title: Modulation of natural killer cell function by alpha-adrenoreceptor-coupled signalling.
abstract: OBJECTIVE
  Our previous work has shown that α-adrenoreceptor (α-AR)-coupled signaling modulates T lymphocyte function. Here, we investigate the expression of α₁- and α₂-ARs in natural killer (NK) cells and roles of the two subtypes of α-ARs and their coupled signals in modulation of NK cell function.
  
  
  METHODS
  NK cells were purified by Ficoll-Isopaque one-step gradient centrifugation and in discontinuous Percoll density gradients from splenic cells of rats. The mRNA expressions of α₁-ARs and α₂-ARs in NK cells were measured by reverse transcription-polymerase chain reaction (RT-PCR). Flow cytometry was employed to detect the cytotoxicity of NK cells.
  
  
  RESULTS
  NK cells expressed both α₁-AR and α₂-AR mRNAs. Phenylephrine, a selective α₁-AR agonist, increased the cytotoxicity of NK cells. This effect of phenylephrine was reduced by corynanthine, a selective α₁-AR antagonist, and was blocked by PLC inhibitor U-73122, but not by PKA inhibitor H-89. Clonidine, a selective α₂-AR agonist, also enhanced the cytotoxicity of NK cells. This action of clonidine was blocked by α₂-AR antagonist yohimbine or by PKA inhibitor H-89, but not by PLC inhibitor U-73122.
  
  
  CONCLUSIONS
  NK cells express α₁- and α₂-ARs. Activation of the either subtype of α-ARs augments NK cell function. This action of α₁-ARs is transduced by PLC, while α₂-AR effect is mediated by PKA signaling.
authors.affiliation: Department of Physiology, School of Medicine, Nantong University, Nantong, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Xiao
authors.forename: Hui-Wei
authors.initials: HW
authors.lastname: Huang
authors.forename: Yu-Ping
authors.initials: YP
authors.lastname: Peng
authors.forename: Jing-Yin
authors.initials: JY
authors.lastname: Bao
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
authors.forename: Yi-Hua
authors.initials: YH
authors.lastname: Qiu
mesh_terms: D058646:Adrenergic alpha-1 Receptor Agonists / Q000494:pharmacology; D058668:Adrenergic alpha-1 Receptor Antagonists / Q000494:pharmacology; D058647:Adrenergic alpha-2 Receptor Agonists / Q000494:pharmacology; D058669:Adrenergic alpha-2 Receptor Antagonists / Q000494:pharmacology; D000818:Animals; D003000:Clonidine / Q000494:pharmacology; D003601:Cytotoxicity Tests, Immunologic / Q000379:methods; D004963:Estrenes / Q000494:pharmacology; D005434:Flow Cytometry; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism* / Q000494:pharmacology; D007546:Isoquinolines / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism; D010656:Phenylephrine / Q000494:pharmacology; D011760:Pyrrolidinones / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018340:Receptors, Adrenergic, alpha-1 / Q000235:genetics / Q000378:metabolism*; D018341:Receptors, Adrenergic, alpha-2 / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics / Q000276:immunology*; D013154:Spleen / Q000166:cytology; D013449:Sulfonamides / Q000494:pharmacology; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015016:Yohimbine / Q000494:pharmacology
chemical_list: D058646:Adrenergic alpha-1 Receptor Agonists; D058668:Adrenergic alpha-1 Receptor Antagonists; D058647:Adrenergic alpha-2 Receptor Agonists; D058669:Adrenergic alpha-2 Receptor Antagonists; D004963:Estrenes; D047908:Intracellular Signaling Peptides and Proteins; D007546:Isoquinolines; D011760:Pyrrolidinones; D012333:RNA, Messenger; D018340:Receptors, Adrenergic, alpha-1; D018341:Receptors, Adrenergic, alpha-2; D013449:Sulfonamides; C015482:protein kinase modulator; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D010656:Phenylephrine; D015016:Yohimbine; D010738:Type C Phospholipases; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide; D003000:Clonidine