title: Regulatory mechanisms of acetylcholine synthesis and release by T cells.
abstract: OBJECTIVE
  Muscarinic and nicotinic acetylcholine (ACh) receptors are expressed in immune cells. ACh synthesized by choline acetyltransferase (ChAT) and released in T cells binds to these receptors. Furthermore, we have recently demonstrated the involvement of mediatophore, a homooligomer of a 16-kDa proteolipid subunit of vacuolar H(+)-ATPase, in ACh release from T cells. In this study, we investigated the effects of phorbol 12-myristate 13-acetate (PMA), dibutyryl cAMP (dbcAMP) and FK506, an immunosuppressant calcineurin inhibitor, on lymphocytic cholinergic activity in T cells.
  
  
  METHODS
  We determined the content and release of ACh in human leukemic T cell line MOLT-3 cells using a sensitive and specific radioimmunoassay for ACh. In addition, expression of ChAT mRNA and ChAT activity were investigated using reverse-transcription-polymerase chain reaction and Fonnum method, respectively.
  
  
  RESULTS
  Phytohemagglutinin (PHA), a T-cell activator, up-regulated ChAT mRNA expression, synthesis and release of ACh. PMA, a protein kinase C (PKC) activator, and dbcAMP, a protein kinase A (PKA) activator, also increased ChAT activity and ACh synthesis by up-regulating ChAT gene expression. FK506 inhibited PHA-induced up-regulation of ChAT mRNA expression, suggesting the involvement of calcineurin-mediated pathways in ChAT gene transcription.
  
  
  CONCLUSIONS
  Activation of PKC and PKA up-regulates ACh synthesis in T cells, and immunological activation triggers ChAT gene transcription through calcineurin-mediated pathways.
authors.affiliation: Department of Pharmacology, Faculty of Pharmaceutical Sciences, Doshisha Women's College of Liberal Arts, Kyotanabe, Kyoto 610-0395, Japan. tfujii@dwc.doshisha.ac.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fujii
authors.forename: Yuki
authors.initials: Y
authors.lastname: Takada-Takatori
authors.forename: Koichiro
authors.initials: K
authors.lastname: Kawashima
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D003994:Bucladesine / Q000494:pharmacology*; D002460:Cell Line; D002795:Choline O-Acetyltransferase / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D010835:Phytohemagglutinins / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics; D013601:T-Lymphocytes / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D016559:Tacrolimus / Q000494:pharmacology*; D013755:Tetradecanoylphorbol Acetate / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D007166:Immunosuppressive Agents; D010835:Phytohemagglutinins; D012333:RNA, Messenger; C016658:phorbolol myristate acetate; D003994:Bucladesine; D002795:Choline O-Acetyltransferase; D000109:Acetylcholine; D013755:Tetradecanoylphorbol Acetate; D016559:Tacrolimus