title: Involvement of SLC17A9-dependent vesicular exocytosis in the mechanism of ATP release during T cell activation.
abstract: Recent reports have shown that T cell receptor (TCR)-dependent ATP release from T cells is involved in production of interleukin-2 (IL-2) through activation of P2 receptors. Stimulation of TCR induces ATP release from T cells through gap junction hemichannels and maxianion channels, at least in part. However, the mechanisms of ATP release from activated T cells are not fully understood. Here, we studied the mechanisms of ATP release during TCR-dependent T cell activation by investigating the effects of various inhibitors on TCR-dependent ATP release from murine T cells. We found that not only anion channel and gap junction hemichannel inhibitors, but also exocytosis inhibitors suppressed the ATP release. These results suggest that ATP release from murine T cells is regulated by various mechanisms, including exocytosis. An inhibitor of exocytosis, bafilomycin A, significantly blocked TCR signaling, such as Ca(2+) elevation and IL-2 production. Furthermore, bafilomycin A, ectonucleotidase, and P2Y(6) receptor antagonist significantly inhibited production of pro-inflammatory cytokines from external antigen-restimulated splenocytes, indicating that vesicular exocytosis-mediated purinergic signaling has a significant role in TCR-dependent cytokine production. We also detected vesicular ATP in murine T cells and human T lymphoma Jurkat cells, both of which also expressed mRNA of SLC17A9, a vesicular nucleotide transporter. Knockdown of SLC17A9 in Jurkat cells markedly reduced ATP release and cytosolic Ca(2+) elevation after TCR stimulation, suggesting involvement of SLC17A9-dependent vesicular exocytosis in ATP release and T cell activation. In conclusion, vesicular exocytosis of ATP appears to play a role in T cell activation and immune responses.
authors.affiliation: Department of Radiation Biosciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi Chiba, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tokunaga
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Tsukimoto
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Harada
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Moriyama
authors.forename: Shuji
authors.initials: S
authors.lastname: Kojima
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry*; D000818:Animals; D002118:Calcium / Q000737:chemistry; D003600:Cytosol / Q000378:metabolism; D005089:Exocytosis; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism; D019169:Jurkat Cells; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D033704:Nucleotide Transport Proteins / Q000737:chemistry*; D011948:Receptors, Antigen, T-Cell; D013601:T-Lymphocytes / Q000378:metabolism*
chemical_list: D007376:Interleukin-2; D033704:Nucleotide Transport Proteins; D011948:Receptors, Antigen, T-Cell; C529437:Slc17a9 protein, human; D000255:Adenosine Triphosphate; D002118:Calcium
references.citation: FASEB J. 2009 Jun;23(6):1685-93
references.pmid: 19211924
references.citation: Am J Physiol. 1998 Nov;275(5):H1726-32
references.pmid: 9815080
references.citation: Physiology (Bethesda). 2005 Aug;20:271-84
references.pmid: 16024515
references.citation: Annu Rev Immunol. 2009;27:591-619
references.pmid: 19132916
references.citation: J Biol Chem. 2007 Sep 28;282(39):28749-28758
references.pmid: 17627942
references.citation: Clin Exp Allergy. 2006 Nov;36(11):1357-66
references.pmid: 17083345
references.citation: Proc Natl Acad Sci U S A. 2008 Apr 15;105(15):5683-6
references.pmid: 18375752
references.citation: Trends Immunol. 2003 Oct;24(10):554-60
references.pmid: 14552840
references.citation: J Gen Physiol. 2001 Sep;118(3):251-66
references.pmid: 11524456
references.citation: J Biol Chem. 2005 Jan 28;280(4):2653-8
references.pmid: 15550367
references.citation: Braz J Med Biol Res. 2009 Jan;42(1):3-8
references.pmid: 18853040
references.citation: Biochem Biophys Res Commun. 1996 May 15;222(2):303-8
references.pmid: 8670200
references.citation: Nat Cell Biol. 2007 Aug;9(8):945-53
references.pmid: 17618272
references.citation: Immunity. 2001 Nov;15(5):847-59
references.pmid: 11728345
references.citation: Sci Signal. 2008 Sep 30;1(39):ra6
references.pmid: 18827222
references.citation: J Biol Chem. 2010 Mar 12;285(11):8138-47
references.pmid: 20071341
references.citation: J Biol Chem. 2002 Mar 22;277(12):10482-8
references.pmid: 11790776
references.citation: Biochem Biophys Res Commun. 2009 Jul 10;384(4):512-8
references.pmid: 19426712
references.citation: Mol Biol Cell. 2005 Aug;16(8):3659-65
references.pmid: 15944221
references.citation: Biochim Biophys Acta. 2010 Jan;1800(1):40-6
references.pmid: 19854240
references.citation: Annu Rev Immunol. 2001;19:497-521
references.pmid: 11244045
references.citation: Science. 2009 Jan 23;323(5913):474-7
references.pmid: 19164740
references.citation: J Cell Sci. 2006 Feb 15;119(Pt 4):605-14
references.pmid: 16467569
references.citation: Biochem Biophys Res Commun. 2009 Oct 9;388(1):1-5
references.pmid: 19619506
references.citation: Blood. 1996 Jan 15;87(2):682-90
references.pmid: 8555491
references.citation: Nature. 2008 Oct 9;455(7214):808-12
references.pmid: 18716618
references.citation: J Gen Physiol. 2002 Jun;119(6):511-20
references.pmid: 12034759
references.citation: Immunol Rev. 2009 Sep;231(1):210-24
references.pmid: 19754899
references.citation: Nat Immunol. 2007 Apr;8(4):345-50
references.pmid: 17375096
references.citation: Nat Immunol. 2009 Jan;10(1):21-7
references.pmid: 19088738
references.citation: Blood. 2007 Feb 1;109(3):1095-102
references.pmid: 17008549
references.citation: J Biol Chem. 2001 Aug 31;276(35):32925-32
references.pmid: 11387334
references.citation: J Immunol. 2006 Sep 1;177(5):2842-50
references.pmid: 16920919
references.citation: Glia. 2002 Dec;40(3):312-23
references.pmid: 12420311