1. Academic Validation
  2. The chemokine SDF-1/CXCL12 binds to and signals through the orphan receptor RDC1 in T lymphocytes

The chemokine SDF-1/CXCL12 binds to and signals through the orphan receptor RDC1 in T lymphocytes

  • J Biol Chem. 2005 Oct 21;280(42):35760-6. doi: 10.1074/jbc.M508234200.
Karl Balabanian 1 Bernard Lagane Simona Infantino Ken Y C Chow Julie Harriague Barbara Moepps Fernando Arenzana-Seisdedos Marcus Thelen Françoise Bachelerie
Affiliations

Affiliation

  • 1 Unité d'Immunologie Virale, Institut Pasteur, 75015 Paris, France.
Abstract

Combined phylogenetic and chromosomal location studies suggest that the orphan receptor RDC1 is related to CXC chemokine receptors. RDC1 provides a co-receptor function for a restricted number of human immunodeficiency virus (HIV) isolates, in particular for the CXCR4-using HIV-2 ROD strain. Here we show that CXCL12, the only known natural ligand for CXCR4, binds to and signals through RDC1. We demonstrate that RDC1 is expressed in T lymphocytes and that CXCL12-promoted chemotaxis is inhibited by an anti-RDC1 monoclonal antibody. Concomitant blockade of RDC1 and CXCR4 produced additive inhibitory effects in CXCL12-induced T cell migration. Furthermore, we provide evidence that interaction of CXCL12 with RDC1 is specific, saturable, and of high affinity (apparent KD approximately 0.4 nM). In CXCR4-negative cells expressing RDC1, CXCL12 promotes internalization of the receptor and chemotactic signals through RDC1. Collectively, our data indicate that RDC1, which we propose to rename as CXCR7, is a receptor for CXCL12.

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