CCL-19 (MIP-3 beta)

CCL19, also known as MIP3β and ELC (EBI1Ligand Chemokine), is a 77 amino acid (aa) β chemokine that is distantly related to other β chemokines (20-30% aa sequence identity) . The gene for MIP3β has been mapped to chromosome 9p13 rather than chromosome 17 where the genes for many human β chemokines are clustered. MIP3β is constitutively expressed in various lymphoid tissues (including thymus, lymph nodes, appendix and spleen) . The expression of MIP3β is downregulated by the antiinflammatory cytokine IL10. Recombinant MIP3β is chemotactic for cultured human lymphocytes. MIP3β is a ligand for CCR7 (previously referred to as the EpsteinBarr virus-induced gene 1 (EBI1) orphan receptor), a chemokine receptor that is expressed in various lymphoid tissues and activated B and T lymphocytes. CCR7 is strongly upregulated in B cells infected with EpsteinBarr virus and T cells infected with herpesvirus 6 or 7.