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1. Enhanced Biodiesel Production from Waste Cooking Oil Using ZnO Nanocatalyst

Author

Gada, P., Dusi, S. K., Abrar, I., Ghosh, Arindam, Series Editor, Chua, Daniel, Series Editor, de Souza, Flavio Leandro, Series Editor, Aktas, Oral Cenk, Series Editor, Han, Yafang, Series Editor, Gong, Jianghong, Series Editor, Jawaid, Mohammad, Series Editor, Khan, Zishan Husain, editor, Jackson, Mark, editor, and Salah, Numan A., editor

Published
2023
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7. TiO2-coated pSi microparticles for nanomedicine

Author

Chistè, E., Ghafarinazari, A., Donini, M., Cremers, V., Dendooven, J., Detavernier, C., Benati, D., Scarpa, M., Dusi, S., and Daldosso, N.

Subjects
porous silicon, nanomedicine
Published
2018

8. Capitolo 2 : Meccanismi di difesa

Author

Berton, G., Dobrina, A., Dusi, S., and Vecile, E.

Subjects
infiammazione acuta, febbre, infiammazione acuta, infiammazione cronica, febbre, infiammazione cronica
Published
2018

10. Analysing the Relevance of ICT Skills on occupations in Web Job Vacancies

Author

Dusi, S, Fontana, M, Mercorio, F, Mezzanzanica, M, Dusi, S, Fontana, M, Mercorio, F, Mezzanzanica, M, Larsen, C, Rand, S, Schmid, A, Holopainen, P, Jokikaarre, P, Kuusela, K, and Alapuranen, N

Subjects
Big Data, Machine Learning, ING-IND/05 - IMPIANTI E SISTEMI AEROSPAZIALI, INF/01 - INFORMATICA, Labour Market Intelligence
Published
2016

13. Metabolic consequences of mitochondrial coenzyme A deficiency in patients with PANK2 mutations

Author

Leoni, V, Strittmatter, L, Zorzi, G, Zibordi, F, Dusi, S, Garavaglia, B, Venco, P, Caccia, C, Souza, A, Deik, A, Clish, C, Rimoldi, M, Ciusani, E, Bertini, E, Nardocci N, Mootha, V, Tiranti, V, Leoni V, Strittmatter L, Zorzi G, Zibordi F, Dusi S, Garavaglia B, Venco P, Caccia C, Souza AL, Deik A, Clish CB, Rimoldi M, Ciusani E, Bertini E, Mootha VK, Tiranti V, Leoni, V, Strittmatter, L, Zorzi, G, Zibordi, F, Dusi, S, Garavaglia, B, Venco, P, Caccia, C, Souza, A, Deik, A, Clish, C, Rimoldi, M, Ciusani, E, Bertini, E, Nardocci N, Mootha, V, Tiranti, V, Leoni V, Strittmatter L, Zorzi G, Zibordi F, Dusi S, Garavaglia B, Venco P, Caccia C, Souza AL, Deik A, Clish CB, Rimoldi M, Ciusani E, Bertini E, Mootha VK, and Tiranti V

Abstract

Pantothenate kinase-associated neurodegeneration (PKAN) is a rare, inborn error of metabolism characterized by iron accumulation in the basal ganglia and by the presence of dystonia, dysarthria, and retinal degeneration. Mutations in pantothenate kinase 2 (PANK2), the rate-limiting enzyme in mitochondrial coenzyme A biosynthesis, represent the most common genetic cause of this disorder. How mutations in this core metabolic enzyme give rise to such a broad clinical spectrum of pathology remains a mystery. To systematically explore its pathogenesis, we performed global metabolic profiling on plasma from a cohort of 14 genetically defined patients and 18 controls. Notably, lactate is elevated in PKAN patients, suggesting dysfunctional mitochondrial metabolism. As predicted, but never previously reported, pantothenate levels are higher in patients with premature stop mutations in PANK2. Global metabolic profiling and follow-up studies in patient-derived fibroblasts also reveal defects in bile acid conjugation and lipid metabolism, pathways that require coenzyme A. These findings raise a novel therapeutic hypothesis, namely, that dietary fats and bile acid supplements may hold potential as disease-modifying interventions. Our study illustrates the value of metabolic profiling as a tool for systematically exploring the biochemical basis of inherited metabolic diseases.

Published
2012

14. Mutations of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Gene Cause a Monocyte-selective Adhesion Deficiency

Author

Sorio, C., Montresor, A., Bolomini-Vittori, M., Caldrer, S., Rossi, B., Dusi, S., Angiari, S., Johansson, J.E., Vezzalini, M., Leal, T., Calcaterra, E., Assael, B.M., Melotti, P., Laudanna, C., Sorio, C., Montresor, A., Bolomini-Vittori, M., Caldrer, S., Rossi, B., Dusi, S., Angiari, S., Johansson, J.E., Vezzalini, M., Leal, T., Calcaterra, E., Assael, B.M., Melotti, P., and Laudanna, C.

Abstract

Item does not contain fulltext, BACKGROUND: Cystic fibrosis (CF) is a common genetic disease caused by mutations of the CF transmembrane conductance regulator (CFTR) gene. Persistent lung inflammation, characterized by increasing polymorphonuclear leukocyte recruitment, is a major cause of the decline in respiratory function in CF patients, and is a leading cause of morbidity and mortality. CFTR is expressed in various cell types, including leukocytes, but its involvement in the regulation of leukocyte recruitment is unknown. METHODS: Ex vivo adhesion and chemotaxis, flow cytometry, immunofluorescence, GTPases activity assays. RESULTS: We found that chemoattractant-induced activation of beta1 and beta2 integrins and of chemotaxis is defective in mononuclear cells isolated from CF patients. In contrast, polymorphonuclear leukocyte adhesion and chemotaxis were normal. The functionality of beta1 and beta2 integrins was restored by treatment of CF monocytes with the CFTR correcting drugs VX325 and VX809. Moreover, treatment of healthy monocytes with the CFTR inhibitor CFTR inh-172 blocked integrin activation by chemoattractants. In a murine model of lung inflammation, we found that integrin-independent migration of CF monocytes into the lung parenchyma was normal, whereas, in contrast, integrin-dependent transmigration into the alveolar space was impaired. Finally, signal transduction analysis showed that in CF monocytes chemoattractant-triggered activation of RhoA and CDC42 rho small GTPases, controlling integrin activation and chemotaxis respectively, was strongly deficient. CONCLUSION: Altogether, these data highlight the critical regulatory role of CFTR in integrin activation by chemoattractants in monocytes and identify CF as a new, cell-type selective, leukocyte adhesion deficiency disease providing new insights on CF pathogenesis.

Published
2016

17. Big Data meets Job Vacancy: Trends, Challenges and Development Directions

Author

Larsen,C, Rand,S, Schmid,A, Mezzanzanica,M, Dusi, S, Mercorio, F, Mezzanzanica, M, DUSI, SILVIA, MERCORIO, FABIO, MEZZANZANICA, MARIO, Larsen,C, Rand,S, Schmid,A, Mezzanzanica,M, Dusi, S, Mercorio, F, Mezzanzanica, M, DUSI, SILVIA, MERCORIO, FABIO, and MEZZANZANICA, MARIO

Published
2015

18. TiO2-coated luminescent porous silicon micro-particles as a promising system for nanomedicine.

Author

Chistè, E., Ghafarinazari, A., Donini, M., Cremers, V., Dendooven, J., Detavernier, C., Benati, D., Scarpa, M., Dusi, S., and Daldosso, N.

Abstract

Porous silicon (pSi) is a sponge-like material obtained by electrochemical etching of a crystalline silicon wafer. Due to quantum confinement effects, this material is photoluminescent and this is a fundamental property from the perspective of bioimaging applications. Limitations in nanomedicine to the use of photoluminescent pSi structures are mainly due to optical quenching in an aqueous environment and to the adverse effects of reactive groups introduced by etching procedures. In this work, we exploited an inorganic TiO2 coating of pSi microparticles by Atomic Layer Deposition (ALD) that resulted in optical stability of pSi particles in a biological buffer (e.g. PBS). The use of a rotary reactor allows deposition of a uniform coating on the particles and enables a fine tuning of its thickness. The ALD parameters were optimized and the photoluminescence (PL) of pSi–TiO2 microparticles was stabilized for more than three months without any significant effect on their morphology. The biocompatibility of the coated microparticles was evaluated by analyzing the release of cytokines and superoxide anion (O2−) by human dendritic cells, which play an essential role in the regulation of inflammatory and immune responses. We demonstrated that the microparticles per se are unable to significantly damage or stimulate human dendritic cells and therefore are suitable candidates for nanomedicine applications. However, a synergistic effect of the microparticles with bacterial products, which are known to stimulate immune-response, was observed, indicating that a condition unfavorable to the use of inorganic nanomaterials in biological systems is the presence of infection diseases. These results, combined with the proved PL stability in biological buffers, open the way for the use of pSi–TiO2 microparticles as promising materials in nanomedicine, but their ability to increase immune cell activation by other agonists should be considered and even exploited. [ABSTRACT FROM AUTHOR]

Published
2018
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19. Mechanisms of stimulation of the respiratory burst by TNF in nonadherent neutrophils: its independence of lipidic transmembrane signaling and dependence on protein tyrosine phosphorylation and cytoskeleton

Author

Dusi, S., Della Bianca, V., Marta Donini, Nadalini, K. A., and Rossi, F.

Subjects
Immunology, Immunology and Allergy
Abstract

This study concerns the controversial problem of whether the TNF-alpha (TNF) induces a respiratory burst in human neutrophils in suspension. The results have shown that in these cells TNF induces a classical respiratory burst. In fact, the production of oxygen free radicals 1) is linked to the translocation of NADPH oxidase components from cytosol to the plasma membrane, 2) does not take place in neutrophils from a patient lacking the cytochrome b558, and 3) does not involve other sources such as mitochondrial respiratory chain or xanthine oxidase. Signal transduction studies have demonstrated that this respiratory burst 1) is not accompanied by calcium transients, stimulation of phosphoinositide turnover, and phospholipase D activity (moreover, this burst is associated with the stimulation of the activity of phospholipase A2, but not of sphingomyelinase); 2) is strictly dependent on activation of tyrosine kinases, which is functional to the translocation to the plasma membrane of the cytosolic NADPH oxidase component rac; and 3) is dependent on the integrity of the cytoskeleton because it is completely suppressed by cytochalasin B. The integrity of the cytoskeleton is required for a full translocation of all the NADPH oxidase components and for an optimal activation of tyrosine kinases, but not for phospholipase A2 activation. Taken together, these findings demonstrate that TNF activates the NADPH oxidase through stimulation of tyrosine kinases, whose function is cytoskeleton-dependent, and raise the problem of whether the activation of this respiratory burst involves signals arising from TNF-activated beta2 integrins.

Published
1996

24. Regulatory T cells suppress the late phase of the immune response in lymph nodes through P-selectin glycoprotein ligand-1

Author

Angiari, S., Rossi, B., Piccio, L., Zinselmeyer, B.H., Budui, S., Zenaro, E., Bianca, V. Della, Bach, S.D., Scarpini, E., Bolomini-Vittori, M., Piacentino, G., Dusi, S., Laudanna, C., Cross, A.H., Miller, M.J., Constantin, G., Angiari, S., Rossi, B., Piccio, L., Zinselmeyer, B.H., Budui, S., Zenaro, E., Bianca, V. Della, Bach, S.D., Scarpini, E., Bolomini-Vittori, M., Piacentino, G., Dusi, S., Laudanna, C., Cross, A.H., Miller, M.J., and Constantin, G.

Abstract

Item does not contain fulltext, Regulatory T cells (Tregs) maintain tolerance toward self-antigens and suppress autoimmune diseases, although the underlying molecular mechanisms are unclear. In this study, we show that mice deficient for P-selectin glycoprotein ligand-1 (PSGL-1) develop a more severe form of experimental autoimmune encephalomyelitis than wild type animals do, suggesting that PSGL-1 has a role in the negative regulation of autoimmunity. We found that Tregs lacking PSGL-1 were unable to suppress experimental autoimmune encephalomyelitis and failed to inhibit T cell proliferation in vivo in the lymph nodes. Using two-photon laser-scanning microscopy in the lymph node, we found that PSGL-1 expression on Tregs had no role in the suppression of early T cell priming after immunization with Ag. Instead, PSGL-1-deficient Tregs lost the ability to modulate T cell movement and failed to inhibit the T cell-dendritic cell contacts and T cell clustering essential for sustained T cell activation during the late phase of the immune response. Notably, PSGL-1 expression on myelin-specific effector T cells had no role in T cell locomotion in the lymph node. Our data show that PSGL-1 represents a previously unknown, phase-specific mechanism for Treg-mediated suppression of the persistence of immune responses and autoimmunity induction.

Published
2013

26. Serological markers of HIV2 infection in subjects from Guinea Bissau

Author

Dimitri G, Biasoli B, Ferro A, Dusi S, Caruso B, Malena M, Ortolani R, Tridente G., LUZZATI, ROBERTO, Istituto Superiore Sanità, Dimitri, G, Biasoli, B, Ferro, A, Dusi, S, Caruso, B, Malena, M, Luzzati, Roberto, Ortolani, R, and Tridente, G.

Subjects
HIV-2, serological marker, Guinea Bissau
Published
1991

40. Interferon-gamma activates human neutrophil oxygen metabolism and exocytosis.

Author

Cassatella, M. A., Cappelli, R., Bianca, V. Della, Grzeskowiak, M., Dusi, S., and Berton, G.

Subjects
RECOMBINANT molecules, INTERFERONS, HYDROGEN peroxide, NEUTROPHILS, EXOCYTOSIS, MONOCLONAL antibodies, CYTOCHROMES
Abstract

Here we have investigated the ability of recombinant interferon-gamma (rIFN-γ) to modulate human neutrophil (PMN) functions. PMN incubated in the presence of rIFN-γ showed an enhanced hydrogen peroxide production in response to Con A, FMLP, PMA or immune complexes. The effect of rIFN-γ was dose dependent, being half maximal at 2 U/ml, and required between 90 min and 240 min of incubation to reach optimal response. The enhancing effect of rIFN-γ on the respiratory response of PMN was not blocked by polymixin B sulphate, but an anti-rIFN-γ monoclonal antibody and cycloheximide and actinomycin D were effective inhibitors. The enhancement of the response to Con A was not accompanied by an enhanced binding of the lectin. Neither the kinetic properties of the Con A-stimulated NADPH oxidase nor the expression of cytochrome b-245 were altered in rIFN-γ-trealed PMN. rIFN-γ also enhanced granule secretion in response to Con A, FMLP and PMA. Initial studies on the possible alterations of transmembrane signalling in rIFN-γ-treated PMN showed that neither inositol phosphates formation nor cytoplasmic calcium transients were altered. [ABSTRACT FROM AUTHOR]

Published
1988

42. beta-amyloid activates the O-2 forming NADPH oxidase in microglia, monocytes, and neutrophils. A possible inflammatory mechanism of neuronal damage in Alzheimer's disease.

Author

Bianca, V D, Dusi, S, Bianchini, E, Dal Prà, I, and Rossi, F

Abstract

The deposition of beta-amyloid in the brain is the key pathogenetic event in Alzheimer's disease. Among the various mechanisms proposed to explain the neurotoxicity of beta-amyloid deposits, a new one, recently identified in our and other laboratories, suggests that beta-amyloid is indirectly neurotoxic by activating microglia to produce toxic inflammatory mediators such as cytokines, nitric oxide, and oxygen free radicals. Three findings presented here support this mechanism, showing that beta-amyloid peptides (25-35), (1-39), and (1-42) activated the classical NADPH oxidase in rat primary culture of microglial cells and human phagocytes: 1) The exposure of the cells to beta-amyloid peptides stimulates the production of reactive oxygen intermediates; 2) the stimulation is associated with the assembly of the cytosolic components of NADPH oxidase on the plasma membrane, the process that corresponds to the activation of the enzyme; 3) neutrophils and monocytes of chronic granulomatous disease patients do not respond to beta-amyloid peptides with the stimulation of reactive oxygen intermediate production. Data are also presented that the activation of NADPH oxidase requires that beta-amyloid peptides be in fibrillary state, is inhibited by inhibitors of tyrosine kinases or phosphatidylinositol 3-kinase and by dibutyryl cyclic AMP, and is potentiated by interferon-gamma or tumor necrosis factor-alpha.

Published
1999

43. Activation of NADPH-dependent superoxide production in plasma membrane extracts of pig neutrophils by phosphatidic acid.

Author

Bellavite, P, Corso, F, Dusi, S, Grzeskowiak, M, Della-Bianca, V, and Rossi, F

Abstract

Phosphatidic acid (PA), a molecule that is rapidly produced by the stimulated turnover of phospholipids in a variety of cells including blood neutrophils, elicited NADPH-dependent superoxide anion (O2-) production in detergent extracts from membranes of resting pig neutrophils. The stimulatory effect of PA was independent of cytosolic factors, differing from arachidonic acid and sodium dodecyl sulfate which, on the contrary, absolutely required the presence of cytosol to elicit the same result. The O2(-)-forming activity of the detergent extract activable by PA, as that by sodium dodecyl sulfate and arachidonic acid plus cytosol, was found in the chromatographic fractions containing cytochrome b558 and presented a chromatographic profile identical to that of the activated NADPH oxidase, which was obtained from neutrophils prestimulated with phorbol 12-myristate 13-acetate. The PA-induced NADPH-dependent O2(-)-forming activity showed kinetic properties and sensitivity to the inhibitors similar to the classical ones of the activated neutrophil NADPH oxidase. The data suggest that, in this cell-free system, PA may stimulate O2- formation by direct interaction with latent NADPH oxidase of neutrophils or with some of its regulatory components.

Published
1988
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45. Studies on the NADPH oxidase of phagocytes

Author

Berton, G, Dusi, S, Serra, M C, Bellavite, P, and Rossi, F

Abstract

We describe in this paper a monoclonal antibody to pig NADPH oxidase which inhibits enzymatic activity. This antibody, designated 1H8.2, was selected from a group of monoclonal antibodies produced against active preparations of purified NADPH oxidase and which showed selectivity of binding. 1H8.2 is an IgM restricted in binding to pig NADPH oxidase and showing higher binding to NADPH oxidase purified from phorbol myristate acetate-stimulated than from resting neutrophils. The antibody inhibits by about 90% the oxidase activity at 20–50 µg/ml. Inhibition is due to a decrease of the Vmaxof the oxidase, and the Kmis not affected. Incubation of the NADPH oxidase with 1H8.2 in the presence of concentrations of NADPH up to 25-fold the Kmdoes not prevent the inhibition. Together with the evidence that the antibody does not inhibit the neutrophil superoxide dismutase-insensitive NADPH cytochrome creductase and the liver NADPH-cytochrome creductase this observation indicates that the 1H8.2 does not bind to an epitope belonging to the NADPH-binding site. Experiments of immunoprecipitation of iodinated membrane proteins and of immunoaffinity purification showed that 1H8.2 recognizes a heterodimer of apparent molecular mass of 16/18 and 14 kDa. These polypeptides can be involved in the NADPH oxidase activity or represent still unrecognized molecules able to modulate its function.

Published
1989
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46. Formation of Inositol (1,4,5) Trisphosphate and Increase of Cytosolic Ca2+ Mediated by Fc Receptors in Human Neutrophils

Author

Dellabianca, V., Grzeskowiak, M., Dusi, S., and Rossi, F.

Abstract

The correlation between the increase of [Ca2+]i and the activation of hydrolysis of phosphoinositide-4,5-bisphosphate and formation of inositol(1,4,5)trisphosphate in neutrophils treated with Fc receptor-binding agonists is still under discussion. In this communication evidence is presented supporting the conclusion that, as it is widely accepted for the activation of other receptors, also upon the activation of Fc receptors the stimulation of the production of inositol(1,4,5) trisphosphate is involved in the increase in [Ca2+]i. In fact: i) treatment of neutrophils with immune complexes induced a very rapid phosphoinositide hydrolysis measured as [3H]inositol phosphates production from [3H]phosphoinositides and as inositol(1,4,5) trisphosphate formation measured with radioreceptor assay; ii) immune complexes caused a dose-dependent increase of [Ca2+]i; iii) the increase of [Ca2+]i correlated with the production of inositol(1,4,5) trisphosphate with respect to time course, dose dependence and pertussis toxin insensitivity.Copyright 1993, 1999 Academic Press

Published
1993
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47. Interferon-gamma activates human neutrophil oxygen metabolism and exocytosis

Author

Cassatella, M A, Cappelli, R, Della Bianca, V, Grzeskowiak, M, Dusi, S, and Berton, G

Subjects
Oxygen, Interferon-gamma, Neutrophils, Concanavalin A, Humans, Calcium, Hydrogen Peroxide, Cytoplasmic Granules, Phosphatidylinositols, Exocytosis, Monocytes, Recombinant Proteins, Research Article
Abstract

Here we have investigated the ability of recombinant interferon-gamma (rIFN-gamma) to modulate human neutrophil (PMN) functions. PMN incubated in the presence of rIFN-gamma showed an enhanced hydrogen peroxide production in response to Con A, FMLP, PMA or immune complexes. The effect of rIFN-gamma was dose dependent, being half maximal at 2 U/ml, and required between 90 min and 240 min of incubation to reach optimal response. The enhancing effect of rIFN-gamma on the respiratory response of PMN was not blocked by polymixin B sulphate, but an anti-rIFN-gamma monoclonal antibody and cycloheximide and actinomycin D were effective inhibitors. The enhancement of the response to Con A was not accompanied by an enhanced binding of the lectin. Neither the kinetic properties of the Con A-stimulated NADPH oxidase nor the expression of cytochrome b-245 were altered in rIFN-gamma-treated PMN. rIFN-gamma also enhanced granule secretion in response to Con A, FMLP and PMA. Initial studies on the possible alterations of transmembrane signalling in rIFN-gamma-treated PMN showed that neither inositol phosphates formation nor cytoplasmic calcium transients were altered.

Published
1988

50. Nicotinamide-adenine dinucleotide phosphate oxidase assembly and activation in EBV-transformed B lymphoblastoid cell lines of normal and chronic granulomatous disease patients

Author

Dusi, S., Nadalini, K. A., Marta Donini, Zentilin, L., Wientjes, F. B., Roos, D., Giacca, M., Rossi, F., S., Dusi, K. A., Nadalini, M., Donini, L., Zentilin, F. B., Wientje, D., Roo, Giacca, Mauro, and F., Rossi

Subjects
Male, Herpesvirus 4, Human, deficiency/genetics/physiology, Membrane Transport Proteins, Mutation, NADPH Dehydrogenase, Neutrophils, Protein Conformation, NADPH Oxidase, pharmacology, X Chromosome, Granulomatous Disease, Chronic, metabolism, Tetradecanoylphorbol Acetate, Superoxides, Immunology and Allergy, genetics, Chronic, Cell Line, Transformed, Respiratory Burst, B-Lymphocytes, Membrane Glycoproteins, B-Lymphocyte, enzymology/genetics/pathology, NADPH Oxidase 2, Tetradecanoylphorbol Acetate, deficiency/genetics/physiology, Protein Conformation, Respiratory Burst, Structure-Activity Relationship, Superoxide, Granulomatous Disease, enzymology/genetics/pathology, Herpesvirus 4, Human, metabolism, Neutrophil, X Chromosome, Macromolecular Substances, Immunology, genetics/metabolism/physiology, Enzyme Activation, Granulomatous Disease, drug effects/enzymology, deficiency/genetics/physiology, immunology, Phosphoprotein, Cell Line, Structure-Activity Relationship, deficiency/genetics/physiology, NADPH Oxidase, drug effects/enzymology, Biological Transport, Cell Line, Humans, Cell Membrane, Herpesvirus 4, NADPH Dehydrogenase, NADPH Oxidases, Membrane Transport Proteins, Biological Transport, Cytochrome b Group, genetics/metabolism/physiology, Phosphoproteins, Enzyme Activation, Transformed, Transformed, Cell Membrane, physiology, Humans, Macromolecular Substances, Male, Membrane Glycoprotein, physiology, Mutation, metabolism, Cytochrome b Group, physiology, Humans, Macromolecular Substances, Male, Membrane Glycoproteins, metabolism, Neutrophils, immunology, Phosphoproteins, deficiency/genetics/physiology, Protein Conformation, Respiratory Burst, Structure-Activity Relationship, Superoxides, pharmacology, metabolism
Abstract

This paper deals with the mechanisms of activation of NADPH oxidase investigated using EBV-transformed human B lymphoblastoid cell lines (B cells) from normal subjects and from patients affected by X-linked chronic granulomatous disease (CGD). The results reported are as follows. 1) In normal B cells, the NADPH oxidase components p67phox, p40phox, p22phox, and gp91phox were less expressed than in polymorphonuclear neutrophils. 2) In normal B cells stimulated with PMA, p47phox, p67phox, and p40phox translocated to the membranes as occurs in polymorphonuclear neutrophils. 3) In CGD, B cells expressing p22phox in the absence of gp91phox, p47phox, p67phox, and p40phox did not translocate to the membranes after stimulation with PMA. 4) In PMA-stimulated B cells from an X91+ CGD patient in which p22phox was normally expressed and gp91phox was present but lacked five amino acids, translocation of p47phox to the membranes was unaffected, but p67phox and p40phox were poorly translocated, and the production of O2− was greatly reduced with respect to that by normal B cells. Taken together, these findings indicate that 1) a low expression of some NADPH oxidase components may represent the molecular basis of the low production of O2− in B lymphocytes; 2) the cytosolic components of NADPH oxidase cannot bind to p22phox on the membranes in the absence of gp91phox; 3) p47phox can translocate to the membranes independently of p67phox and p40phox; and 4) gp91phox may have a role in mediating and/or stabilizing the binding of p67phox and p40phox to the membranes of activated cells.

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