The Experts below are selected from a list of 243 Experts worldwide ranked by ideXlab platform
P J Lachmann - One of the best experts on this subject based on the ideXlab platform.
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neutrophil fcγ and complement receptors involved in binding soluble igg immune complexes and in Specific Granule release induced by soluble igg immune complexes
European Journal of Immunology, 1997Co-Authors: Julia Kate Voice, P J LachmannAbstract:We examined the effect of soluble IgG immune complex (IC) characteristics on the binding of IC to human neutrophils and IC-induced Specific Granule release of neutrophils via Fc gamma receptors (CD16 and CD32) and complement receptors (CR1 and CR3). A set of soluble IgG IC varying in size, IgG subclass, antigen epitope density and complement (C) incorporation were formed between 5-iodo-4-hydroxy-3-nitrophenacetyl (NIP) coupled to bovine serum albumin (BSA) and chimeric mouse-human anti-NIP monoclonal antibodies (mAb) of all four IgG subclasses. High and low epitope density IC of all four IgG subclasses induced Specific Granule release with C, but in the absence of C only IgG1 and IgG3 IC were functionally active. The Fc gamma and C receptors responsible for IgG IC-induced Specific Granule release and IC binding were determined using mAb Specific for the ligand binding sites of CD16, CD32 and CR3, and recombinant soluble CR1. Each defined IC displayed a unique pattern of receptor preference, dependent upon subclass and antigenic epitope density. IC binding and IC-induced Specific Granule release was not mediated by the same receptor, or combination of receptors. High and low epitope density IgG3 IC binding and induction of Specific Granule release was mediated predominantly via CD16. Other IC subclasses bound differently, i.e. IgG1 IC used CD16 and CR3; IgG2 and IgG4 predominantly used complement receptors; but all three induced Specific Granule release via CD32. In vivo these results may translate into differential activation of neutrophils by soluble IC dependent upon their characteristics, leading to subtle nuances in the etiology, pathology and control of the immune response in IC-related diseases.
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neutrophil fc gamma and complement receptors involved in binding soluble igg immune complexes and in Specific Granule release induced by soluble igg immune complexes
European Journal of Immunology, 1997Co-Authors: Julia Kate Voice, P J LachmannAbstract:We examined the effect of soluble IgG immune complex (IC) characteristics on the binding of IC to human neutrophils and IC-induced Specific Granule release of neutrophils via Fc gamma receptors (CD16 and CD32) and complement receptors (CR1 and CR3). A set of soluble IgG IC varying in size, IgG subclass, antigen epitope density and complement (C) incorporation were formed between 5-iodo-4-hydroxy-3-nitrophenacetyl (NIP) coupled to bovine serum albumin (BSA) and chimeric mouse-human anti-NIP monoclonal antibodies (mAb) of all four IgG subclasses. High and low epitope density IC of all four IgG subclasses induced Specific Granule release with C, but in the absence of C only IgG1 and IgG3 IC were functionally active. The Fc gamma and C receptors responsible for IgG IC-induced Specific Granule release and IC binding were determined using mAb Specific for the ligand binding sites of CD16, CD32 and CR3, and recombinant soluble CR1. Each defined IC displayed a unique pattern of receptor preference, dependent upon subclass and antigenic epitope density. IC binding and IC-induced Specific Granule release was not mediated by the same receptor, or combination of receptors. High and low epitope density IgG3 IC binding and induction of Specific Granule release was mediated predominantly via CD16. Other IC subclasses bound differently, i.e. IgG1 IC used CD16 and CR3; IgG2 and IgG4 predominantly used complement receptors; but all three induced Specific Granule release via CD32. In vivo these results may translate into differential activation of neutrophils by soluble IC dependent upon their characteristics, leading to subtle nuances in the etiology, pathology and control of the immune response in IC-related diseases.
Ravindra N Chibbar - One of the best experts on this subject based on the ideXlab platform.
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wheat genome Specific Granule bound starch synthase i differentially influence grain starch synthesis
Carbohydrate Polymers, 2014Co-Authors: Geetika Ahuja, Sarita Jaiswal, Pierre Hucl, Ravindra N ChibbarAbstract:Wheat grain development is a complex process and is characterized by changes in physicochemical and structural properties of starch. The present study deals with endosperm starch physicochemical properties and structure during development in different Granule-bound starch synthase I (GBSSI) null also known as waxy (Wx) genotypes. The study was conducted with pure starch isolated from wheat grains at 3-30 days post anthesis (DPA), at 3-day intervals. Amylose concentration increased throughout grain development in non-waxy (7.2-30.5%) and partial waxy genotypes (6.0-26.8%). Completely waxy genotype showed 7.0% amylose at 3 and 6 DPA, which declined during development and reached non-detectable quantities by 30 DPA. Amylopectin structure had a higher content of short chains at 3 DPA, which decreased continuously until 12 DPA, after which there were only minor changes in amylopectin chain length distribution. Similarly, the average degree of polymerization (DP) increased from 3 DPA (12.3) to 12 DPA (15.0), and then did not differ significantly up to 30 DPA (15.0). This suggests the formation of basic amylopectin architecture in wheat by 12 DPA. Wx-B and Wx-D affected amylopectin short chains mostly of DP 6-8 at 3 and 6 DPA. Wx-A affected the same fraction of chains at 9 and 12 DPA, and Wx-D affected DP 18-25 chains from 18 to 30 DPA, suggesting differential effect of waxy isoproteins on amylopectin structure formation.
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genome Specific Granule bound starch synthase i gbssi influences starch biochemical and functional characteristics in near isogenic wheat triticum aestivum l lines
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Geetika Ahuja, Sarita Jaiswal, Pierre Hucl, Ravindra N ChibbarAbstract:Near-isogenic wheat (Triticum aestivum L.) lines differing at the Waxy locus were studied for the influence of genome-Specific Granule-bound starch synthase I (GBSSI/Waxy; Wx-A, Wx-B, Wx-D) on star...
Niels Borregaard - One of the best experts on this subject based on the ideXlab platform.
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intractable diarrhoea of infancy caused by neutrophil Specific Granule deficiency and cured by stem cell transplantation
Gut, 2006Co-Authors: Robert Wynn, Niels Borregaard, Adrian F Gombart, Manu R Sood, Kim Theilgaardmonch, C J Jones, Maged I Gharib, H P Koeffler, Peter D ArkwrightAbstract:Intractable diarrhoea of infancy (IDI) can often become life threatening and still poses a major diagnostic challenge. It embraces a diverse group of disorders1 and in a significant number of infants the underlying cause cannot be identified. We describe a child who presented with IDI where routine investigations were unhelpful, but more detailed tests of neutrophil function revealed a congenital defect of neutrophil Specific Granule formation. A three week old baby girl of Pakistani origin of non-consanguineous parents living in the UK was referred because of pyrexia of unknown origin, as well as vomiting and severe watery diarrhoea associated with failure to thrive. Rhodococcus equi isolated after repeated blood culture responded to treatment with teicoplanin and Co-trimoxazole. The umbilical cord finally separated at five weeks of age. No pathogens were isolated from repeated stool cultures. …
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Sorting of the Specific Granule protein, NGAL, during granulocytic maturation of HL-60 cells.
Blood, 1997Co-Authors: V Le Cabec, Jero Calafat, Niels BorregaardAbstract:The different types of human neutrophil Granules (azurophil, Specific, and gelatinase Granules) are formed sequentially during maturation of neutrophils from the promyelocyte stage to the band cell stage. The promyelocytic HL-60 cells can maturate to segmented granulocytes but are incapable of activating the transcription of any known intragranular protein, normally located in Specific or gelatinase Granules. To study the sorting of Granule proteins during maturation, we transfected HL-60 cells with the Specific Granule protein NGAL, inserted under control of a cytomegalovirus promoter. We previously showed that NGAL is sorted to azurophil Granules and colocalizes with myeloperoxidase in undifferentiated HL-60 cells. We show here that, when such transfected HL-60 cells differentiate into granulocytes, newly synthesized NGAL is not retained in Granules but is constitutively secreted. This indicates that highly Specific mechanisms must exist that are responsible for diverting transport vesicles into storage Granules, and that HL-60 cells not only lack the ability to activate transcription of Specific Granule proteins, but also lose the ability to form storage Granules during maturation.
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Targeting of proteins to Granule subsets is determined by timing and not by sorting: The Specific Granule protein NGAL is localized to azurophil Granules when expressed in HL-60 cells.
Proceedings of the National Academy of Sciences of the United States of America, 1996Co-Authors: V Le Cabec, J B Cowland, Jero Calafat, Niels BorregaardAbstract:The mechanism of protein targeting to individual Granules in cells that contain different subsets of storage Granules is poorly understood. The neutrophil contains two highly distinct major types of Granules, the peroxidase positive (azurophil) Granules and the peroxidase negative (Specific and gelatinase) Granules. We hypothesized that targeting of proteins to individual Granule subsets may be determined by the stage of maturation of the cell, at which the Granule proteins are synthesized, rather than by individual sorting information present in the proteins. This was tested by transfecting the cDNA of the Specific Granule protein, NGAL, which is normally synthesized in metamyelocytes, into the promyelocytic cell line HL-60, which is developmentally arrested at the stage of formation of azurophil Granules, and thus does not contain Specific and gelatinase Granules. Controlled by a cytomegalovirus promoter, NGAL was constitutively expressed in transfected HL-60 cells. This resulted in the targeting of NGAL to azurophil Granules as demonstrated by colocalization of NGAL with myeloperoxidase, visualized by immunoelectron microscopy. This shows that targeting of proteins into distinct Granule subsets may be determined solely by the time of their biosynthesis and does not depend on individual sorting information present in the proteins.
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sgp28 a novel matrix glycoprotein in Specific Granules of human neutrophils with similarity to a human testis Specific gene product and to a rodent sperm coating glycoprotein
FEBS Letters, 1996Co-Authors: Lars Kjeldsen, J B Cowland, Anders H Johnsen, Niels BorregaardAbstract:Abstract A novel 28 kDa glycoprotein was purified from exocytosed material from human neutrophils and its primary structure partially determined. Degenerate oligonucleotide primers were used to amplify cDNA clones from a human bone marrow cDNA library. The deduced 245 amino acid sequence of the 2124 bp full-length cDNA showed high degrees of similarity to the deduced sequences of the human gene TPX-1 and of sperm coating glycoprotein from rat and mouse. Subcellular fractionation of human neutrophils indicated that the protein is localized in Specific Granules. The protein was named SGP28 (Specific Granule protein of 28 kDa).
Julia Kate Voice - One of the best experts on this subject based on the ideXlab platform.
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neutrophil fcγ and complement receptors involved in binding soluble igg immune complexes and in Specific Granule release induced by soluble igg immune complexes
European Journal of Immunology, 1997Co-Authors: Julia Kate Voice, P J LachmannAbstract:We examined the effect of soluble IgG immune complex (IC) characteristics on the binding of IC to human neutrophils and IC-induced Specific Granule release of neutrophils via Fc gamma receptors (CD16 and CD32) and complement receptors (CR1 and CR3). A set of soluble IgG IC varying in size, IgG subclass, antigen epitope density and complement (C) incorporation were formed between 5-iodo-4-hydroxy-3-nitrophenacetyl (NIP) coupled to bovine serum albumin (BSA) and chimeric mouse-human anti-NIP monoclonal antibodies (mAb) of all four IgG subclasses. High and low epitope density IC of all four IgG subclasses induced Specific Granule release with C, but in the absence of C only IgG1 and IgG3 IC were functionally active. The Fc gamma and C receptors responsible for IgG IC-induced Specific Granule release and IC binding were determined using mAb Specific for the ligand binding sites of CD16, CD32 and CR3, and recombinant soluble CR1. Each defined IC displayed a unique pattern of receptor preference, dependent upon subclass and antigenic epitope density. IC binding and IC-induced Specific Granule release was not mediated by the same receptor, or combination of receptors. High and low epitope density IgG3 IC binding and induction of Specific Granule release was mediated predominantly via CD16. Other IC subclasses bound differently, i.e. IgG1 IC used CD16 and CR3; IgG2 and IgG4 predominantly used complement receptors; but all three induced Specific Granule release via CD32. In vivo these results may translate into differential activation of neutrophils by soluble IC dependent upon their characteristics, leading to subtle nuances in the etiology, pathology and control of the immune response in IC-related diseases.
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neutrophil fc gamma and complement receptors involved in binding soluble igg immune complexes and in Specific Granule release induced by soluble igg immune complexes
European Journal of Immunology, 1997Co-Authors: Julia Kate Voice, P J LachmannAbstract:We examined the effect of soluble IgG immune complex (IC) characteristics on the binding of IC to human neutrophils and IC-induced Specific Granule release of neutrophils via Fc gamma receptors (CD16 and CD32) and complement receptors (CR1 and CR3). A set of soluble IgG IC varying in size, IgG subclass, antigen epitope density and complement (C) incorporation were formed between 5-iodo-4-hydroxy-3-nitrophenacetyl (NIP) coupled to bovine serum albumin (BSA) and chimeric mouse-human anti-NIP monoclonal antibodies (mAb) of all four IgG subclasses. High and low epitope density IC of all four IgG subclasses induced Specific Granule release with C, but in the absence of C only IgG1 and IgG3 IC were functionally active. The Fc gamma and C receptors responsible for IgG IC-induced Specific Granule release and IC binding were determined using mAb Specific for the ligand binding sites of CD16, CD32 and CR3, and recombinant soluble CR1. Each defined IC displayed a unique pattern of receptor preference, dependent upon subclass and antigenic epitope density. IC binding and IC-induced Specific Granule release was not mediated by the same receptor, or combination of receptors. High and low epitope density IgG3 IC binding and induction of Specific Granule release was mediated predominantly via CD16. Other IC subclasses bound differently, i.e. IgG1 IC used CD16 and CR3; IgG2 and IgG4 predominantly used complement receptors; but all three induced Specific Granule release via CD32. In vivo these results may translate into differential activation of neutrophils by soluble IC dependent upon their characteristics, leading to subtle nuances in the etiology, pathology and control of the immune response in IC-related diseases.
Geetika Ahuja - One of the best experts on this subject based on the ideXlab platform.
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wheat genome Specific Granule bound starch synthase i differentially influence grain starch synthesis
Carbohydrate Polymers, 2014Co-Authors: Geetika Ahuja, Sarita Jaiswal, Pierre Hucl, Ravindra N ChibbarAbstract:Wheat grain development is a complex process and is characterized by changes in physicochemical and structural properties of starch. The present study deals with endosperm starch physicochemical properties and structure during development in different Granule-bound starch synthase I (GBSSI) null also known as waxy (Wx) genotypes. The study was conducted with pure starch isolated from wheat grains at 3-30 days post anthesis (DPA), at 3-day intervals. Amylose concentration increased throughout grain development in non-waxy (7.2-30.5%) and partial waxy genotypes (6.0-26.8%). Completely waxy genotype showed 7.0% amylose at 3 and 6 DPA, which declined during development and reached non-detectable quantities by 30 DPA. Amylopectin structure had a higher content of short chains at 3 DPA, which decreased continuously until 12 DPA, after which there were only minor changes in amylopectin chain length distribution. Similarly, the average degree of polymerization (DP) increased from 3 DPA (12.3) to 12 DPA (15.0), and then did not differ significantly up to 30 DPA (15.0). This suggests the formation of basic amylopectin architecture in wheat by 12 DPA. Wx-B and Wx-D affected amylopectin short chains mostly of DP 6-8 at 3 and 6 DPA. Wx-A affected the same fraction of chains at 9 and 12 DPA, and Wx-D affected DP 18-25 chains from 18 to 30 DPA, suggesting differential effect of waxy isoproteins on amylopectin structure formation.
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genome Specific Granule bound starch synthase i gbssi influences starch biochemical and functional characteristics in near isogenic wheat triticum aestivum l lines
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Geetika Ahuja, Sarita Jaiswal, Pierre Hucl, Ravindra N ChibbarAbstract:Near-isogenic wheat (Triticum aestivum L.) lines differing at the Waxy locus were studied for the influence of genome-Specific Granule-bound starch synthase I (GBSSI/Waxy; Wx-A, Wx-B, Wx-D) on star...