@article{SchulteSchweinlinWestermannetal.2020,
  author    = {Schulte, Leon N. and Schweinlin, Matthias and Westermann, Alexander J. and Janga, Harshavardhan and Santos, Sara C. and Appenzeller, Silke and Walles, Heike and Vogel, J{\"o}rg and Metzger, Marco},
  title     = {An Advanced Human Intestinal Coculture Model Reveals Compartmentalized Host and Pathogen Strategies during Salmonella Infection},
  series = {mBio},
  volume    = {11, 2020},
  journal   = {mBio},
  number    = {1},
  doi       = {10.1128/mBio.03348-19},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-229428},
  year      = {2020},
  abstract  = {A major obstacle in infection biology is the limited ability to recapitulate human disease trajectories in traditional cell culture and animal models, which impedes the translation of basic research into clinics. Here, we introduce a three-dimensional (3D) intestinal tissue model to study human enteric infections at a level of detail that is not achieved by conventional two-dimensional monocultures. Our model comprises epithelial and endothelial layers, a primary intestinal collagen scaffold, and immune cells. Upon Salmonella infection, the model mimics human gastroenteritis, in that it restricts the pathogen to the epithelial compartment, an advantage over existing mouse models. Application of dual transcriptome sequencing to the Salmonella-infected model revealed the communication of epithelial, endothelial, monocytic, and natural killer cells among each other and with the pathogen. Our results suggest that Salmonella uses its type III secretion systems to manipulate STAT3-dependent inflammatory responses locally in the epithelium without accompanying alterations in the endothelial compartment. Our approach promises to reveal further human-specific infection strategies employed by Salmonella and other pathogens. IMPORTANCE Infection research routinely employs in vitro cell cultures or in vivo mouse models as surrogates of human hosts. Differences between murine and human immunity and the low level of complexity of traditional cell cultures, however, highlight the demand for alternative models that combine the in vivo-like properties of the human system with straightforward experimental perturbation. Here, we introduce a 3D tissue model comprising multiple cell types of the human intestinal barrier, a primary site of pathogen attack. During infection with the foodborne pathogen Salmonella enterica serovar Typhimurium, our model recapitulates human disease aspects, including pathogen restriction to the epithelial compartment, thereby deviating from the systemic infection in mice. Combination of our model with state-of-the-art genetics revealed Salmonella-mediated local manipulations of human immune responses, likely contributing to the establishment of the pathogen's infection niche. We propose the adoption of similar 3D tissue models to infection biology, to advance our understanding of molecular infection strategies employed by bacterial pathogens in their human host.},
  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}
}
@article{DaeullaryImdahlDietrichetal.2023,
  author    = {D{\"a}ullary, Thomas and Imdahl, Fabian and Dietrich, Oliver and Hepp, Laura and Krammer, Tobias and Fey, Christina and Neuhaus, Winfried and Metzger, Marco and Vogel, J{\"o}rg and Westermann, Alexander J. and Saliba, Antoine-Emmanuel and Zdzieblo, Daniela},
  title     = {A primary cell-based in vitro model of the human small intestine reveals host olfactomedin 4 induction in response to Salmonella Typhimurium infection},
  series = {Gut Microbes},
  volume    = {15},
  journal   = {Gut Microbes},
  number    = {1},
  doi       = {10.1080/19490976.2023.2186109},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350451},
  year      = {2023},
  abstract  = {Infection research largely relies on classical cell culture or mouse models. Despite having delivered invaluable insights into host-pathogen interactions, both have limitations in translating mechanistic principles to human pathologies. Alternatives can be derived from modern Tissue Engineering approaches, allowing the reconstruction of functional tissue models in vitro. Here, we combined a biological extracellular matrix with primary tissue-derived enteroids to establish an in vitro model of the human small intestinal epithelium exhibiting in vivo-like characteristics. Using the foodborne pathogen Salmonella enterica serovar Typhimurium, we demonstrated the applicability of our model to enteric infection research in the human context. Infection assays coupled to spatio-temporal readouts recapitulated the established key steps of epithelial infection by this pathogen in our model. Besides, we detected the upregulation of olfactomedin 4 in infected cells, a hitherto unrecognized aspect of the host response to Salmonella infection. Together, this primary human small intestinal tissue model fills the gap between simplistic cell culture and animal models of infection, and shall prove valuable in uncovering human-specific features of host-pathogen interplay.},
  language  = {en}
}