title: Differentiation associated regulation of microRNA expression in vivo in human CD8+ T cell subsets.
abstract: BACKGROUND
  The differentiation of CD8+ T lymphocytes following priming of naïve cells is central in the establishment of the adaptive immune response. Yet, the molecular events underlying this process are not fully understood. MicroRNAs have been recently shown to play a key role in the regulation of haematopoiesis in mouse, but their implication in peripheral lymphocyte differentiation in humans remains largely unknown.
  
  
  METHODS
  In order to explore the potential implication of microRNAs in CD8+ T cell differentiation in humans, microRNA expression profiles were analysed using microarrays and quantitative PCR in several human CD8+ T cell subsets defining the major steps of the T cell differentiation pathway.
  
  
  RESULTS
  We found expression of a limited set of microRNAs, including the miR-17~92 cluster. Moreover, we reveal the existence of differentiation-associated regulation of specific microRNAs. When compared to naive cells, miR-21 and miR-155 were indeed found upregulated upon differentiation to effector cells, while expression of the miR-17~92 cluster tended to concomitantly decrease.
  
  
  CONCLUSIONS
  This study establishes for the first time in a large panel of individuals the existence of differentiation associated regulation of microRNA expression in human CD8+ T lymphocytes in vivo, which is likely to impact on specific cellular functions.
authors.affiliation: Division of Clinical Onco-Immunology, Ludwig Center for Cancer Research of the University of Lausanne, Switzerland.
authors.forename: Bruno
authors.initials: B
authors.lastname: Salaun
authors.forename: Takuya
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Bassam
authors.initials: B
authors.lastname: Badran
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Tsunetsugu-Yokota
authors.forename: Antoine
authors.initials: A
authors.lastname: Roux
authors.forename: Lukas
authors.initials: L
authors.lastname: Baitsch
authors.forename: Redouane
authors.initials: R
authors.lastname: Rouas
authors.forename: Hussein
authors.initials: H
authors.lastname: Fayyad-Kazan
authors.forename: Petra
authors.initials: P
authors.lastname: Baumgaertner
authors.forename: Estelle
authors.initials: E
authors.lastname: Devevre
authors.forename: Anirudh
authors.initials: A
authors.lastname: Ramesh
authors.forename: Marion
authors.initials: M
authors.lastname: Braun
authors.forename: Daniel
authors.initials: D
authors.lastname: Speiser
authors.forename: Brigitte
authors.initials: B
authors.lastname: Autran
authors.forename: Philippe
authors.initials: P
authors.lastname: Martiat
authors.forename: Victor
authors.initials: V
authors.lastname: Appay
authors.forename: Pedro
authors.initials: P
authors.lastname: Romero
mesh_terms: D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism*; D002454:Cell Differentiation; D005786:Gene Expression Regulation; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D016176:T-Lymphocyte Subsets
chemical_list: D035683:MicroRNAs