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Daffé M, Marrakchi H. Unraveling the Structure of the Mycobacterial Envelope. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0027-2018. [PMID: 31267927 PMCID: PMC10957186 DOI: 10.1128/microbiolspec.gpp3-0027-2018] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Indexed: 12/28/2022] Open
Abstract
The mycobacterial cell envelope consists of a typical plasma membrane of lipid and protein surrounded by a complex cell wall composed of carbohydrate and lipid. In pathogenic species, such as Mycobacterium tuberculosis, an outermost "capsule" layer surrounds the cell wall. This wall embraces a fundamental, covalently linked "cell-wall skeleton" composed of peptidoglycan, solidly attached to arabinogalactan, whose penta-saccharide termini are esterified by very-long-chain fatty acids (mycolic acids). These fatty acids form the inner leaflet of an outer membrane, called the mycomembrane, whose outer leaflet consists of a great variety of non-covalently linked lipids and glycolipids. The thickness of the mycomembrane, which is similar to that of the plasma membrane, is surprising in view of the length of mycoloyl residues, suggesting dedicated conformations of these fatty acids. Finally, a periplasmic space also exists in mycobacteria, between the plasma membrane and the peptidoglycan. This article provides a comprehensive overview of this biologically important and structurally unique mycobacterial cell compartment.
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Affiliation(s)
- Mamadou Daffé
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Department of Tuberculosis and Infection Biology, Toulouse, France
| | - Hedia Marrakchi
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Department of Tuberculosis and Infection Biology, Toulouse, France
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Abstract
This article summarizes what is currently known of the structures, physiological roles, involvement in pathogenicity, and biogenesis of a variety of noncovalently bound cell envelope lipids and glycoconjugates of Mycobacterium tuberculosis and other Mycobacterium species. Topics addressed in this article include phospholipids; phosphatidylinositol mannosides; triglycerides; isoprenoids and related compounds (polyprenyl phosphate, menaquinones, carotenoids, noncarotenoid cyclic isoprenoids); acyltrehaloses (lipooligosaccharides, trehalose mono- and di-mycolates, sulfolipids, di- and poly-acyltrehaloses); mannosyl-beta-1-phosphomycoketides; glycopeptidolipids; phthiocerol dimycocerosates, para-hydroxybenzoic acids, and phenolic glycolipids; mycobactins; mycolactones; and capsular polysaccharides.
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Shimada KI, Takimoto H, Yano I, Kumazawa Y. Involvement of Mannose Receptor in Glycopeptidolipid-Mediated Inhibition of Phagosome-Lysosome Fusion. Microbiol Immunol 2013; 50:243-51. [PMID: 16547422 DOI: 10.1111/j.1348-0421.2006.tb03782.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We previously reported that glycopeptidolipid (GPL) isolated from Mycobacterium avium serovar 4 inhibited phagosome-lysosome (P-L) fusion when macrophages phagocytosed heat-killed Staphylococcus aureus (SA). In the present study we analyzed the underlying inhibitory mechanism of GPL coated on SA. Elimination of oligosaccharide from GPL abrogated its inhibitory activity. GPL did not inhibit P-L fusion of opsonized SA phagocytosed via complement receptors. The inhibitory activity of GPL was competitively reduced by the presence of alpha-methyl-D-mannoside and anti-mannose receptor antibody, suggesting that inhibition of P-L fusion by GPL is mediated through mannose receptor. Recruitment of early endosome antigen 1 and Ca2+/calmodulin kinase II in human macrophage-like THP-1 cells were significantly suppressed by GPL, indicating that GPL inhibits steps for leading to the P-L fusion.
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Affiliation(s)
- Ken-ichi Shimada
- Department of Bioscience, School of Science, Kitasato University, Sagamihara, Kanagawa 228-8555, Japan
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Mukherjee R, Chatterji D. Glycopeptidolipids: immuno-modulators in greasy mycobacterial cell envelope. IUBMB Life 2012; 64:215-25. [PMID: 22252955 DOI: 10.1002/iub.602] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2011] [Accepted: 11/10/2011] [Indexed: 11/12/2022]
Abstract
Species of opportunistic mycobacteria are the major causative agent for disseminating pulmonary infections in immuno-compromised individuals. These naturally resistant strains recruit a unique type of glycolipid known as glycopeptidolipids (GPLs), noncovalently attached to the outer surface of their thick lipid rich cell envelope. Species specific GPLs constitute the chemical determinants of most nontuberculous mycobacterial serotypes, and their absence from the cell surface confers altered colony morphology, hydrophobicity, and inability to grow as biofilms. The objective of this review is to present a comprehensive account and highlight the renewed interest on this much neglected group of pleiotropic molecules with respect to their structural diversity and biosynthesis. In addition, the role of GPLs in mycobacterial survival, both intracellular and in the environment is also discussed. It also explores the possibility of identifying new targets for intervening Mycobacterium avium complex-related infections. These antigenic molecules have been considered to play a pivotal role in immune suppression and can also induce various cytokine mediated innate immune responses, the molecular mechanism of which remains obscure.
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Affiliation(s)
- Raju Mukherjee
- Swiss Federal Institute of Technology, Lausanne, Switzerland.
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Widespread abundance of functional bacterial amyloid in mycolata and other gram-positive bacteria. Appl Environ Microbiol 2009; 75:4101-10. [PMID: 19395568 DOI: 10.1128/aem.02107-08] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Until recently, extracellular functional bacterial amyloid (FuBA) has been detected and characterized in only a few bacterial species, including Escherichia coli, Salmonella, and the gram-positive organism Streptomyces coelicolor. Here we probed gram-positive bacteria with conformationally specific antibodies and revealed the existence of FuBA in 12 of 14 examined mycolata species, as well as six other distantly related species examined belonging to the phyla Actinobacteria and Firmicutes. Most of the bacteria produced extracellular fimbriae, sometimes copious amounts of them, and in two cases large extracellular fibrils were also produced. In three cases, FuBA was revealed only after extensive removal of extracellular material by saponification, indicating that there is integrated attachment within the cellular envelope. Spores of species in the genera Streptomyces, Bacillus, and Nocardia were all coated with amyloids. FuBA was purified from Gordonia amarae (from the cell envelope) and Geodermatophilus obscurus, and they had the morphology, tinctorial properties, and beta-rich structure typical of amyloid. The presence of approximately 9-nm-wide amyloids in the cell envelope of G. amarae was visualized by transmission electron microscopy analysis. We conclude that amyloid is widespread among gram-positive bacteria and may in many species constitute a hitherto overlooked integral part of the spore and the cellular envelope.
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Bhatnagar S, Schorey JS. Exosomes released from infected macrophages contain Mycobacterium avium glycopeptidolipids and are proinflammatory. J Biol Chem 2007; 282:25779-89. [PMID: 17591775 PMCID: PMC3636815 DOI: 10.1074/jbc.m702277200] [Citation(s) in RCA: 249] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Mycobacterium avium is a major opportunistic pathogen in HIV-positive individuals and is responsible for increased morbidity and mortality in AIDS patients. M. avium express glycopeptidolipids (GPLs) as a major cell wall constituent, and recent studies suggest that GPLs play an important role in M. avium pathogenesis. In the present study we show that M. avium-infected macrophages release GPLs, which are trafficked from the phagosome through the endocytic network to multivesicular bodies. Prior studies have shown that multivesicular bodies can fuse with the plasma membrane releasing small 50 to 100 nm vesicles known as exosomes. We found that M. avium-infected macrophages release exosomes containing GPLs leading to the transfer of GPLs from infected to uninfected macrophages. Interestingly, exosomes isolated from M. avium-infected but not from uninfected macrophages can stimulate a proinflammatory response in resting macrophages. This proinflammatory response is dependent on Toll like receptor (TLR) 2, TLR4, and MyD88 suggesting that released exosomes contain M. avium-expressed TLR ligands. Our studies are the first to demonstrate that exosomes isolated from mycobacteria-infected macrophages can induce a proinflammatory response, and we hypothesize that exosomes play an important role in immune surveillance during intracellular bacteria infections.
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Affiliation(s)
| | - Jeffrey S. Schorey
- To whom correspondence should be addressed: Dept. of Biology, University, of Notre Dame, 130 Galvin Life Science Center, Notre Dame, IN 46556. Tel.: 574-631-3734; Fax: 574-631-7413; E-mail:
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Etienne G, Villeneuve C, Billman-Jacobe H, Astarie-Dequeker C, Dupont MA, Daffé M. The impact of the absence of glycopeptidolipids on the ultrastructure, cell surface and cell wall properties, and phagocytosis of Mycobacterium smegmatis. MICROBIOLOGY (READING, ENGLAND) 2002; 148:3089-3100. [PMID: 12368442 DOI: 10.1099/00221287-148-10-3089] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Glycopeptidolipids (GPLs) are a class of species- or type-specific mycobacterial lipids and major constituents of the cell envelopes of many non-tuberculous mycobacteria. To determine the function of GPLs in the physiology of these bacteria, a mutant of Mycobacterium smegmatis in which the gene encoding a mycobacterial nonribosomal peptide synthetase has been inactivated by transposon mutagenesis was analysed. Labelling experiments indicated that half of the bacterial GPLs were located on the cell surface and represented 85% of the surface-exposed lipids of the parent strain whereas the mutant was defective in the production of the GPLs. Compared to the parent smooth morphotype strain, the GPL-deficient mutant strain exhibited a rough colony morphology, an increase of the cell hydrophobicity and formed huge aggregates. As a consequence, the mutant cells were no longer able to bind ruthenium red, as observed by transmission electron microscopy. The altered surface properties of the mutant cells also affected the phagocytosis of individual bacilli by human monocyte-derived macrophages since mutant cells were internalized more rapidly than cells from the parent strain. Nevertheless, no specific release of surface constituents into the culture broth of the mutant was observed, indicating that the cell surface is composed of substances other than GPLs and that these are essential for maintaining the architecture of the outermost layer of the cell envelope. Importantly, the absence of these major extractable lipids of M. smegmatis from the mutant strain has a profound effect on the uptake of the hydrophobic chenodeoxycholate by cells, indicating that GPLs are involved in the cell wall permeability barrier of M. smegmatis. Altogether, these data showed that, in addition to being distinctive markers of numerous mycobacterial species, GPLs play a role in the bacterial phenotype, surface properties and cell wall permeability.
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Affiliation(s)
- Gilles Etienne
- Institut de Pharmacologie et de Biologie Structurale, Unité Mixte de Recherche du Centre de National de Recherche Scientifique et de l'Université Paul Sabatier (UMR 5089), 205 route de Narbonne, 31077 Toulouse cedex 04, France1
| | - Christelle Villeneuve
- Institut de Pharmacologie et de Biologie Structurale, Unité Mixte de Recherche du Centre de National de Recherche Scientifique et de l'Université Paul Sabatier (UMR 5089), 205 route de Narbonne, 31077 Toulouse cedex 04, France1
| | - Helen Billman-Jacobe
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia2
| | - Catherine Astarie-Dequeker
- Institut de Pharmacologie et de Biologie Structurale, Unité Mixte de Recherche du Centre de National de Recherche Scientifique et de l'Université Paul Sabatier (UMR 5089), 205 route de Narbonne, 31077 Toulouse cedex 04, France1
| | - Marie-Ange Dupont
- Institut d'Exploration Fonctionnelle des Génomes (IFR 109), 118 route de Narbonne, 31062 Toulouse cedex, France3
| | - Mamadou Daffé
- Institut de Pharmacologie et de Biologie Structurale, Unité Mixte de Recherche du Centre de National de Recherche Scientifique et de l'Université Paul Sabatier (UMR 5089), 205 route de Narbonne, 31077 Toulouse cedex 04, France1
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Shiratsuchi H, Ellner JJ. Expression of IL-18 by Mycobacterium avium-infected human monocytes; association with M. avium virulence. Clin Exp Immunol 2001; 123:203-9. [PMID: 11207649 PMCID: PMC1905986 DOI: 10.1046/j.1365-2249.2001.01411.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Disseminated Mycobacterium avium infection is the most frequent bacterial infection in patients with advanced AIDS and also associated with interferon-gamma (IFN-gamma) or IL-12 receptor deficiency. IFN-gamma is a key cytokine in host defence against M. avium infection. Expression of IL-18, a potent IFN-gamma inducer, and IFN-gamma by human monocytes after infection with M. avium was examined. Monocytes were co-cultured with isogenic smooth-transparent (SmT: virulent) or smooth-domed (SmD: avirulent) M. avium strains (10 organisms per monocyte). Infection with the SmD strain induced significantly higher concentration of IL-18 and IFN-gamma in culture supernatants than did the SmT strain. IFN-gamma production in response to M. avium was partially inhibited by anti-human IL-18 MoAb. Both recombinant human IL-12 (77 +/- 42 pg/ml, control versus 1492 +/- 141 pg/ml, cultures with IL-12 1 ng/ml) and IL-18 (126 +/- 37 pg/ml, control versus 2683 +/- 864 pg/ml, cultures with IL-18 10 ng/ml) augmented M. avium-induced IFN-gamma production. Freshly isolated uninfected monocytes expressed constitutive levels of IL-18. Following infection with M. avium, enhancement of IL-18 mRNA expression peaked at 3-6 h. IL-18 protein was detected in monocyte lysates as early as 1 h after infection with both SmT and SmD M. avium strains by Western blotting. Higher IL-18 expression by monocytes infected with the avirulent strain may result in more IFN-gamma production, thus modulating its pathogenicity. Local induction of IL-18 may be important both for M. avium pathogenicity and host defence and become a potential candidate for immunotherapy.
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Affiliation(s)
- H Shiratsuchi
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106-4984, USA.
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Recht J, Martínez A, Torello S, Kolter R. Genetic analysis of sliding motility in Mycobacterium smegmatis. J Bacteriol 2000; 182:4348-51. [PMID: 10894747 PMCID: PMC101957 DOI: 10.1128/jb.182.15.4348-4351.2000] [Citation(s) in RCA: 169] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A screen for nonsliding mutants of Mycobacterium smegmatis yielded 20 mutants with transposon insertions in the mps gene, which is involved in glycopeptidolipid biosynthesis. One mutant had an insertion in a gene predicted to encode a membrane transport protein. All mutants lacked glycopeptidolipids and were unable to form biofilms on polyvinyl chloride.
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Affiliation(s)
- J Recht
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
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Vergne I, Desbat B. Influence of the glycopeptidic moiety of mycobacterial glycopeptidolipids on their lateral organization in phospholipid monolayers. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1467:113-23. [PMID: 10930514 DOI: 10.1016/s0005-2736(00)00212-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glycopeptidolipids (GPLs) from the cell wall of opportunistic pathogenic mycobacteria are potential factors of pathogenicity which can interact with biological membranes. GPL suspensions uncouple oxidative phosphorylation of mitochondria and increase membrane permeability of liposomes. Heavily glycosylated GPLs are less active than lightly glycosylated ones. GPL-phospholipid interactions into preformed mixed films at the air-water interface were investigated in order to understand the permeabilization efficiency differences among GPLs. Polarization modulation infrared reflection absorption spectroscopy (PMIRRAS) was used to determine, in situ, the organization of GPL and of 1,2-di(perdeuteropalmitoyl)phosphatidylcholine (DPPC) molecules in mixed films. Compression isotherms of GPL alone or mixed with DPPC in various proportions showed that the less the GPL was glycosylated the higher its miscibility with DPPC. PMIRRAS studies indicated that low miscibility may result from large self-association of GPL molecules in beta-sheet structures. Low glycosylated GPL molecules increased disorder of DPPC acyl chains. Based on these results, an explanatory model is proposed for membrane permeabilization. Increase of passive permeability may arise from disruption of phospholipid packing induced by GPL molecules. GPL segregation is proposed as the cause of low activity of GPL with high sugar content, by decreasing the number of GPL molecules interacting with phospholipids.
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Affiliation(s)
- I Vergne
- Institut de Pharmacologie et de Biologie Structurale, CNRS and Université Paul Sabatier, Toulouse, France.
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Horgen L, Barrow EL, Barrow WW, Rastogi N. Exposure of human peripheral blood mononuclear cells to total lipids and serovar-specific glycopeptidolipids from Mycobacterium avium serovars 4 and 8 results in inhibition of TH1-type responses. Microb Pathog 2000; 29:9-16. [PMID: 10873486 DOI: 10.1006/mpat.2000.0358] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies have suggested that large quantities of bacterial lipids may accumulate and persist within host cells during chronic stages of Mycobacterium avium infections. This study intended to assess the ability of purified M. avium lipids to affect TH-1-type responses in human peripheral blood mononuclear cells (PBMC) from healthy donors. PBMC were exposed to total lipids and serovar-specific glycopeptidolipids (GPL) extracted from M. avium serovars 4 and 8, which have been reported to predominate as opportunistic infection among AIDS patients. After 24 h exposure to lipids followed by PHA/PMA treatment, IL-2 and IFN-gamma were assayed in the supernatants. Reverse transcriptase polymerase chain reaction (RT-PCR) was used for a semiquantitative estimation of mRNA for IL-2 and IFN-gamma in cell pellets at various time points. Exposure of PBMC to M. avium total lipids significantly suppressed PHA/PMA-induced secretion of IL-2 and IFN-gamma as determined by ELISA. The GPL antigens from serovar 4 were more efficient at inhibiting TH-1 responses than GPL from serovar 8. CD4(+)T-lymphocyte enrichment of PBMC demonstrated that suppression by M. avium lipids was intact without the presence of other cell populations such as monocytes and B-cells. Preliminary RT-PCR experiments showed that the secretion of TH-1 cytokines was partially affected at the transcriptional level. The results obtained showed that M. avium lipids are indeed able to modify the induction of TH-1-type cytokines by human PBMC, and suggest that accumulation of M. avium lipids in the chronic stages of infection may play an important role in the pathogenesis of HIV infection.
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Affiliation(s)
- L Horgen
- Unité de la Tuberculose et des Mycobactéries, Institut Pasteur, Morne Jolivière, BP 484, F-97165-Pointe-à-Pitre, Guadeloupe
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Abstract
Mycobacteria are nonflagellated gram-positive microorganisms. Previously thought to be nonmotile, we show here that Mycobacterium smegmatis can spread on the surface of growth medium by a sliding mechanism. M. smegmatis spreads as a monolayer of cells which are arranged in pseudofilaments by close cell-to-cell contacts, predominantly along their longitudinal axis. The monolayer moves away from the inoculation point as a unit with only minor rearrangements. No extracellular structures such as pili or fimbriae appear to be involved in this process. The ability to translocate over the surface correlates with the presence of glycopeptidolipids, a mycobacterium-specific class of amphiphilic molecules located in the outermost layer of the cell envelope. We present evidence that surface motility is not restricted to M. smegmatis but is also a property of the slow-growing opportunistic pathogen M. avium. This form of motility could play an important role in surface colonization by mycobacteria in the environment as well as in the host.
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Affiliation(s)
- A Martínez
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
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Pourshafie MR, Sonnenfeld G, Barrow WW. Immunological and ultrastructural disruptions of T lymphocytes following exposure to the glycopeptidolipid isolated from the Mycobacterium avium complex. Scand J Immunol 1999; 49:405-10. [PMID: 10219767 DOI: 10.1046/j.1365-3083.1999.00529.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In this study, we examined the effects of the serovar-specific glycopeptidolipid (GPL) on the ultrastructure of purified T lymphocytes and the interleukin secretion by spleen and purified T lymphocytes. Electron microscopy indicated extensive disruption of the cytoplasmic compartment of T lymphocytes, which could result in altered function of immune cells. Despite the cellular damage as viewed by the electron microscopy, the expression of T-cell surface markers, Thy 1.2 and Lyt-2, were not affected. The data indicate that GPL is capable of inducing in-vitro interleukin (IL)-6 and IL-2 production by whole spleen or purified spleen T lymphocytes. The level of production of IL-6 and IL-2 following the exposure of the mycobacteria-infected cells to GPL was approximately the same as the uninfected control. A similar finding was also obtained with the total lipid extraction from the mycobacterium. The results suggest that the ability of the total lipid extraction, in inducing cytokine production, may be attributed to its GPL content.
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Affiliation(s)
- M R Pourshafie
- Pasteur Institute of Iran, Department of Microbiology, Tehran
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15
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Abstract
The review discusses current knowledge of the biosynthesis, composition and arrangement of the mycobacterial envelope, describes the biological activities of the constituents and considers how these activities may be relevant to the pathology of mycobacterial disease. The envelope possesses three structural components: plasma membrane, wall and capsule. Although the major biomolecules occurring in each of these parts are known, the distribution of numerous minor substances is poorly understood; an attempt has been made to assign them to particular positions on rational grounds. The plasma membrane appears to be a typical bacterial membrane but, though vital to the mycobacterium, probably plays little part in pathological processes. The wall partly resembles a Gram-positive wall, but is unusual in having a layer of lipid (mycolate esters) which is probably arranged to form a permeability barrier to polar molecules. The capsule, whose chemical composition has only recently been recognized, consists of polysaccharide and protein with traces of lipid; the arrangement of these components is imperfectly understood. Constituents of all parts of the envelope have biological activities which may be relevant. The likely importance of these activities in the overall effect of the envelope is considered.
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Affiliation(s)
- M Daffé
- Institut de Pharmacologie et de Biologie Structurale, Toulouse, France
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Burns JL, Malhotra U, Lingappa J, Smith S. Unusual presentations of nontuberculous mycobacterial infections in children. Pediatr Infect Dis J 1997; 16:802-6. [PMID: 9271044 DOI: 10.1097/00006454-199708000-00013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- J L Burns
- Department of Pediatrics, University of Washington, Seattle, USA
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Rivière M, Puzo G, Wright EL, Barrow WW. A unique phenylalanine-containing lipopeptide isolated from a rough-colony variant of Mycobacterium avium. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 241:682-90. [PMID: 8917472 DOI: 10.1111/j.1432-1033.1996.00682.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Previous investigations have suggested that the biosynthesis of the Mycobacterium avium serovar-specific glycopeptidolipid antigens involves initial steps that include the participation of lipopeptides. The prevailing assumption is that subsequent glycosylation of those lipopeptides results in the fully glycosylated form of the glycopeptidolipid components. In an effort to identify potential precursors in the biosynthetic pathway of glycopeptidolipid components, we have identified a unique lipopeptide from an M. avium rough variant (MAC702) that was isolated from a patient suffering from a chronic M. avium lung infection. Upon examination it was revealed that although the total lipid extract from MAC702 lacked serovar-specific glycopeptidolipid antigens, it did contain a unique lipopeptide, possessing some amino acids identical to those found in the serovar-specific glycopeptidolipid antigens. Initial examination of acid-hydrolyzed samples of the lipopeptide (lipopeptide-I) revealed the presence of phenylalanine, alanine, and isoleucine, but no carbohydrate. Subsequent mass spectrometric and 1H-NMR and 1H-13C-NMR correlation spectroscopy analysis confirmed the initial results and also revealed the presence of N-methylisoleucine. The following structure for lipopeptide-I was proposed: fatty acyl (C19 or C17)-Phe-N-methyl-Ile-Ile-Phe-Ala-Ile-Ala-Phe. Lipopeptide-I is unlike any heretofore identified compound, however, it does have similar features to lipopeptides previously reported in mycobacteria and fungi. Although its structure does not verify that it is a direct precursor in glycopeptidolipid biosynthesis, the presence of certain components in lipopeptide-I indicate that it may share at least some pathways associated with the biosynthesis of the M. avium serovar-specific glycopeptidolipids.
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Affiliation(s)
- M Rivière
- Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique, Toulouse, France
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Sacco RE, Jensen RJ, Thoen CO, Sandor M, Weinstock J, Lynch RG, Dailey MO. Cytokine secretion and adhesion molecule expression by granuloma T lymphocytes in Mycobacterium avium infection. THE AMERICAN JOURNAL OF PATHOLOGY 1996; 148:1935-48. [PMID: 8669479 PMCID: PMC1861647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Mice experimentally infected with Mycobacterium avium develop a chronic disease characterized by widespread noncaseating granulomas. In this report, we describe the phenotype and cytokine secretion profile of these granuloma-infiltrating effector T lymphocytes. In response to specific antigen, granuloma T cells and, to a lesser extent, spleen cells secrete interferon-gamma, but no interleukin-4 or -5. The importance of this Th1-like response to the host was demonstrated by the massively increased bacterial load and lethal disease in interferon-gamma knockout mice. One function of localized cytokine secretion is to recruit inflammatory T cells bearing surface adhesion molecules complementary to counter-receptors on vascular endothelial cells. Granuloma T cells express high levels of these pro-inflammatory adhesion molecules but have down-regulated their expression of L-selectin (CD62L). The expression of these adhesion molecules on granuloma-infiltrating T lymphocytes would alter the migration pathway of these cells and is likely to be important in facilitating the traffic of effector T cells to the granulomatous inflammatory site. In addition, T cells from Schistosoma mansoni granulomas express the same set of adhesion molecules, showing that this phenotype is not specifically dependent upon the Th1 pattern of cytokine secretion.
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Affiliation(s)
- R E Sacco
- Department of Pathology, University of Iowa College of Medicine, Iowa City, IA 52242, USA
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Ortalo-Magné A, Lemassu A, Lanéelle MA, Bardou F, Silve G, Gounon P, Marchal G, Daffé M. Identification of the surface-exposed lipids on the cell envelopes of Mycobacterium tuberculosis and other mycobacterial species. J Bacteriol 1996; 178:456-61. [PMID: 8550466 PMCID: PMC177678 DOI: 10.1128/jb.178.2.456-461.1996] [Citation(s) in RCA: 216] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The surface-exposed lipids of Mycobacterium tuberculosis, Mycobacterium avium, Mycobacterium kansasii, Mycobacterium gastri, Mycobacterium smegmatis, and Mycobacterium aurum were isolated by gentle mechanical treatment of cells with glass beads. Analysis of the exposed lipids demonstrated a selective location of classes of ubiquitous lipids on the surfaces of mycobacteria. While phosphatidylethanolamine and phosphatidylinositol mannosides were exposed in all the species examined, dimycoloyl trehalose ("cord factor") was identified in the surface components of M. aurum only. Furthermore, monomycoloyl trehaloses and triacylglycerides were identified in the surface-exposed lipids of M. avium and M. smegmatis but not in those of the other mycobacterial species examined. The species- and type-species specific lipids were present on the mycobacterial cell surface: phenolic glycolipids, dimycocerosates of phthiocerols, and lipooligosaccharides were identified in the surface-exposed materials of M. tuberculosis (Canetti), M. kansasii, and M. gastri, whereas glycopeptidolipids were identified in the outermost lipid constituents of M. avium and M. smegmatis. This difference in the surface exposure of lipids of various mycobacterial species may reflect differences in their cell envelope organizations. Brief treatments of M. tuberculosis with Tween 80 prior to the use of glass beads led to erosion of regions of the capsule to expose gradually both cord factor and other lipids on the cell surface of the tubercle bacillus, demonstrating that the latter lipids are buried more deeply in the cell envelope and leading to the proposal of a scheme for the location of the capsular lipids of the tubercle bacillus.
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Affiliation(s)
- A Ortalo-Magné
- Laboratoire de Pharmacologie et Toxicologie Fondamentales du Centre National de la Recherche Scientifique, Toulouse, France
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20
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Hunter RL, Jagannath C, Tinkley A, Behling CA, Nolte F. Enhancement of antibiotic susceptibility and suppression of Mycobacterium avium complex growth by poloxamer 331. Antimicrob Agents Chemother 1995; 39:435-9. [PMID: 7726511 PMCID: PMC162556 DOI: 10.1128/aac.39.2.435] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The resistance of Mycobacterium avium complex (MAC) to antibiotics is thought to be enhanced by its outer glycolipid layer, which protects the organisms from antibiotics and host defense mechanisms. We hypothesized that surfactants which disrupt the lipid barrier might be of therapeutic value. We evaluated the ability of 10 poloxamer surfactants to inhibit the growth of MAC organisms and to potentiate antimycobacterial drug activity in broth culture using a radiometric assay. Very large, small, or hydrophilic poloxamers had little or no effect. However, certain hydrophobic poloxamers, especially P331, retarded the growth of most isolates of MAC and produced a synergistic effect with rifampin. The MIC of rifampin required to inhibit the growth of MAC was reduced from a mean of 14.6 micrograms/ml (range, 4 to > 32 micrograms/ml) to 1.4 micrograms/ml (range, < 1.125 to 4 micrograms/ml) by 1.0 mg of P331 per ml (P < 0.01). Enhancement of antibiotic susceptibility was observed with concentrations of poloxamer as low as 10 micrograms/ml. These studies suggest that P331 might be useful in increasing the effectiveness of antibiotic therapy of MAC infections.
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Affiliation(s)
- R L Hunter
- Department of Pathology, Emory University, Atlanta, Georgia 30322, USA
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21
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Aspinall GO, Chatterjee D, Brennan PJ. The variable surface glycolipids of mycobacteria: structures, synthesis of epitopes, and biological properties. Adv Carbohydr Chem Biochem 1995; 51:169-242. [PMID: 7484363 DOI: 10.1016/s0065-2318(08)60194-8] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- G O Aspinall
- Department of Chemistry, York University, Ontario, Canada
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22
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Barrow WW, Davis TL, Wright EL, Labrousse V, Bachelet M, Rastogi N. Immunomodulatory spectrum of lipids associated with Mycobacterium avium serovar 8. Infect Immun 1995; 63:126-33. [PMID: 7806348 PMCID: PMC172968 DOI: 10.1128/iai.63.1.126-133.1995] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Lipid fractions obtained from Mycobacterium avium serovar 8 were assessed for the ability to affect various immune functions of human peripheral blood mononuclear cells (PBM). Lipids included a total lipid fraction and fractions eluted from silicic acid column separation of that total lipid fraction, using chloroform and chloroform-methanol combinations. Lipid fractions were assayed for total carbohydrate and total 6-deoxyhexose content and were assessed for the ability to influence human macrophage function and the capacity to induce secretion of prostaglandin E2 (PGE2) and tumor necrosis factor alpha in PBM. The total lipid and serovar-specific glycopeptidolipid (GPL) fractions both induced significant levels of tumor necrosis factor alpha, as well as PGE2, in PBM exposed to a sublethal concentration of 100 micrograms lipid per 2 x 10(6) cells. In addition, the same concentrations of the 5 to 7% and GPL fractions induced significant levels of leukotriene B4 in PBM. Comparison of carbohydrate and 6-deoxyhexose contents of each fraction suggested a relationship to carbohydrate content and ability of fractions to induce immune modulator secretion. Analysis of GPL fractions from M. avium serovars 4 and 20 revealed that those GPL lacked the ability to induce PGE2. These results are explained by considering the difference in the carbohydrate residues of the oligosaccharide moieties.
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Affiliation(s)
- W W Barrow
- Unité de la Tuberculose et des Mycobactéries, Institut Pasteur, Pointe-à-Pitre, Guadeloupe, French West Indies
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23
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Saha B, Das G, Vohra H, Ganguly NK, Mishra GC. Macrophage-T cell interaction in experimental mycobacterial infection. Selective regulation of co-stimulatory molecules on Mycobacterium-infected macrophages and its implication in the suppression of cell-mediated immune response. Eur J Immunol 1994; 24:2618-24. [PMID: 7525297 DOI: 10.1002/eji.1830241108] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The most important immunopathological consequence of experimental mycobacterial infection is the suppression of T cell-mediated immune response to both mitogens and mycobacterial antigens. We registered that there was decreased concanavalin A-induced spleen cell proliferation in infected susceptible BALB/c mice as compared to normal mice. In resistant (C3H/HeJ) mice, infection with the bacteria did not induce any suppression in the mitogen-induced lymphoproliferation. Likewise, delayed-type hypersensitivity (DTH) responses, to keyhole limpet hemocyanin and mycobacterial crude soluble antigen were suppressed in infected BALB/c mice but not in C3H/HeJ mice. This depressed T helper cell function may either be due to defective T cell-receptor occupancy by antigen-Ia complex or altered co-stimulatory signals provided by antigen-presenting cells. In the present study, we have investigated the status of certain co-stimulatory molecules on the infected macrophages from both susceptible and resistant mice. Our results demonstrate that upon mycobacterial infection, the macrophages are rendered incapable of delivering the co-stimulatory signals to T helper cells, possibly due to the involvement of prostaglandin, as inhibition of its biosynthesis by indomethacin reversed the defect. Furthermore, the selective regulation was bacteria-induced as killing of the bacteria by rifampicin abrogated the derangements in the expression of co-stimulatory molecules on the Mycobacterium-infected macrophages. Our observations revealed that upon infection with Mycobacterium tuberculosis, B7 was down-regulated while ICAM-1 was increased only in BALB/c but not in C3H/HeJ mice. Expression of VCAM-1 did not change during the infection in either strain of mice. We found that these changes in ICAM-1 and B7 expression on the surface of infected macrophages resulted in inhibition of DTH-mediating functions of T helper cells from BALB/c mice. The results obtained in this study describe not only a novel immune evasion strategy adopted by Mycobacterium, but also open up the possibility of immunotherapy of mycobacterial infection by selective manipulation of co-stimulatory molecules.
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Affiliation(s)
- B Saha
- Immunology Lab, Institute of Microbial Technology, Chandigarh, India
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24
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Abstract
The worldwide increase in tuberculosis, the additional problem of increasing multiple drug resistance (MDR) and the primary resistance of Mycobacterium avium requires new strategies in drug development and in therapy. The reason for development of MDR is manifold. One important factor is the change in cell wall construction which limits the penetration of the drug to the target receptor. This is supported by the observation that within a class of tuberculostatic drugs (identical mode of action) the more lipophilic derivative is more effective. In addition, it has been shown that mycobacteria within macrophages are able to synthesize additional multilamellar cell wall components. Several possibilities exist to overcome MDR. Besides improving the permeation properties of drugs, the development of synergistic drug combinations based on their special mode of action is a promising approach. This is illustrated with the highly synergistic combination of newly developed hydrazones and thiacetazone respectively with rifampicin. Chance combinations which may even lead to antagonism have to be avoided. Examples of antagonistic behavior of the combinations clofazimine-dapsone and ofloxacin-rifampicin are discussed. An optimization procedure has been developed based on the determination of the specific resistance of patient-derived mycobacteria against single drugs and their combinations. With its use, an individual optimal treatment becomes feasible. Preliminary clinical experience is encouraging.
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Affiliation(s)
- J K Seydel
- Institut für Experimentelle Biologie und Medizin, Borstel, Germany
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25
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Rastogi N, Goh KS, Wright EL, Barrow WW. Potential drug targets for Mycobacterium avium defined by radiometric drug-inhibitor combination techniques. Antimicrob Agents Chemother 1994; 38:2287-95. [PMID: 7840559 PMCID: PMC284732 DOI: 10.1128/aac.38.10.2287] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Previously established radiometric techniques were used to assess the effectiveness of combined antimicrobial drug-inhibitory drug (drug-inhibitor) treatment on two clinical isolates of the Mycobacterium avium complex representing three colony variants: smooth opaque (dome) (SmO), smooth transparent (SmT), and rough (Rg). All variants were identified as members of the M. avium complex; however, only the SmT colony type of strain 373 possessed characteristic serovar-specific glycopeptidolipid (GPL) antigens. MICs, determined radiometrically, of drugs with the potential to inhibit the biosynthesis of GPL antigens or other cell envelope constituents were similar for all strains. These drugs included cerulenin, N-carbamyl-DL-phenylalanine, N-carbamyl-L-isoleucine, trans-cinnamic acid, ethambutol, 1-fluoro-1-deoxy-beta-D-glucose, 2-deoxy-D-glucose, and m-fluoro-phenylalanine. The MICs of the antimicrobial drugs amikacin, sparfloxacin, and clarithromycin varied, but overall the MICs for the SmO variant were the lowest. Radiometric assessment of drug-inhibitor combinations by using established x/y determinations revealed enhanced activity when either ethambutol or cerulenin were used in combination with all antimicrobial agents for all variants except the Rg variant of strain 424, for which ethambutol was not effective. Enhanced activity with amino acid analogs was observed with the Rg colony variants of strains 373 and 424. Two potential sites for drug targeting were identified: fatty acid synthesis, for all strains assayed, and peptide biosynthesis, particularly for Rg colony variants that possess previously identified phenylalanine-containing lipopeptides as potential targets for future drug development.
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Affiliation(s)
- N Rastogi
- Unité de la Tuberculose et des Mycobactéries, Institut Pasteur de la Guadeloupe, French West Indies
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26
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Paul TR, Beveridge TJ. Preservation of surface lipids and determination of ultrastructure of Mycobacterium kansasii by freeze-substitution. Infect Immun 1994; 62:1542-50. [PMID: 8168915 PMCID: PMC186351 DOI: 10.1128/iai.62.5.1542-1550.1994] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The cell wall architecture of a slowly growing mycobacterium, Mycobacterium kansasii, was examined by freeze-substitution following growth in vitro. Freeze-substituted bacteria were marked by the presence of an electron-translucent space (or electron-transparent zone [ETZ] described by previous workers [T. Yamamoto, M. Nishiura, N. Harada, and T. Imaeda, Int. J. Lepr. 26:111-114, 1958]) surrounding the majority of cells. At least two morphotypes of mycobacteria were revealed by freeze-substitution. In the first, a relatively thin (11 +/- 2.3 to 3.5 +/- 3.1 nm), uniform ETZ surrounded intact cells which contained cytoplasm filled with well-stained ribosomes and a DNA nucleoid distributed throughout the cell. The second morphotype consisted of a small proportion of organisms that were distorted in shape and were surrounded by a much thicker (59 +/- 2.6 to 198 +/- 2.5 nm) ETZ in areas of the cell which appeared to have retracted from the space it had originally occupied, leaving depressions in the ETZ. The lipid nature of the ETZ was demonstrated because cells were devoid of an ETZ when organisms were freeze-substituted in the absence of osmium tetroxide in the substitution medium or treated with neutral lipid solvents (acetone or ethanol) before freeze-substitution. Moreover, thin-layer chromatography of acetone or ethanol extracts obtained from solvent-treated cells identified a lipid component which corresponded to the M. kansasii-specific phenolic glycolipid. In contrast, negligible amounts of glycolipids were detected in extracts obtained from control HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid) buffer-treated cells, and these cells retained an ETZ. These results demonstrate that species-specific phenolic glycolipids are essential components in the architecture of the M. kansasii ETZ. Furthermore, we show that freeze-substitution is a reliable technique for the retention and precise preservation of lipid-containing polymers in the mycobacterial cell wall.
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Affiliation(s)
- T R Paul
- Department of Microbiology, College of Biological Science, University of Guelph, Ontario, Canada
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27
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Affiliation(s)
- H Shiratsuchi
- Case Western Reserve University, University Hospital, Cleveland, OH 44106
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28
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Rastogi N, Barrow WW. Cell envelope constituents and the multifaceted nature of Mycobacterium avium pathogenicity and drug resistance. Res Microbiol 1994; 145:243-52; discussion 252-61. [PMID: 7809479 DOI: 10.1016/0923-2508(94)90025-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- N Rastogi
- Laboratoire de la Tuberculose et des Mycobactéries, Institut Pasteur, Pointe à Pitre, Guadeloupe, French West Indies
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29
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Abstract
Mycobacterium avium complex (MAC) disease emerged early in the epidemic of AIDS as one of the common opportunistic infections afflicting human immunodeficiency virus-infected patients. However, only over the past few years has a consensus developed about its significance to the morbidity and mortality of AIDS. M. avium was well known to mycobacteriologists decades before AIDS, and the MAC was known to cause disease, albeit uncommon, in humans and animals. The early interest in the MAC provided a basis for an explosion of studies over the past 10 years largely in response to the role of the MAC in AIDS opportunistic infection. Molecular techniques have been applied to the epidemiology of MAC disease as well as to a better understanding of the genetics of antimicrobial resistance. The interaction of the MAC with the immune system is complex, and putative MAC virulence factors appear to have a direct effect on the components of cellular immunity, including the regulation of cytokine expression and function. There now is compelling evidence that disseminated MAC disease in humans contributes to both a decrease in the quality of life and survival. Disseminated disease most commonly develops late in the course of AIDS as the CD4 cells are depleted below a critical threshold, but new therapies for prophylaxis and treatment offer considerable promise. These new therapeutic modalities are likely to be useful in the treatment of other forms of MAC disease in patients without AIDS. The laboratory diagnosis of MAC disease has focused on the detection of mycobacteria in the blood and tissues, and although the existing methods are largely adequate, there is need for improvement. Indeed, the successful treatment of MAC disease clearly will require an early and rapid detection of the MAC in clinical specimens long before the establishment of the characteristic overwhelming infection of bone marrow, liver, spleen, and other tissue. Also, a standard method of susceptibility testing is of increasing interest and importance as new effective antimicrobial agents are identified and evaluated. Antimicrobial resistance has already emerged as an important problem, and methods for circumventing resistance that use combination therapies are now being studied.
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Affiliation(s)
- C B Inderlied
- Department of Pathology and Laboratory Medicine, Childrens Hospital, Los Angeles, California 90027
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30
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Pourshafie M, Ayub Q, Barrow WW. Comparative effects of Mycobacterium avium glycopeptidolipid and lipopeptide fragment on the function and ultrastructure of mononuclear cells. Clin Exp Immunol 1993; 93:72-9. [PMID: 8324905 PMCID: PMC1554752 DOI: 10.1111/j.1365-2249.1993.tb06499.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Among the various lipids associated with the cell envelope of the Mycobacterium avium complex, the species-specific glycopeptidolipids (GPL) are responsible for distinguishing one serovar from another. In a continuing effort to study the immunomodulatory capabilities of these mycobacterial lipids, we have examined and compared the effects of the GPL and its lipopeptide fragment (beta-lipid) on mononuclear cell function. It was observed that the lymphoproliferative response of murine splenic mononuclear cells to mitogen stimulation was reduced by both the GPL and its lipopeptide fragment. Although the responsiveness appeared to be down-regulated to a greater degree by the beta-lipid, treatment with either GPL or beta-lipid resulted in the release of soluble factors from peritoneal macrophages that caused suppression of the lymphoproliferative responsiveness of splenic mononuclear cells. Flow cytometric analysis of peritoneal macrophages revealed that treatment with the beta-lipid fragment caused a marked decrease in expression of the C3bi complement receptor, Mac-1, on macrophages, whereas treatment with GPL resulted in a marked increase in the expression of Mac-2 receptor on macrophages. Treatment of peritoneal macrophages with either GPL or beta-lipid resulted in the release of tumour necrosis factor (TNF), as determined by an L929 biological cytotoxicity assay. Perturbation of macrophage membrane ultrastructure by both GPL and beta-lipid was confirmed by electron microscopy, and may be a possible explanation for the resulting alterations in mononuclear cell function observed in this study.
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Affiliation(s)
- M Pourshafie
- Department of Immunotherapy, Wadley Institute of Molecular Medicine, Dallas, TX
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31
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Barrow WW, Wright EL, Goh KS, Rastogi N. Activities of fluoroquinolone, macrolide, and aminoglycoside drugs combined with inhibitors of glycosylation and fatty acid and peptide biosynthesis against Mycobacterium avium. Antimicrob Agents Chemother 1993; 37:652-61. [PMID: 8494359 PMCID: PMC187730 DOI: 10.1128/aac.37.4.652] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Smooth- and rough-colony variants of Mycobacterium avium serovar 4 were treated with three classes of drugs. The drugs were chosen for their potential inhibitory effects on the biosynthesis of the cell envelope-associated serovar-specific glycopeptidolipid antigens. Growth was monitored radiometrically with a BACTEC 460-TB instrument, and MICs were determined for each drug. Both variants were then treated with inhibitory drugs in combination with antimicrobial agents that have demonstrated effectiveness against M. avium. No growth inhibition was observed with 6-fluoro-6-deoxy-D-glucose or avidin. Inhibitors of glycosylation, i.e., 2-deoxy-D-glucose, bacitracin, and ethambutol, were inhibitory to smooth- and rough-colony variants, whereas drugs that inhibit peptide synthesis, i.e., N-carbamyl-L-isoleucine and m-fluoro-phenylalanine, were more inhibitory for the rough-colony variant. Cerulenin, which affects fatty acid synthesis, was inhibitory for both variants, but it appeared to be more effective at inhibiting the growth of the smooth-colony variant at equivalent concentrations. Generally, when inhibitors of glycosylation were used with sparfloxacin and amikacin, a synergistic effect was observed for only the smooth variant. When drugs that affect peptide synthesis were used in combination with amikacin, a synergistic effect was observed for the rough variant, and when cerulenin was used in combination with sparfloxacin or amikacin, a synergistic effect was observed for both variants. Lipid analysis revealed that although the rough variant lacks the serovar-specific glycopeptidolipid antigens, it does possess a group of phenylalanine-isoleucine-containing lipopeptides that may explain its different susceptibility patterns to m-fluoro-phenylalanine and N-carbamyl-L-isoleucine. The significance of these results is discussed with reference to various components in the cell envelope and their importance in cell wall permeability.
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Affiliation(s)
- W W Barrow
- Department of Microbiology and Immunology, Texas College of Osteopathic Medicine, Fort Worth 76107
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32
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Majumdar S, Flasher D, Friend DS, Nassos P, Yajko D, Hadley WK, Düzgüneş N. Efficacies of liposome-encapsulated streptomycin and ciprofloxacin against Mycobacterium avium-M. intracellulare complex infections in human peripheral blood monocyte/macrophages. Antimicrob Agents Chemother 1992; 36:2808-15. [PMID: 1482150 PMCID: PMC245550 DOI: 10.1128/aac.36.12.2808] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Current treatments of disseminated infection caused by the Mycobacterium avium-M. intracellulare complex (MAC) are generally ineffective. Liposome-mediated delivery of antibiotics to MAC-infected tissues in vivo can enhance the efficacy of the drugs (N. Düzgüneş, V. K. Perumal, L. Kesavalu, J. A. Goldstein, R. J. Debs, and P. R. J. Gangadharam, Antimicrob. Agents Chemother. 32:1404-1411, 1988; N. Düzgüneş, D. A. Ashtekar, D. L. Flasher, N. Ghori, R. J. Debs, D. S. Friend, and P. R. J. Gangadharam, J. Infect. Dis. 164:143-151, 1991). We investigated the therapeutic efficacies of liposome-encapsulated streptomycin and ciprofloxacin against growth of the MAC inside human peripheral blood monocyte/macrophages. Treatment was initiated 24 h after infection of macrophages with the MAC and stopped after 20 h, and the cells were incubated for another 7 days. The antimycobacterial activity of streptomycin was enhanced when the drug was delivered to macrophages in liposome-encapsulated form, reducing the CFU about threefold more than the free drug did throughout the concentration range studied (10 to 50 micrograms/ml). With 50 micrograms of encapsulated streptomycin per ml, the CFU were reduced to 11% of the initial level of infection. Liposome-encapsulated ciprofloxacin was at least 50 times more effective against the intracellular bacteria than was the free drug: at a concentration of 0.1 microgram/ml, liposome-encapsulated ciprofloxacin had greater antimycobacterial activity than the free drug at 5 microgram/ml. With liposome-encapsulated ciprofloxacin at 5 micrograms/ml, the CFU were reduced by more than 1,000-fold at the end of the 7-day incubation period, compared with untreated controls. These results suggest that liposome-encapsulated ciprofloxacin or other fluoroquinolones may be effective against MAC infections in vivo.
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Affiliation(s)
- S Majumdar
- Department of Microbiology, University of the Pacific School of Dentistry, San Francisco, California 94115-2399, USA
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