title: Probing host pathogen cross-talk by transcriptional profiling of both Mycobacterium tuberculosis and infected human dendritic cells and macrophages.
abstract: BACKGROUND
  Transcriptional profiling using microarrays provides a unique opportunity to decipher host pathogen cross-talk on the global level. Here, for the first time, we have been able to investigate gene expression changes in both Mycobacterium tuberculosis, a major human pathogen, and its human host cells, macrophages and dendritic cells.
  
  
  RESULTS
  In addition to common responses, we could identify eukaryotic and microbial transcriptional signatures that are specific to the cell type involved in the infection process. In particular M. tuberculosis shows a marked stress response when inside dendritic cells, which is in accordance with the low permissivity of these specialized phagocytes to the tubercle bacillus and to other pathogens. In contrast, the mycobacterial transcriptome inside macrophages reflects that of replicating bacteria. On the host cell side, differential responses to infection in macrophages and dendritic cells were identified in genes involved in oxidative stress, intracellular vesicle trafficking and phagosome acidification.
  
  
  CONCLUSIONS
  This study provides the proof of principle that probing the host and the microbe transcriptomes simultaneously is a valuable means to accessing unique information on host pathogen interactions. Our results also underline the extraordinary plasticity of host cell and pathogen responses to infection, and provide a solid framework to further understand the complex mechanisms involved in immunity to M. tuberculosis and in mycobacterial adaptation to different intracellular environments.
authors.affiliation: Institut Pasteur, Unit of Mycobacterial Genetics, Paris, France.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Tailleux
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Waddell
authors.forename: Mattia
authors.initials: M
authors.lastname: Pelizzola
authors.forename: Alessandra
authors.initials: A
authors.lastname: Mortellaro
authors.forename: Michael
authors.initials: M
authors.lastname: Withers
authors.forename: Antoine
authors.initials: A
authors.lastname: Tanne
authors.forename: Paola Ricciardi
authors.initials: PR
authors.lastname: Castagnoli
authors.forename: Brigitte
authors.initials: B
authors.lastname: Gicquel
authors.forename: Neil G
authors.initials: NG
authors.lastname: Stoker
authors.forename: Philip D
authors.initials: PD
authors.lastname: Butcher
authors.forename: Maria
authors.initials: M
authors.lastname: Foti
authors.forename: Olivier
authors.initials: O
authors.lastname: Neyrolles
mesh_terms: D003713:Dendritic Cells / Q000276:immunology / Q000382:microbiology*; D020869:Gene Expression Profiling; D006801:Humans; D008264:Macrophages / Q000276:immunology / Q000382:microbiology*; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000276:immunology / Q000502:physiology; D014158:Transcription, Genetic