title: Protein kinase C-dependent activation of CaV1.2 channels selectively controls human TH2-lymphocyte functions.
abstract: BACKGROUND
  In addition to calcium release-activated calcium channel/ORAI calcium channels, the role of voltage-gated calcium (Cav1) channels in T-cell calcium signaling is emerging. Cav1 channels are formed by α1 (CaV1.1 to CaV1.4) and auxiliary subunits. We previously demonstrated that mouse TH2 cells selectively overexpressed CaV1.2 and CaV1.3 channels. Knocking down these channels with Cav1 antisense (AS) oligonucleotides inhibited TH2 functions and experimental asthma.
  
  
  OBJECTIVE
  We investigated the expression profile and role of Cav1 channels in human T-cell subsets, with a focus on TH2 cells.
  
  
  METHODS
  We compared the profile of CaV1 channel subunit expression in T-cell subsets isolated ex vivo from the blood of healthy donors, as well as in vitro-polarized T-cell subsets, and tested the effect of the Cav1 inhibitors nicardipine and Cav1.2AS on their functions.
  
  
  RESULTS
  CaV1.4 expression was detectable in CD4(+) T cells, ex vivo TH1 cells, and TH17 cells, whereas Cav1.2 channels predominated in TH2 cells only. T-cell activation resulted in Cav1.4 downregulation, whereas Cav1.2 expression was selectively maintained in polarized TH2 cells and absent in TH1 or TH9 cells. Nicardipine and CaV1.2AS decreased Ca(2+) and cytokine responses in TH2, but not TH1, cells. Protein kinase C (PKC) α/β inhibition decreased Ca(2+) and cytokine responses, whereas both calcium and cytokine responses induced by PKC activation were inhibited by nicardipine or Cav1.2AS in TH2 cells.
  
  
  CONCLUSIONS
  This study highlights the selective expression of Cav1.2 channels in human TH2 cells and the role of PKC-dependent Cav1.2 channel activation in TH2 cell function. Blocking PKC or Cav1.2 channel activation in TH2 cells might represent new strategies to treat allergic diseases in human subjects.
authors.affiliation: INSERM U1043, CNRS U5282, University Paul Sabatier, Center of Physiopathology from Toulouse Purpan, Toulouse, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Robert
authors.affiliation: INSERM U1043, CNRS U5282, University Paul Sabatier, Center of Physiopathology from Toulouse Purpan, Toulouse, France.
authors.forename: Emily
authors.initials: E
authors.lastname: Triffaux
authors.affiliation: INSERM U1043, CNRS U5282, University Paul Sabatier, Center of Physiopathology from Toulouse Purpan, Toulouse, France.
authors.forename: Pierre-Emmanuel
authors.initials: PE
authors.lastname: Paulet
authors.affiliation: INSERM U1043, CNRS U5282, University Paul Sabatier, Center of Physiopathology from Toulouse Purpan, Toulouse, France.
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Guéry
authors.affiliation: INSERM U1043, CNRS U5282, University Paul Sabatier, Center of Physiopathology from Toulouse Purpan, Toulouse, France. Electronic address: lucette.pelletier@inserm.fr.
authors.forename: Lucette
authors.initials: L
authors.lastname: Pelletier
authors.affiliation: INSERM U1043, CNRS U5282, University Paul Sabatier, Center of Physiopathology from Toulouse Purpan, Toulouse, France. Electronic address: magali.savignac@inserm.fr.
authors.forename: Magali
authors.initials: M
authors.lastname: Savignac
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D020746:Calcium Channels, L-Type / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects; D016207:Cytokines / Q000096:biosynthesis; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D009529:Nicardipine / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism*; D021122:Protein Subunits / Q000235:genetics; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D018417:Th1 Cells / Q000276:immunology / Q000378:metabolism; D058504:Th17 Cells / Q000276:immunology / Q000378:metabolism; D018418:Th2 Cells / Q000276:immunology* / Q000378:metabolism*
chemical_list: D020746:Calcium Channels, L-Type; D016207:Cytokines; C419385:L-type calcium channel alpha(1C); D021122:Protein Subunits; D011948:Receptors, Antigen, T-Cell; D009529:Nicardipine; D011493:Protein Kinase C
keywords: Chemoattractant receptor-homologous molecule expressed on T(H)2 cells; T(H)2 cytokines; asthma; calcium; protein kinase C α/β; voltage-dependent calcium channels