title: Comparative proteome analysis reveals conserved and specific adaptation patterns of Staphylococcus aureus after internalization by different types of human non-professional phagocytic host cells.
abstract: Staphylococcus aureus is a human pathogen that can cause a wide range of diseases. Although formerly regarded as extracellular pathogen, it has been shown that S. aureus can also be internalized by host cells and persist within these cells. In the present study, we comparatively analyzed survival and physiological adaptation of S. aureus HG001 after internalization by two human lung epithelial cell lines (S9 and A549), and human embryonic kidney cells (HEK 293). Combining enrichment of bacteria from host-pathogen assays by cell sorting and quantitation of the pathogen's proteome by mass spectrometry we characterized S. aureus adaptation during the initial phase between 2.5 h and 6.5 h post-infection. Starting with about 2 × 10(6) bacteria, roughly 1450 S. aureus proteins, including virulence factors and metabolic enzymes were identified by spectral comparison and classical database searches. Most of the bacterial adaptation reactions, such as decreased levels of ribosomal proteins and metabolic enzymes or increased amounts of proteins involved in arginine and lysine biosynthesis, enzymes coding for terminal oxidases and stress responsive proteins or activation of the sigma factor SigB were observed after internalization into any of the three cell lines studied. However, differences were noted in central carbon metabolism including regulation of fermentation and threonine degradation. Since these differences coincided with different intracellular growth behavior, complementary profiling of the metabolome of the different non-infected host cell types was performed. This revealed similar levels of intracellular glucose but host cell specific differences in the amounts of amino acids such as glycine, threonine or glutamate. With this comparative study we provide an impression of the common and specific features of the adaptation of S. aureus HG001 to specific host cell environments as a starting point for follow-up studies with different strain isolates and regulatory mutants.
authors.affiliation: Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald Greifswald, Germany.
authors.forename: Kristin
authors.initials: K
authors.lastname: Surmann
authors.affiliation: ZIK-FunGene Junior Research Group Applied Proteomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald Greifswald, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Michalik
authors.affiliation: ZIK-FunGene Junior Research Group Applied Proteomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald Greifswald, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Hildebrandt
authors.affiliation: Institute of Biochemistry, Ernst-Moritz-Arndt-University Greifswald Greifswald, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Gierok
authors.affiliation: ZIK-FunGene Junior Research Group Applied Proteomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald Greifswald, Germany.
authors.forename: Maren
authors.initials: M
authors.lastname: Depke
authors.affiliation: Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald Greifswald, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Brinkmann
authors.affiliation: Institute for Microbiology, Ernst-Moritz-Arndt-University Greifswald Greifswald, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Bernhardt
authors.affiliation: Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald Greifswald, Germany.
authors.forename: Manuela G
authors.initials: MG
authors.lastname: Salazar
authors.affiliation: Institute for Systems Biology Seattle, WA USA.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Institute for Systems Biology Seattle, WA USA.
authors.forename: David
authors.initials: D
authors.lastname: Shteynberg
authors.affiliation: Institute for Systems Biology Seattle, WA USA.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Kusebauch
authors.affiliation: Institute for Systems Biology Seattle, WA USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Moritz
authors.affiliation: Institute of Molecular Systems Biology, ETH Zurich Zurich, Switzerland.
authors.forename: Bernd
authors.initials: B
authors.lastname: Wollscheid
authors.affiliation: Institute of Biochemistry, Ernst-Moritz-Arndt-University Greifswald Greifswald, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Lalk
authors.affiliation: Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald Greifswald, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Völker
authors.affiliation: ZIK-FunGene Junior Research Group Applied Proteomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald Greifswald, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Schmidt
keywords: Staphylococcus aureus; host-pathogen interaction; human cell lines; label-free quantitation; proteomics