title: Platelet-derived sphingosine 1-phosphate induces migration of Jurkat T cells.
abstract: BACKGROUND
  The migration of T cell to atherosclerotic lesions is proposed to be involved in the pathogenesis of the atherosclerosis. Sphingosine 1-phosphate (S1P), a bioactive lysophospholipid released from activated platelets, exerts a variety of responses such as cell migration and proliferation, and reportedly induces T cell migration. Accordingly, platelet-T cell interactions may exist based on T cell responses triggered by platelet-derived S1P.
  
  
  METHODS
  S1P was measured using two-step lipid extraction followed by high-performance liquid chromatography (HPLC) separation while other phospholipids were determined by an enzymatic assay. The expression of S1P and lysophosphatidic acid receptors on Jurkat T cells was examined by RT-PCR and flow cytometry. Jurkat cell migration by S1P and the supernatant of activated platelets (SAP) was evaluated by a modified Boyden's chamber assay.
  
  
  RESULTS
  S1P1 receptor was confirmed to be expressed on Jurkat T cell by RT-PCR and flow cytometry. S1P at 10-100 nM induced strong Jurkat cell migration, which was inhibited by the S1P1 (and S1P3) antagonist VPC23019 and the Gi inactivator pertussis toxin (PTX). We found that the supernatant (releasate) of human platelets activated by collagen stimulation, which contains S1P abundantly, induced Jurkat cell migration and that the migration was inhibited by VPC23019 and PTX. In addition, human serum, into which platelet contents (including S1P) are fully released, induced the Jurkat cell migration, which was also inhibited by VPC23019.
  
  
  CONCLUSIONS
  Our findings suggest that platelet-derived S1P induces Jurkat T cell migration possibly via S1P1. S1P may be a key molecule involved in the responses triggered by platelet-T cell interactions, including atherosclerosis.
authors.forename: Junko
authors.initials: J
authors.lastname: Iino
authors.forename: Makoto
authors.initials: M
authors.lastname: Osada
authors.forename: Makoto
authors.initials: M
authors.lastname: Kurano
authors.forename: Makoto
authors.initials: M
authors.lastname: Kaneko
authors.forename: Ryunosuke
authors.initials: R
authors.lastname: Ohkawa
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Satoh
authors.forename: Shigeo
authors.initials: S
authors.lastname: Okubo
authors.forename: Yukio
authors.initials: Y
authors.lastname: Ozaki
authors.forename: Minoru
authors.initials: M
authors.lastname: Tozuka
authors.forename: Nelson H
authors.initials: NH
authors.lastname: Tsuno
authors.affiliation: Department of Clinical Laboratory, The University of Tokyo Hospital, Tokyo, Japan. yatoyuta-tky@umin.ac.jp.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yatomi
mesh_terms: D001792:Blood Platelets / Q000378:metabolism*; D002450:Cell Communication; D002465:Cell Movement; D006801:Humans; D019169:Jurkat Cells; D008246:Lysophospholipids / Q000502:physiology*; D049368:Receptors, Lysophosphatidic Acid / Q000378:metabolism; D049349:Receptors, Lysosphingolipid / Q000378:metabolism; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000502:physiology
chemical_list: D008246:Lysophospholipids; D049368:Receptors, Lysophosphatidic Acid; D049349:Receptors, Lysosphingolipid; C060506:sphingosine 1-phosphate; D013110:Sphingosine