@article{TuchscherrBischoffLattaretal.2015,
  author    = {Tuchscherr, Lorena and Bischoff, Markus and Lattar, Santiago M. and Noto Llana, Mariangeles and Pf{\"o}rtner, Henrike and Niemann, Silke and Geraci, Jennifer and Van de Vyver, H{\´e}l{\`e}ne and Fraunholz, Martin J. and Cheung, Ambrose L. and Herrmann, Mathias and V{\"o}lker, Uwe and Sordelli, Daniel O. and Peters, Georg and Loeffler, Bettina},
  title     = {Sigma factor SigB is crucial to mediate Staphylococcus aureus adaptation during chronic infections},
  series = {PLoS Pathogens},
  volume    = {11},
  journal   = {PLoS Pathogens},
  number    = {4},
  doi       = {10.1371/journal.ppat.1004870},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-143419},
  pages     = {e1004870},
  year      = {2015},
  abstract  = {Staphylococcus aureus is a major human pathogen that causes a range of infections from acute invasive to chronic and difficult-to-treat. Infection strategies associated with persisting S. aureus infections are bacterial host cell invasion and the bacterial ability to dynamically change phenotypes from the aggressive wild-type to small colony variants (SCVs), which are adapted for intracellular long-term persistence. The underlying mechanisms of the bacterial switching and adaptation mechanisms appear to be very dynamic, but are largely unknown. Here, we analyzed the role and the crosstalk of the global S. aureus regulators agr, sarA and SigB by generating single, double and triple mutants, and testing them with proteome analysis and in different in vitro and in vivo infection models. We were able to demonstrate that SigB is the crucial factor for adaptation in chronic infections. During acute infection, the bacteria require the simultaneous action of the agr and sarA loci to defend against invading immune cells by causing inflammation and cytotoxicity and to escape from phagosomes in their host cells that enable them to settle an infection at high bacterial density. To persist intracellularly the bacteria subsequently need to silence agr and sarA. Indeed agr and sarA deletion mutants expressed a much lower number of virulence factors and could persist at high numbers intracellularly. SigB plays a crucial function to promote bacterial intracellular persistence. In fact, \(\Delta\)sigB-mutants did not generate SCVs and were completely cleared by the host cells within a few days. In this study we identified SigB as an essential factor that enables the bacteria to switch from the highly aggressive phenotype that settles an acute infection to a silent SCV-phenotype that allows for long-term intracellular persistence. Consequently, the SigB-operon represents a possible target to develop preventive and therapeutic strategies against chronic and therapy-refractory infections.},
  language  = {en}
}
@article{WaeldchenLehmannKleinetal.2015,
  author    = {W{\"a}ldchen, Sina and Lehmann, Julian and Klein, Teresa and van de Linde, Sebastian and Sauer, Markus},
  title     = {Light-induced cell damage in live-cell super-resolution microscopy},
  series = {Scientific Reports},
  volume    = {5},
  journal   = {Scientific Reports},
  number    = {15348},
  doi       = {10.1038/srep15348},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-145207},
  year      = {2015},
  abstract  = {Super-resolution microscopy can unravel previously hidden details of cellular structures but requires high irradiation intensities to use the limited photon budget efficiently. Such high photon densities are likely to induce cellular damage in live-cell experiments. We applied single-molecule localization microscopy conditions and tested the influence of irradiation intensity, illumination-mode, wavelength, light-dose, temperature and fluorescence labeling on the survival probability of different cell lines 20-24 hours after irradiation. In addition, we measured the microtubule growth speed after irradiation. The photo-sensitivity is dramatically increased at lower irradiation wavelength. We observed fixation, plasma membrane permeabilization and cytoskeleton destruction upon irradiation with shorter wavelengths. While cells stand light intensities of similar to 1 kW cm\(^{-2}\) at 640 nm for several minutes, the maximum dose at 405 nm is only similar to 50 J cm\(^{-2}\), emphasizing red fluorophores for live-cell localization microscopy. We also present strategies to minimize phototoxic factors and maximize the cells ability to cope with higher irradiation intensities.},
  language  = {en}
}
@article{DuehringGermerodtSkerkaetal.2015,
  author    = {D{\"u}hring, Sybille and Germerodt, Sebastian and Skerka, Christine and Zipfel, Peter F. and Dandekar, Thomas and Schuster, Stefan},
  title     = {Host-pathogen interactions between the human innate immune system and Candida albicans - understanding and modeling defense and evasion strategies},
  series = {Frontiers in Microbiology},
  volume    = {6},
  journal   = {Frontiers in Microbiology},
  number    = {625},
  doi       = {10.3389/fmicb.2015.00625},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-151621},
  year      = {2015},
  abstract  = {The diploid, polymorphic yeast Candida albicans is one of the most important human pathogenic fungi. C. albicans can grow, proliferate and coexist as a commensal on or within the human host for a long time. However, alterations in the host environment can render C. albicans virulent. In this review, we describe the immunological cross-talk between C. albicans and the human innate immune system. We give an overview in form of pairs of human defense strategies including immunological mechanisms as well as general stressors such as nutrient limitation, pH, fever etc. and the corresponding fungal response and evasion mechanisms. Furthermore, Computational Systems Biology approaches to model and investigate these complex interactions are highlighted with a special focus on game-theoretical methods and agent-based models. An outlook on interesting questions to be tackled by Systems Biology regarding entangled defense and evasion mechanisms is given.},
  language  = {en}
}