title: Proteome changes of Caenorhabditis elegans upon a Staphylococcus aureus infection.
abstract: BACKGROUND
  The success of invertebrates throughout evolution is an excellent illustration of the efficiency of their defence strategies. Caenorhabditis elegans has proven to be an appropriate model for transcriptome studies of host-pathogen interactions. The aim of this paper is to complement this knowledge by investigating the worm's response to a Staphylococcus aureus infection through a 2-dimensional differential proteomics approach.
  
  
  RESULTS
  Different types of growth media in combination with either E. coli OP50 or Staphylococcus aureus were tested for an effect on the worm's lifespan. LB agar was chosen and C. elegans samples were collected 1 h, 4 h, 8 h and 24 h post S. aureus infection or E. coli incubation. Proteomics analyses resulted in the identification of 130 spots corresponding to a total of 108 differentially expressed proteins.
  
  
  CONCLUSIONS
  Exploring four time-points discloses a dynamic insight of the reaction against a gram-positive infection at the level of the whole organism. The remarkable upregulation after 8 h and 24 h of many enzymes involved in the citric acid cycle might illustrate the cost of fighting off an infection. Intriguing is the downregulation of chaperone molecules, which are presumed to serve a protective role. A comparison with a similar experiment in which C. elegans was infected with the gram-negative Aeromonas hydrophila reveals that merely 9% of the identified spots, some of which even exhibiting an opposite regulation, are present in both studies. Hence, our findings emphasise the complexity and pathogen-specificity of the worm's immune response and form a firm basis for future functional research.
  
  
  METHODS
  This article was reviewed by Itai Yanai, Dieter Wolf and Torben Luebke (nominated by Walter Lutz).
authors.affiliation: Research Group of Functional Genomics and Proteomics, KU Leuven, Naamsestraat 59, Leuven, Belgium. Annelies.Bogaerts@bio.kuleuven.be
authors.forename: Annelies
authors.initials: A
authors.lastname: Bogaerts
authors.forename: Isabel
authors.initials: I
authors.lastname: Beets
authors.forename: Liesbet
authors.initials: L
authors.lastname: Temmerman
authors.forename: Liliane
authors.initials: L
authors.lastname: Schoofs
authors.forename: Peter
authors.initials: P
authors.lastname: Verleyen
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000378:metabolism* / Q000382:microbiology*; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D053208:Kaplan-Meier Estimate; D020543:Proteome / Q000378:metabolism*; D013203:Staphylococcal Infections / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000502:physiology*; D016019:Survival Analysis; D013997:Time Factors
chemical_list: D029742:Caenorhabditis elegans Proteins; D020543:Proteome