@phdthesis{Rizzo2023, author = {Rizzo, Giuseppe}, title = {Determinants of macrophage and neutrophil heterogeneity in cardiac repair after myocardial infarction}, doi = {10.25972/OPUS-31068}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-310680}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Current therapeutic strategies efficiently improve survival in patients after myocardial infarction (MI). Nevertheless, long-term consequences such as heart failure development, are still one of the leading causes of death worldwide. Inflammation is critically involved in the cardiac healing process after MI and has a dual role, contributing to both tissue healing and tissue damage. In the last decade, a lot of attention was given to targeting inflammation as a potential therapeutic approach in MI, but the poor understanding of inflammatory cell heterogeneity and function is a limit to the development of immune modulatory strategies. The recent development of tools to profile immune cells with high resolution has provided a unique opportunity to better understand immune cell heterogeneity and dynamics in the ischemic heart. In this thesis, we employed single-cell RNA-sequencing combined with detection of epitopes by sequencing (CITE-seq) to refine our understanding of neutrophils and monocytes/macrophages heterogeneity and dynamic after experimental myocardial infarction. Neutrophils rapidly invade the infarcted heart shortly after ischemic damage and have previously been proposed to display time-dependent functional heterogeneity. At the single-cell level, we observed dynamic transcriptional heterogeneity in neutrophil populations during the acute post-MI phase and defined previously unknown cardiac neutrophil states. In particular, we identified a locally acquired SiglecFhi neutrophil state that displayed higher ROS production and phagocytic ability compared to newly recruited neutrophils, suggesting the acquisition of specific function in the infarcted heart. These findings highlight the importance of the tissue microenvironment in shaping neutrophil response. From the macrophage perspective, we characterized MI-associated monocyte-derived macrophage subsets, two with a pro-inflammatory gene signature (MHCIIhiIl1βhi) and three Trem2hi macrophage populations with a lipid associated macrophage (LAM) signature, also expressing pro-fibrotic and tissue repair genes. Combined analysis of blood monocytes and cardiac monocyte/macrophages indicated that the Trem2hi LAM signature is acquired in the infarcted heart. We furthermore characterized the role of TREM2, a surface protein expressed mainly in macrophages and involved in macrophage survival and function, in the post-MI macrophage response and cardiac repair. Using TREM2 deficient mice, we demonstrate that acquisition of the LAM signature in cardiac macrophages after MI is partially dependent on TREM2. While their cardiac function was not affected, TREM2 deficient mice showed reduced collagen deposition in the heart after MI. Thus, our data in Trem2-deficient mice highlight the role of TREM2 in promoting a macrophage pro-fibrotic phenotype, in line with the pro-fibrotic/tissue repair gene signature of the Trem2hi LAM-signature genes. Overall, our data provide a high-resolution characterization of neutrophils and macrophage heterogeneity and dynamics in the ischemic heart and can be used as a valuable resource to investigate how these cells modulate the healing processes after MI. Furthermore, our work identified TREM2 as a regulator of macrophage phenotype in the infarcted heart}, subject = {Makrophage}, language = {en} } @phdthesis{Ranecky2023, author = {Ranecky, Maria Helena}, title = {Experimentelle Charakterisierung intestinaler, GvHD-protektiver myeloider Empf{\"a}ngerzellen nach allogener Stammzelltransplantation}, doi = {10.25972/OPUS-31092}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-310924}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Die akute Graft-versus-Host Disease (GvHD) und speziell ihre intestinale Manifestation ist eine schwere Komplikation der allogenen Stammzelltransplantation mit erheblichem Einfluss auf Mortalit{\"a}t und Morbidit{\"a}t der Patienten. Pathophysiologisch stellt sie eine Immunreaktion von Spender-T-Zellen auf Empf{\"a}ngergewebestrukturen dar. In Versuchsm{\"a}usen ist die experimentelle Depletion CD11c+ Antigen-pr{\"a}sentierender Empf{\"a}ngerzellen in der fr{\"u}hen GvHD-Effektorphase assoziiert mit einem schlechteren klinischen Outcome, einer h{\"o}heren Dichte alloreaktiver T-Zellen und einer verst{\"a}rkten Entz{\"u}ndungsreaktion in der intestinalen Mukosa. Ziel der Studie war eine umfassende Charakterisierung und systematische Einordnung der folglich GvHD-protektiven intestinalen CD11c+ Empf{\"a}ngerzellen. Bez{\"u}glich ihrer Oberfl{\"a}chenproteinsignatur analysierten wir die myeloiden Zellen der intestinalen Mukosa am Tag 6 nach allogener Stammzelltransplantation. Mittels durchflusszytometrischer Analyse und Vergleich zwischen gesunden, allein bestrahlten und GvHD-M{\"a}usen ordneten wir die CD11c+ Empf{\"a}ngerzellen als Makrophagen ein und schlossen eine Identit{\"a}t als dendritische Zellen aus. In der Immunfluoreszenzmikroskopie wiesen wir ihre Kolokalisation mit allogenen T-Zellen nach und best{\"a}tigten darin eine PD-L1 Expression als m{\"o}glichen T-Zell-Suppressionsmechanismus. Bez{\"u}glich ihres Transkriptoms f{\"u}hrten wir eine Einzelzell-RNA-Sequenzierung intestinaler h{\"a}matopoetischer Empf{\"a}ngerzellen aus CD11c+ Zell-depletierten und nicht depletierten M{\"a}usen durch. Auf rein bioinformatischer Grundlage wurden die Einzelzellen kombiniert und anhand ihrer Transkriptomprofile in Cluster eingeteilt. Der Vergleich beider Versuchsgruppen offenbarte zwei unterschiedliche pr{\"a}sente bzw. depletierte und damit GvHD-protektive Zellcluster: Cluster 4 enthielt Zellen mit deutlicher Makrophagensignatur und gewebeprotektivem, antipathogenem Effektorprofil, welches in Kombination mit weiteren Genen ein Kontinuum der in Hom{\"o}ostase vorhandenen Makrophagen nahelegte. Cluster 10 dagegen enthielt Zellen mit immun- und spezifisch T-Zell-suppressivem Effektorprofil, weniger deutlicher Makrophagensignatur und {\"A}hnlichkeit zu myeloiden Suppressorzellen. Somit lieferte die Studie wichtige Hinweise auf einen Mechanismus der GvHD- bzw. T-Zell-Suppression und Gewebeprotektion in Form von physiologisch vorhandenen bzw. im Laufe der GvHD auftretenden Empf{\"a}ngermakrophagen.}, subject = {Makrophage}, language = {de} } @phdthesis{Reinsberg2023, author = {Reinsberg, Friederike Anna Christine}, title = {Die Bedeutung des gp130-Internalisierungmotivs f{\"u}r IL-6-vermittelte Signale und das Antigenpr{\"a}sentationspotential muriner Knochenmarksmakrophagen}, doi = {10.25972/OPUS-27705}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-277052}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Interleukin 6 (IL-6) bewirkt als Entz{\"u}ndungsmediator eine autokrine Makrophagen (MΦ) -Stimulation. Zur Verhinderung pathologischer Entz{\"u}ndungsaktivit{\"a}t sind IL-6-Signale stark reguliert, unter anderem durch die Dileucin-vermittelte Endozytose des Signaltransduktors gp130. Klassisches IL-6-Signaling ist abh{\"a}ngig von der Expression von IL-6Rα und gp130 auf der Zelloberfl{\"a}che, w{\"a}hrend IL-6-trans-Signaling durch l{\"o}slichen IL-6Rα nur von der gp130-Expression abh{\"a}ngt. Die Bedeutung des Dileucin-Internalisierungsmotivs f{\"u}r IL-6-vermittelte Signale in MΦ ist jedoch unklar. Ziel der vorliegenden Arbeit war eine Charakterisierung muriner GM-CSF- und M-CSF-ausgereifter Knochenmarks (KM) -MΦ hinsichtlich der Relevanz des gp130-Internalisierungsmotivs f{\"u}r IL-6-vermittelte-Signale. Hierzu wurde die gp130LLAA-Mauslinie als knock in-Modell zur Suppression der gp130-Endozytose verwendet. KM-MΦ entwickeln durch die Ausreifung mittels GM-CSF oder M-CSF einen distinkten Ph{\"a}notyp: M-CSF-ausgereifte KM-MΦ exprimieren mehr gp130 und IL-6Rα auf der Zelloberfl{\"a}che als GM-CSF-ausgereifte KM-MΦ. Dies limitiert sowohl klassisches als auch IL-6-trans-Signaling in GM-CSF-ausgereiften KM-MΦ: IL-6 induziert in diesen eine geringere STAT1-Aktivierung, das IL-6/IL-6Ra-Fusionsprotein hyper-IL-6 eine geringere STAT1- und STAT3-Aktivierung. KM-MΦ aus gp130LLAA-M{\"a}usen exprimieren mehr gp130 als KM-MΦ aus WT-M{\"a}usen bei {\"a}hnlichen Mengen IL-6Rα. Dabei ist die Rezeptorexpression auf gp130LLAA-KM-MΦ unabh{\"a}ngig vom Ausreifungsfaktor GM-CSF oder M-CSF. Durch die erh{\"o}hte gp130-Expression induziert IL-6-trans-Signaling in gp130LLAA-KM-MΦ eine st{\"a}rkere STAT1-Aktivierung als in WT-KM-MΦ, dies gilt insbesondere bei Ausreifung mit GM-CSF. Dagegen sind die STAT3-Aktivierung durch IL-6-trans-Signaling und die STAT1- und STAT3-Aktivierung durch klassisches IL-6-Signaling unabh{\"a}ngig von der Expression des Dileucin-Internalisierungsmotivs. Unklar bleibt, warum IL6-vermittelte Signale in GM-CSF-ausgereiften KM-MΦ st{\"a}rker durch Dileucin-abh{\"a}ngige gp130-Endozytose reguliert werden als in M-CSF-ausgereifte KM-MΦ. Weitere Untersuchungen sind n{\"o}tig.}, subject = {Makrophage}, language = {de} } @phdthesis{Tylek2021, author = {Tylek, Tina}, title = {Establishment of a Co-culture System of human Macrophages and hMSCs to Evaluate the Immunomodulatory Properties of Biomaterials}, doi = {10.25972/OPUS-20357}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-203570}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {The outcome of the innate immune response to biomaterials mainly determines whether the material will be incorporated in the body to fulfill its desired function or, when it gets encapsulated, will be rejected in the worst case. Macrophages are key players in this process, and their polarization state with either pro- (M1), anti-inflammatory (M2), or intermediate characteristics is crucial for deciding on the biomaterial's fate. While a transient initial pro-inflammatory state is helpful, a prolonged inflammation deteriorates the proper healing and subsequent regeneration. Therefore, biomaterial-based polarization may aid in driving macrophages in the desired direction. However, the in vivo process is highly complex, and a mono-culture of macrophages in vitro displays only one part of the cellular system, but, to this date, there is a lack of established co-cultures to assess the immune response to biomaterials. Thus, this thesis aimed to establish a functional co-culture system of human macrophages and human mesenchymal stromal cells (hMSCs) to improve the assessment of the immune response to biomaterials in vitro. Together with macrophages, hMSCs are involved in tissue regeneration and inflammatory reactions and can modulate the immune response. In particular, endogenously derived hMSCs considerably contribute to the successful engrafting of biomaterials. This thesis focused on poly(ε-caprolactone) (PCL) fiber-based scaffolds produced by the technique of melt electrowriting (MEW) as biomaterial constructs. Via this fabrication technique, uniform, precisely ordered scaffolds varying in geometry and pore size have been created in-house. To determine the impact of scaffold geometries and pore sizes on macrophages, mono-cultures incubated on scaffolds were conducted. As a pre-requisite to achieve a functional co-culture system on scaffolds, setups for direct and indirect systems in 2D have initially been established. These setups were analyzed for the capability of cell-cell communication. In parallel, a co-culture medium suitable for both cell types was defined, prior to the establishment of a step-by-step procedure for the co-cultivation of human macrophages and hMSCs on fiber-based scaffolds. Regarding the scaffold morphologies tested within this thesis to improve M2-like polarization, box-shaped scaffolds outperformed triangular-, round- or disordered-shaped ones. Upon further investigation of scaffolds with box-shaped pores and precise inter-fiber spacing from 100 µm down to only 40 µm, decreasing pore sizes facilitated primary human macrophage elongation accompanied by their differentiation towards the M2 type, which was most pronounced for the smallest pore size of 40 µm. To the best of my knowledge, this was the first time that the elongation of human macrophages in a 3D environment has been correlated to their M2-like polarization. Thus, these results may set the stage for the design, the assessment, and the selection of new biomaterials, which can positively affect the tissue regeneration. The cell communication of both cell types, detected via mitochondria exchange in direct and indirect co-cultures systems, took place in both directions, i.e., from hMSCs to macrophages and vice versa. Thereby, in direct co-culture, tunneling nanotubes enabled the transfer from one cell type to the respective other, while in indirect co-culture, a non-directional transfer through extracellular vesicles (EVs) released into the medium seemed likely. Moreover, the phagocytic activity of macrophages after 2D co-cultivation and hence immunomodulation by hMSCs increased with the highest phagocytic rate after 48 h being most pronounced in direct co-cultivation. As the commonly used serum supplements for macrophages and hMSCs, i.e., human serum (hS) and fetal calf serum (FCS), respectively, failed to support the respective other cell type during prolonged cultivation, these sera were replaced by human platelet lysate (hPL), which has been proven to be the optimal supplement for the co-cultivation of human macrophages with hMSCs within this thesis. Thereby, the phenotype of both cell types, the distribution of both cell populations, the phagocytic activity of macrophages, and the gene expression profiles were maintained and comparable to the respective standard mono-culture conditions. This was even true when hPL was applied without the anticoagulant heparin in all cultures with macrophages, and therefore, heparin was omitted for further experiments comprising hPL and macrophages. Accordingly, a step-by-step operating procedure for the co-cultivation on fiber-based scaffolds has been established comprising the setup for 3D cultivation as well as the description of methods for the analysis of phenotypical and molecular changes upon contact with the biomaterial. The evaluation of the macrophage response depending on the cultivation with or without hMSCs and either on scaffolds or on plastic surfaces has been successfully achieved and confirmed the functionality of the suggested procedures. In conclusion, the functional co-culture system of human macrophages and hMSCs established here can now be employed to assess biomaterials in terms of the immune response in a more in vivo-related way. Moreover, specifically designed scaffolds used within the present thesis showed auspicious design criteria positively influencing the macrophage polarization towards the anti-inflammatory, pro-healing type and might be adaptable to other biomaterials in future approaches. Hence, follow-up experiments should focus on the evaluation of the co-culture outcome on promising scaffolds, and the suggested operating procedures should be adjusted to further kinds of biomaterials, such as cements or hydrogels.}, subject = {Makrophage}, language = {en} } @phdthesis{Krakow2021, author = {Krakow, S{\"o}ren}, title = {CD14-Reexpression definiert einen immunregulatorischen Phänotyp Monozyten-gereifter Zellen nach IL-10/R848-Stimulation}, doi = {10.25972/OPUS-22428}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224280}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Dendritische Zellen k{\"o}nnen als antigenpr{\"a}sentierende Zellen sowohl immunogene als auch tolerogene Funktionen im Immunsystem wahrnehmen und werden in der Therapie von Tumorerkrankungen und Autoimmunerkrankungen eingesetzt. IL-10 gilt als Induktor tolerogener dendritischer Zellen. Diese werden in der Literatur oft als unreif bezeichnet und stehen im Gegensatz zu den reifen immunogenen dendritischen Zellen, die durch die Expression des Reifungsmarkers CD83 gekennzeichnet sind. Ausdifferenzierte dendritische Zellen exprimieren zudem das Antigen CD86, das der T-Zell-Aktivierung dient. In der vorliegenden Arbeit wurde der Einfluss von IL-10 auf den Reifungsprozess dendritischer Zellen in vitro untersucht. Zur Generierung unreifer dendritischer Zellen wurden humane Monozyten nach etabliertem Protokoll mit IL-4 und GM-CSF stimuliert. Nach anschließender IL-10-Stimulation, insbesondere in Kombination mit einem TLR-Agonisten, bildeten sich zwei exklusive Zellpopulationen: eine CD14+ Population und eine CD83+ Population. Unreife CD14-CD83- dendritische Zellen reexprimierten einerseits CD14 oder exprimierten andererseits CD83. Dabei zeigte sich, dass das kostimulierende Antigen CD86 gleichermaßen sowohl mit als auch ohne IL-10-Inkubation hoch exprimiert wurde und IL-10 folglich keinen zus{\"a}tzlichen Einfluss auf dessen Expression hat. Insgesamt waren Ver{\"a}nderungen bez{\"u}glich der Oberfl{\"a}chenantigene, die bei der Betrachtung der Gesamtheit aller Zellen auffallen, auf eine quantitative Verschiebung der beiden Zellpopulationen zur{\"u}ckzuf{\"u}hren. IL-10 beeinflusst also nicht direkt einzelne kostimulierende oder inhibitorische Molek{\"u}le, sondern beeinflusst den Anteil der CD14+ Zellen gegen{\"u}ber den CD83+ dendritischen Zellen. Funktionell betrachtet zeigten die CD14+ Zellen eine gesteigerte Makropinozytose im Gegensatz zu den reifen CD83+ dendritischen Zellen. Zusammenfassend f{\"u}hrt IL-10 zu einer Reexpression von CD14 auf unreifen dendritischen Zellen und aktiviert einen alternativen Differenzierungsweg. Die CD14+ Zellen weisen einen stabilen immunregulatorischen Ph{\"a}notyp auf und unterscheiden sich somit von reifen dendritischen Zellen, die nach Inkubation mit IL-10 nicht reguliert werden. Damit muss die Begrifflichkeit und Klassifikation tolerogener dendritischer Zellen weiter diskutiert werden.}, subject = {Dendritische Zelle}, language = {de} } @phdthesis{Schreiber2019, author = {Schreiber, David Lukas}, title = {CSF-1-Rezeptor Inhibitor als Therapieansatz in Mausmodellen f{\"u}r Charcot-Marie-Tooth Neuropathien Typ 1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-174931}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {Charcot-Marie-Tooth Neuropathien sind die h{\"a}ufigsten heredit{\"a}ren Erkrankungen des peripheren Nervensystems und dennoch bis heute nicht therapierbar. Die Lebensqualit{\"a}t der Patienten ist durch motorische und sensorische Defizite der Extremit{\"a}ten h{\"a}ufig stark eingeschr{\"a}nkt. Ursache k{\"o}nnen unter anderem Mutationen in Schwann-Zellen sein, die zu dem typischen Bild von Demyelinisierung und axonalem Schaden f{\"u}hren. In den letzten Jahren konnte in Mausmodellen das Immunsystem als wichtiger Mediator in der Pathogenese der CMT 1 Subtypen A, B und X identifiziert werden. Insbesondere Makrophagen spielen eine tragende Rolle bei dem Verlust der axonalen Integrit{\"a}t, bei der Sch{\"a}digung der Myelinscheiden, sowie bei der Dedifferenzierung von Schwann-Zellen. Entscheidender Faktor f{\"u}r Proliferation und Aktivierung der Makrophagen ist hierbei das Zytokin CSF-1, dessen korrespondierender Rezeptor auf Makrophagen exprimiert wird. Der CSF-1/CSF1R Signalweg bietet somit einen vielversprechenden Angriffspunkt. In der vorliegenden Arbeit wurden Mausmodelle der CMT 1 Subtypen A, B und X mit einem niedermolekularen CSF-1-Rezeptor Inhibitor behandelt. Anschließend erfolgte eine funktionelle und strukturelle Auswertung der peripheren Nerven. Das beste Ansprechen auf die Therapie zeigten Cx32def Mutanten. Strukturell fielen ein verringerter axonaler Schaden und eine verbesserte axonale Regenerationsf{\"a}higkeit sowie erhaltene neuromuskul{\"a}re Synapsen auf. Funktionell {\"a}ußerte sich dies in verbesserten elektrophysiologischen Parametern und einem Krafterhalt, welcher als klinischer Parameter die gr{\"o}ßte Relevanz f{\"u}r betroffene Patienten hat und somit besonders hervorzuheben ist. Auch P0het Mutanten zeigten Verbesserungen nach der CSF1RI Behandlung. Anders als bei Cx32def Tieren zeigte sich hier jedoch vor allem ein Erhalt der Myelinintegrit{\"a}t. Weiterhin wirkte sich die Therapie positiv auf elektrophysiologische Parameter und Krafttests aus. Vor allem besonders stark betroffene Individuen schienen hierbei von der CSF1RI Behandlung zu profitieren. Bei PMP22tg Mutanten hingegen konnten keine positiven Effekte der CSF1RI Behandlung nachgewiesen werden. Strukturelle und funktionelle Parameter behandelter Tiere unterschieden sich nicht von unbehandelten. Diese Ergebnisse unterstreichen die Relevanz der sekund{\"a}ren Entz{\"u}ndungsreaktion in CMT 1 Neuropathien als wichtigen Mediator in der Pathogenese. Weiterhin konnte gezeigt werden, dass eine Intervention im CSF-1/CSF1R Signalweg einen vielversprechenden m{\"o}glichen Ansatz f{\"u}r die Therapie der bisher nicht behandelbaren CMT 1 Subypen X und B darstellt. Unausweichlich ist hierbei ein m{\"o}glichst fr{\"u}her Therapiestart vor Auspr{\"a}gung der ersten molekularen und histologischen Ver{\"a}nderungen. Im Hinblick auf die nicht die Lebenserwartung reduzierende Erkrankung muss ferner eine Minimierung der Nebenwirkungen der Therapie gew{\"a}hrleistet sein. Besonders hervorzuheben ist hier die Verwendung eines Inhibitors, welcher nicht in das zentrale Nervensystem vordringen kann und somit die Funktion der Mikroglia nicht beeintr{\"a}chtigt.}, subject = {CSF-1}, language = {de} } @phdthesis{Werner2015, author = {Werner, Vera}, title = {Pharmaceutically relevant protein-protein interactions for controlled drug delivery}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117409}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2015}, abstract = {Protein-protein interactions play a crucial role in the development of drug delivery devices for the increasingly important biologicals, including antibodies, growth factors and cytokines. The understanding thereof might offer opportunities for tailoring carriers or drug proteins specifically for this purpose and thereby allow controlled delivery to a chosen target. The possible applications range from trigger-dependent release to sustained drug delivery and possibly permanently present stimuli, depending on the anticipated mechanism. Silk fibroin (SF) is a biomaterial that is suitable as a carrier for protein drug delivery devices. It combines processability under mild conditions, good biocompatibility and stabilizing effects on incorporated proteins. As SF is naturally produced by spiders and silkworms, the understanding of this process and its major factors might offer a blueprint for formulation scientists, interested in working with this biopolymer. The natural process of silk spinning covers a fascinating versatility of aggregate states, ranging from colloidal solutions through hydrogels to solid systems. The transition among these states is controlled by a carefully orchestrated process in vivo. Major players within the natural process include the control of spatial pH throughout passage of the silk dope, the composition and type of ions, and fluid flow mechanics within the duct, respectively. The function of these input parameters on the spinning process is reviewed before detailing their impact on the design and manufacture of silk based drug delivery systems (DDS). Examples are reported including the control of hydrogel formation during storage or significant parameters controlling precipitation in the presence of appropriate salts, respectively. The review details the use of silk fibroin to develop liquid, semiliquid or solid DDS with a focus on the control of SF crystallization, particle formation, and drug-SF interaction for tailored drug load. Although we were able to show many examples for SF drug delivery applications and there are many publications about the loading of biologics to SF systems, the mechanism of interaction between both in solution was not yet extensively explored. This is why we made this the subject of our work, as it might allow for direct influence on pharmaceutical parameters, like aggregation and drug load. In order to understand the underlying mechanism for the interaction between SF and positively charged model proteins, we used isothermal titration calorimetry for thermodynamic characterization. This was supported by hydrophobicity analysis and by colloidal characterization methods including static light scattering, nanoparticle tracking analysis and zeta potential measurements. We studied the effects of three Hofmeister salts - NaCl (neutral), NaSCN (chaotropic) and Na2SO4 (cosmotropic) - and the pH on the interaction of SF with the model proteins in dependence of the ratio from one to another. The salts impacted the SF structure by stabilizing (cosmotropic) or destabilizing (chaotropic) the SF micelles, resulting in completely abolished (cosmotropic) or strongly enhanced (chaotropic) interaction. These effects were responsible for different levels of loading and coacervation when varying type of salt and its concentration. Additionally, NaCl and NaSCN were able to prolong the stability of aqueous SF solution during storage at 25°C in a preliminary study. Another approach to influence protein-protein interactions was followed by covalent modification. Interleukin-4 (IL-4) is a cytokine driving macrophages to M2 macrophages, which are known to provide anti-inflammatory effects. The possibility to regulate the polarization of macrophages to this state might be attractive for a variety of diseases, like atherosclerosis, in which macrophages are involved. As these cases demand a long-term treatment, this polarization was supposed to be maintained over time and we were planning to achieve this by keeping IL-4 permanently present in an immobilized way. In order to immobilize it, we genetically introduced an alkyne-carrying, artificial amino acid in the IL-4 sequence. This allowed access to a site-specific click reaction (Cu(I)-catalyzed Huisgen azide-alkyne cycloaddition) with an azide partner. This study was able to set the basis for the project by successful expression and purification of the IL-4 analogue and by proving the availability for the click reaction and maintained bioactivity. The other side of this project was the isolation of human monocytes and the polarization and characterization of human macrophages. The challenge here was that the majority of related research was based on murine macrophages which was not applicable to human cells and the successful work was so far limited to establishing the necessary methods. In conclusion, we were able to show two different methods that allow the influence of protein-protein interactions and thereby the possible tailoring of drug loading. Although the results were very promising for both systems, their applicability in the development of drug delivery devices needs to be shown by further studies.}, subject = {Protein-Protein-Wechselwirkung}, language = {en} } @phdthesis{Wenzel2014, author = {Wenzel, Jens}, title = {Regulation of TLR-induced macrophage responses by cytoskeleton-associated phosphoproteins}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-98843}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2014}, abstract = {Toll-like receptors (TLR) are pattern recognition receptors (PRR) by which macrophages (M{\O}) sense pathogen-associated molecular patterns (PAMPs). The recognition of lipopolysaccharide (LPS), the PAMP of gram negative bacteria, by TLR4 triggers signaling cascades and leads to the pro-inflammatory activation of the cells. A recent quantitative and kinetic analysis of the phosphoproteome of LPS-activated primary macrophages highlighted the cytoskeleton as a cell compartment with an enriched protein phosphorylation. In total 44 cytoskeleton-associated proteins were regulated by this post-translational modification and thus might be involved in the control and regulation of key macrophage functions like spreading, motility and phagocytosis. To investigate the control of cytoskeleton-associated cell functions by TLR4 activation, we first developed a method to quantitatively measure the spreading response of bone marrow M{\O} after stimulation with LPS. Fluorescence microscopy was used for cell imaging and visualisation of the M{\O} contact area. In collaboration with the Fraunhofer Institute Erlangen, we developed and validated a software tool for the semi-automated segmentation and quantitation of M{\O} fluorescence microscopy data, which allowed fast, robust and objective image analysis. Using this method, we observed that LPS caused time-dependent spreading, which was detectable after 1-2 h and maximal after 24 h. Next, the impact of genetic or pharmacological inhibition of known TLR signaling components was investigated. Deficiency in the adapter protein MYD88 strongly reduced spreading activity at the late time points, but had no impact early after LPS-stimulation. A similar effect was observed upon pharmacological inhibition of ERK1/2 signaling, indicating that ERK1/2 mediates MYD88-dependent M{\O} spreading. In contrast, M{\O} lacking the MAPK p38 were impaired in the initial spreading response but responded normally 8-24 h after stimulation. The genetic deletion of the MAPK phosphatases DUSP1 and DUSP16 resulted in impaired late spreading, corroborating the essential role for functional MAPK signaling in TLR4-driven M{\O} spreading. To identify the contribution of other cytoskeletal phosphoproteins to M{\O} spreading, siRNA knockdown of selected candidate genes in primary murine M{\O} was employed and combined with automated quantitative image analysis. These experiments revealed a functional role for the Myosins MYO1e and MYO1f in M{\O} spreading. These motor proteins are strongly phosphorylated in LPS-activated M{\O}. Because of their ability to simultaneously bind to actin filaments and cell membrane or other proteins, we investigated their role in phagocytosis, cytokine production and antigen presentation. Phagocytosis and killing of bacteria were not affected in Myo1e-/- macrophages. However, MYO1e plays a role in chemokine secretion and antigen presentation processes. MCP1 (CCL2) release was selectively increased in Myo1e-deficient M{\O} and dendritic cells (DC), while cytokine secretion was unaffected. Furthermore, macrophages and DCs lacking MYO1e showed lower levels of MHC-II on the cell surface. However, mRNA levels of CCL2 and of MHC-II were unaltered. These data suggest a role for MYO1e in the transport of selected chemokines and of MHC-II molecules to the cell surface. MHC-II-restricted antigen presentation assays revealed an impaired capacity of macrophages and DC lacking MYO1e to stimulate antigen-specific T cells, suggesting that the reduced MHC-II expression is functionally relevant. Taken together, in this study first a quantitative image analysis method was developed which allows the unbiased, robust and efficient investigation of the macrophage spreading response. Combination of this method with siRNA knockdown of selected cytoskeleton-associated phosphoproteins led to the identification of MYO1e and MYO1f as regulators of macrophage spreading. Furthermore, we identified MYO1e in M{\O} and DC to be essential for the intracellular transport of CCL2 and MHC-II to the cell surface and for optimal stimulation of antigen-specific CD4 T cells.}, subject = {Toll-like-Rezeptoren}, language = {en} } @phdthesis{Heydenreich2013, author = {Heydenreich, Nadine}, title = {Studies on the contact-kinin system and macrophage activation in experimental focal cerebral ischemia}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-94534}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Traditionally, ischemic stroke has been regarded as the mere consequence of cessation of cerebral blood flow, e.g. due to the thromboembolic occlusion of a major brain supplying vessel. However, the simple restoration of blood flow via thrombolysis and/or mechanical recanalization alone often does not guarantee a good functional outcome. It appears that secondary detrimental processes are triggered by hypoxia and reoxygenation, which are referred to as ischemia/reperfusion (I/R) injury. During recent years it became evident that, beside thrombosis inflammation and edema formation are key players in the pathophysiology of cerebral ischemia. The contact-kinin system represents an interface between thrombotic, inflammatory and edematous circuits. It connects the intrinsic coagulation pathway with the plasma kallikrein-kinin system (KKS) via coagulation factor FXII. The serine protease inhibitor C1-inhibitor (C1-INH) has a wide spectrum of inhibitory activities and counteracts activation of the contact-kinin system at multiple levels. The first part of the thesis aimed to multimodally interfere with infarct development by C1-INH and to analyze modes of actions of human plasma derived C1-INH Berinert® P in a murine model of focal cerebral ischemia. It was shown that C57BL/6 mice following early application of 15.0 units (U) C1-INH, but not 7.5 U developed reduced brain infarctions by ~60\% and less neurological deficits in the model of transient occlusion of the middle cerebral artery (tMCAO). This protective effect was preserved at more advanced stages of infarction (day 7), without increasing the risk of intracerebral bleeding or affecting normal hemostasis. Less neurological deficits could also be observed with delayed C1-INH treatment, whereas no improvement was achieved in the model of permanent MCAO (pMCAO). Blood-brain-barrier (BBB) damage, inflammation and thrombosis were significantly improved following 15.0 U C1-INH application early after onset of ischemia. Based on its strong antiedematous, antiinflammatory and antithrombotic properties C1-INH constitutes a multifaceted therapeutic compound that protects from ischemic neurodegeneration in 'clinically meaningful' settings. The second part of the thesis addresses the still elusive functional role of macrophages in the early phase of stroke, especially the role of the macrophage-specific adhesion molecule sialoadhesin (Sn). For the first time, sialoadhesin null (Sn-/-) mice, homozygous deficient for Sn on macrophages were subjected to tMCAO to assess the clinical outcome. Neurological and motor function was significantly improved in Sn-/- mice on day 1 after ischemic stroke compared with wildtype (Sn+/+) animals. These clinical improvements were clearly detectable even on day 3 following tMCAO. Infarctions on day 1 were roughly the same size as in Sn+/+ mice and did not grow until day 3. No intracerebral bleeding could be detected at any time point of data acquisition. Twenty four hours after ischemia a strong induction of Sn was detectable in Sn+/+ mice, which was previously observed only on perivascular macrophages in the normal brain. Deletion of Sn on macrophages resulted in less disturbance of the BBB and a reduced number of CD11b+ (specific marker for macrophages/microglia) cells, which, however, was not associated with altered expression levels of inflammatory cytokines. To further analyze the function of macrophages following stroke this thesis took advantage of LysM-Cre+/-/IKK2-/- mice bearing a nuclear factor (NF)-ϰB activation defect in the myeloid lineage, including macrophages. Consequently, macrophages were not able to synthesize inflammatory cytokines under the control of NF-ϰB. Surprisingly, infarct sizes and neurological deficits upon tMCAO were roughly the same in conditional knockout mice and respective wildtype littermates. These findings provide evidence that macrophages do not contribute to tissue damage and neurological deficits, at least, not by release of inflammatory cytokines in the early phase of cerebral ischemia. In contrast, Sn which is initially expressed on perivascular macrophages and upregulated on macrophages/microglia within the parenchyma following stroke, influenced functional outcome.}, subject = {Blut-Hirn-Schranke}, language = {en} } @phdthesis{Li2014, author = {Li, Xiang}, title = {Molecular imaging of inflammation in atherosclerosis: Preclinical study in Apolipoprotein E-Deficient mice and preliminary evaluation in human using positron emission tomography}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-104622}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2014}, abstract = {Motivation and Aim: Cardiovascular disease has been the leading cause of mortality and morbidity throughout the world. In developed countries, cardiovascular diseases are already responsible for a majority of deaths and will become the pre-eminent health problem worldwide (1,2). Rupture of atherosclerotic plaque accounts for approximately 70\% of fatal acute myocardial infarction and sudden heart deaths. Conventional criterias for the diagnosis of "vulnerable plaques" are calcified nodules, yellow appearance of plaque, a thin cap, a large lipid core, severe luminal stenosis, intraplaque hemorrhage, inflammation, thrombogenicity, and plaque injury (3-5). Noninvasive diagnosis of vulnerable plaque still remains a great challenge and a huge research prospect, which triggered us to investigate the feasibility of PET imaging on the evaluation of atherosclerosis. Nuclear imaging of atherosclerosis, especially co-registered imaging modalities, could provide a promising diagnostic tool including both anatomy and activities to identify vulnerable atherosclerotic plaque or early detection of inflammatory endothelium at risk. Furthermore, the development of specific imaging tracers for clinical applications is also a challenging task. The aim of this work was to assess the potential of novel PET imaging probes associated with intra-plaque inflammation on animal models and in human respectively. Methods In this work, several molecular imaging modalities were employed for evaluation of atherosclerosis. They included Positron emission tomography / Computed tomography (PET/CT) for human studies, and micro-PET, autoradiography and high-resolution magnetic resonance imaging (MRI) for animal studies. Radiotracers for PET imaging included the glucose analogue 18F-Fluorodeoxyglucose (18F-FDG), the somatostatin receptor avide tracer 68Ga-DOTATATE, and the Gallium-68 labeled fucoidan (68Ga-Fucoidan), which was developed as a PET tracer to detect endothelial P-selectin, which overexpressed at early stage of atherosclerosis and endothelial overlying activated plaque. Tracer's capabilities were firstly assessed on cellular level in vitro. Subsequently, Animal studies were conducted in two animal models: 1, Apolipoprotein E (ApoE-/-) mice having severe atherosclerotic plaque; 2, Lipopolysaccharide (LPS) -induced mice for receiving acute vascular inflammation. Corresponding analyses on protein and histological level were conducted as well to confirm our results. In human study, 16 patients with neuroendocrine tumors (NETs) were investigated on imaging vascular inflammation. These patients had undergone both 68Ga-DOTATATE PET/CT and 18F-FDG PET/CT for staging or restaging within 6 weeks. 16 patients were randomized into two groups: high-risk group and low-risk group. Uptake ratio of both tracers from two groups were compared and correlated with common cardiovascular risk factors. Results and Conclusion In murine study, the expression of somatostatin receptor 2, which is the main bio-target of 68Ga-DOTATATE on macrophage/monocyte was confirmed by flow cytometry and immunohistochemistry. Prospectively, high specific accumulation of 68Ga-DOTATATE to the macrophage within the plaques was observed in aorta lesions by autoradiography and by micro-PET. In study with 68Ga-fucoidan, a strong expression of P-selectin on active endothelium overlying on inflamed plaque but weaker on inactive plaques was confirmed. Specific focal uptake of 68Ga-fucoidan were detected at aorta segments by micro-PET, and correlated with high-resolution magnetic resonance imaging (MRI), which was used to characterize the morphology of plaques. 68Ga-fucoidan also showed a greater affinity to active inflamed plaque in comparison of inactive fibrous plaque, which was assessed by autoradiography. Specificity of 68Ga-DOTATATE and 68Ga-fucoidan were confirmed by ex-vivo blocking autoradiography and in vivo blocking PET imaging respectively. In human study, focal uptake of both 18F-FDG and 68Ga-DOTATATE was detected. Analyzing concordance of two tracers' uptake ratio, Out of the 37 sites with highest focal 68Ga-DOTATATE uptake, 16 (43.2\%) also had focal 18F-FDG uptake. Of 39 sites with highest 18F-FDG uptake, only 11 (28.2\%) had a colocalized 68Ga-DOTATATE accumulation. Correlated tracers' uptake and calcium burden and risk factors, Mean target-to-background ratio (TBR) of 68Ga-DOTATATE correlated significantly with the presence of calcified plaques (r=0.52), hypertension (r=0.60), age (r=0.56) and uptake of 18F-FDG (r=0.64). TBRmean of 18F-FDG correlated significantly only with hypertension (r=0.58; p<0.05). Additionally, TBRmean of 68Ga-DOTATATE is significant higher in the high risk group while TBRmean of 18F-FDG is not. In conclusion, we evaluated vascular inflammation of atherosclerosis non-invasively using the two PET tracers: 68Ga-DOTATATE and 68Ga-Fucoidan. 68Ga-DOTATATE show specific affinity to infiltrated macrophage within the plaques. 68Ga-Fucoidan may hold the potential to discriminate between active and inactive atherosclerotic plaques in terms of variant accumulation on different-types of plaques. PET as leading molecular imaging technique provides superiority in assessing cellular activity, which is pivotal for understanding internal activity of atherosclerotic plaques. Since diagnosis of atherosclerosis is a complex and multi-dimensional task. More integrated imaging technology such as PET/MRI, faster imaging algorithm, more efficient radiotracer are required for further development of atherosclerosis imaging,}, subject = {Arteriosklerose}, language = {en} } @article{DickneiteSchorlemmerSedlaceketal.1987, author = {Dickneite, G. and Schorlemmer, H. U. and Sedlacek, H. H. and Falk, W. and Ulrichs, Karin and M{\"u}ller-Ruchholtz, W.}, title = {Suppression of macrophage function and prolongation of graft survival by the new guanidinic-like structure, 15-deoxyspergualin}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86991}, year = {1987}, abstract = {No abstract available.}, subject = {Makrophage}, language = {en} } @phdthesis{Patzko2012, author = {Patzk{\´o}, {\´A}gnes}, title = {CSF-1 receptor as a target for the treatment of Charcot-Marie-Tooth disease 1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85325}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2012}, abstract = {Previous studies by our group revealed that chronic low grade inflammation implicating phagocytosing macrophages is a highly relevant mechanism in the pathogenesis of Charcot-Marie-Tooth disease. The lack of CSF-1, the primary regulator of macrophage function and survival, led to a robust and persistent amelioration of the phenotype in two authentic mouse models of CMT. Moreover, a close contact between CSF-1 producing fibroblasts and endoneurial macrophages carrying CSF-1R has been confirmed in nerve biopsies of CMT patients, further supporting the clinical significance of this pathway. In the current study we treated 3 distinct mouse models of CMT1: the PMP22tg mice as a model for CMT1A, the P0+/- mice as a model for CMT1B and the Cx32def mice as a model for CMT1X, with a CSF-1R specific kinase (c-FMS) inhibitor (800-1200 mg PLX5622/ kg chow) according to different treatment regimes mimicking an ideal early onset treatment, a late onset treatment and the withdrawal of the drug. Using the above mentioned doses of PLX5622, we documented a dramatic decrease in macrophage numbers in the PNS of all 3 myelin mutants, except for the quadriceps nerve of Cx32def mice. Fibroblast numbers remained unchanged in treated animals. Surprisingly, in spite of the decrease in the number of detrimental macrophages we could not detect an unequivocal phenotypic improvement. CMAP amplitudes were reduced in both wild type and myelin mutant mice treated with CSF-1R inhibitor in comparison to untreated littermates. Corresponding to the electrophysiological findings, the axon number and the percentage of large diameter axons were reduced in the quadriceps nerve of treated P0+/- and Cx32def mice. By contrast we observed a higher number of fully myelinated axons, in parallel with a decrease in the percentage of demyelinated (and hypermyelinated in PMP22tg mice) fibers in the ventral roots of P0+/- mice treated with CSF-1R inhibitor from 3 months up to 6 months of age and PMP22tg animals treated from 9 months up to 15 months of age. Our results indicate that CSF-1R inhibitor has the potential to improve the demyelinating phenotype of at least two models of CMT1. Nevertheless, further studies are necessary (for example with lower doses of the inhibitor) to minimize or even eliminate the putative neurotoxic effect we observed with high dose treatment conditions.}, subject = {Makrophage}, language = {en} } @phdthesis{Hausmann2012, author = {Hausmann, Michael Franz Toni}, title = {Untersuchungen zum Differenzierungspotential humaner Monozyten / Makrophagen in vitro}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-77801}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2012}, abstract = {Unter dem Einfluss von M-CSF und GM-CSF entwickeln sich CD14-positive periphere humane Blutmonozyten zu CD68-positiven M-CSF- bzw. GM-CSF-Makrophagen. M-CSF-Makrophagen lassen sich mit INFg und LPS zu klassisch aktivierten M1-Makrophagen, oder mit IL-4 und IL-10 zu alternativ aktivierten M2-Makrophagen differenzieren. Durch GM-CSF werden aus Monozyten GM-CSF-Makrophagen induziert. Im Gegensatz zu M1-Makrophagen sind GM1-Makrophagen bisher noch wenig untersucht. Mit INFg und LPS werden GM-CSF-Makrophagen zu GM1-Makrophagen aktivert. In der vorliegenden Arbeit wurde {\"u}berpr{\"u}ft, wie groß die {\"U}bereinstimmung zwischen M-CSF- und M2-Makrophagen sowie zwischen GM-CSF- und M1-Makrophagen / GM1-Makrophagen ist. Im Gegensatz zu M-CSF- und GM-CSF stellt Laktat aber keinen Differenzierungsfaktor f{\"u}r Monozyten dar. Jedoch beeinflusst Laktat den Ph{\"a}notyp von M2-Makrophagen und hemmt die Aussch{\"u}ttung von IL-12 und NO durch M1- und GM1-Makrophagen.}, subject = {Differenzierung}, language = {de} } @phdthesis{Bremicker2011, author = {Bremicker, Johannes}, title = {T2/T2*-Messung an VSOP-gelabelten Makrophagen und Sensitivit{\"a}t der Preußisch-Blau-F{\"a}rbung}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72766}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2011}, abstract = {Zielsetzung: Diese Arbeit untersuchte die Beziehung zwischen intrazellul{\"a}rem Eisengehalt (pgFe/Zelle) und der F{\"a}higkeit der Histochemie und des MRT, in vitro mit Eisenoxidnanopartikel gelabelte Zellen zu detektieren. Methoden: Immortalisierte murine Peritonealmakrophagen wurden mit Very Small Iron Oxide Nanoparticles (VSOP) in aufsteigenden Konzentrationen (n=10) von 0 bis 200 µg/ml f{\"u}r 4 Stunden inkubiert. Die MRT-Messungen wurden an einem 7-Tesla Bruker Biospec durchgef{\"u}hrt. F{\"u}r jedes Label-Protokoll wurden Objekttr{\"a}gerproben (n=6) mit den Zellen angefertigt und mit der PB-, DAB-PB- und AgAu-DAB-PB-F{\"a}rbung gef{\"a}rbt. Es wurde der prozentuale Anteil der sichtbar gef{\"a}rbten Zellen ermittelt. {\"U}ber ICP-MS bestimmten wir den intrazellul{\"a}ren Eisengehalt und TEM-Aufnahmen best{\"a}tigten den vesikul{\"a}ren Uptake von VSOP. Zus{\"a}tzlich wurde der Einfluss der Zelldichte auf MR-Detektionsgrenzen an identisch gelabelten Zellen zwischen 2x10^5 und 8x10^6 Zellen/0,5ml zwischen nierigen (0,22 pgFe/Zelle) und hohen (3,81pgFe/Zelle) Eisenbeladungen untersucht. Ergebnisse: Der intrazellul{\"a}re Eisengehalt reichte von 0.12 bis 12.25 pgFe/Zelle. Die Histochemie zeigte einen h{\"o}heren Prozentsatz an eisen-positiven Zellen mit steigendem Eisengehalt. Das Enhancement der Preußisch Blau F{\"a}rbung(PB) mit Diaminobenzidin (DAB) und einer modifizierten AgAu-DAB F{\"a}rbung f{\"u}hrte zu einer h{\"o}heren Sensitivit{\"a}t f{\"u}r intrazellul{\"a}res Eisen (>50\% gef{\"a}rbte Zellen bei 1,3 pgFe/Zelle versus 1,6 pgFe/Zelle) als die Preußisch Blau F{\"a}rbung selbst (2,2 pgFe/Zelle). Jedoch zeigten beide F{\"a}rbungen bei einem Eisengehalt unter 0,7 pgFe/Zelle weniger als 25\% eisenpositive Zellen. Die T2 und T2* verk{\"u}rzenden Effekte von VSOP zeigten eine positive Korrelation zur intrazellul{\"a}ren Eisenbeladung und zur Zelldichte. Selbst bei 0.26 pgFe/Zelle war eine sichtbare {\"A}nderung der Relaxationsraten sichtbar. Schlussfolgerung: Diese Arbeit zeigte, dass in MRT-Messungen selbst kleinste Mengen an intrazellul{\"a}rem VSOP nachgewiesen werden k{\"o}nnen, welche in der Histochemie noch nicht nachgewiesen werden k{\"o}nnen. Es wurde ebenso gezeigt, dass positive Korrelationen zwischen der Zelldichte, dem intrazellul{\"a}ren Eisengehalt und der T2/T2*-Relaxationsraten bestehen.}, subject = {Makrophage}, language = {de} } @phdthesis{Schnitzer2012, author = {Schnitzer, Johannes K.}, title = {Mechanism of dendritic cell-based vaccination against Leishmania major}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-74865}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2012}, abstract = {Die Impfung mittels Antigen-beladener dendritischer Zellen [DZ] ist mittlerweile eine gut etablierte Technik, die dann zum Einsatz kommt, wenn Standard-Impftechniken versagen, vor Krankheiten zu sch{\"u}tzen beziehungsweise diese zu heilen. Die Effizienz dieser Technik konnte bereits f{\"u}r diverse Infektionskrankheiten und Krebserkrankungen in experimentellen Tiermodellen sowie am Menschen gezeigt werden. Hierbei ist die M{\"o}glichkeit zur wohldefinierten Manipulation und Antigenbeladung der DZ ein großer Vorteil gegen{\"u}ber den konventionellen Ans{\"a}tzen. Jedoch ist vor allem bei der Anwendung im klinischen Bereich die Pr{\"a}paration, Herstellung und Manipulation dieser autologen DZ mit einem erheblichen technischen, zeitlichen sowie finanziellen Aufwand verbunden. Hinsichtlich einer Pr{\"a}ventivimpfung gegen eine pandemische Infektionskrankheit, die in haupts{\"a}chlich unterentwickelten L{\"a}ndern vorkommt, wird dieser Aufwand sicherlich ein Hindernis darstellen. Daher muss f{\"u}r solche F{\"a}lle ein maßgeschneiderter Impfstoff entwickelt werden, der sich am Vorbild des effektiven DZ-basierten Impfstoffs orientiert. F{\"u}r die Impfung gegen die Leishmania Parasiten besteht so ein DZ-basierter Impfstoff bereits. Dessen Wirkung, eine T-Zell Antwort vom Typ Th1 zu induzieren, wurde bereits in mehreren Ver{\"o}ffentlichungen demonstriert. Zus{\"a}tzlich hat aber eine unserer Studien gezeigt, dass das typische Th1-bezogene Zytokin IL-12 zur Differenzierung naiver T-Zellen nicht von den injizierten DZ bereitgestellt werden muss, sondern von der geimpften Maus. Dies gab erste Hinweise auf eine st{\"a}rkere Beteiligung des Wirts-Immunsystems als zuvor angenommen. Daher sollte hier vertieft der Mechanismus dieser DZ-basierten Impfung untersucht werden, wobei modifizierte Impfstoff-Ans{\"a}tze zum Einsatz kommen sollten. Dabei wurden die Fragen nach der vom Impfstoff transportierten Information und dem Empf{\"a}nger dieser Information ber{\"u}cksichtigt. Das aktuelle Paradigma zur DZ-basierten Impfung besagt, dass transferierte DZ im direkten Kontakt mittels dreier Signale T-Zellen stimulieren und aktivieren. Daf{\"u}r m{\"u}ssen diese DZ mit dem entsprechenden Antigen beladen und aktiviert worden sein um das Antigen-Peptide mittels MHC Molek{\"u}l im Kontext der Co-Stimulation pr{\"a}sentieren zu k{\"o}nnen. Jedoch zeigt diese Studie hier, dass weder eine Aktivierung der DZ noch die Pr{\"a}sentation des Antigens mittels passender MHC Molek{\"u}le notwendig ist f{\"u}r die Induktion einer protektiven Immunantwort gegen Leishmania Parasiten. Aufgeschlossene, mit Antigen beladene DZ m{\"u}ssen nicht vor dem Transfer mit CpG ODN aktiviert worden sein, um entsprechende Immunit{\"a}t zu verleihen. Ebenso hat der MHC Typ in diesem Falle auch keinen Einfluss auf die Effektivit{\"a}t des Impfstoffs. Da im Weiteren aufgeschlossene mit Leishmania-Antigen beladene Makrophagen nach Impfung die gleiche Wirkung erzielen, wie vorangegangene DZ-basierte Impfstoffe, k{\"o}nnen keine DZ spezifischen Mechanismen Schl{\"u}sselkomponenten der Induktion einer protektiven Immunit{\"a}t sein. Dar{\"u}ber hinaus konnte gezeigt werden, dass die DZ der geimpften M{\"a}use, eine maßgebliche Rolle bei der Verarbeitung transferierter Signale spielen. Suspensionen aufgeschlossener DZ stellen eine Kombination aus freigesetzten l{\"o}slichen Molek{\"u}len sowie Membranvesikeln dar, die sich nach dem Aufschluss gebildet haben. Nach Auftrennung dieser beiden Fraktionen konnte gezeigt werden, dass ausschließlich die Membran-Fraktion nach Verimpfung eine geeignete Immunantwort zum Schutz vor Leishmania Parasiten induzieren kann. Als Vorteil dieser Aufreinigung erweist sich zudem die stabile Lagerm{\"o}glichkeit bei -80°C. Somit ist klar gezeigt, dass die Immunit{\"a}t-verleihende Einheit dieser Impfstoffvarianten in der Membran-Fraktion liegt. Verfolgt man die Induktion Th1-zugeh{\"o}riger Zytokine in in vivo Experimenten so ergibt sich im Falle der Gesamtsuspension aufgeschlossener, mit Leishmania-Antigen beladener DZ ein klares Bild. Diese Suspension erzeugt das volle Spektrum der DZ-basierten Impfung gegen Leishmania Parasiten. Es kann sowohl Produktion von IL-12 und IL-2 als auch eine antigenspezifische T-Zell Proliferation nach Stimulation von Splenozyten mit der entsprechenden Suspension verzeichnet werden. Außerdem produzieren Splenozyten von entsprechend geimpften M{\"a}usen nach Stimulation mit Leishmania-Antigen erhebliche Mengen des entscheidenden Zytokins IFNγ. Obwohl jedoch die Verimpfung aufgereinigter Membranvesikel dieses Ansatzes im Tierversuch zu biologisch sowie statistisch signifikanten Ergebnissen f{\"u}hrt, lassen sich die entsprechend Th1-bezogenen Zytokine im in vivo Ansatz nur in geringen Maße nachweisen. Ob dies jedoch f{\"u}r einen in vivo unbemerkten Aktivit{\"a}tsverlust des Vakzins oder f{\"u}r andere lymphatische Organe als Ort der T-Zell Instruktion spricht, ist noch unbekannt und muss noch gekl{\"a}rt werden.}, subject = {Leishmania major}, language = {en} } @phdthesis{Mertens2011, author = {Mertens, Christina}, title = {Ph{\"a}notypische und funktionelle Charakterisierung von Alveolarmakrophagen der Ratte}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-69309}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2011}, abstract = {Makrophagen spielen als Zellen der angeborenen Abwehr eine wichtige Rolle bei der Immunabwehr. Ziel dieser Arbeit war die ph{\"a}notypische und funktionelle Charakterisierung von Alveolarmakrophagen der Ratte. Hierzu wurden die durch eine bronchoalveol{\"a}re Lavage gewonnenen Alveolarmakrophagen immunhistologisch und durchflusszytometrisch untersucht. Zus{\"a}tzlich wurden sie in vitro mit LPS und IFN-g stimuliert. Die Produktion von Stickstoffmonoxid wurde mit dem Griess Reagenz bestimmt und die Expression von iNOS im Immunoblot nachgewiesen. Zudem wurde die Interaktion mit naiven T-Lymphozyten untersucht. Als Vergleichszellen wurden Peritonealmakrophagen verwendet. Bei den aus bronchoalveol{\"a}ren Lavagen gewonnenen Zellen handelte es sich eindeutig um CD68- und CD11b-positive Alveolarmakrophagen. Vollst{\"a}ndig aktivierte Alveolarmakrophagen exprimierten zum Teil andere Oberfl{\"a}chenmolek{\"u}le als nicht-aktivierte. So stieg nach Stimulierung der Anteil der Makrophagen, die die kostimulatorischen Molek{\"u}le CD80 und CD86 exprimierten, auf ca. 80 Prozent an. Ebenso bildeten sie große Mengen an Stickstoffmonoxid (380 μmol/L NO nach 48 Stunden bei 1 μg/mL LPS) und exprimierten auch das Enzym iNOS. Die aktivierten Alveolarmakrophagen waren nicht in der Lage, naive T-Lymphozyten zu aktivieren. Die Stimulierung der Alveolarmakrophagen in vitro hat gezeigt, dass LPS und IFN-g in den getesteten Konzentrationen in der Lage waren, Makrophagen vollst{\"a}ndig zu aktivieren. Die zweistufige Aktivierung von Makrophagen durch ein Priming mit IFN-g und eine darauf folgende vollst{\"a}ndige Aktivierung mit LPS, ist bei hohen lokalen Konzentrationen auch nur mit LPS bzw. IFN- g m{\"o}glich. Dies unterstreicht die besondere Bedeutung der beiden Mediatoren f{\"u}r die Aktivierung von Makrophagen.}, subject = {Makrophage}, language = {de} } @phdthesis{Sienerth2010, author = {Sienerth, Arnold R.}, title = {Regulation of anti-inflammatory cytokine IL-10 by the Polycomb Group Protein Bmi1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49990}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2010}, abstract = {Macrophages are important effector cells of the innate and adaptive immune response and exert a wide variety of immunological functions which necessitates a high level of plasticity on the chromatin level. In response to pathogen-associated molecular patterns (PAMPs) or inflammatory signals macrophages undergo a process of cellular activation which is associated with morphologic, functional and biochemical changes. Toll-like receptors (TLR) are able to sense many different PAMPs. TLR4 is an important sensor for lipopolysaccharide (LPS) which elicits a major portion of the host's inflammatory response through the activation of many different signaling pathways such as the NF-\&\#954;B and the MAPK protein kinase pathways RASRAF- MEK-ERK, p38 and JNK. Polycomb group (PcG) proteins are well known chromatin modifiers which function in large complexes and are required to maintain chromatin structure in a transcriptionally repressed state. It has previously been shown that the PcG protein Bmi1 is phosphorylated by 3pK, a downstream effector kinase of the MAPK protein kinase pathways RAS-RAF-MEK-ERK, p38 and JNK. In this work I analyzed the role of Bmi1 as a downstream effector of MAPK signaling during macrophage activation. Unexpectedly a rapid up-regulation on the Bmi1 protein level was observed in bone marrow derived macrophages (BMDMs) after LPS treatment. The Bmi1 induction was associated with transient protein phosphorylation that occured downstream of MAPK signaling. LPS treatment of BMDMs in the absence of Bmi1 resulted in a pronounced increase of IL-10 secretion. This secretion of the anti-inflammatory cytokine IL-10 was associated with increased IL-10 mRNA levels. Furthermore, siRNA mediated knock down of Bmi1 in J774A.1 macrophages also resulted in elevated IL-10 mRNA levels in response to LPS. ChIP analysis revealed that Bmi1 binds to throughout the il-10 locus. Alternative activation of wild type BMDMs via concomitant TLR4 and Fc\&\#947;R activation which triggers high IL-10 expression is paralleled by an attenuated Bmi1 protein expression. These results identify Bmi1 as a repressor of IL-10 expression during activation of macrophages.}, subject = {Interleukin 10}, language = {en} } @phdthesis{Kohl2009, author = {Kohl, Bianca Dorothea}, title = {PMP22-overexpressing mice as a model for Charcot-Marie-Tooth 1A neuropathy implicate a role of immune-related cells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-43066}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2009}, abstract = {Charcot-Marie-Tooth disease (CMT) is a cohort of human hereditary disorders of the peripheral nervous system (PNS) which exhibit symptoms like sensory dysfunction, muscle weakness and gait disturbances. Different mutations are described as causation for this neuropathy, such as a duplication of chromosome 17 comprising the gene for the peripheral myelin protein-22 (PMP22). Based on different animal models former studies identified immune cells, i.e. macrophages and T-lymphocytes, as crucial mediators of pathology in these neuropathies. In this study, PMP22-overexpressing mice (PMP22tg, C61), serving as a model for a specific type of CMT - CMT1A - were crossbred with immune-deficient mutant mice to examine the impact of the immune system on nerve pathology. Crossbreeding of PMP22tg mice with recombination activating gene-1 (RAG-1) deficient mice, lacking mature T- and B-lymphocytes, caused no striking alterations of pathogenesis in peripheral nerves of mutant mice. In contrast, crossbreeding of PMP22tg myelin mutants with mice deficient in the chemokine monocyte chemoattractant protein-1 (MCP-1, CCL2) caused an amelioration of the demyelinating phenotype of peripheral nerves when MCP-1 was either reduced or completely absent. Furthermore, functional investigations, i.e. neurographic recordings and examinations of the grip strength of the extremities, revealed an amelioration in PMP22tg/MCP-1-/- mice in regard to a symptomatic improvement in the compound action muscle potential (CMAP) and stronger grip strength of the hindlimbs. Interestingly, peripheral nerves of PMP22tg mice showed an irregular distribution of potassium channels in presence of MCP-1, whereas the absence of MCP-1 in the myelin mutants rescued the ion channel distribution and resulted in a more wild type-like phenotype. Having shown the impact of MCP-1 as an important mediator of nerve pathology in PMP22/MCP-1 double mutants, the regulation of this chemokine became an important target for potential treatment strategies. We found that the signaling cascade MEK1/2/ERK1/2 was more strongly activated in peripheral nerves of PMP22tg mice compared to nerves of wild type mice. This activation corresponded to an increase in MCP-1 mRNA expression in peripheral nerves at the same age. Furthermore, a MEK1/2-inhibitor was used in vivo to confirm the regulation of MCP-1 by the MEK1/2/ERK1/2 pathway. After a treatment period of three weeks, a clear reduction of ERK1/2-phosphorylation as well as a reduction of MCP-1 mRNA expression was observed, accompanied by a decline in macrophage number in peripheral nerves of PMP22tg mice. These observations suggest that the expression of MCP-1 is crucial for the neuropathological progression in a mouse model for CMT1A. Therefore, this chemokine could provide a basis for a putative treatment strategy of inherited neuropathies.}, subject = {Myelin}, language = {en} } @phdthesis{Galmbacher2008, author = {Galmbacher, Katharina Monika}, title = {Caspase-1 as a target of bacterial tumor therapy}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33506}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2008}, abstract = {Tumorstroma und Tumor-assoziierte Makrophagen (TAMs) spielen in neoplastischen Erkrankungen eine wichtige Rolle im Bezug auf Tumorwachstum und Progression. In einigen Krebsarten besteht zwischen den Tumor-assoziierten Makrophagen und den Krebszellen eine intensive Interaktion, welche zu vermehrter Angiogenese und zur Unterdr{\"u}ckung lokaler Immunantworten f{\"u}hrt. Aus diesem Grund stellen TAMs einen vielversprechenden Angriffspunkt f{\"u}r eine Krebstherapie da. In dieser Arbeit wird gezeigt, dass intrazellul{\"a}re Bakterien wie Salmonella und Shigella haupts{\"a}chlich TAMs im Tumorgewebe infizierten. Um dieses Verhalten n{\"a}her zu untersuchen, konstruierten wir einen im Wachstum abgeschw{\"a}chten Shigella Stamm, welcher jedoch noch die F{\"a}higkeit hat, Apoptose in Makrophagen zu induzieren. Shigellen sind invasive Bakterien, die in das Darmgewebe einwandern und dort eine massive Inflammation induzieren. Intrazellul{\"a}re Shigellen aktivieren Caspase-1 und induzieren dadurch Apoptose in Makrophagen durch den sekretierten Virulenzfaktor IpaB. Durch eine Deletion des genomischen aroA-Gens, wurde ein Shigella Stamm konstruiert, der Defekte im intrazellul{\"a}ren Wachstum aufweist. Dennoch war dieser Stamm noch f{\"a}hig eukaryotische Zellen zu infizieren, sich interzellul{\"a}r fortzubewegen, Caspase-1 zu aktivieren und Apoptose in Makrophagen zu induzieren. Es wurde gezeigt, dass dieser Shigellen Stamm nach i.v. Injektion haupts{\"a}chlich die TAMs im 4T1-induzierten und transgenen MMTV-HER2/neu Brustkrebsmodel infizieren. Diese attenuierten Shigellen wurden im Tumorgewebe haupts{\"a}chlich intrazellul{\"a}r detektiert, im Gegensatz dazu wurden attenuierte Salmonellen zu sp{\"a}ten Zeitpunkten (7 d p.i.) auch extrazellul{\"a}r im Tumorgewebe aufgefunden. Der metabolisch aber nicht in der Virulenz attenuierte Shigella Stamm konnte in beiden Brustkrebsmodellen zu allen Zeitpunkten (4 h, 6h and 7 d p.i.) Caspase-1 in TAMs aktivieren und Apoptose induzieren. Diese Apoptose f{\"u}hrte in beiden Brustkrebsmodellen zu einer langandauernden und hoch signifikanten Reduktion der TAMs-Anzahl (bis zu 70 \%). Im Gegensatz dazu konnten Salmonellen nur zu fr{\"u}hen Zeitpunkten (6 h p.i.) Apoptose in TAMs induzieren und dies f{\"u}hrte in beiden Modellen zu keiner Reduzierung der TAMs-Anzahl. In dem 4T1-induzierten Tumormodel wurden die M{\"a}use mit dem attenuierten Shigella Stamm behandelt, was zu einer kompletten Blockierung des Tumorwachstums f{\"u}hrte, dies traf aber nicht f{\"u}r den avirulenten Stamm zu. Dar{\"u}berhinaus infizierte Shigella haupts{\"a}chlich die Makrophagen Fraktion eines Ovarkarzinoms ex vivo und induzierte in diesen Zellen Caspase- 1 Aktivierung und Apoptose. Zusammenfassend zeigen diese Daten, dass im Wachstum attenuierte intrazellul{\"a}re Bakterien dazu f{\"a}hig sind Apoptose in TAMs zu induzieren. Dadurch werden sie zu einem vielversprechenden Therapeutikum zur Behandlung von betimmten Krebserkrankungen, bei denen TAMs eine erwiesene Rolle im Tumorwachstum und der Tumorprogression spielen.}, subject = {Shigella flexneri}, language = {en} } @phdthesis{Fischer2008, author = {Fischer, Stefan Martin}, title = {Regulation and functional consequences of MCP-1 expression in a model of Charcot-Marie-Tooth 1B disease}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29189}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2008}, abstract = {Charcot-Marie-Tooth 1B (CMT1B) is a progressive inherited demyelinating disease of human peripheral nervous system leading to sensory and/or motor function disability and is caused by mutations in the P0 gene. Mice heterozygously deficient for P0 (P0+/-) are an adequate model of this human disorder showing myelin degeneration, formation of onion bulbs, remyelination and a reduced motor conduction velocity of around 30m/s similar to patients. Previously, it had been shown that T-lymphocytes and macrophages play a crucial role during pathogenesis in peripheral nerves of P0+/- mice. Both, T-lymphocytes and macrophages increase in number in the endoneurium and deletion of T-lymphocytes or deletion of a macrophage-directed cytokine ameliorates the disease. In this study the monocyte chemoattractant protein-1 (MCP-1) was identified as an early regulated cytokine before onset of disease is visible at the age of six months. MCP-1 mRNA and protein expression could be detected in femoral quadriceps and sciatic nerves of P0+/- mice already at the age of one month but not in cutaneous saphenous nerves which are never affected by the disease. MCP-1 was shown to be expressed by Schwann cells and to mediate the immigration of immune cells into peripheral nerves. Deletion of MCP-1 in P0+/- mice accomplished by crossbreeding P0 and MCP-1 deficient mice revealed a substantial reduction of immune cells in peripheral nerves of P0+/-/MCP-1+/- and P0+/-/MCP-1-/- mice at the age of six months. In twelve months old mice reduction of immune cells in peripheral nerves is accompanied by amelioration of demyelinating disease in P0+/-/MCP-1+/- and aggravation of demyelinating disease in lumbar ventral roots of P0+/ /MCP-1-/- mice in comparison to P0+/ /MCP 1+/+ mice. Furthermore, activation of the MEK1/2-ERK1/2 signalling cascade could be demonstrated to take place in Schwann cells of affected peripheral nerves of P0+/- mice overlapping temporarily and spatially with MCP-1 expression. An animal experiment using a MEK1/2-inhibitor in vivo, CI-1040, revealed that upon reduction of ERK1/2 phosphorylation MCP-1 mRNA expression is diminished suggesting that the activation of the MEK1/2-ERK1/2 signalling cascade is necessary for MCP-1 expression. Additionally, peripheral nerves of P0+/- mice showing reduced ERK1/2 phosphorylation and MCP-1 mRNA expression also show reduced numbers of macrophages in the endoneurium. This study shows a molecular link between a Schwann cell based mutation and immune cell function. Inhibition of the identified signalling cascade might be a putative target for therapeutic approaches.}, subject = {Schwann-Zelle}, language = {en} }