TI  - Human <prot>CC chemokine liver-expressed chemokine</prot>/   <prot>CCL16</prot>    is a functional ligand
      for  <prot>CCR1</prot> ,  <prot>CCR2</prot>  and  <prot>CCR5</prot> , and constitutively expressed by hepatocytes.
PG  - 1021-9
AB  - <prot>Liver-expressed chemokine</prot> (<prot>LEC</prot>)/<prot>CCL16</prot> is a human CC chemokine selectively
      expressed in the liver. Here, we investigated its receptor usage by
      calcium mobilization and chemotactic assays using mouse L1.2 pre-B cell
      lines stably expressing a panel of 12 human chemokine receptors. At
      relatively high concentrations,   <prot>LEC</prot>   induced calcium mobilization and
      chemotaxis via  <prot>CCR1</prot>  and  <prot>CCR2</prot> .  <prot>LEC</prot>  also induced calcium mobilization, but
      marginal chemotaxis via  <prot>CCR5</prot> . Consistently,    <prot>LEC</prot>    was found to bind to  <prot>CCR1</prot> ,
       <prot>CCR2</prot>  and  <prot>CCR5</prot>  with relatively low affinities. The binding of  <prot>LEC</prot>  to  <prot>CCR8</prot> 
      was much less significant. In spite of its binding to  <prot>CCR5</prot> ,  <prot>LEC</prot>  was unable
      to inhibit infection of an R5-type HIV-1 to activated human peripheral
      blood mononuclear cells even at high concentrations. In human liver
      sections, hepatocytes were strongly stained by anti-LEC antibody. HepG2, a
      human hepatocarcinoma cell line, was found to constitutively express <prot>LEC</prot>.
      <prot>LEC</prot> was also present in the plasma samples from healthy adult donors at
      relatively high concentrations (0.3--4 nM). Taken together,    <prot>LEC</prot>    is a new
      low-affinity functional ligand for  <prot>CCR1</prot> ,  <prot>CCR2</prot>  and  <prot>CCR5</prot> , and is
      constitutively expressed by liver parenchymal cells. The presence of <prot>LEC</prot>
      in normal plasma at relatively high concentrations may modulate
      inflammatory responses.
AD  - Department of Biochemistry, Kumamoto University Medical School, Honjo,
