprolol, a standard drug in heart failure. While bisoprolol mono-therapy was able to stop disease-progression, \(β_1EC2-CP\) mono-therapy -or as an add-on to bisoprolol- almost fully reversed antibody-induced cardiac damage. The cyclo¬peptide acted both by scavenging free \(anti-β_1EC2-antibodies\) and by targeting \(β_1EC2\)-specific memory B-cells involved in antibody-production. Our model provides the basis for the clinical translation of a novel double-acting therapeutic strategy that scavenges harmful \(anti-β_1EC2-antibodies\) and also selectively depletes memory B-cells involved in the production of such antibodies. Treatment with immuno-modulating cyclopeptides alone or as an add-on to \(β_1\)-blockade represents a promising new therapeutic option in immune-mediated heart failure.}, language = {en} } @article{BergesKerkauWerneretal.2016, author = {Berges, Carsten and Kerkau, Thomas and Werner, Sandra and Wolf, Nelli and Winter, Nadine and H{\"u}nig, Thomas and Einsele, Hermann and Topp, Max S. and Beyersdorf, Niklas}, title = {Hsp90 inhibition ameliorates CD4\(^{+}\) T cell-mediated acute Graft versus Host disease in mice}, series = {Immunity, Inflammation and Disease}, volume = {4}, journal = {Immunity, Inflammation and Disease}, number = {4}, doi = {10.1002/iid3.127}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-168318}, pages = {463-473}, year = {2016}, abstract = {Introduction: For many patients with leukemia only allogeneic bone marrow transplantion provides a chance of cure. Co-transplanted mature donor T cells mediate the desired Graft versus Tumor (GvT) effect required to destroy residual leukemic cells. The donor T cells very often, however, also attack healthy tissue of the patient inducing acute Graft versus Host Disease (aGvHD)—a potentially life-threatening complication. Methods: Therefore, we used the well established C57BL/6 into BALB/c mouse aGvHD model to evaluate whether pharmacological inhibition of heat shock protein 90 (Hsp90) would protect the mice from aGvHD. Results: Treatment of the BALB/c recipient mice from day 0 to +2 after allogeneic CD4\(^{+}\) T cell transplantation with the Hsp90 inhibitor 17-(dimethylaminoethylamino)-17-demethoxygeldanamycin (DMAG) partially protected the mice from aGvHD. DMAG treatment was, however, insufficient to prolong overall survival of leukemia-bearing mice after transplantation of allogeneic CD4\(^{+}\) and CD8\(^{+}\) T cells. Ex vivo analyses and in vitro experiments revealed that DMAG primarily inhibits conventional CD4\(^{+}\) T cells with a relative resistance of CD4\(^{+}\) regulatory and CD8\(^{+}\) T cells toward Hsp90 inhibition. Conclusions: Our data, thus, suggest that Hsp90 inhibition might constitute a novel approach to reduce aGvHD in patients without abrogating the desired GvT effect.}, 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{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{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{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} } @article{LangenhorstHaackGoebetal.2018, author = {Langenhorst, Daniela and Haack, Stephanie and G{\"o}b, Selina and Uri, Anna and L{\"u}hder, Fred and Vanhove, Bernhard and H{\"u}nig, Thomas and Beyersdorf, Niklas}, title = {CD28 costimulation of T helper 1 cells enhances cytokine release in vivo}, series = {Frontiers in Immunology}, volume = {9}, journal = {Frontiers in Immunology}, number = {1060}, doi = {10.3389/fimmu.2018.01060}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176726}, year = {2018}, abstract = {Compared to naive T cells, differentiated T cells are thought to be less dependent on CD28 costimulation for full activation. To revisit the role of CD28 costimulation in mouse T cell recall responses, we adoptively transferred in vitro generated OT-II T helper (Th) 1 cells into C57BL/6 mice (Thy1.2\(^{+}\)) and then either blocked CD28-ligand interactions with Fab fragments of the anti-CD28 monoclonal antibody (mAb) E18 or deleted CD28 expression using inducible CD28 knock-out OT-II mice as T cell donors. After injection of ovalbumin protein in adjuvant into the recipient mice we observed that systemic interferon (IFN)γ release strongly depended on CD28 costimulation of the Th1 cells, while secondary clonal expansion was not reduced in the absence of CD28 costimulation. For human memory CD4\(^{+}\) T cell responses we also noted that cytokine release was reduced upon inhibition of CD28 costimulation. Together, our data highlight the so far underestimated role of CD28 costimulation for the reactivation of fully differentiated CD4\(^{+}\) T cells.}, language = {en} } @article{DasariShopovaStroeetal.2018, author = {Dasari, Prasad and Shopova, Iordana A. and Stroe, Maria and Wartenberg, Dirk and Martin-Dahse, Hans and Beyersdorf, Niklas and Hortschansky, Peter and Dietrich, Stefanie and Cseresny{\´e}s, Zolt{\´a}n and Figge, Marc Thilo and Westermann, Martin and Skerka, Christine and Brakhage, Axel A. and Zipfel, Peter F.}, title = {Aspf2 From Aspergillus fumigatus Recruits Human Immune Regulators for Immune Evasion and Cell Damage}, series = {Frontiers in Immunology}, volume = {9}, journal = {Frontiers in Immunology}, number = {1635}, issn = {1664-3224}, doi = {10.3389/fimmu.2018.01635}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-197013}, year = {2018}, abstract = {The opportunistic fungal pathogen Aspergillus fumigatus can cause life-threatening infections, particularly in immunocompromised patients. Most pathogenic microbes control host innate immune responses at the earliest time, already before infiltrating host immune cells arrive at the site of infection. Here, we identify Aspf2 as the first A. fumigatus Factor H-binding protein. Aspf2 recruits several human plasma regulators, Factor H, factor-H-like protein 1 (FHL-1), FHR1, and plasminogen. Factor H contacts Aspf2 via two regions located in SCRs6-7 and SCR20. FHL-1 binds via SCRs6-7, and FHR1 via SCRs3-5. Factor H and FHL-1 attached to Aspf2-maintained cofactor activity and assisted in C3b inactivation. A Δaspf2 knockout strain was generated which bound Factor H with 28\% and FHL-1 with 42\% lower intensity. In agreement with less immune regulator acquisition, when challenged with complement-active normal human serum, Δaspf2 conidia had substantially more C3b (>57\%) deposited on their surface. Consequently, Δaspf2 conidia were more efficiently phagocytosed (>20\%) and killed (44\%) by human neutrophils as wild-type conidia. Furthermore, Aspf2 recruited human plasminogen and, when activated by tissue-type plasminogen activator, newly generated plasmin cleaved the chromogenic substrate S2251 and degraded fibrinogen. Furthermore, plasmin attached to conidia damaged human lung epithelial cells, induced cell retraction, and caused matrix exposure. Thus, Aspf2 is a central immune evasion protein and plasminogen ligand of A. fumigatus. By blocking host innate immune attack and by disrupting human lung epithelial cell layers, Aspf2 assists in early steps of fungal infection and likely allows tissue penetration.}, language = {en} }