Expression and Activity of NOX5 in the Circulating Malignant B Cells of Hairy Cell Leukemia

Autor: David Allsup, Lena Serrander, Joseph R. Slupsky, Mirko Zuzel, Ke Lin, Karl-Heinz Krause, John C. Cawley, Robert J. Harris, Aura S. Kamiguti
Rok vydání: 2005
Předmět:
rac1 GTP-Binding Protein
Cell signaling
NADPH Oxidase/analysis/ metabolism
Sialic Acid Binding Ig-like Lectin 2
Reactive Oxygen Species/analysis/metabolism
Immunology
Protein tyrosine phosphatase
ddc:616.07
Cell Fractionation
Leukemia
Hairy Cell/ pathology
Neoplastic Cells
Circulating/ chemistry
Protein Tyrosine Phosphatases/metabolism
chemistry.chemical_compound
Superoxides/analysis/metabolism
B-Lymphocytes/ enzymology
Superoxides
Membrane Proteins/analysis/ metabolism
Protein Phosphatase 1
Humans
Immunology and Allergy
Protein kinase A
B-Lymphocytes
Leukemia
Hairy Cell
Oxidase test
NADPH oxidase
biology
Superoxide
Kinase
Protein Tyrosine Phosphatase
Non-Receptor Type 6
Intracellular Signaling Peptides and Proteins
Membrane Proteins
NADPH Oxidases
Neoplastic Cells
Circulating
Cell biology
Antigens
CD22/metabolism
Intracellular Signaling Peptides and Proteins/metabolism
NADPH Oxidase 5
Biochemistry
chemistry
embryonic structures
biology.protein
Calcium
Protein Tyrosine Phosphatases
Reactive Oxygen Species
Proto-oncogene tyrosine-protein kinase Src
Zdroj: Journal of Immunology, Vol. 175, No 12 (2005) pp. 8424-8430
ISSN: 1550-6606
0022-1767
DOI: 10.4049/jimmunol.175.12.8424
Popis: Hairy cells (HCs) are mature malignant B cells that contain a number of constitutively active signaling molecules including GTP-bound Rac1, protein kinase C, and Src family kinases. Because Rac1 is a component of the reactive oxidant species (ROS)-generating NADPH oxidase system, we investigated the role of this GTPase in ROS production in HCs. In this study, we show that ROS production in HCs involves a flavin-containing oxidase dependent on Ca2+, but not on GTP-Rac1 or protein kinase C. This suggests the involvement of the nonphagocytic NADPH oxidase NOX5, an enzyme found in lymphoid tissues, but not in circulating lymphocytes. By using RT-PCR and Southern and Western blotting and by measuring superoxide anion production in membrane fractions in the absence of cytosolic components, we demonstrate for the first time that HCs (but not circulating normal B cells or some other lymphoid cell types) express NOX5. We also demonstrate that inhibition of NADPH oxidase in HCs results in a selective increase in the activity of Src homology region 2 domain-containing phosphatase 1 (SHP-1). Furthermore, SHP-1 in HCs coimmunoprecipitates with tyrosine phosphorylated CD22 and localizes in the same cellular compartment as NOX5. This allows the inactivation of SHP-1 by NOX5-generated ROS and contributes to the maintenance of the constitutive activation of HCs.
Databáze: OpenAIRE
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