@phdthesis{Kalleda2018, author = {Kalleda, Nataraja Swamy}, title = {Spatiotemporal analysis of immune cell recruitment and Neutrophil defence functions in \(Aspergillus\) \(fumigatus\) lung infections}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-150931}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2018}, abstract = {Humans are continuously exposed to airborne spores of the saprophytic fungus Aspergillus fumigatus. In healthy individuals, local pulmonary host defence mechanisms can efficiently eliminate the fungus without any overt symptoms. In contrast, A. fumigatus causes devastating infections in immunocompromised patients. However, local host immune responses against A. fumigatus lung infections in immunocompromised conditions have remained largely elusive. Given the dynamic changes in immune cell subsets within tissues upon immunosuppressive therapy, we dissected the spatiotemporal pulmonary immune response after A. fumigatus infection to reveal basic immunological events that fail to effectively control the invasive fungal disease. In different immunocompromised murine models, myeloid but not lymphoid cells were strongly recruited upon infection. Notably, neutrophils and macrophages were recruited to infected lungs in different immunosuppressed regimens. Other myeloid cells, particularly dendritic cells and monocytes were only recruited in the corticosteroid model after infection. Lymphoid cells, particularly CD4+ or CD8+ T-cells and NK cells were highly reduced upon immunosuppression and were not recruited after A. fumigatus infection. Importantly, adoptive CD11b+ myeloid cell transfer rescued immunosuppressed mice from lethal A. fumigatus infection. These findings illustrate that CD11b+ myeloid cells are critical for anti-A. fumigatus defence under immunocompromised conditions. Despite improved antifungal agents, invasive A. fumigatus lung infections cause a high rate morbidity and mortality in neutropenic patients. Granulocyte transfusions have been tested as an alternative therapy for the management of high-risk neutropenic patients with invasive A. fumigatus infections. To increase the granulocyte yield for transfusion, donors are treated with corticosteroids. Yet, the efficacy of granulocyte transfusion and the functional defence mechanisms of granulocytes collected from corticosteroid treated donors remain largely elusive. We aimed to assess the efficacy of granulocyte transfusion and functional defence mechanisms of corticosteroid treated granulocytes using mouse models. In this thesis, we show that transfusion of granulocytes from corticosteroid treated mice did not protect cyclophosphamide immunosuppressed mice against lethal A. fumigatus infection in contrast to granulocytes from untreated mice. Upon infection, increased levels of inflammatory cytokines helped to recruit granulocytes to the lungs without any recruitment defects in corticosteroid treated and infected mice or in cyclophosphamide immunosuppressed and infected mice that have received the granulocytes from corticosteroid treated mice. However, corticosteroid treated human or mouse neutrophils failed to form neutrophil extracellular traps (NETs) in in vitro and in vivo conditions. Further, corticosteroid treated granulocytes exhibited impaired ROS production against A. fumigatus. Notably, corticosteroids impaired the β-glucan receptor Dectin-1 (CLEC7A) on mouse and human granulocytes to efficiently recognize and phagocytize A. fumigatus, which markedly impaired fungal killing. We conclude that corticosteroid treatment of granulocyte donors for increasing neutrophil yields or patients with ongoing corticosteroid treatment could result in deleterious effects on granulocyte antifungal functions, thereby limiting the benefit of granulocyte transfusion therapies against invasive fungal infections.}, subject = {Aspergillus fumigatus}, language = {en} } @phdthesis{Dagvadorj2016, author = {Dagvadorj, Nergui}, title = {Improvement of T-cell response against WT1-overexpressing leukemia by newly developed anti-hDEC205-WT1 antibody fusion proteins}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149098}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2016}, abstract = {Wilms tumor protein 1 (WT1) is a suitable target to develop an immunotherapeutic approach against high risk acute myeloid leukemia (AML), particularly their relapse after allogeneic hematopoietic stem cell transplantation (HSCT). As an intracellular protein traversing between nucleus and cytoplasm, recombinant expression of WT1 is difficult. Therefore, an induction of WT1-specific T-cell responses is mostly based on peptide vaccination as well as dendritic cell (DC) electroporation with mRNA encoding full-length protein to mount WT1-derived peptide variations presented to T cells. Alternatively, the WT1 peptide presentation could be broadened by forcing receptor-mediated endocytosis of DCs. In this study, antibody fusion proteins consisting of an antibody specific to the human DEC205 endocytic receptor and various fragments of WT1 (anti-hDEC205-WT1) were generated for a potential DC-targeted recombinant WT1 vaccine. Anti-hDEC205-WT1 antibody fusion proteins containing full-length or major parts of WT1 were not efficiently expressed and secreted due to their poor solubility and secretory capacity. However, small fragment-containing variants: anti-hDEC205-WT110-35, anti-hDEC205-WT191-138, anti-hDEC205-WT1223-273, and anti-hDEC205-WT1324-371 were obtained in good yields. Since three of these fusion proteins contain the most of the known immunogenic epitopes in their sequences, the anti-hDEC205-WT191-138, anti-hDEC205-WT1223-273, and anti-hDEC205-WT1324-371 were tested for their T-cell stimulatory capacities. Mature monocyte-derived DCs loaded with anti-hDEC205-WT191-138 could induce ex vivo T-cell responses in 12 of 16 blood samples collected from either healthy or HSC transplanted individuals compared to included controls (P < 0.01). Furthermore, these T cells could kill WT1-overexpressing THP-1 leukemia cells in vitro after expansion. In conclusion, alongside proving the difficulty in expression and purification of intracellular WT1 as a vaccine protein, our results from this work introduce an alternative therapeutic vaccine approach to improve an anti-leukemia immune response in the context of allogeneic HSCT and potentially beyond.}, subject = {Akute myeloische Leuk{\"a}mie}, language = {en} } @phdthesis{Schmithausen2019, author = {Schmithausen, Patrick Alexander Gerhard}, title = {Three-dimensional fluorescence image analysis of megakaryocytes and vascular structures in intact bone}, doi = {10.25972/OPUS-17854}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-178541}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {The thesis provides insights in reconstruction and analysis pipelines for processing of three-dimensional cell and vessel images of megakaryopoiesis in intact murine bone. The images were captured in a Light Sheet Fluorescence Microscope. The work presented here is part of Collaborative Research Centre (CRC) 688 (project B07) of the University of W{\"u}rzburg, performed at the Rudolf-Virchow Center. Despite ongoing research within the field of megakaryopoiesis, its spatio-temporal pattern of megakaryopoiesis is largely unknown. Deeper insight to this field is highly desirable to promote development of new therapeutic strategies for conditions related to thrombocytopathy as well as thrombocytopenia. The current concept of megakaryopoiesis is largely based on data from cryosectioning or in vitro studies indicating the existence of spatial niches within the bone marrow where specific stages of megakaryopoiesis take place. Since classic imaging of bone sections is typically limited to selective two-dimensional views and prone to cutting artefacts, imaging of intact murine bone is highly desired. However, this has its own challenges to meet, particularly in image reconstruction. Here, I worked on processing pipelines to account for irregular specimen staining or attenuation as well as the extreme heterogeneity of megakaryocyte morphology. Specific challenges for imaging and image reconstruction are tackled and solution strategies as well as remaining limitations are presented and discussed. Fortunately, modern image processing and segmentation strongly benefits from continuous advances in hardware as well as software-development. This thesis exemplifies how a combined effort in biomedicine, computer vision, data processing and image technology leads to deeper understanding of megakaryopoiesis. Tailored imaging pipelines significantly helped elucidating that the large megakaryocytes are broadly distributed throughout the bone marrow facing a surprisingly dense vessel network. No evidence was found for spatial niches in the bone marrow, eventually resulting in a revised model of megakaryopoiesis.}, subject = {Megakaryozytopoese}, language = {en} } @phdthesis{Rothaug2019, author = {Rothaug, Moritz}, title = {Entwicklung neuer Antik{\"o}rper Fusionsproteine}, doi = {10.25972/OPUS-17704}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177043}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {Bei agonistischen Antik{\"o}rpern gegen Rezeptoren der TNFRSF reicht eine einfache Bindung der Antik{\"o}rper an die Rezeptoren oft nicht aus, um ein intrazellul{\"a}res Signal zu erzeugen. Es konnte herausgefunden werden, dass die Verankerung der Antik{\"o}rper {\"u}ber ihren Fc-Anteil an Fc gamma Rezeptoren ihre F{\"a}higkeit zur agonistischen Aktivierung der TNFR extrem steigert. Diese Arbeit besch{\"a}ftigt sich mit der Frage, ob die Verankerung {\"u}ber andere Rezeptoren m{\"o}glich ist. Mit scFv:CD70 als Beispiel, konnte diese Frage positiv beantwortet werden.}, subject = {Antik{\"o}rper-Fusionsproteine}, 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{Frank2015, author = {Frank, Benjamin}, title = {Untersuchungen zur Autophagieinduktion in Leishmania major-infizierten Knochenmarksmakrophagen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-137277}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2015}, abstract = {Die von der WHO zu den 17 wichtigsten NTDs gez{\"a}hlte Leishmaniose wird durch intrazellul{\"a}re Parasiten der Gattung Leishmania hervorgerufen. Der Lebenszyklus der Parasiten besteht aus zwei Phasen. Die l{\"a}nglichen und beweglichen Promastigoten kennzeichnen die Phase in der Sandm{\"u}cke - der Vektor der Leishmaniose. Hingegen ist die Phase im S{\"a}ugerwirt durch runde unbewegliche Amastigoten charakterisiert. Aufgrund des Mangels an potenten antileishmanialen Therapien wurde in der vorliegenden Arbeit die Interaktion zwischen L. m. Parasiten und der Hauptwirtszelle, der Makrophage, v. a. in Hinblick auf autophage Prozesse in den infizierten Makrophagen n{\"a}her untersucht, um demgem{\"a}ß neue Erkenntnisse zu gewinnen, welche bei der Herstellung zuk{\"u}nftiger anti-leishmanialer Medikamente helfen k{\"o}nnten. Bei der Autophagie handelt es sich um einen katabolen Prozess, wodurch Zellen bei Nahrungsmangel oder zellul{\"a}rem Stress ihre Hom{\"o}ostase erhalten k{\"o}nnen. Durch diesen Prozess k{\"o}nnen {\"u}berfl{\"u}ssige oder besch{\"a}digte Organellen recycelt werden, um die Funktionen der Zelle aufrechtzuerhalten. Daneben {\"u}bernimmt Autophagie auch eine essenzielle Rolle bei der Abwehr von ins Zytosol eindringenden Pathogenen. Mittels des neu etablierten totalen Autophagiescore konnte festgestellt werden, dass Autophagie in L. m.-infizierten BMDM induziert wird. Die intrazellul{\"a}ren Amastigoten werden durch Autophagie in den BMDM verdaut. Die erh{\"o}hte autophage Aktivit{\"a}t konnte zudem durch Western-Blot-Analysen der autophagierelevanten Proteine ATG5, LC3B und UB best{\"a}tigt werden. Die molekulargenetischen Untersuchungen von L. m.-infizier-ten BMDM mithilfe von Affymetrix Microarrays f{\"u}hrten zu einem Netzwerk aus autophagierelevanten und infektionsspezifischen Genen, welches als LISA bezeichnet worden ist. Hier hat sich ebenfalls eine starke Verkn{\"u}pfung von autophagierelevanten Genen und den Genen der Glykolyse, einem zweiten katabolen Prozess, gezeigt. Zudem konnten zwei weitere autophagierelevante und infektionsspezifische Gene außerhalb von LISA identifiziert werden, n{\"a}mlich Bnip3 und Ctse, welche im Anschluss genauer untersucht worden sind. Bei beiden Genen konnte auf Proteinebene gezeigt werden, dass sie in L. m.-infizierten BMDM signifikant erh{\"o}ht sind. Durch siRNA-Analysen konnte {\"u}berdies beobachtet werden, dass beide f{\"u}r die erfolgreiche Elimination der Amastigoten essenziell sind. Somit konnte mit den Proteinen BNIP3 und CTSE zwei potenzielle neue Ansatzpunkte f{\"u}r m{\"o}gliche zuk{\"u}nftige antileishmaniale Therapien gefunden werden. Auch die in LISA enthaltenen Gene stellen prinzipiell vielversprechende Ziele f{\"u}r k{\"u}nftige Medikamente gegen Leishmaniose dar. Durch all diese Untersuchungen kommt man dem Ziel einer neuen, gezielten und nebenwirkungs{\"a}rmeren Behandlung der Leishmaniose einen Schritt n{\"a}her.}, subject = {Autophagie}, language = {de} } @phdthesis{Shahnian2021, author = {Shahnian, Andrej}, title = {Regulation von DNAM-1, CD96 und TIGIT durch IL-12 in Nat{\"u}rlichen Killer (NK-) Zellen}, doi = {10.25972/OPUS-23883}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-238830}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Ziel dieser Arbeit war es, den Einfluss von IL-12 auf die Rezeptoren DNAM-1, TIGIT und CD96 auf NK-Zellen n{\"a}her zu untersuchen. Wir konnten nachweisen, dass IL-12 den Rezeptor DNAM-1 hochreguliert. CD96 wurde nach 48-st{\"u}ndiger Inkubation mit IL-12 bei frisch isolierten NK-Zellen zun{\"a}chst ebenfalls hochreguliert, nach l{\"a}ngerer in vitro Kultur mit IL-2/IL-15 und anschließender Intervention mit IL-12 f{\"u}r 48h fiel CD96 allerdings wieder unter das Ausgangsniveau ab. Die h{\"o}chste Steigerung der Expression durch IL-12 konnte an den Rezeptoren CD62L (Adh{\"a}sion) und CD161 (Inhibition) beobachtet werden. Die Ergebnisse wiesen darauf hin, dass IL-12 einen Einfluss auf das Verh{\"a}ltnis der NK-Subpopulationen besitzt, indem es durch Hochregulation von CD56 und Herabregulation von CD16 zu einer Umwandlung von CD56dimCD16+ NK-Zellen zu CD56brightCD16- NK-Zellen beitrug. W{\"a}hrend bei beiden Populationen DNAM-1 hochreguliert wurde, stieg die Expression von CD96 in der CD56dim Population, fiel aber in der CD56bright Population. Die Expression von TIGIT verhielt sich in der IL-15 Gruppe gegens{\"a}tzlich dazu. IFN-γ konnte die Expression der Liganden f{\"u}r DNAM-1, TIGIT und CD96 auf einer der untersuchten Tumorzelllinien (SK-ES-1) steigern. Die Zytotoxizit{\"a}t von NK-Zellen konnte nicht durch IL-12 gesteigert werden. Indessen konnten wir feststellen, dass DNAM-1 f{\"u}r die Aufrechterhaltung der zytotoxischen Funktion essentiell war und eine Blockierung von DNAM-1 zu einer drastischen Verringerung derselben gef{\"u}hrt hat. Dagegen konnten die NK-Zellen ihre Funktion nach der Blockierung von CD96 weitestgehend aufrechterhalten, es kam allerdings auch nicht zu einer gesteigerten Lyse von Tumorzellen. Die Ergebnisse verdeutlichten, dass IL-12 zwar die Expression von DNAM-1 auf NK-Zellen zu steigern vermochte, dies allerdings nicht zu einer gesteigerten Zytotoxizit{\"a}t der NK-Zellen gegen{\"u}ber den getesteten drei Tumorzelllinien gef{\"u}hrt hat.}, subject = {Interleukin 12}, language = {de} } @phdthesis{Austein2021, author = {Austein, Kristof}, title = {Entwicklung und Charakterisierung von 4-1BB-spezifischen Agonisten}, doi = {10.25972/OPUS-23428}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234285}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Um eine Signaltransduktion mittels agnostischer Antik{\"o}rper an Rezeptoren der TNFRSF zu bewirken, ist eine vorherige Immobilisation {\"u}ber des Fc Anteil des Antik{\"o}rpers Grundvorraussetzung. In dieser Arbeit sollte die M{\"o}glichkeit der Verankerung {\"u}ber eine andere Bindungsdom{\"a}ne untersucht werden. Es konnte gezeigt werden, dass eine Immobilisation mittels scFv:CD70 zu einer starken Signalaktivierung f{\"u}hrt.}, subject = {Monoklonaler Antik{\"o}rper}, language = {de} } @phdthesis{JordanGarrote2014, author = {Jordan Garrote, Ana-Laura}, title = {The role of host dendritic cells during the effector phase of intestinal graft-versus-host disease}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-102130}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2014}, abstract = {Monocytes can be functionally divided in two subsets, both capable to differentiate into dendritic cells (DCs): CX3CR1loCCR2+ classical monocytes, actively recruited to the sites of inflammation and direct precursors of inflammatory DCs; and CX3CR1hiCCR2- non-classical monocytes, characterized by CX3CR1-dependent recruitment to non-inflamed tissues. Yet, the function of non-classical monocyte-derived DCs (nc-mo-DCs), and the factors, which trigger their recruitment and DC differentiation, have not been clearly defined to date. Here we show that in situ differentiated nc-moDCs mediate immunosuppression in the context of intestinal graft-versus-host disease (GVHD). Employing multi-color confocal microscopy we observed a dramatic loss of steady state host-type CD103+ DC subset immediately after transplantation, followed by an enrichment of immune-regulatory CD11b+ nc-moDCs. Parabiosis experiments revealed that tissue-resident non-classical CX3CR1+ monocytes differentiated in situ into intestinal CD11b+ nc-moDCs after allogeneic hematopoietic cell transplantation (allo-HCT). Differentiation of this intestinal DC subset depended on CSF-1 but not on Flt3L, thus defining the precursors as monocytes and not pre-DCs. Importantly, CX3CR1 but not CCR2 was required for this DC subset differentiation, hence defining the precursors as non-classical monocytes. In addition, we identify PD-L1 expression by CX3CR1+ nc-moDCs as the major mechanism they employ to suppress alloreactive T cells during acute intestinal GVHD. All together, we demonstrate that host nc-moDCs surprisingly mediate immunosuppression in the context of murine intestinal GVHD - as opposed to classical "inflammatory" monocyte-derived dendritic cells (mo-DCs) - via coinhibitory signaling. This thorough study unravels for the first time a biological function of a - so far only in vitro and phenotypically described - DC subset. Our identification of this beneficial immunoregulatory DC subset points towards alternate future strategies in underpinning molecular pathways to foster their function. We describe an unexpected mechanism of nc-moDCs in allo-HCT and intestinal GVHD, which might also be important for autoimmune disorders or infections of the gastrointestinal tract.}, subject = {Knochenmarktransplantation}, language = {en} } @phdthesis{Hapke2023, author = {Hapke, Nils}, title = {Cardiac antigen derived T cell epitopes in the frame of myocardial infarction}, doi = {10.25972/OPUS-30196}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301963}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Cardiovascular disease and the acute consequence of myocardial infarc- tion remain one of the most important causes of morbidity and mortality in all western societies. While much progress has been made in mitigating the acute, life-threatening ischemia caused by infarction, heart failure of the damaged my- ocardium remains prevalent. There is mounting evidence for the role of T cells in the healing process after myocardial infarction, but relevant autoantigens, which might trigger and regulate adaptive immune involvement have not been discov- ered in patients. In this work, we discovered an autoantigenic epitope in the adrenergic receptor beta 1, which is highly expressed in the heart. This autoantigenic epitope causes a pro-inflammatory immune reaction in T cells isolated from pa- tients after myocardial infarction (MI) but not in control patients. This immune reaction was only observed in a subset of MI patients, which carry at least one allele of the HLA-DRB1*13 family. Interestingly, HLA-DRB1*13 was more com- monly expressed in patients in the MI group than in the control group. Taken together, our data suggests antigen-specific priming of T cells in MI patients, which leads to a pro-inflammatory phenotype. The primed T cells react to a cardiac derived autoantigen ex vivo and are likely to exhibit a similar phenotype in vivo. This immune phenotype was only observed in a certain sub- set of patients sharing a common HLA-allele, which was more commonly ex- pressed in MI patients, suggesting a possible role as a risk factor for cardiovas- cular disease. While our results are observational and do not have enough power to show strong clinical associations, our discoveries provide an essential tool to further our understanding of involvement of the immune system in cardiovascu- lar disease. We describe the first cardiac autoantigen in the clinical context of MI and provide an important basis for further translational and clinical research in cardiac autoimmunity.}, subject = {Immunologie}, language = {en} }