title: B and T Lymphocyte Attenuator is a Target of miR-155 during Naïve CD4+ T Cell Activation.
abstract: BACKGROUND
  MicroRNA-155 (miR-155) is upregulated during T cell activation, but the exact mechanisms by which it influences CD4+ T cell activation remain unclear.
  
  
  OBJECTIVE
  To examine whether the B and T lymphocyte attenuator (BTLA) is a target of miR-155 during naïve CD4+ T cell activation.
  
  
  METHODS
  Firefly luciferase reporter plasmids pEZX-MT01-wild-type-BTLA and pEZX-MT01-mutant-BTLA were constructed. Lymphocytes were nucleofected with miR-155 inhibitor or negative control (NC). Then, naïve CD4+ CD62L+ helper T cells purified from lymphocytes were stimulated with immobilized antibody to CD3 and soluble antibody to CD28. miR-155 and BTLA expression were examined by real-time RT-PCR. Cell surface CD69 expression and IL-2 secretion were measured by ELISA and flowcytometry, respectively.
  
  
  RESULTS
  Luciferase reporter assay showed that miR-155 targeted the BTLA 3'UTR region. Compared with non-stimulated condition, both miR-155 and BTLA mRNA expression were upregulated after T cell activation. Similar results were observed for BLTA protein expression. Compared with NC, the miR-155 inhibitor decreased miR-155 by about 45%, but did not influence BTLA mRNA expression. Compared with NC, the miR-155 inhibitor decreased the surface BTLA expression by about 60%. Upregulation of BTLA in miR-155 knockdown CD4+ T cells did not influence the cell surface expression of CD69, an early activation marker (p=0.523). Similarly, IL-2 production was not changed.
  
  
  CONCLUSIONS
  miR-155 is involved in the inhibition of BTLA during CD4+ T cell activation. These results might serve as a basis for an eventual therapeutic manipulation of this pathway to treat inflammatory and autoimmune diseases.
authors.affiliation: Department of Intensive Care Medicine, Hospital of PLA, Shanghai, China, Email: liuyongan411h@sina.com.
authors.forename: Yongan
authors.initials: Y
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Nie
authors.forename: Yu
authors.initials: Y
authors.lastname: Jin
authors.forename: Anshan
authors.initials: A
authors.lastname: Zhuo
authors.forename: Yuansheng
authors.initials: Y
authors.lastname: Zang
authors.forename: Qingyu
authors.initials: Q
authors.lastname: Xiu
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D000818:Animals; D000906:Antibodies / Q000276:immunology; D015703:Antigens, CD / Q000378:metabolism*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism*; D001402:B-Lymphocytes / Q000502:physiology*; D018106:CD28 Antigens / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology*; D002478:Cells, Cultured; D007376:Interleukin-2 / Q000378:metabolism; D037181:Lectins, C-Type / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000235:genetics; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism*; D000099192:CD69 Antigens
chemical_list: D020413:3' Untranslated Regions; D000906:Antibodies; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D018106:CD28 Antigens; D017252:CD3 Complex; D007376:Interleukin-2; D037181:Lectins, C-Type; D035683:MicroRNAs; D034741:RNA, Small Interfering; D011971:Receptors, Immunologic; D000099192:CD69 Antigens; C488868:BTLA protein, mouse; C532623:Mirn155 microRNA, mouse