Expression of the G-protein-coupled receptor BLR1 defines mature, recirculating B cells and a subset of T-helper memory cells

Item Type:	Article
Title:	Expression of the G-protein-coupled receptor BLR1 defines mature, recirculating B cells and a subset of T-helper memory cells
Creators Name:	Foerster, R. and Emrich, T. and Kremmer, E. and Lipp, M.
Abstract:	The G-protein-coupled receptor BLR1 related to receptors for chemokines and neuropeptides has been identified as the first lymphocyte-specific member of the gene family characterized by seven transmembrane-spanning regions. Using a high-affinity anti-BLR1 monoclonal antibody (MoAb) and three-color flow cytometry it is shown that BLR1 expression on peripheral blood cells is limited to B cells and to a subset of CD4+ (14%) and CD8+ (2%) lymphocytes. T cells expressing BLR1 were positive for CD45R0, were negative for interleukin-2 receptors, show high levels of CD44, and show low levels of L-selectin. The majority of CD4+ cells originating from secondary lymphatic tissue, but none of cord blood-derived T cells, express BLR1. These observations suggest that BLR1 is a marker for memory T cells. Furthermore, BLR1 expression was detected on all CD19+ peripheral or tonsillar B lymphocytes, but only on a fraction of cord blood cells and bone marrow cells expressing CD19, sIgM, or sIgD. Interestingly, activation of both mature B and T cells by CD40 MoAb and CD3 MoAb, respectively, led to complete downregulation of BLR1. These data suggest that the G-protein-coupled receptor BLR1 is involved in functional control of mature recirculating B cells and T-helper memory cells participating in cell migration and cell activation.
Keywords:	B-Lymphocyte Differentiation Antigens, B-Lymphocyte Subsets, CD4-Positive T-Lymphocytes, Chemokine Receptors, CXCR5 Receptors, Cytokine Receptors, Down-Regulation, Flow Cytometry, GTP-Binding Proteins, Helper-Inducer T-Lymphocytes, Immunologic Memory, Immunophenotyping, Lymphocyte Activation, Lymphocyte Subsets, Monoclonal Antibodies, Palatine Tonsil, Plasmacytoma, Spleen, T-Lymphocyte Differentiation Antigens
Source:	Blood
ISSN:	0006-4971
Publisher:	American Society of Hematology
Volume:	84
Number:	3
Page Range:	830-840
Date:	1 August 1994
Official Publication:	http://bloodjournal.hematologylibrary.org/cgi/content/abstract/84/3/830
PubMed:	View item in PubMed

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