@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{Sauerwein2023, author = {Sauerwein, Till}, title = {Implementation and application of bioinformatical software for the analysis of dual RNA sequencing data of host and pathogen during infection}, doi = {10.25972/OPUS-30307}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303075}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Since the advent of high-throughput sequencing technologies in the mid-2010s, RNA se- quencing (RNA-seq) has been established as the method of choice for studying gene expression. In comparison to microarray-based methods, which have mainly been used to study gene expression before the rise of RNA-seq, RNA-seq is able to profile the entire transcriptome of an organism without the need to predefine genes of interest. Today, a wide variety of RNA-seq methods and protocols exist, including dual RNA sequenc- ing (dual RNA-seq) and multi RNA sequencing (multi RNA-seq). Dual RNA-seq and multi RNA-seq simultaneously investigate the transcriptomes of two or more species, re- spectively. Therefore, the total RNA of all interacting species is sequenced together and only separated in silico. Compared to conventional RNA-seq, which can only investi- gate one species at a time, dual RNA-seq and multi RNA-seq analyses can connect the transcriptome changes of the species being investigated and thus give a clearer picture of the interspecies interactions. Dual RNA-seq and multi RNA-seq have been applied to a variety of host-pathogen, mutualistic and commensal interaction systems. We applied dual RNA-seq to a host-pathogen system of human mast cells and Staphylo- coccus aureus (S. aureus). S. aureus, a commensal gram-positive bacterium, can become an opportunistic pathogen and infect skin lesions of atopic dermatitis (AD) patients. Among the first immune cells S. aureus encounters are mast cells, which have previously been shown to be able to kill the bacteria by discharging antimicrobial products and re- leasing extracellular traps made of protein and deoxyribonucleic acid (DNA). However, S. aureus is known to evade the host's immune response by internalizing within mast cells. Our dual RNA-seq analysis of different infection settings revealed that mast cells and S. aureus need physical contact to influence each other's gene expression. We could show that S. aureus cells internalizing within mast cells undergo profound transcriptome changes to adjust their metabolism to survive in the intracellular niche. On the host side, we found out that infected mast cells elicit a type-I interferon (IFN-I) response in an autocrine manner and in a paracrine manner to non-infected bystander-cells. Our study provides the first evidence that mast cells are capable to produce IFN-I upon infection with a bacterial pathogen.}, subject = {Biologie}, language = {en} }