Anne Venisse - Academia.edu (original) (raw)

Papers by Anne Venisse

European journal of biochemistry, 1995

Infection by Mycobacterium tuberculosis first involves its adhesion to mononuclear host phagocyte... more Infection by Mycobacterium tuberculosis first involves its adhesion to mononuclear host phagocytes. Various macrophage opsonic and non-opsonic receptors are known to mediate this adhesion, with some specificity of mannosyl receptors for the more virulent strains. Mannosylated lipoarabinomannan, a major component of cell walls from M. tuberculosis and Mycobacterium bovis BCG, is endowed with mannooligosaccharide units that could mediate its binding to these latter receptors. To explore its interaction with murine immune cells by flow cytometry, we report a new procedure to fluorescently tag the polysaccharide molecules. We covalently labeled mannosylated lipoarabinomannan from M. bovis BCG with biotin, allowing formation of stable complexes with streptavidin coupled to a fluorochrome. In this work, we demonstrated that this major carbohydrate antigen interacts selectively with murine phagocytes, i.e. granulocytes and macrophages. This binding was affected by temperature and was serum...

Http Www Theses Fr, 1994

Le lipoarabinomannane (lam) est un antigene majeur de la paroi des mycobacteries et les fonctions... more Le lipoarabinomannane (lam) est un antigene majeur de la paroi des mycobacteries et les fonctions biologiques attribuees au lam de mycobacterium tuberculosis le designent comme un immunomodulateur important de la reponse immunitaire de l'hote, voire comme un des facteurs de virulence de ce pathogene. L'objet de nos travaux a ete d'etablir la structure du lam de m. Bovis bcg, souche a la virulence attenuee utilisee comme vaccin antituberculeux, et d'etudier ses proprietes fonctionnelles comparativement a celles du lam d'une souche virulente de m. Tuberculosis. Les analyses par rmn bidimensionnelle homo- et heteronucleaire et la caracterisation, par hplc et fab-ms, d'oligosaccharides obtenus apres hydrolyse partielle du lam, ont permis de montrer que ces deux lams possedent la meme structure globale, avec des unites oligomannosyles presentes aux extremites des chaines arabinanes, unites decrites comme caracteristiques des souches virulentes. De plus, la masse moleculaire du lam a ete determinee pour la premiere fois avec precision par spectrometrie de masse grace a l'ionisation par desorption par laser assistee d'une matrice et est de l'ordre de 17,3 kda pour les deux molecules. Cette etude ainsi que l'analyse structurale plus approfondie du domaine mannane de la molecule montrent une heterogeneite importante de la molecule fonction du nombre d'unites osidiques et de phosphates. Apres mise au point du marquage du lam de m. Bovis bcg avec de la biotine, son interaction avec les cellules phagocytaires murines a ete mise en evidence par cytofluorimetrie. Cette liaison semble faire intervenir les residus mannosyles de la molecule qui pourrait constituer un mediateur de l'adhesion de la mycobacterie sur leurs cellules hotes, favorisant ainsi l'invasion de ces cellules. L'ensemble des resultats suggerent que le lam pourrait constituer un facteur de virulence intervenant de facon precoce dans l'infection

Journal of Biological Chemistry

Lipoarabinomannan (LAM) is a major antigen of mycobacterial cell walls, involved in host-Mycobact... more Lipoarabinomannan (LAM) is a major antigen of mycobacterial cell walls, involved in host-Mycobacterium interactions. In a previous work, LAM from the vaccine strain, Mycobacterium bovis BCG, was found to exhibit mannooligosaccharides at its arabinan nonreducing ends (ManLAM). The present report concerns the mannan core structure of this ManLAM. After partial hydrolysis of ManLAM, two populations of mannans (Ma1 and Ma2) were obtained by gel filtration chromatography. Their structural features were defined by means of two-dimensional homo- and heteronuclear (1H-C) NMR sequences and methylation analysis. They were both found to be composed of an α-(1 6)-linked mannan backbone with α-(1 2)-Manp-linked side chains. They are highly branched, and Ma2 presents a higher frequency of branching than Ma1. Moreover, chemical analysis indicates that only Ma1 is phosphorylated. By a two-dimensional heteronuclear 1H-P total correlation experiment, the phosphate was found to be involved in a phosph...

The complete primary structure of the carbohydrate moiety of a new phenolic glycolipid antigen na... more The complete primary structure of the carbohydrate moiety of a new phenolic glycolipid antigen namely PheGl K-IV from Mycobacterium kansasii was successfully established from only one-and two-dimensional 'H-NMR data. Among the scalar two-dimensional techniques, correlated spectroscopy with a 45 O mixing pulse and phasesensitive double-quantum-filtered correlated spectroscopy were selected, combined with two-dimensional dipolar techniques (nuclear Overhauser effect). These techniques using milligram of quantities native PheGl K-IV allowed the following monoacetylated tetrasaccharide to be proposed for its carbohydrate part: 4-O-Me-a-Manp-(l+ 3)-4-0-Ac-2-0-Me-a-Fucp-(l+3)-2-0-Me-cc-Rhap-(l+3)-2,4-di-0-Me-a-Rhap. The PheGl K-IV shares, with the other phenolic glycolipids isolated from M. kansasii (K-I, K-II), a common core assigned to the lipid aglycone glycosylated by the monoacetylated trisaccharide part. It differs in the structure of the distal monosaccharide residue. Most mycobacterial cell walls are endowed with speciesspecific immunoreactive glycolipids. From their structure, these glycolipids have been classified into three types: the phenolic glycolipids (PheGl), the trehalose-containing lipooligosaccharides and the glycopeptidolipids [l-31. Whatever the glycolipid type, it has been established, in most cases, that the distal disaccharide residue of their oligosaccharide part contains the epitope. Its species-specificity results from the presence of partially 0-methylated sugars and, in some cases, of monosaccharides unique in nature [4-61. Thus, with the aim of determining the structure of these glycolipids, it appears that the critical step after their purification was the structural elucidation of their non-ubiquitous oligosaccharide part. This structural problem was solved using both sophisticated and modern analytical tools such as fast-atom-bombardment (FAB) mass spectrometry [7], plasma desorption [8], desorption chemical ionization [9] for molecular mass assignments and FAB-tandem mass spectrometry [ 101 for oligosaccharide sequence determination, combined with one-dimensional (1 D)

Journal of Biological …, 1997

Lipoarabinomannans from fast growing Mycobacterium sp., namely AraLAMs, stimulate the early event... more Lipoarabinomannans from fast growing Mycobacterium sp., namely AraLAMs, stimulate the early events of macrophage activation. The immunological activities of all of these AraLAMs drastically decrease with the loss of the mild alkali groups, which were believed to be restricted to the fatty acid residues from the phosphatidyl-myo-inositol anchor. This report reveals the presence and the structure of mild alkali-labile phosphoinositide units linked via the phosphate to the C-5 of the ␤-D-Araf in the AraLAMs of Mycobacterium smegmatis, a fast growing mycobacterial species. Their structure was unambiguously established with a strategy based on both one-dimensional 31 P and two-dimensional 1 H-31 P heteronuclear multiple quantum correlation spectroscopy (HMQC) and HMQC-homonuclear Hartmann-Hahn spectroscopy NMR experiments applied to native AraLAMs and to AraLAMs treated in mild alkali conditions. Next to these alkali-labile phosphoinositides estimated at three per molecule, two other mild alkali-stable phosphoinositide units were identified: the expected (myo-inositol-1)-phosphate-(3-glycerol) unit typifying the well known glycosylphosphatidylinositol anchor of the mannan core and, more surprisingly, one (myo-inositol-1)-phosphate-(5-␤-D-Araf) unit having the same structure as the alkali-labile ones. Moreover, these four phosphoinositide units were found capping the arabinan side chains. Thus, their different behavior toward mild alkaline hydrolysis was explained according to their accessibility to the alkali reagent. This novel class of LAMs, namely phosphoinositols-glyceroarabinomannans (PI-GAMs), are characterized by their phosphoinositide units but also by the absence of fatty acid residues. These PI-GAMs were found to elicit the secretion of tumor necrosis factor-␣, suggesting that phosphoinositides are the major PI-GAM epitope involved in this process.

Mycobacterial species-specific antigens belong to the three following classes: phenolic glycolipi... more Mycobacterial species-specific antigens belong to the three following classes: phenolic glycolipids (Phe Gl), acyltrehalose-containing lipooligosaccharides and polar glycopeptidolipids. These antigens have been chemically defined and alkali-labile epitopes were found to characterize the lipooligosaccharide antigen type. In the present study the major Mycobacterium kansasii phenolic glycolipid epitope namely Phe Gl K-I was delineated as the distal monoacetylated disaccharidic residue: 2,6-dideoxy-4-O-methyl-alpha-D-arabino-hexopyranosyl-(1----3)-2-O-methyl -4-O- acetyl-alpha-L-fucopyranose. This acetoxy group is required for K-I epitope recognition demonstrating that alkali-labile epitopes also occur in the phenolic glycolipid antigen class. Using immunoelectron microscopy, the Phe Gl K-I epitope was localized around the electron-transparent layer on the M. kansasii cell-wall surface. Furthermore, two new phenolic glycolipids namely Phe Gl K-III and Phe Gl K-IV were discovered in min...

European journal of biochemistry, 1995

Infection by Mycobacterium tuberculosis first involves its adhesion to mononuclear host phagocyte... more Infection by Mycobacterium tuberculosis first involves its adhesion to mononuclear host phagocytes. Various macrophage opsonic and non-opsonic receptors are known to mediate this adhesion, with some specificity of mannosyl receptors for the more virulent strains. Mannosylated lipoarabinomannan, a major component of cell walls from M. tuberculosis and Mycobacterium bovis BCG, is endowed with mannooligosaccharide units that could mediate its binding to these latter receptors. To explore its interaction with murine immune cells by flow cytometry, we report a new procedure to fluorescently tag the polysaccharide molecules. We covalently labeled mannosylated lipoarabinomannan from M. bovis BCG with biotin, allowing formation of stable complexes with streptavidin coupled to a fluorochrome. In this work, we demonstrated that this major carbohydrate antigen interacts selectively with murine phagocytes, i.e. granulocytes and macrophages. This binding was affected by temperature and was serum...

Http Www Theses Fr, 1994

Le lipoarabinomannane (lam) est un antigene majeur de la paroi des mycobacteries et les fonctions... more Le lipoarabinomannane (lam) est un antigene majeur de la paroi des mycobacteries et les fonctions biologiques attribuees au lam de mycobacterium tuberculosis le designent comme un immunomodulateur important de la reponse immunitaire de l'hote, voire comme un des facteurs de virulence de ce pathogene. L'objet de nos travaux a ete d'etablir la structure du lam de m. Bovis bcg, souche a la virulence attenuee utilisee comme vaccin antituberculeux, et d'etudier ses proprietes fonctionnelles comparativement a celles du lam d'une souche virulente de m. Tuberculosis. Les analyses par rmn bidimensionnelle homo- et heteronucleaire et la caracterisation, par hplc et fab-ms, d'oligosaccharides obtenus apres hydrolyse partielle du lam, ont permis de montrer que ces deux lams possedent la meme structure globale, avec des unites oligomannosyles presentes aux extremites des chaines arabinanes, unites decrites comme caracteristiques des souches virulentes. De plus, la masse moleculaire du lam a ete determinee pour la premiere fois avec precision par spectrometrie de masse grace a l'ionisation par desorption par laser assistee d'une matrice et est de l'ordre de 17,3 kda pour les deux molecules. Cette etude ainsi que l'analyse structurale plus approfondie du domaine mannane de la molecule montrent une heterogeneite importante de la molecule fonction du nombre d'unites osidiques et de phosphates. Apres mise au point du marquage du lam de m. Bovis bcg avec de la biotine, son interaction avec les cellules phagocytaires murines a ete mise en evidence par cytofluorimetrie. Cette liaison semble faire intervenir les residus mannosyles de la molecule qui pourrait constituer un mediateur de l'adhesion de la mycobacterie sur leurs cellules hotes, favorisant ainsi l'invasion de ces cellules. L'ensemble des resultats suggerent que le lam pourrait constituer un facteur de virulence intervenant de facon precoce dans l'infection

Journal of Biological Chemistry

Lipoarabinomannan (LAM) is a major antigen of mycobacterial cell walls, involved in host-Mycobact... more Lipoarabinomannan (LAM) is a major antigen of mycobacterial cell walls, involved in host-Mycobacterium interactions. In a previous work, LAM from the vaccine strain, Mycobacterium bovis BCG, was found to exhibit mannooligosaccharides at its arabinan nonreducing ends (ManLAM). The present report concerns the mannan core structure of this ManLAM. After partial hydrolysis of ManLAM, two populations of mannans (Ma1 and Ma2) were obtained by gel filtration chromatography. Their structural features were defined by means of two-dimensional homo- and heteronuclear (1H-C) NMR sequences and methylation analysis. They were both found to be composed of an α-(1 6)-linked mannan backbone with α-(1 2)-Manp-linked side chains. They are highly branched, and Ma2 presents a higher frequency of branching than Ma1. Moreover, chemical analysis indicates that only Ma1 is phosphorylated. By a two-dimensional heteronuclear 1H-P total correlation experiment, the phosphate was found to be involved in a phosph...

The complete primary structure of the carbohydrate moiety of a new phenolic glycolipid antigen na... more The complete primary structure of the carbohydrate moiety of a new phenolic glycolipid antigen namely PheGl K-IV from Mycobacterium kansasii was successfully established from only one-and two-dimensional 'H-NMR data. Among the scalar two-dimensional techniques, correlated spectroscopy with a 45 O mixing pulse and phasesensitive double-quantum-filtered correlated spectroscopy were selected, combined with two-dimensional dipolar techniques (nuclear Overhauser effect). These techniques using milligram of quantities native PheGl K-IV allowed the following monoacetylated tetrasaccharide to be proposed for its carbohydrate part: 4-O-Me-a-Manp-(l+ 3)-4-0-Ac-2-0-Me-a-Fucp-(l+3)-2-0-Me-cc-Rhap-(l+3)-2,4-di-0-Me-a-Rhap. The PheGl K-IV shares, with the other phenolic glycolipids isolated from M. kansasii (K-I, K-II), a common core assigned to the lipid aglycone glycosylated by the monoacetylated trisaccharide part. It differs in the structure of the distal monosaccharide residue. Most mycobacterial cell walls are endowed with speciesspecific immunoreactive glycolipids. From their structure, these glycolipids have been classified into three types: the phenolic glycolipids (PheGl), the trehalose-containing lipooligosaccharides and the glycopeptidolipids [l-31. Whatever the glycolipid type, it has been established, in most cases, that the distal disaccharide residue of their oligosaccharide part contains the epitope. Its species-specificity results from the presence of partially 0-methylated sugars and, in some cases, of monosaccharides unique in nature [4-61. Thus, with the aim of determining the structure of these glycolipids, it appears that the critical step after their purification was the structural elucidation of their non-ubiquitous oligosaccharide part. This structural problem was solved using both sophisticated and modern analytical tools such as fast-atom-bombardment (FAB) mass spectrometry [7], plasma desorption [8], desorption chemical ionization [9] for molecular mass assignments and FAB-tandem mass spectrometry [ 101 for oligosaccharide sequence determination, combined with one-dimensional (1 D)

Journal of Biological …, 1997

Lipoarabinomannans from fast growing Mycobacterium sp., namely AraLAMs, stimulate the early event... more Lipoarabinomannans from fast growing Mycobacterium sp., namely AraLAMs, stimulate the early events of macrophage activation. The immunological activities of all of these AraLAMs drastically decrease with the loss of the mild alkali groups, which were believed to be restricted to the fatty acid residues from the phosphatidyl-myo-inositol anchor. This report reveals the presence and the structure of mild alkali-labile phosphoinositide units linked via the phosphate to the C-5 of the ␤-D-Araf in the AraLAMs of Mycobacterium smegmatis, a fast growing mycobacterial species. Their structure was unambiguously established with a strategy based on both one-dimensional 31 P and two-dimensional 1 H-31 P heteronuclear multiple quantum correlation spectroscopy (HMQC) and HMQC-homonuclear Hartmann-Hahn spectroscopy NMR experiments applied to native AraLAMs and to AraLAMs treated in mild alkali conditions. Next to these alkali-labile phosphoinositides estimated at three per molecule, two other mild alkali-stable phosphoinositide units were identified: the expected (myo-inositol-1)-phosphate-(3-glycerol) unit typifying the well known glycosylphosphatidylinositol anchor of the mannan core and, more surprisingly, one (myo-inositol-1)-phosphate-(5-␤-D-Araf) unit having the same structure as the alkali-labile ones. Moreover, these four phosphoinositide units were found capping the arabinan side chains. Thus, their different behavior toward mild alkaline hydrolysis was explained according to their accessibility to the alkali reagent. This novel class of LAMs, namely phosphoinositols-glyceroarabinomannans (PI-GAMs), are characterized by their phosphoinositide units but also by the absence of fatty acid residues. These PI-GAMs were found to elicit the secretion of tumor necrosis factor-␣, suggesting that phosphoinositides are the major PI-GAM epitope involved in this process.

Mycobacterial species-specific antigens belong to the three following classes: phenolic glycolipi... more Mycobacterial species-specific antigens belong to the three following classes: phenolic glycolipids (Phe Gl), acyltrehalose-containing lipooligosaccharides and polar glycopeptidolipids. These antigens have been chemically defined and alkali-labile epitopes were found to characterize the lipooligosaccharide antigen type. In the present study the major Mycobacterium kansasii phenolic glycolipid epitope namely Phe Gl K-I was delineated as the distal monoacetylated disaccharidic residue: 2,6-dideoxy-4-O-methyl-alpha-D-arabino-hexopyranosyl-(1----3)-2-O-methyl -4-O- acetyl-alpha-L-fucopyranose. This acetoxy group is required for K-I epitope recognition demonstrating that alkali-labile epitopes also occur in the phenolic glycolipid antigen class. Using immunoelectron microscopy, the Phe Gl K-I epitope was localized around the electron-transparent layer on the M. kansasii cell-wall surface. Furthermore, two new phenolic glycolipids namely Phe Gl K-III and Phe Gl K-IV were discovered in min...