CD21 is a ligand for CD23 and regulates IgE production

来自 EBSCO

阅读量：

作者：

KU Jansen，JY Bonnefoy，JP Aubry，S Pochon，P Graber

展开

摘要：

THE molecule CD23, a low-affinity receptor for IgE (FcεR 2 ) 1,2 , is a type II transmembrane molecule expressed on many haemopoietic cell types 3,4 . CD23 has pleiotropic roles in the control of lymphocyte behaviour 5–9 , suggesting that CD23 may interact with another ligand in addition to IgE. To identify such a CD23 ligand, we expressed and purified full-length recombinant CD23, incorporated it into fluorescent liposomes and used these as a probe. We report here that fluorescent liposomes carrying CD23 interact specifically with the cell-surface protein CD21, identified as the receptor for Epstein–Barr virus and the complement recep-tor-2 on B cells, some T cells and follicular dendritic cells. In addition, fluorescent CD23–liposomes were shown to bind to ham-ster kidney cells (BHK-21) transfected with CD21 complementary DNA. The interaction between fluorescent CD23–liposomes and B cells or CD21-transfected BHK-21 cells was specifically inhibited by anti-CD21 and anti-CD23 monoclonal antibodies. Western blotting analysis revealed that 14 C-labelled liposomes carrying CD23, in contrast to anti-CD21 antibodies, reacted with a subtype of CD21 molecules. Triggering of CD21 either with an anti-CD21 antibody or with recombinant soluble CD23 was shown to increase specifically interleukin-4-induced IgE production from blood mononuclear cells. These results demonstrate that the cell-surface protein CD21 is a ligand for CD23 and that the pairing of these molecules may participate in the control of IgE production.

展开

关键词：

Animals Humans B-Lymphocytes T-Lymphocytes Cell Line Tumor Cells, Cultured Immunoglobulin E Recombinant Proteins Receptors, Complement Receptors, Complement 3d