mBLC/BCA-1 MAb (Cl 1 (25 ug)

Background: CXCL13/BLC/BCA-1

CXCL13, also known as B-lymphocyte chemoattractant (BLC) and BCA-1, is a CXC chemokine that is constitutively expressed in secondary lymphoid organs. Mouse CXCL13 cDNA encodes a precursor protein of 109 amino acid residues with a putative leader sequence of 21 residues. Mature mouse CXCL13 shares 64% amino acid sequence similarity with the human protein and 23-34% amino acid sequence identity with other known CXC chemokines. Recombinant or chemically synthesized CXCL13 is a potent chemoattractant for B lymphocytes but not T lymphocytes, monocytes or neutrophils. BLR1, a G protein-coupled receptor originally isolated from Burkitt’s lymphoma cells, has now been shown to be the specific receptor for CXCL13. Among cells of the hematopoietic lineages, the expression of BLR1, now designated CXCR5, is restricted to B lymphocytes and a subpopulation of T helper memory cells. Mice lacking BLR1 have been shown to lack inguinal lymph nodes. These mice were also found to have impaired development of Peyer’s patches and defective formation of primary follicles and germinal centers in the spleen as a result of the inability of B lymphocytes to migrate into B cell areas.