Identification of CCR6, the specific receptor for a novel lymphocyte-directed CC chemokine LARC

J Biol Chem. 1997 Jun 6;272(23):14893-8. doi: 10.1074/jbc.272.23.14893.

Abstract

Liver and activation-regulated chemokine (LARC) is a recently identified CC chemokine that is expressed mainly in the liver. LARC functions as a selective chemoattractant for lymphocytes that express a class of receptors specifically binding to LARC with high affinity. To identifiy the receptor for LARC, we examined LARC-induced calcium mobilization in cells stably expressing five CC chemokine receptors (CCR1-CCR5) and five orphan seven-transmembrane receptors. LARC specifically induced calcium flux in K562 cells as well as 293/EBNA-1 cells stably expressing an orphan receptor GPR-CY4. LARC induced migration in 293/EBNA-1 cells stably expressing GPR-CY4 with a bi-modal dose-response curve. LARC fused with secreted alkaline phosphatase (LARC-SEAP) bound specifically to Raji cells stably expressing GPR-CY4 with a Kd of 0.9 nM. Only LARC but not five other CC chemokines (MCP-1, RANTES, MIP-1alpha, MIP-1beta, and TARC) competed with LARC-SEAP for binding to GPR-CY4. By Northern blot analysis, GPR-CY4 mRNA was expressed mainly in spleen, lymph nodes, Appendix, and fetal liver among various human tissues. Among various leukocyte subsets, GPR-CY4 mRNA was detected in lymphocytes (CD4(+) and CD8(+) T cells and B cells) but not in natural killer cells, monocytes, or granulocytes. Expression of GPR-CY4 mRNA in CD4(+) and CD8(+) T cells was strongly up-regulated by IL-2. Taken together, GPR-CY4 is the specific receptor for LARC expressed selectively on lymphocytes, and LARC is a unique functional ligand for GPR-CY4. We propose GPR-CY4 to be designated as CCR6.

MeSH terms

  • B-Lymphocytes / physiology
  • Binding, Competitive
  • CD4-Positive T-Lymphocytes / physiology
  • CD8-Positive T-Lymphocytes / physiology
  • Calcium / metabolism
  • Cell Line
  • Chemokine CCL20
  • Chemokines / metabolism
  • Chemokines / pharmacology*
  • Chemokines, CC*
  • Chemotaxis
  • Cloning, Molecular
  • Hematopoietic Stem Cells
  • Humans
  • Kidney
  • Kinetics
  • Liver / metabolism
  • Lymphocytes / physiology*
  • Macrophage Inflammatory Proteins*
  • RNA, Messenger / biosynthesis
  • Receptors, CCR6
  • Receptors, Chemokine*
  • Receptors, Cytokine / biosynthesis
  • Receptors, Cytokine / physiology*
  • Recombinant Fusion Proteins / metabolism
  • Recombinant Fusion Proteins / pharmacology
  • Transcription, Genetic
  • Transfection
  • Tumor Cells, Cultured

Substances

  • CCL20 protein, human
  • CCR6 protein, human
  • Chemokine CCL20
  • Chemokines
  • Chemokines, CC
  • Macrophage Inflammatory Proteins
  • RNA, Messenger
  • Receptors, CCR6
  • Receptors, Chemokine
  • Receptors, Cytokine
  • Recombinant Fusion Proteins
  • Calcium

Associated data

  • GENBANK/U45984