BCA2 ELISA Kits

A study identified a novel activation related B-cell gene (bca) through differential hybridization screening of a murine B cell cDNA library. The deduced amino acid sequence predicted a protein of 482 amino acids with strong sequence similarity to the SH2 and SH3 domains present within the non-catalytic regions of several protein tyrosine kinases. Bca was transcribed at low levels in resting spleen cells from a variety of normal mouse strains and was strongly expressed in kidney RNA. Bca expression was markedly increased in RNA prepared from mitogen activated B cells, and in freshly isolated spleen and lymph node cells of MRL/lpr and NZB autoimmune strains. The unique sequence of bca suggests that this gene encodes a novel protein potentially involved in B-cell signal transduction.

The CXC chemokine CXCL13, known as BCA-1 (B cell-attracting chemokine 1) has been identified as an efficacious attractant selective for B lymphocytes. The chemokine receptor BLR1 (Burkitt's lymphoma receptor 1)/CXCR5 expressed by all mature B cells has to date been identified as the only known receptor for BCA-1. A study reports that human BCA-1 competes with radiolabeled interferon gamma (IFN-gamma) inducible protein 10 (IP-10) for binding to the human CXCR3 receptor expressed in Ba/F3 and 293EBNA cell lines. The data of the study suggest that human BCA-1 is a specific and functional G-protein-linked chemotactic ligand for the human CXCR3 receptor. The biological significance of this finding is supported by the observation that human BCA-1 induces chemotaxis of activated T cells and the BCA-1-induced chemotaxis is inhibited by a monoclonal antibody against human CXCR3.