Recombinant Human CCL19/MIP-3 beta Protein

MIP-3 beta, also known as ELC (EBI1-Ligand Chemokine), is one of many novel beta chemokines identified through bioinformatics. MIP-3 beta cDNA encodes a 98 amino acid (aa) residue precursor protein with a predicted 21 aa residue signal peptide that is cleaved to form the 77 aa residue mature secreted protein. MIP-3 beta is distantly related to other beta chemokines (20-30% aa sequence identity) and the gene for MIP-3 beta has been mapped to chromosome 9p13 rather than chromosome 17 where the genes for many human beta chemokines are clustered. MIP-3 beta has been shown to be constitutively expressed in various lymphoid tissues (including thymus, lymph nodes, appendix and spleen). The expression of MIP-3 beta is down-regulated by the anti-inflammatory cytokine IL-10. Recombinant MIP-3 beta has been shown to be chemotactic for cultured human lymphocytes. MIP-3 beta has also been shown to be a unique functional ligand for CCR-7 (previously referred to as the Epstein-Barr virus-induced gene 1 (EBI1) orphan receptor), a chemokine receptor that is expressed in various lymphoid tissues and activated B and T lymphocytes. EBI1 is strongly up-regulated in B cells infected with Epstein-Barr virus and T cells infected with herpesvirus 6 or 7.