@article{AlzheimerSvenssonKoenigetal.2020,
  author    = {Alzheimer, Mona and Svensson, Sarah L. and K{\"o}nig, Fabian and Schweinlin, Matthias and Metzger, Marco and Walles, Heike and Sharma, Cynthia M.},
  title     = {A three-dimensional intestinal tissue model reveals factors and small regulatory RNAs important for colonization with Campylobacter jejuni},
  series = {PLoS Pathogens},
  volume    = {16},
  journal   = {PLoS Pathogens},
  number    = {2},
  doi       = {10.1371/journal.ppat.1008304},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-229454},
  year      = {2020},
  abstract  = {The Gram-negative Epsilonproteobacterium Campylobacter jejuni is currently the most prevalent bacterial foodborne pathogen. Like for many other human pathogens, infection studies with C. jejuni mainly employ artificial animal or cell culture models that can be limited in their ability to reflect the in-vivo environment within the human host. Here, we report the development and application of a human three-dimensional (3D) infection model based on tissue engineering to study host-pathogen interactions. Our intestinal 3D tissue model is built on a decellularized extracellular matrix scaffold, which is reseeded with human Caco-2 cells. Dynamic culture conditions enable the formation of a polarized mucosal epithelial barrier reminiscent of the 3D microarchitecture of the human small intestine. Infection with C. jejuni demonstrates that the 3D tissue model can reveal isolate-dependent colonization and barrier disruption phenotypes accompanied by perturbed localization of cell-cell junctions. Pathogenesis-related phenotypes of C. jejuni mutant strains in the 3D model deviated from those obtained with 2D-monolayers, but recapitulated phenotypes previously observed in animal models. Moreover, we demonstrate the involvement of a small regulatory RNA pair, CJnc180/190, during infections and observe different phenotypes of CJnc180/190 mutant strains in 2D vs. 3D infection models. Hereby, the CJnc190 sRNA exerts its pathogenic influence, at least in part, via repression of PtmG, which is involved in flagellin modification. Our results suggest that the Caco-2 cell-based 3D tissue model is a valuable and biologically relevant tool between in-vitro and in-vivo infection models to study virulence of C. jejuni and other gastrointestinal pathogens.},
  language  = {en}
}
@article{BeckerOelschlaegerWullaertetal.2013,
  author    = {Becker, Svetlana and Oelschlaeger, Tobias A. and Wullaert, Andy and Pasparakis, Manolis and Wehkamp, Jan and Stange, Eduard F. and Gersemann, Michael},
  title     = {Bacteria Regulate Intestinal Epithelial Cell Differentiation Factors Both In Vitro and In Vivo},
  series = {PLoS ONE},
  volume    = {8},
  journal   = {PLoS ONE},
  number    = {2},
  doi       = {10.1371/journal.pone.0055620},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131168},
  pages     = {e55620},
  year      = {2013},
  abstract  = {Background: The human colon harbours a plethora of bacteria known to broadly impact on mucosal metabolism and function and thought to be involved in inflammatory bowel disease pathogenesis and colon cancer development. In this report, we investigated the effect of colonic bacteria on epithelial cell differentiation factors in vitro and in vivo. As key transcription factors we focused on Hes1, known to direct towards an absorptive cell fate, Hath1 and KLF4, which govern goblet cell. Methods: Expression of the transcription factors Hes1, Hath1 and KLF4, the mucins Muc1 and Muc2 and the defensin HBD2 were measured by real-time PCR in LS174T cells following incubation with several heat-inactivated E. coli strains, including the probiotic E. coli Nissle 1917+/- flagellin, Lactobacilli and Bifidobacteria. For protein detection Western blot experiments and chamber-slide immunostaining were performed. Finally, mRNA and protein expression of these factors was evaluated in the colon of germfree vs. specific pathogen free vs. conventionalized mice and colonic goblet cells were counted. Results: Expression of Hes1 and Hath1, and to a minor degree also of KLF4, was reduced by E. coli K-12 and E. coli Nissle 1917. In contrast, Muc1 and HBD2 expression were significantly enhanced, independent of the Notch signalling pathway. Probiotic E. coli Nissle 1917 regulated Hes1, Hath1, Muc1 and HBD2 through flagellin. In vivo experiments confirmed the observed in vitro effects of bacteria by a diminished colonic expression of Hath1 and KLF4 in specific pathogen free and conventionalized mice as compared to germ free mice whereas the number of goblet cells was unchanged in these mice. Conclusions: Intestinal bacteria influence the intestinal epithelial differentiation factors Hes1, Hath1 and KLF4, as well as Muc1 and HBD2, in vitro and in vivo. The induction of Muc1 and HBD2 seems to be triggered directly by bacteria and not by Notch.},
  language  = {en}
}
@article{BrehmKoziol2014,
  author    = {Brehm, Klaus and Koziol, Uriel},
  title     = {On the importance of targeting parasite stem cells in anti-echinococcosis drug development},
  series = {Parasite},
  volume    = {21},
  journal   = {Parasite},
  issn      = {1252-607X},
  doi       = {10.1051/parasite/2014070},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-118030},
  pages     = {72},
  year      = {2014},
  abstract  = {The life-threatening diseases alveolar and cystic echinococcoses are caused by larvae of the tapeworms Echinococcus multilocularis and E. granulosus, respectively. In both cases, intermediate hosts, such as humans, are infected by oral uptake of oncosphere larvae, followed by asexual multiplication and almost unrestricted growth of the metacestode within host organs. Besides surgery, echinococcosis treatment relies on benzimidazole-based chemotherapy, directed against parasite beta-tubulin. However, since beta-tubulins are highly similar between cestodes and humans, benzimidazoles can only be applied at parasitostatic doses and are associated with adverse side effects. Mostly aiming at identifying alternative drug targets, the nuclear genome sequences of E. multilocularis and E. granulosus have recently been characterized, revealing a large number of druggable targets that are expressed by the metacestode. Furthermore, recent cell biological investigations have demonstrated that E. multilocularis employs pluripotent stem cells, called germinative cells, which are the only parasite cells capable of proliferation and which give rise to all differentiated cells. Hence, the germinative cells are the crucial cell type mediating proliferation of E. multilocularis, and most likely also E. granulosus, within host organs and should also be responsible for parasite recurrence upon discontinuation of chemotherapy. Interestingly, recent investigations have also indicated that germinative cells might be less sensitive to chemotherapy because they express a beta-tubulin isoform with limited affinity to benzimidazoles. In this article, we briefly review the recent findings concerning Echinococcus genomics and stem cell research and propose that future research into anti-echinococcosis drugs should also focus on the parasite's stem cell population.},
  language  = {en}
}
@article{CeteciCeteciZanuccoetal.2012,
  author    = {Ceteci, Fatih and Ceteci, Semra and Zanucco, Emanuele and Thakur, Chitra and Becker, Matthias and El-Nikhely, Nefertiti and Fink, Ludger and Seeger, Werner and Savai, Rajkumar and Rapp, Ulf R.},
  title     = {E-Cadherin Controls Bronchiolar Progenitor Cells and Onset of Preneoplastic Lesions in Mice},
  series = {Neoplasia},
  volume    = {14},
  journal   = {Neoplasia},
  number    = {12},
  doi       = {10.1593/neo.121088},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-135407},
  pages     = {1164-1177},
  year      = {2012},
  abstract  = {Although progenitor cells of the conducting airway have been spatially localized and some insights have been gained regarding their molecular phenotype, relatively little is known about the mechanisms regulating their maintenance, activation, and differentiation. This study investigates the potential roles of E-cadherin in mouse Clara cells, as these cells were shown to represent the progenitor/stem cells of the conducting airways and have been implicated as the cell of origin of human non-small cell lung cancer. Postnatal inactivation of E-cadherin affected Clara cell differentiation and compromised airway regeneration under injury conditions. In steady-state adult lung, overexpression of the dominant negative E-cadherin led to an expansion of the bronchiolar stem cells and decreased differentiation concomitant with canonical Wnt signaling activation. Expansion of the bronchiolar stem cell pool was associated with an incessant proliferation of neuroepithelial body-associated Clara cells that ultimately gave rise to bronchiolar hyperplasia. Despite progressive hyperplasia, only a minority of the mice developed pulmonary solid tumors, suggesting that the loss of E-cadherin function leads to tumor formation when additional mutations are sustained. The present study reveals that E-cadherin plays a critical role in the regulation of proliferation and homeostasis of the epithelial cells lining the conducting airways.},
  language  = {en}
}
@phdthesis{Ehrig2012,
  author    = {Ehrig, Klaas},
  title     = {Effects of stem cell transcription factor-expressing vaccinia viruses in oncolytic virotherapy},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85139},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {Krebserkrankungen bleiben auch im Jahr 2012 die zweith{\"a}uftigste Todesursache in der industralisierten Welt. Zus{\"a}tzlich hat die Etablierung der Krebsstammzell-Hypothese grunds{\"a}tzliche Auswirkungen auf die Erfolgsaussichten konventioneller Krebstherapie, wie Chemotherapie oder Strahlentherapie. Deswegen ist es von gr{\"o}βter Notwendigkeit, dass neue Ans{\"a}tze zur Krebstherapie entwickelt werden, die den Ausgang der Behandlung verbessern und zu weniger Nebenwirkungen f{\"u}hren. Diverse vorklinische Studien haben gezeigt, dass die onkolytische Virotherapie mit Vaccinia-Viren ein potentes und gut tolerierbares neues Werkzeug in der Krebstherapie darstellt. Die Effizienz des Vaccinia-Virus als Therapeutikum allein oder in Kombination mit Strahlen- oder Chemotherapie wird aktuell in mehreren klinischen Studien der Phasen I \& II getestet. Krebsstammzellen und Stammzellen teilen eine Vielzahl von Eigenschaften, wie die F{\"a}higkeit zur Selbst-Erneuerung und Pluripotenz, Stilllegung der Zellproliferation, Resistenz gegen Medikamente oder Bestrahlung, die Expression von diversen Zelloberfl{\"a}chen-molek{\"u}len, die Aktivierung und Hemmung spezifischer Signaltransduktionswege oder die Expression von Stammzell-spezifischen Genen. In dieser Arbeit wurden zwei neue rekombinante Vaccinia-Viren entwickelt, welche die Stammzell-Transkriptionsfaktoren Nanog (GLV-1h205) und Oct4 (GLV-1h208) exprimieren, um tiefere Einblicke in die Rolle dieser Masterregulatoren in der Entstehung von Krebs und ihrem Einfluss auf die onkolytische Virotherapie zu gewinnen. Das Replikationspotential beider Virusst{\"a}mme in menschlichen A549-Zellen und PC-3-Zellen wurde anhand von Replikations-Assays bestimmt. Die Expression der Virus-spezifischen Markergene Ruc-GFP und beta-Galaktosidase, wie auch die Expression der Transkriptionsfaktoren Nanog und Oct4 wurde mit Hilfe von RT-PCR, SDS-PAGE und Western blotting, sowie immunozytochemischen Experimenten nachgewiesen. Des Weiteren wurde der Einfluss einer GLV-1h205-Infektion von A549-Zellen auf den Zellzyklus untersucht. Zudem wurde die Bedeutung der Virus-vermittelten Transkriptionsfaktor-Expression auf die Behandlung von subkutanen A549-Tumoren in einem Xenograft-Modell untersucht. Zur Untersuchung, ob die beobachteten Vorteile in der Behandlung von Lungenadenokarzinomen in M{\"a}usen mit GLV-1h205 Promoter- oder Transkriptionsfaktor-abh{\"a}ngig sind, wurde ein Kontroll-Virus (GLV-1h321) hergestellt, dass f{\"u}r eine unfunktionale Nanog-Mutante codiert. Mittels SDS-PAGE und Western blotting sowie Immunozytochemie wurde die Transgen-Expression analysiert. Ein weitere Aspekt dieser Arbeit war die Fragestellung, ob sich das onkolyische Vaccinia-Virus GLV-1h68 eignet, als neues und weniger invasives Therapeutikum effizient Darmkrebszellen zu infizieren um sich in ihnen zu replizieren und diese anschlieβend zu lysieren. Ein derartiger Therapieansatz w{\"u}rde besonders im Hinblick auf sp{\"a}t diagnostizierten, metastasierenden Darmkrebs eine interessante Behandlungsalternative darstellen. Virale Markergen-expression wurde anhand von Fluoreszenzmikroskopie und FACS-Analyse untersucht. Desweiteren wurde gezeigt, dass die einmalige Administration von GLV-1h68 in mindestens zwei verschiedenen Darmkrebszelllinien zu einer signifikanten Inhibierung des Tumorwachstums in vivo und zu signifikant verbessertem {\"U}berleben f{\"u}hrt. Der Transkriptionsfaktor Klf4 wird zwar stark in ruhenden, ausdifferenzierten Zellen des Darmepithels exprimiert, ist hingegen bei Darmkrebs generell dramatisch herabreguliert. Die Expression von Klf4 f{\"u}hrt zu einem Stop der Zellproliferation und inhibiert die Aktivit{\"a}t des Wnt-Signalweges, indem es im Zellkern an die Transaktivierungsdom{\"a}ne von beta-Catenin bindet. Um die Behandlung von Darmkrebs mit Hilfe onkolytischer Virotherapie weiter zu verbessern, wurden verschiedene Vaccinia-Viren (GLV-1h290-292) erzeugt, die durch verschiedene Promoterst{\"a}rken die Expression unterschiedlicher Mengen an Tumorsuppressor Klf4 vermitteln. Die anf{\"a}ngliche Charakterisierung der drei Virusst{\"a}mme mittels Replikations-Assay, Zytotoxizit{\"a}tstudien, SDS-PAGE und Western blotting, Immunozytochemie sowie die Analyse der Proteinfunktion mit Hilfe von qPCR- und ELISA-Analysen zur Bestimmung von zellul{\"a}rem beta-Catenin, zeigten eine Promoter-abh{\"a}ngige Expression und Wirkung von Klf4. F{\"u}r weitere Analysen wurde das Virus GLV-1h291 gew{\"a}hlt, welches nach Infektion die gr{\"o}βte Menge an Klf4 produziert und zus{\"a}tzlich durch die C-terminale Fusion einer TAT Transduktionsdom{\"a}ne Membran-g{\"a}ngig gemacht (GLV-1h391). Die erhaltenen Befunde machen das Klf4-TAT-kodierende Vaccinia-Virus GLV-1h391 zu einem vielversprechenden Kandidaten f{\"u}r eine Behandlung von Darmkrebs beim Menschen.},
  subject      = {Lungenkrebs},
  language  = {en}
}
@phdthesis{Esterlechner2013,
  author    = {Esterlechner, Jasmina},
  title     = {Role of the DREAM complex in mouse embryonic stem cells and identification of ZO-2 as a new LIN9 interacting protein},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-90440},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {The DREAM complex plays an important role in regulation of gene expression during the cell cycle. It was previously shown that the DREAM subunits LIN9 and B-MYB are required for early embryonic development and for the maintenance of the inner cell mass in vitro. In this work the effect of LIN9 or B-MYB depletion on embryonic stem cells (ESC) was examined. It demonstrates that LIN9 and B-MYB knock down changes the cell cycle distribution of ESCs and results in an accumulation of cells in G2 and M and in an increase of polyploid cells. By using genome-wide expression studies it was revealed that the depletion of LIN9 leads to downregulation of mitotic genes and to upregulation of differentiation-specific genes. ChIP-on chip experiments determined that mitotic genes are direct targets of LIN9 while lineage specific markers are regulated indirectly. Importantly, depletion of LIN9 does not alter the expression of the pluripotency markers Sox2 and Oct4 and LIN9 depleted ESCs retain alkaline phosphatase activity. I conclude that LIN9 is essential for proliferation and genome stability of ESCs by activating genes with important functions in mitosis and cytokinesis. The exact molecular mechanisms behind this gene activation are still unclear as no DREAM subunit features a catalytically active domain. It is assumed that DREAM interacts with other proteins or co-factors for transcriptional activation. This study discovered potential binding proteins by combining in vivo isotope labeling of proteins with mass spectrometry (MS) and further analysed the identified interaction of the tight junction protein ZO-2 with DREAM which is cell cycle dependent and strongest in S-phase. ZO-2 depletion results in reduced cell proliferation and decreased G1 gene expression. As no G2/M genes, typical DREAM targets, are affected upon ZO-2 knock down, it is unlikely that ZO-2 binding is needed for a functional DREAM complex. However, this work demonstrates that with (MS)-based quantitative proteomics, DREAM interacting proteins can be identified which might help to elucidate the mechanisms underlying DREAM mediated gene activation.},
  subject      = {Zellzyklus},
  language  = {en}
}
@article{GenslerLeikeimMoellmannetal.2020,
  author    = {Gensler, Marius and Leikeim, Anna and M{\"o}llmann, Marc and Komma, Miriam and Heid, Susanne and M{\"u}ller, Claudia and Boccaccini, Aldo R. and Salehi, Sahar and Groeber-Becker, Florian and Hansmann, Jan},
  title     = {3D printing of bioreactors in tissue engineering: A generalised approach},
  series = {PLoS One},
  volume    = {15},
  journal   = {PLoS One},
  number    = {11},
  doi       = {10.1371/journal.pone.0242615},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-231368},
  year      = {2020},
  abstract  = {3D printing is a rapidly evolving field for biological (bioprinting) and non-biological applications. Due to a high degree of freedom for geometrical parameters in 3D printing, prototype printing of bioreactors is a promising approach in the field of Tissue Engineering. The variety of printers, materials, printing parameters and device settings is difficult to overview both for beginners as well as for most professionals. In order to address this problem, we designed a guidance including test bodies to elucidate the real printing performance for a given printer system. Therefore, performance parameters such as accuracy or mechanical stability of the test bodies are systematically analysed. Moreover, post processing steps such as sterilisation or cleaning are considered in the test procedure. The guidance presented here is also applicable to optimise the printer settings for a given printer device. As proof of concept, we compared fused filament fabrication, stereolithography and selective laser sintering as the three most used printing methods. We determined fused filament fabrication printing as the most economical solution, while stereolithography is most accurate and features the highest surface quality. Finally, we tested the applicability of our guidance by identifying a printer solution to manufacture a complex bioreactor for a perfused tissue construct. Due to its design, the manufacture via subtractive mechanical methods would be 21-fold more expensive than additive manufacturing and therefore, would result in three times the number of parts to be assembled subsequently. Using this bioreactor we showed a successful 14-day-culture of a biofabricated collagen-based tissue construct containing human dermal fibroblasts as the stromal part and a perfusable central channel with human microvascular endothelial cells. Our study indicates how the full potential of biofabrication can be exploited, as most printed tissues exhibit individual shapes and require storage under physiological conditions, after the bioprinting process.},
  language  = {en}
}
@article{GeyerChalmersMacKintoshetal.2013,
  author    = {Geyer, Kathrin K. and Chalmers, Iain W. and MacKintosh, Neil and Hirst, Julie E. and Geoghegan, Rory and Badets, Mathieu and Brophy, Peter M. and Brehm, Klaus and Hoffmann, Karl F.},
  title     = {Cytosine methylation is a conserved epigenetic feature found throughout the phylum Platyhelminthes},
  series = {BMC Genomics},
  volume    = {14},
  journal   = {BMC Genomics},
  number    = {462},
  issn      = {1471-2164},
  doi       = {10.1186/1471-2164-14-462},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121892},
  year      = {2013},
  abstract  = {Background: The phylum Platyhelminthes (flatworms) contains an important group of bilaterian organisms responsible for many debilitating and chronic infectious diseases of human and animal populations inhabiting the planet today. In addition to their biomedical and veterinary relevance, some platyhelminths are also frequently used models for understanding tissue regeneration and stem cell biology. Therefore, the molecular (genetic and epigenetic) characteristics that underlie trophic specialism, pathogenicity or developmental maturation are likely to be pivotal in our continued studies of this important metazoan group. Indeed, in contrast to earlier studies that failed to detect evidence of cytosine or adenine methylation in parasitic flatworm taxa, our laboratory has recently defined a critical role for cytosine methylation in Schistosoma mansoni oviposition, egg maturation and ovarian development. Thus, in order to identify whether this epigenetic modification features in other platyhelminth species or is a novelty of S. mansoni, we conducted a study simultaneously surveying for DNA methylation machinery components and DNA methylation marks throughout the phylum using both parasitic and non-parasitic representatives. Results: Firstly, using both S. mansoni DNA methyltransferase 2 (SmDNMT2) and methyl-CpG binding domain protein (SmMBD) as query sequences, we illustrate that essential DNA methylation machinery components are well conserved throughout the phylum. Secondly, using both molecular (methylation specific amplification polymorphism, MSAP) and immunological (enzyme-linked immunoabsorbent assay, ELISA) methodologies, we demonstrate that representative species (Echinococcus multilocularis, Protopolystoma xenopodis, Schistosoma haematobium, Schistosoma japonicum, Fasciola hepatica and Polycelis nigra) within all four platyhelminth classes (Cestoda, Monogenea, Trematoda and 'Turbellaria') contain methylated cytosines within their genome compartments. Conclusions: Collectively, these findings provide the first direct evidence for a functionally conserved and enzymatically active DNA methylation system throughout the Platyhelminthes. Defining how this epigenetic feature shapes phenotypic diversity and development within the phylum represents an exciting new area of metazoan biology.},
  language  = {en}
}
@article{GomesWestermannSauerweinetal.2019,
  author    = {Gomes, Sara F. Martins and Westermann, Alexander J. and Sauerwein, Till and Hertlein, Tobias and F{\"o}rstner, Konrad U. and Ohlsen, Knut and Metzger, Marco and Shusta, Eric V. and Kim, Brandon J. and Appelt-Menzel, Antje and Schubert-Unkmeir, Alexandra},
  title     = {Induced pluripotent stem cell-derived brain endothelial cells as a cellular model to study Neisseria meningitidis infection},
  series = {Frontiers in Microbiology},
  volume    = {10},
  journal   = {Frontiers in Microbiology},
  number    = {1181},
  doi       = {10.3389/fmicb.2019.01181},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201562},
  year      = {2019},
  abstract  = {Meningococcal meningitis is a severe central nervous system infection that occurs when Neisseria meningitidis (Nm) penetrates brain endothelial cells (BECs) of the meningeal blood-cerebrospinal fluid barrier. As a human-specific pathogen, in vivo models are greatly limited and pose a significant challenge. In vitro cell models have been developed, however, most lack critical BEC phenotypes limiting their usefulness. Human BECs generated from induced pluripotent stem cells (iPSCs) retain BEC properties and offer the prospect of modeling the human-specific Nm interaction with BECs. Here, we exploit iPSC-BECs as a novel cellular model to study Nm host-pathogen interactions, and provide an overview of host responses to Nm infection. Using iPSC-BECs, we first confirmed that multiple Nm strains and mutants follow similar phenotypes to previously described models. The recruitment of the recently published pilus adhesin receptor CD147 underneath meningococcal microcolonies could be verified in iPSC-BECs. Nm was also observed to significantly increase the expression of pro-inflammatory and neutrophil-specific chemokines IL6, CXCL1, CXCL2, CXCL8, and CCL20, and the secretion of IFN-γ and RANTES. For the first time, we directly observe that Nm disrupts the three tight junction proteins ZO-1, Occludin, and Claudin-5, which become frayed and/or discontinuous in BECs upon Nm challenge. In accordance with tight junction loss, a sharp loss in trans-endothelial electrical resistance, and an increase in sodium fluorescein permeability and in bacterial transmigration, was observed. Finally, we established RNA-Seq of sorted, infected iPSC-BECs, providing expression data of Nm-responsive host genes. Altogether, this model provides novel insights into Nm pathogenesis, including an impact of Nm on barrier properties and tight junction complexes, and suggests that the paracellular route may contribute to Nm traversal of BECs.},
  language  = {en}
}
@phdthesis{Gotthard2023,
  author    = {Gotthard, Hannes},
  title     = {Targeting Colorectal Cancer Stem Cells with Hemibodies},
  doi       = {10.25972/OPUS-30309},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303090},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {The cancer stem cell hypothesis is a cancer development model which elicited great interest in the last decades stating that cancer heterogeneity arises from a stem cell through asymmetrical division. The Cancer Stem Cell subset is described as the only population to be tumorigenic and having the potential to renew. Conventional therapy often fails to eradicate CSC resulting in tumor relapse. Consequently, it is of great inter-est to eliminate this subset of cells to provide the best patient outcome. In the last years several approaches to target CSC were developed, one of them being immunotherapeu-tic targeting with antibodies. Since markers associated with CSC are also expressed on normal stem cells or healthy adjacent tissue in colorectal cancer, dual targeting strate-gies are preferred over targeting only a single antigen. Subsequently, the idea of dual targeting two CSC markers in parallel by a newly developed split T cell-engaging anti-body format termed as Hemibodies emerged. In a preliminary single cell RNA sequenc-ing analysis of colorectal cancer cells CD133, CD24, CD166 and CEA were identified as suitable targets for the combinatorial targeting strategy. Therefore, this study focused on trispecific and trivalent Hemibodies comprising a split binding moiety against CD3 and a binding moiety against either CD133, CD24, CD166 or CEA to overcome the occurrence of resistance and to efficiently eradicate all tumor cells including the CSC compartment. The study showed that the Hemibody combinations CD133xCD24, CD133xCD166 and CD133xCEA are able to eliminate double positive CHO cells with high efficacy while having a high specificity indicated by no killing of single antigen positive cells. A thera-peutic window ranging between one to two log levels could be achieved for all combina-tions mentioned above. The combinations CD133xCD24 and CD133xCD166 further-more proved its efficacy and specificity on established colorectal cancer cell lines. Be-sides the evaluation of specificity and efficacy the already introduced 1st generation of Hemibodies could be improved into a 2nd generation Hemibody format with increased half-life, stability and production yield. In future experiments the applicability of above-mentioned Hemibodies will be proven on patient-derived micro tumors to also include variables like tumor microenvironment and infiltration.},
  subject      = {Monoklonaler bispezifischer Antik{\"o}rper},
  language  = {en}
}