Role of CD5 in growth regulation of B-1 cells.
CD5 is a membrane glycoprotein that is expressed on a subset of B lymphocytes called B-1 cells, thymocytes and T cells. The CD5+ B-1 cells are normally unresponsive to surface Ig receptor induced growth signals unless the CD5 gene is deleted or sequestered away. Here we show that CD5 mediated negative regulation is unique to B cell receptor (BCR) signaling. The CD5 molecule in normal B-1 cells is constitutively tyrosine phosphorylated and associates specifically with SHP-1, an SH2 domain containing protein tyrosine phosphatase. CD5 promotes a prolonged interaction between BCR and SHP-1, which may be inhibitory to BCR signaling. CD5 was shown to modulate the function of autoantibody producing B cells in transgenic mice expressing anti-DNA antibodies.
Bondada
S
S
Department of Microbiology and Immunology, Sanders Brown Center on Aging, University of Kentucky, Lexington, KY 40536-0230, USA.
Bikah
G
G
Robertson
D A
DA
Sen
G
G
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D000974:Antibodies, Antinuclear / Q000096:biosynthesis; D015703:Antigens, CD / Q000502:physiology; D000944:Antigens, Differentiation, B-Lymphocyte / Q000502:physiology; D017209:Apoptosis; D016175:B-Lymphocyte Subsets / Q000166:cytology*; D019013:CD40 Antigens / Q000502:physiology; D018956:CD5 Antigens / Q000737:chemistry / Q000502:physiology*; D007075:Immunoglobulin M / Q000276:immunology; D047908:Intracellular Signaling Peptides and Proteins; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D016328:NF-kappa B / Q000502:physiology; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases / Q000502:physiology; D011947:Receptors, Antigen, B-Cell / Q000502:physiology*; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases; D015398:Signal Transduction; D018909:src Homology Domains
D000888:Antibodies, Anti-Idiotypic; D000974:Antibodies, Antinuclear; D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D019013:CD40 Antigens; D018956:CD5 Antigens; C064228:CD72 protein, human; D007075:Immunoglobulin M; D047908:Intracellular Signaling Peptides and Proteins; D016328:NF-kappa B; D011947:Receptors, Antigen, B-Cell; C044203:anti-IgM; C516724:PTPN11 protein, human; C509249:PTPN6 protein, human; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases; C516725:Ptpn11 protein, mouse; C509248:Ptpn6 protein, mouse; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases