90 results on '"Leadbetter E"'
Search Results
2. Equivalence of Hydrogen and Thiosulfate in Bacterial Photosyntheses
- Author
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Leadbetter, E. R. and Whittenbury, Roger
- Published
- 1963
3. Isolation and characterization of a Chryseobacterium strain from the gut of the American cockroach, Periplaneta americana
- Author
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Dugas, J. E., Zurek, L., Paster, B. J., Keddie, B. A., and Leadbetter, E. R.
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- 2001
- Full Text
- View/download PDF
4. Colonoscopically detected colorectal cancer in Fe deficiency-is completion gastroscopy necessary?: Surgical Audit 0647
- Author
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Montgomery, S., Leadbetter, E., Sillars, A., Stevens, N., and Macdonald, A.
- Published
- 2012
5. Sulfonates: novel electron acceptors in anaerobic respiration
- Author
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Lie, Thomas J., Pitta, Thomas, Leadbetter, E. R., Godchaux III., Walter, and Leadbetter, Jared R.
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- 1996
- Full Text
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6. Toll-like receptors, autoantigen, and SLE: IS60
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Rifkin, I. R., Boule, M. W., Broughton, C., Ling, T., Lau, C., Leadbetter, E. A., Busconi, L., and Marshak-Rothstein, A.
- Published
- 2004
7. Ultrastructure of Bacteroides Species: Bacteroides asaccharolyticus, Bacteroides fragilis, Bacteroides melaninogenicus Subspecies melaninogenicus, and B. melaninogenicus Subspecies intermedius
- Author
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Woo, D. D. L., Holt, S. C., and Leadbetter, E. R.
- Published
- 1979
8. Capnocytophaga: New genus of gram-negative gliding bacteria I. General characteristics, taxonomic considerations and significance
- Author
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Leadbetter, E. R., Holt, S. C., and Socransky, S. S.
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- 1979
- Full Text
- View/download PDF
9. Preparation and characterization of a soluble nitrate reductase from Azotobacter chroococcum
- Author
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Guerrero, M. G., Vega, J. Ma, Leadbetter, E., and Losada, M.
- Published
- 1973
- Full Text
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10. Capnocytophaga: New genus of Gram-negative gliding bacteria. III. Physiological characterization
- Author
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Socransky, S. S., Holt, S. C., Leadbetter, E. R., Tanner, A. C. R., Savitt, E., and Hammond, B. F.
- Published
- 1979
- Full Text
- View/download PDF
11. Surface-induced synthesis of new sulfonolipids in the gliding bacterium Cytophaga johnsonae
- Author
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Abbanat, D. R., Godchaux, III, W., and Leadbetter, E. R.
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- 1988
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12. Capnocytophaga: New genus of Gram-negative gliding bacteria. II. Morphology and ultrastructure
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Holt, Stanley C., Leadbetter, E. R., and Socransky, S. S.
- Published
- 1979
- Full Text
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13. Fine structure of Sporocytophaga myxococcoides
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Holt, Stanley C. and Leadbetter, E. R.
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- 1967
- Full Text
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14. On the isolation of dipicolinic acid from endospores of Sarcina ureae
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Thompson, R. S. and Leadbetter, E. R.
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- 1963
- Full Text
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15. On methylamine assimilation in a bacterium
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Leadbetter, E. R. and Gottlieb, J. A.
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- 1967
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16. Bacterial oxidation of gaseous alkanes
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Leadbetter, E. R. and Foster, J. W.
- Published
- 1960
- Full Text
- View/download PDF
17. Intestinal helminth infection impacts the systemic distribution and function of the naive lymphocyte pool.
- Author
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King, I L, Mohrs, K, Meli, A P, Downey, J, Lanthier, P, Tzelepis, F, Fritz, J H, Tumanov, A V, Divangahi, M, Leadbetter, E A, and Mohrs, M
- Published
- 2017
- Full Text
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18. Memantine-induced myoclonus and delirium exacerbated by trimethoprim.
- Author
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Moellentin D, Picone C, and Leadbetter E
- Published
- 2008
- Full Text
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19. The Genus Capnocytophaga.
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Dworkin, Martin, Falkow, Stanley, Rosenberg, Eugene, Schleifer, Karl-Heinz, Stackebrandt, Erko, and Leadbetter, E. R.
- Published
- 2006
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20. SULFONOLIPIDS NOVEL IN PROCARYOTES ARE SIGNIFICANT CELLULAR COMPONENTS OF MANY GLIDING BACTERIA
- Author
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Leadbetter, E. R., Godchaux III, Walter, and Biological Sciences Group, U-42 The University of Connecticut Storrs, CT 06268 USA
- Abstract
At least two different sulfonolipids, of chemical structure not heretofore recognized to occur in procaryotes, have been isolated, characterized and shown to be present in several genera of non-fruiting gliding bacteria. One of the lipids, capnine, is 2-amino-3-hydroxy-isoheptadecane-1l-sulfonic acid. Capnine and N-acylcapnine (the acyl group(s) of which appear to be C-15, C-16, and C-17 3-hydroxy moieties in the one organism studied) constitute 10% to 20% of the lipids of Capnocytophaga, Cytophaga, Beggiatoa, Flexibacter, Vitreoscilla and Sporocytophaga, and up to 3% of the cell dry weight. These quantitatively significant cell components may represent an important chemotaxonomic marker of non-fruiting gliding bacteria, for they appear to be absent from the fruiting myxobacters thus far examined, as they are also from E. coli and other bacteria which are either nonmotile, or motile as a result of flagellar action. The prospect that they may be associated with, or responsible for, motility in non-fruiting, gliding bacteria is raised.
- Published
- 1981
21. Holger Jannasch — an appreciation.
- Author
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Leadbetter, E. R.
- Subjects
- *
MICROBIOLOGISTS , *DEATH - Abstract
Announces the death of microbiologist Holger Jannasch who died on September 8, 1988 in Woods Hole, Massachusetts. Personal information; Educational background; Contributions in the field of microbiology.
- Published
- 1999
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22. Incorporation of Molecular Oxygen in Bacterial Cells Utilizing Hydrocarbons for Growth.
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LEADBETTER, E. R. and FOSTER, J. W.
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- 1959
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23. Control of Growth and Morphogenesis in some Myxococcus Species.
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LEADBETTER, E. R.
- Published
- 1963
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24. Immunologic resilience and COVID-19 survival advantage.
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Lee GC, Restrepo MI, Harper N, Manoharan MS, Smith AM, Meunier JA, Sanchez-Reilly S, Ehsan A, Branum AP, Winter C, Winter L, Jimenez F, Pandranki L, Carrillo A, Perez GL, Anzueto A, Trinh H, Lee M, Hecht JM, Martinez-Vargas C, Sehgal RT, Cadena J, Walter EA, Oakman K, Benavides R, Pugh JA, Letendre S, Steri M, Orrù V, Fiorillo E, Cucca F, Moreira AG, Zhang N, Leadbetter E, Agan BK, Richman DD, He W, Clark RA, Okulicz JF, and Ahuja SK
- Subjects
- Adult, Aged, COVID-19 epidemiology, COVID-19 mortality, Cohort Studies, Disease Resistance, Female, Humans, Immunocompetence, Interleukin-6 blood, Longitudinal Studies, Male, Middle Aged, Prospective Studies, Severity of Illness Index, Survival Analysis, Transcriptome immunology, United States epidemiology, Viral Load, COVID-19 immunology, HIV Infections epidemiology, HIV-1 physiology, Respiratory Insufficiency epidemiology, SARS-CoV-2 physiology, Sex Factors, T-Lymphocytes immunology
- Abstract
Background: The risk of severe coronavirus disease 2019 (COVID-19) varies significantly among persons of similar age and is higher in males. Age-independent, sex-biased differences in susceptibility to severe COVID-19 may be ascribable to deficits in a sexually dimorphic protective attribute that we termed immunologic resilience (IR)., Objective: We sought to examine whether deficits in IR that antedate or are induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection independently predict COVID-19 mortality., Methods: IR levels were quantified with 2 novel metrics: immune health grades (IHG-I [best] to IHG-IV) to gauge CD8
+ and CD4+ T-cell count equilibrium, and blood gene expression signatures. IR metrics were examined in a prospective COVID-19 cohort (n = 522); primary outcome was 30-day mortality. Associations of IR metrics with outcomes in non-COVID-19 cohorts (n = 13,461) provided the framework for linking pre-COVID-19 IR status to IR during COVID-19, as well as to COVID-19 outcomes., Results: IHG-I, tracking high-grade equilibrium between CD8+ and CD4+ T-cell counts, was the most common grade (73%) among healthy adults, particularly in females. SARS-CoV-2 infection was associated with underrepresentation of IHG-I (21%) versus overrepresentation (77%) of IHG-II or IHG-IV, especially in males versus females (P < .01). Presentation with IHG-I was associated with 88% lower mortality, after controlling for age and sex; reduced risk of hospitalization and respiratory failure; lower plasma IL-6 levels; rapid clearance of nasopharyngeal SARS-CoV-2 burden; and gene expression signatures correlating with survival that signify immunocompetence and controlled inflammation. In non-COVID-19 cohorts, IR-preserving metrics were associated with resistance to progressive influenza or HIV infection, as well as lower 9-year mortality in the Framingham Heart Study, especially in females., Conclusions: Preservation of immunocompetence with controlled inflammation during antigenic challenges is a hallmark of IR and associates with longevity and AIDS resistance. Independent of age, a male-biased proclivity to degrade IR before and/or during SARS-CoV-2 infection predisposes to severe COVID-19., (Published by Elsevier Inc.)- Published
- 2021
- Full Text
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25. Alpha-galactosylceramide (αGalCer) enhances vaccine-induced protection in a model of ricin intoxication.
- Author
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Yates JL, Leadbetter E, and Mantis NJ
- Subjects
- Animals, Antibodies, Neutralizing blood, Antibodies, Neutralizing immunology, Disease Models, Animal, Galactosylceramides immunology, Humans, Immunogenicity, Vaccine, Immunoglobulin G blood, Immunoglobulin G immunology, Mice, Poisoning blood, Poisoning etiology, Poisoning immunology, Ricin immunology, Treatment Outcome, Vaccines immunology, Adjuvants, Immunologic administration & dosage, Galactosylceramides administration & dosage, Poisoning therapy, Ricin toxicity, Vaccines administration & dosage
- Abstract
Alpha-galactosylceramide (αGalCer) is a glycolipid derived from a marine sponge that is a potent activator of both mouse and human invariant natural killer T (iNKT) cells. For that reason, αGalCer is a promising vaccine adjuvant that has been shown to improve both humoral and cellular immunity when co-administered with various vaccines, including candidate vaccines for biodefense. In the current study, we tested the effectiveness of αGalCer as an adjuvant for the clinically-relevant ricin toxin subunit vaccine, RiVax. αGalCer had a potent adjuvant effect, as shown by a rapid onset of anti-ricin IgG titers, accelerated development of serum toxin-neutralizing activity, and enhanced protection from lethal ricin challenge in a mouse model. These results underscore the potential of αGalCer to augment the protective immune response to a vaccine designed to counteract ricin toxin, a fast-acting biothreat agent.
- Published
- 2018
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26. Unveiling microbial activities along the halocline of Thetis, a deep-sea hypersaline anoxic basin.
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Pachiadaki MG, Yakimov MM, LaCono V, Leadbetter E, and Edgcomb V
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- Archaea classification, Archaea genetics, Archaea isolation & purification, Archaea metabolism, Bacteria classification, Bacteria genetics, Bacteria isolation & purification, Bacteria metabolism, Carbon Cycle, Ecosystem, Mediterranean Sea, Phylogeny, Salinity, Transcriptome, Seawater microbiology
- Abstract
Deep-sea hypersaline anoxic basins (DHABs) in the Eastern Mediterranean Sea are considered some of the most hostile environments on Earth. Little is known about the biochemical adaptations of microorganisms living in these habitats. This first metatranscriptome analysis of DHAB samples provides significant insights into shifts in metabolic activities of microorganisms as physicochemical conditions change from deep Mediterranean sea water to brine. The analysis of Thetis DHAB interface indicates that sulfate reduction occurs in both the upper (7.0-16.3% salinity) and lower (21.4-27.6%) halocline, but that expression of dissimilatory sulfate reductase is reduced in the more hypersaline lower halocline. High dark-carbon assimilation rates in the upper interface coincided with high abundance of transcripts for ribulose 1,5-bisphosphate carboxylase affiliated to sulfur-oxidizing bacteria. In the lower interface, increased expression of genes associated with methane metabolism and osmoregulation is noted. In addition, in this layer, nitrogenase transcripts affiliated to uncultivated putative methanotrophic archaea were detected, implying nitrogen fixation in this anoxic habitat, and providing evidence of linked carbon, nitrogen and sulfur cycles.
- Published
- 2014
- Full Text
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27. Invariant natural killer T (iNKT) cells prevent autoimmunity, but induce pulmonary inflammation in cystic fibrosis.
- Author
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Siegmann N, Worbs D, Effinger F, Bormann T, Gebhardt M, Ulrich M, Wermeling F, Müller-Hermelink E, Biedermann T, Tighe M, Edwards MJ, Caldwell C, Leadbetter E, Karlsson MC, Becker KA, Gulbins E, and Döring G
- Subjects
- Animals, Autoantibodies metabolism, Autoimmunity, B-Lymphocytes immunology, B-Lymphocytes metabolism, Cystic Fibrosis metabolism, Cystic Fibrosis pathology, Cystic Fibrosis Transmembrane Conductance Regulator deficiency, Cystic Fibrosis Transmembrane Conductance Regulator genetics, Cystic Fibrosis Transmembrane Conductance Regulator metabolism, Disease Models, Animal, Interleukin-17 metabolism, Killer Cells, Natural metabolism, Lung immunology, Lung metabolism, Mice, Mice, Inbred C57BL, Mice, Inbred CFTR, Pneumonia metabolism, Pneumonia pathology, Killer Cells, Natural immunology
- Abstract
Background/aims: Inflammation is a major and critical component of the lung pathology in the hereditary disease cystic fibrosis. The molecular mechanisms of chronic inflammation in cystic fibrosis require definition., Methods: We used several genetic mouse models to test a role of iNKT cells and ceramide in pulmonary inflammation of cystic fibrosis mice. Inflammation was determined by the pulmonary cytokine profil and the abundance of inflammatory cells in the lung., Results: Here we provide a new concept how inflammation in the lung of individuals with cystic fibrosis is initiated. We show that in cystic fibrosis mice the mutation in the Cftr gene provokes a significant up-regulation of iNKT cells in the lung. Accumulation of iNKT cells serves to control autoimmune disease, which is triggered by a ceramide-mediated induction of cell death in CF organs. Autoimmunity becomes in particular overt in cystic fibrosis mice lacking iNKT cells and although suppression of the autoimmune response by iNKT cells is beneficial, IL-17(+) iNKT cells attract macrophages and neutrophils to CF lungs resulting in chronic inflammation. Genetic deletion of iNKT cells in cystic fibrosis mice prevents inflammation in CF lungs., Conclusion: Our data demonstrate an important function of iNKT cells in the chronic inflammation affecting cystic fibrosis lungs. iNKT cells suppress the auto-immune response induced by ceramide-mediated death of epithelial cells in CF lungs, but also induce a chronic pulmonary inflammation.
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- 2014
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28. The Yin and Yang of inflammation.
- Author
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Blackman MA, Yates JL, Spencer CM, Vomhof-DeKrey EE, Cooper AM, and Leadbetter EA
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- Animals, Anti-Inflammatory Agents pharmacology, Anti-Inflammatory Agents therapeutic use, Disease Models, Animal, Humans, Inflammation drug therapy, Inflammation Mediators metabolism, Microbiota immunology, Inflammation metabolism
- Abstract
Inflammation is an essential protective part of the body's response to infection, yet many diseases are the product of inflammation. For example, inflammation can lead to autoimmune disease and tissue damage, and is a key element in chronic health conditions such as heart disease, diabetes, rheumatoid arthritis, and also drives changes associated with aging. Animal models of infectious and chronic disease are important tools with which to dissect the pathways whereby inflammatory responses are initiated and controlled. Animal models therefore provide a prism through which the role of inflammation in health and disease can be viewed, and are important means by which to dissect mechanisms and identify potential therapies to be tested in the clinic. A meeting, "The Yin and Yang of Inflammation" was organized by Trudeau Institute and was held between April 4-6, 2014. The main goal was to bring together experts from biotechnology and academic organizations to examine and describe critical pathways in inflammation and place these pathways within the context of human disease. A group of ~80 scientists met for three days of intense formal and informal exchanges. A key focus was to stimulate interactions between basic research and industry.
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- 2014
- Full Text
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29. Presence of the oral bacterium Capnocytophaga canimorsus in the tooth plaque of canines.
- Author
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Dilegge SK, Edgcomb VP, and Leadbetter ER
- Subjects
- Animals, Capnocytophaga classification, Capnocytophaga genetics, DNA, Bacterial genetics, Dogs, Female, Gram-Negative Bacterial Infections microbiology, Logistic Models, Male, Mouth microbiology, Phylogeny, Sequence Analysis, DNA, Capnocytophaga isolation & purification, Dental Plaque microbiology, Dog Diseases microbiology, Gram-Negative Bacterial Infections veterinary
- Abstract
Capnocytophaga canimorsus is a potentially pathogenic microorganism when transmitted to humans from the oral cavity of canines. Although there is some knowledge about the frequency of occurrence in canines, it is uncertain whether there is a correlation between its occurrence and lifestyle, health, or breed of dog. Samples of tooth plaque from a total of 131 canines were collected, cultured on selective media, and tested using physiological and molecular analyses to help discern the presence of C. canimorsus. Phylogenetic analyses determined that 49.2% of canines sampled carried a species of Capnocytophaga and 21.7% of the canines sampled in this study carried C. canimorsus. Statistical analyses found that male dogs and those that are neutered and spayed are more likely to host Capnocytophaga species. The data also suggested that breed was a statistically significant predictor of C. canimorsus, with the smaller breeds more likely to carry the potential pathogen. In addition, three "human" species of Capnocytophaga; C. ochracea, C. haemolytica, and one isolate of either C. gingivalis or C. granulosa were cultured from five canines. Sixteen canines sampled carried an unidentified Capnocytophaga species, with the sequences from all isolates forming a well-defined phylogenetic clade with 100% bootstrap support that may well represent a new species of Capnocytophaga., (Copyright © 2010 Elsevier B.V. All rights reserved.)
- Published
- 2011
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30. Visualizing the onset and evolution of an autoantibody response in systemic autoimmunity.
- Author
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William J, Euler C, Leadbetter E, Marshak-Rothstein A, and Shlomchik MJ
- Subjects
- Animals, Antibody-Producing Cells metabolism, Antibody-Producing Cells pathology, Antigen-Antibody Complex biosynthesis, Autoimmune Diseases genetics, Autoimmune Diseases pathology, B-Lymphocyte Subsets metabolism, B-Lymphocyte Subsets pathology, Disease Progression, Germinal Center cytology, Germinal Center immunology, Germinal Center metabolism, Immunoglobulin Allotypes biosynthesis, Immunoglobulin G biosynthesis, Immunoglobulin Light Chains biosynthesis, Immunoglobulin Variable Region biosynthesis, Kinetics, Lymphocyte Count, Mice, Mice, Inbred MRL lpr, Mice, Transgenic, Rheumatoid Factor blood, Rheumatoid Factor genetics, Spleen immunology, Spleen metabolism, Spleen pathology, Autoimmune Diseases immunology, B-Lymphocyte Subsets immunology, Evolution, Molecular, Rheumatoid Factor biosynthesis
- Abstract
The onset of systemic autoimmunity is variable, making it difficult to identify early events. In this study, we show in rheumatoid factor (RF) Ig-transgenic autoimmune-prone mice that the appearance of RF B cells in blood signifies the onset of RF B cell activation in spleen, providing a novel window into the initiation of an autoantibody response. This allowed us to study the early and late phases of spontaneous induction of the B cell autoimmune response. Using this approach we showed that extensive Ab-forming cell generation in spleen, accompanied by somatic hypermutation, occurred despite the lack of an early germinal center response. The onset of the RF response correlated with the levels of IgG2a-containing immune complexes but not total IgG2a. By identifying the time of onset in individual mice, we were able to track progression of disease. We found remissions of RF Ab-forming cell production in some mice, suggesting that at the clonal level, chronic autoantibody responses are dynamic and episodic, much like acute pathogen responses. Surprisingly, there was little accumulation of long-lived plasma cells in bone marrow of mice with long-standing RF responses in spleen. These studies are among the first to define the early events of a spontaneous B cell autoimmune response.
- Published
- 2005
- Full Text
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31. Immune complexes present in the sera of autoimmune mice activate rheumatoid factor B cells.
- Author
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Rifkin IR, Leadbetter EA, Beaudette BC, Kiani C, Monestier M, Shlomchik MJ, and Marshak-Rothstein A
- Subjects
- Animals, Antibodies, Monoclonal pharmacology, Antigen-Antibody Complex metabolism, B-Lymphocyte Subsets metabolism, Fas Ligand Protein, Haptens immunology, Histocompatibility Testing, Hot Temperature, Immune Sera pharmacology, Immunoglobulin Allotypes genetics, Immunoglobulin Allotypes physiology, Immunoglobulin G physiology, Lymphocyte Activation genetics, Membrane Glycoproteins deficiency, Membrane Glycoproteins genetics, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Mice, Inbred MRL lpr, Mice, Knockout, Mice, Transgenic, Nucleosomes immunology, Rheumatoid Factor biosynthesis, fas Receptor genetics, Antigen-Antibody Complex blood, Antigen-Antibody Complex physiology, Autoimmune Diseases blood, Autoimmune Diseases immunology, B-Lymphocyte Subsets immunology, Lymphocyte Activation immunology, Rheumatoid Factor metabolism
- Abstract
The fate of an autoreactive B cell is determined in part by the nature of the interaction of the B cell receptor with its autoantigen. In the lpr model of systemic autoimmunity, as well as in certain human diseases, autoreactive B cells expressing rheumatoid factor (RF) binding activity are prominent. A murine B cell transgenic model in which the B cell receptor is a RF that recognizes IgG2a of the j allotype (IgG2aj), but not the b allotype, was used in this study to investigate how the form of the autoantigen influences its ability to activate B cells. We found that sera from autoimmune mice, but not from nonautoimmune mice, were able to induce the proliferation of these RF+ B cells but did not stimulate B cells from RF- littermate controls. The stimulatory factor in serum was found to be IgG2aj, but the IgG2aj was stimulatory only when in the form of immune complexes. Monomeric IgG2aj failed to stimulate. Immune complexes containing lupus-associated nuclear and cytoplasmic autoantigens were particularly potent B cell activators in this system. Appropriate manipulation of such autoantibody/autoantigen complexes may eventually provide a means for therapeutic intervention in patients with certain systemic autoimmune disorders.
- Published
- 2000
- Full Text
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32. Sulfonates as terminal electron acceptors for growth of sulfite-reducing bacteria (Desulfitobacterium spp.) and sulfate-reducing bacteria: effects of inhibitors of sulfidogenesis.
- Author
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Lie TJ, Godchaux W, and Leadbetter ER
- Subjects
- Adenosine Triphosphate analysis, Anthraquinones pharmacology, Desulfovibrio metabolism, Ecology, Oxidation-Reduction, Tungsten Compounds pharmacology, Sulfates metabolism, Sulfites metabolism, Sulfonic Acids metabolism
- Abstract
This study demonstrates the ability of Desulfitobacterium spp. to utilize aliphatic sulfonates as terminal electron acceptors (TEA) for growth. Isethionate (2-hydroxyethanesulfonate) reduction by Desulfitobacterium hafniense resulted in acetate as well as sulfide accumulation in accordance with the expectation that the carbon portion of isethionate was oxidized to acetate and the sulfur was reduced to sulfide. The presence of a polypeptide, approximately 97 kDa, was evident in isethionate-grown cells of Desulfitobacterium hafniense, Desulfitobacterium sp. strain PCE 1, and the two sulfate-reducing bacteria (SRB)-Desulfovibrio desulfuricans IC1 (T. J. Lie, J. R. Leadbetter, and E. R. Leadbetter, Geomicrobiol. J. 15:135-149, 1998) and Desulfomicrobium norvegicum; this polypeptide was not detected when these bacteria were grown on TEA other than isethionate, suggesting involvement in its metabolism. The sulfate analogs molybdate and tungstate, effective in inhibiting sulfate reduction by SRB, were examined for their effects on sulfonate reduction. Molybdate effectively inhibited sulfonate reduction by strain IC1 and selectively inhibited isethionate (but not cysteate) reduction by Desulfitobacterium dehalogenans and Desulfitobacterium sp. strain PCE 1. Desulfitobacterium hafniense, however, grew with both isethionate and cysteate in the presence of molybdate. In contrast, tungstate only partially inhibited sulfonate reduction by both SRB and Desulfitobacterium spp. Similarly, another inhibitor of sulfate reduction, 1,8-dihydroxyanthraquinone, effectively inhibited sulfate reduction by SRB but only partially inhibited sulfonate reduction by both SRB and Desulfitobacterium hafniense.
- Published
- 1999
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33. Sulfidogenesis from 2-aminoethanesulfonate (taurine) fermentation by a morphologically unusual sulfate-reducing bacterium, Desulforhopalus singaporensis sp. nov.
- Author
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Lie TJ, Clawson ML, Godchaux W, and Leadbetter ER
- Subjects
- Bacteria genetics, Bacteria ultrastructure, Fermentation, Inclusion Bodies metabolism, Inclusion Bodies ultrastructure, Microscopy, Electron, Scanning, Molecular Sequence Data, Oxidation-Reduction, Phylogeny, RNA, Bacterial genetics, RNA, Ribosomal, 16S genetics, Sulfates metabolism, Terminology as Topic, Bacteria metabolism, Sulfides metabolism, Taurine metabolism
- Abstract
A pure culture of an obligately anaerobic marine bacterium was obtained from an anaerobic enrichment culture in which taurine (2-aminoethanesulfonate) was the sole source of carbon, energy, and nitrogen. Taurine fermentation resulted in acetate, ammonia, and sulfide as end products. Other sulfonates, including 2-hydroxyethanesulfonate (isethionate) and cysteate (alanine-3-sulfonate), were not fermented. When malate was the sole source of carbon and energy, the bacterium reduced sulfate, sulfite, thiosulfate, or nitrate (reduced to ammonia) but did not use fumarate or dimethyl sulfoxide as a terminal electron acceptor for growth. Taurine-grown cells had significantly lower adenylylphosphosulfate reductase activities than sulfate-grown cells had, which was consistent with the notion that sulfate was not released as a result of oxidative C-S bond cleavage and then assimilated. The name Desulforhopalus singaporensis is proposed for this sulfate-reducing bacterium, which is morphologically unusual compared to the previously described sulfate-reducing bacteria by virtue of the spinae present on the rod-shaped, gram-negative, nonmotile cells; endospore formation was not discerned, nor was desulfoviridin detected. Granules of poly-beta-hydroxybutyrate were abundant in taurine-grown cells. This organism shares with the other member of the genus Desulforhopalus which has been described a unique 13-base deletion in the 16S ribosomal DNA. It differs in several ways from a recently described endospore-forming anaerobe (K. Denger, H. Laue, and A. M. Cook, Arch. Microbiol. 168:297-301, 1997) that reportedly produces thiosulfate but not sulfide from taurine fermentation. D. singaporensis thus appears to be the first example of an organism which exhibits sulfidogenesis during taurine fermentation. Implications for sulfonate sulfur in the sulfur cycle are discussed.
- Published
- 1999
- Full Text
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34. Low-molecular-weight sulfonates, a major substrate for sulfate reducers in marine microbial mats.
- Author
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Visscher PT, Gritzer RF, and Leadbetter ER
- Subjects
- Cysteic Acid metabolism, Ecosystem, Kinetics, Marine Biology, Molecular Weight, Oxidation-Reduction, Seawater microbiology, Sulfates metabolism, Sulfides metabolism, Sulfonic Acids chemistry, Taurine metabolism, Sulfonic Acids metabolism, Water Microbiology, Water Pollutants, Chemical metabolism
- Abstract
Several low-molecular-weight sulfonates were added to microbial mat slurries to investigate their effects on sulfate reduction. Instantaneous production of sulfide occurred after taurine and cysteate were added to all of the microbial mats tested. The rates of production in the presence of taurine and cysteate were 35 and 24 microM HS(-) h(-1) in a stromatolite mat, 38 and 36 microM HS(-) h(-1) in a salt pond mat, and 27 and 18 microM HS(-) h(-1) in a salt marsh mat, respectively. The traditionally used substrates lactate and acetate stimulated the rate of sulfide production 3 to 10 times more than taurine and cysteate stimulated the rate of sulfide production in all mats, but when ethanol, glycolate, and glutamate were added to stromatolite mat slurries, the resulting increases were similar to the increases observed with taurine and cysteate. Isethionate, sulfosuccinate, and sulfobenzoate were tested only with the stromatolite mat slurry, and these compounds had much smaller effects on sulfide production. Addition of molybdate resulted in a greater inhibitory effect on acetate and lactate utilization than on sulfonate use, suggesting that different metabolic pathways were involved. In all of the mats tested taurine and cysteate were present in the pore water at nanomolar to micromolar concentrations. An enrichment culture from the stromatolite mat was obtained on cysteate in a medium lacking sulfate and incubated anaerobically. The rate of cysteate consumption by this enrichment culture was 1.6 pmol cell(-1) h(-1). Compared to the results of slurry studies, this rate suggests that organisms with properties similar to the properties of this enrichment culture are a major constituent of the sulfidogenic population. In addition, taurine was consumed at some of highest dilutions obtained from most-probable-number enrichment cultures obtained from stromatolite samples. Based on our comparison of the sulfide production rates found in various mats, low-molecular-weight sulfonates are important sources of C and S in these ecosystems.
- Published
- 1999
- Full Text
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35. Experimental autoimmune encephalomyelitis induced with a combination of myelin basic protein and myelin oligodendrocyte glycoprotein is ameliorated by administration of a single myelin basic protein peptide.
- Author
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Leadbetter EA, Bourque CR, Devaux B, Olson CD, Sunshine GH, Hirani S, Wallner BP, Smilek DE, and Happ MP
- Subjects
- Animals, Crosses, Genetic, Disease Models, Animal, Drug Combinations, Encephalomyelitis, Autoimmune, Experimental etiology, Female, Immunoglobulin G biosynthesis, Immunoglobulin G blood, Injections, Subcutaneous, Lymphocyte Activation, Mice, Mice, Inbred Strains, Myelin Proteins, Myelin-Oligodendrocyte Glycoprotein, Peptide Fragments administration & dosage, Peptide Fragments immunology, T-Lymphocytes immunology, Encephalomyelitis, Autoimmune, Experimental immunology, Encephalomyelitis, Autoimmune, Experimental therapy, Myelin Basic Protein immunology, Myelin-Associated Glycoprotein immunology, Peptide Fragments therapeutic use
- Abstract
Multiple sclerosis is an autoimmune disease of the central nervous system in which T cell reactivity to several myelin proteins, including myelin basic protein (MBP), proteolipid protein, and myelin oligodendrocyte glycoprotein (MOG), has been implicated in the perpetuation of the disease state. Experimental autoimmune encephalomyelitis (EAE) is used commonly as a model in which potential therapies for multiple sclerosis are evaluated. The ability of T cell epitope-containing peptides to down-regulate the disease course is well documented for both MBP- and proteolipid protein-induced EAE, and recently has been shown for MOG-induced EAE. In this study, we describe a novel EAE model, in which development of severe disease symptoms in (PL/J x SJL)F1 mice is dependent on reactivity to two different immunizing Ags, MBP and MOG. The disease is often fatal, with a relapsing/progressive course in survivors, and is more severe than would be predicted by immunization with either Ag alone. The MOG plus MBP disease can be treated postinduction with a combination of the MOG 41-60 peptide (identified as the major therapeutic MOG epitope for this strain) and the MBP Ac1-11[4Y] peptide. A significant treatment effect can also be obtained by administration of the MBP peptide alone, but this effect is strictly dose dependent. This MBP peptide does not treat the disease induced only with MOG. These results suggest that peptide immunotherapy can provide an effective means of mitigating disease in this model, even when the treatment is targeted to only one component epitope or one component protein Ag of a diverse autoimmune response.
- Published
- 1998
36. Taurine-sulfur assimilation and taurine-pyruvate aminotransferase activity in anaerobic bacteria.
- Author
-
Chien C, Leadbetter ER, and Godchaux W
- Abstract
We demonstrated the ability of strictly fermentative, as well as facultatively fermentative, bacteria to assimilate sulfonate sulfur for growth. Taurine (2-aminoethanesulfonate) can be utilized by Clostridium pasteurianum C1 but does not support fermentative growth of two Klebsiella spp. and two different Clostridium spp. However, the latter are able to assimilate the sulfur of a variety of other sulfonates (e.g., cysteate, 3-sulfopyruvate, and 3-sulfolactate) anaerobically. A novel taurine-pyruvate aminotransferase activity was detected in cell extracts of C. pasteurianum C1 grown with taurine as the sole sulfur source. This activity was not detected in extracts of other bacteria examined, in C. pasteurianum C1 grown with sulfate or sulfite as the sulfur source, or in a Klebsiella isolate assimilating taurine-sulfur by aerobic respiration. More common aminotransferase activities (e.g., with aspartate or glutamate as the amino donor and pyruvate, oxalacetate, or (alpha)-ketoglutarate as the amino acceptor) were present, no matter what sulfur source was used for growth. Partial characterization of the taurine-pyruvate aminotransferase revealed an optimal temperature of 37(deg)C and a broad optimal pH range of 7.5 to 9.5.
- Published
- 1997
- Full Text
- View/download PDF
37. Sulfonate-sulfur utilization involves a portion of the assimilatory sulfate reduction pathway in Escherichia coli.
- Author
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Uria-Nickelsen MR, Leadbetter ER, and Godchaux W 3rd
- Subjects
- Acetyltransferases genetics, Cysteine Synthase genetics, Escherichia coli genetics, Mutation, Oxidation-Reduction, Serine O-Acetyltransferase, Cysteine metabolism, Escherichia coli metabolism, Sulfates metabolism, Sulfonic Acids metabolism
- Abstract
Strains of Escherichia coli lacking serine transacetylase or a positive regulator (Cys B protein) of the assimilatory sulfate reduction (ASR) pathway were unable to assimilate sulfonate-S, while single mutants in O-acetyl-L-serine sulfhydrylase (either 'A' or 'B') were able to do so. Mutants unable to reduce sulfate to sulfite were nonetheless able to form and accumulate sulfide and then cysteine from sulfonates, while strains lacking sulfite reductase were not. Thus terminal portions of the ASR pathway are involved in reduction of sulfonate-S to that of cysteine. E. coli K-12 formed cysteine more slowly, and accumulated lesser amounts of it with sulfonate-sulfur than it did from either sulfate or sulfite. These observations are consistent with our earlier report that sulfate is the preferred sulfur source when present simultaneously with a sulfonate.
- Published
- 1994
- Full Text
- View/download PDF
38. Comparative aspects of utilization of sulfonate and other sulfur sources by Escherichia coli K12.
- Author
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Uria-Nickelsen MR, Leadbetter ER, and Godchaux W 3rd
- Subjects
- Cysteine pharmacology, Sulfates antagonists & inhibitors, Sulfonic Acids antagonists & inhibitors, Escherichia coli metabolism, Sulfates metabolism, Sulfonic Acids metabolism
- Abstract
Selected biochemical features of sulfonate assimilation in Escherichia coli K-12 were studied in detail. Competition between sulfonate-sulfur and sulfur sources with different oxidation states, such as cysteine, sulfite and sulfate, was examined. The ability of the enzyme sulfite reductase to attack the C-S linkage of sulfonates was directly examined. Intact cells formed sulfite from sulfonate-sulfur. In cysteine-grown cells, when cysteine was present with either cysteate or sulfate, assimilation of both of the more oxidized sulfur sources was substantially inhibited. In contrast, none of three sulfonates had a competitive effect on sulfate assimilation. In studies of competition between different sulfonates, the presence of taurine resulted in a decrease in cysteate uptake by one-half, while in the presence of isethionate, cysteate uptake was almost completely inhibited. In sulfite-grown cells, sulfonates had no competitive effect on sulfite utilization. An E. coli mutant lacking sulfite reductase and unable to utilize isethionate as the sole source of sulfur formed significant amounts of sulfite from isethionate. In cell extracts, sulfite reductase itself did not utilize sulfonate-sulfur as an electron acceptor. These findings indicate that sulfonate utilization may share some intermediates (e.g., sulfite) and regulatory features (repression by cysteine) of the assimilatory sulfate reductive pathway, but sulfonates do not exert regulatory effects on sulfate utilization. Other results suggest that unrecognized aspects of sulfonate metabolism, such as specific transport mechanisms for sulfonates and different regulatory features, may exist.
- Published
- 1994
- Full Text
- View/download PDF
39. 5 alpha-reduced progesterone metabolites are essential in hamster VTA for sexual receptivity.
- Author
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Frye CA and Leadbetter EA
- Subjects
- 5-alpha Reductase Inhibitors, Analysis of Variance, Animals, Azasteroids pharmacology, Cholesterol pharmacology, Cricetinae, Dihydrotestosterone analogs & derivatives, Dihydrotestosterone pharmacology, Estrus drug effects, Estrus physiology, Female, Mesocricetus, Progestins metabolism, Receptors, GABA metabolism, Sexual Behavior, Animal drug effects, Progesterone metabolism, Sexual Behavior, Animal physiology, Ventral Tegmental Area metabolism
- Abstract
Progesterone's (P) actions in the ventral medial hypothalamus (VMH) and the ventral tegmental area (VTA) are essential for sexual receptivity in hamsters. This study investigates the notion that P works in the VTA in the absence of intracellular P receptors (PRs) by 5 alpha-reduction to progestins, which would subsequently bind to membrane gamma-Aminobutyric Acid receptor complexes (GBRs). To test the importance of P metabolism, a 5 alpha-reductase inhibitor, 17 beta-N, N-diethylcarbamoyl-4-methyl-4aza-5 alpha-androstan-3-one (4MA) was administered SC (0, 3, 9, 15, 24, or 30 mg/kg) to ovx estradiol benzoate(EB)-primed hamsters, followed by one of six doses of SC P (0, 25, 50, 100, 200, or 500 micrograms) and sexual receptivity testing. 200 micrograms P-treated animals administered higher (24 and 30 mg/kg) doses of 4MA had significantly decreased total lordosis durations (TLDs) compared to 0 mg/kg 4MA controls (exp 1). In exp 2, 4MA was aimed bilaterally at the VTA prior to SC P. After 200 micrograms P, animals had significantly lower TLDs than after 500 micrograms P, 3 hours following bilateral VTA implantation of 4MA, but not cholesterol. In exp 3, cycling female hamsters were infused with 1.0 microgram 4MA or vehicle unilaterally into the VTA on diestrus, proestrus, and estrus. 4MA, but not vehicle, infusions into the VTA interrupted receptivity in estrus and proestrus animals, but had no effect on diestrus animals. 4MA's reduction of receptivity when given systemically and intracranially strongly supports the hypothesis that 5 alpha-reduced P metabolites, possibly interacting with GBRs in the VTA, are essential for sexual receptivity in hamsters.
- Published
- 1994
- Full Text
- View/download PDF
40. Sulfonate-sulfur assimilation by yeasts resembles that of bacteria.
- Author
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Uria-Nickelsen MR, Leadbetter ER, and Godchaux W 3rd
- Subjects
- Aerobiosis, Culture Media, Cysteic Acid metabolism, Cysteine metabolism, Isethionic Acid metabolism, Mutation, Taurine metabolism, Yeasts enzymology, Yeasts growth & development, Sulfur metabolism, Yeasts metabolism
- Abstract
Three sulfonates were tested for their ability to serve as nutrients for Hansenula wingei, Rhodotorula glutinis, Trigonopsis variabilis and Saccharomyces cerevisiae. Cysteate, taurine and isethionate, under aerobic conditions, could be utilized as sources of sulfur, although in some instances final cell yields were less than those obtained with an equimolar amount of sulfate-sulfur. Sulfonate assimilation by S. cerevisiae resembled that of bacteria (reported earlier by us) in several aspects: first, sulfate-S was used in preference to that of sulfonate, when both were present; second, mutants unable to use sulfate as a source of sulfur because of deficiencies in ATP sulfurylase, adenylylsulfate kinase (APS kinase) or PAPS reductase were able to utilize sulfonates; and third, mutants deficient in sulfite reductase were unable to utilize sulfonates.
- Published
- 1993
- Full Text
- View/download PDF
41. Sulphonate utilization by enteric bacteria.
- Author
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Uria-Nickelsen MR, Leadbetter ER, and Godchaux W 3rd
- Subjects
- Anaerobiosis, Culture Media, Cysteic Acid metabolism, Enterobacter growth & development, Enterobacter metabolism, Enterobacteriaceae growth & development, Escherichia coli growth & development, Escherichia coli metabolism, Isethionic Acid metabolism, Serratia marcescens growth & development, Serratia marcescens metabolism, Sulfates metabolism, Sulfites metabolism, Taurine metabolism, Enterobacteriaceae metabolism, Sulfonic Acids metabolism
- Abstract
A variety of sulphonates were tested for their ability to serve as nutrients for Escherichia coli, Enterobacter aerogenes and Serratia marcescens. Cysteate, taurine and isethionate could not serve as sole sources of carbon and energy but, under aerobic conditions, could be utilized as sources of sulphur. Both sulphate and sulphonate supported equivalent cell yields, but the generation times varied with the sulphonate being metabolized. The sulphonate-S of HEPES buffer, dodecane sulphonate and methane sulphonate was also utilized by some strains, whereas the sulphonate-S of taurocholate was not. None of the sulphonates tested served as a sulphur source for growth under anaerobic conditions. Sulphonate utilization appears to be a constitutive trait; surprisingly, however, cells of E. coli and Ent. aerogenes utilized sulphate-S in preference to that of sulphonate, when both were present. E. coli mutants unable to use sulphate as a source of sulphur because of deficiencies in sulphate permease, ATP sulphurylase, adenylylsulphate kinase (APS kinase) or glutaredoxin and thioredoxin were able to utilize sulphonates; hence sulphate is not an obligatory intermediate in sulphonate utilization. However, mutants deficient in sulphite reductase were unable to utilize sulphonates; therefore, this enzyme must be involved in sulphonate utilization, though it is not yet known whether it acts upon the sulphonates themselves or upon the inorganic sulphite derived from them.
- Published
- 1993
- Full Text
- View/download PDF
42. Temporal sequence of the recovery of traits during phenotypic curing of a Cytophaga johnsonae motility mutant.
- Author
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Gorski L, Leadbetter ER, and Godchaux W 3rd
- Subjects
- Adsorption, Bacteriophages drug effects, Bacteriophages genetics, Bacteriophages physiology, Cell Membrane physiology, Cell Movement genetics, Cysteic Acid pharmacology, Cytophaga cytology, Cytophaga drug effects, Cytophaga physiology, Kinetics, Membrane Lipids biosynthesis, Membrane Lipids physiology, Mutagenesis, Phenotype, Time Factors, Cytophaga genetics
- Abstract
The lack of cell translocation and the resulting formation of nonspreading colonies of mutants of the gram-negative gliding bacterium Cytophaga johnsonae have been correlated with the loss of cell surface features of the organism. These cell surface traits include the ability to move polystyrene-latex beads over the cell surface and the ability to be infected by bacteriophages that infect the parent strain. In order to assess whether these traits reflect structures or functions that actually play a role in gliding, we studied a mutant (21A2I) selected for its inability to form spreading colonies; it is deficient in sulfonolipid, lacks bead movement ability, and is resistant to at least one bacteriophage. The provision of cysteate (a specific sulfonolipid precursor) restores lipid content and gliding to the mutant; hence, the lipids are necessary for motility. Growth with cysteate also restores bead movement and phage sensitivity. In order to determine the temporal relationship of these traits, we undertook a kinetic study of the appearance of them after addition of cysteate to the mutant. One predicts that appearance of a trait essential for cell translocation will either precede or accompany the appearance of this ability, while a nonessential trait need not do so. Sulfonolipid synthesis was the only trait that appeared before gliding; this is consistent with its established importance for motility. Bead movement and phage sensitivity first appeared only after gliding started, suggesting that the machinery involved in those processes is not necessary, at least for the initiation of gliding.
- Published
- 1991
- Full Text
- View/download PDF
43. Defects in gliding motility in mutants of Cytophaga johnsonae lacking a high-molecular-weight cell surface polysaccharide.
- Author
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Godchaux W 3rd, Lynes MA, and Leadbetter ER
- Subjects
- Carbohydrates analysis, Cell Movement genetics, Chromatography, Gel, Cytophaga cytology, Cytophaga genetics, Electrophoresis, Polyacrylamide Gel, Gas Chromatography-Mass Spectrometry, Immune Sera, Molecular Weight, Polysaccharides, Bacterial isolation & purification, Cytophaga physiology, Mutation, Polysaccharides, Bacterial physiology
- Abstract
We previously observed (W. Godchaux, L. Gorski, and E.R. Leadbetter, J. Bacteriol. 172:1250-1255, 1990) that two mutants (strains 21 and NS-1) of the gliding bacterium Cytophaga johnsonae that were totally deficient in motility-dependent colony spreading, movement of rafts (groups) of cells as observed with a microscope, and movement of polystyrene-latex spheres that attached to the cell surface (observed in wet mounts) were also deficient in a high-molecular-weight cell surface polysaccharide (HMPS) and suggested a role for that substance in gliding motility. Antisera have been prepared against the purified HMPS, and these were used to select mutants specifically and highly deficient in the polysaccharide. All five such mutants had rates of colony spreading and raft movement that were much lower than those of the parent strain, but the rate of increase in colony diameter was higher than that found for strains NS-1 and 21 (which do not undergo raft movement at all). Unlike these latter two strains, the HMPS mutants retained the ability to move polystyrene-latex spheres over their surfaces. Hence, HMPS deficiency results in defective motility but not nonmotility, and the HMPS deficiency cannot fully explain the phenotype of mutants 21 and NS-1; in these strains, gliding must be affected by additional biochemical lesions. The HMPS may, nonetheless, be advantageous in that it supports greater gliding speeds.
- Published
- 1991
- Full Text
- View/download PDF
44. Outer membrane polysaccharide deficiency in two nongliding mutants of Cytophaga johnsonae.
- Author
-
Godchaux W 3rd, Gorski L, and Leadbetter ER
- Subjects
- Cell Fractionation, Cell Membrane ultrastructure, Chromatography, Gel, Electrophoresis, Polyacrylamide Gel, Molecular Weight, Polysaccharides, Bacterial isolation & purification, Cell Membrane analysis, Cytophaga genetics, Mutation, Polysaccharides, Bacterial genetics
- Abstract
Phenol-extractable polysaccharides firmly associated with the outer membrane of the gliding bacterium Cytophaga johnsonae could be resolved by gel filtration in sodium dodecyl sulfate (SDS) or by SDS-polyacrylamide gel electrophoresis into a high-molecular-weight (H) fraction (excluded by Sephadex G-200) and a low-molecular-weight (L) fraction. Fraction L was rich in components typical of lipid A and the core region of lipopolysaccharide (P, 3-hydroxy fatty acids, and 2-keto-3-deoxyoctonate) and evidently was a lipopolysaccharide with a limited number of distal, repeating polysaccharide units, as judged by SDS-polyacrylamide gel electrophoresis. In relation to total carbohydrate, the H fraction was rich in amino sugar but poor in (possibly devoid of) the lipid A and core components. Two nongliding mutants were highly deficient in the H fraction; one of these was deficient in sulfonolipid but could be cured by provision of a specific sulfonolipid precursor, a process that also resulted in the return of both the H fraction and gliding, as well as the ability to move polystyrene latex spheres over the cell surface. Hence, the polysaccharide may be the component that is directly involved in motility, and the presence of sulfonolipids in the outer membrane is necessary for the synthesis or accumulation of the polysaccharide. This conclusion was reinforced by the fact that the second nongliding, polysaccharide-deficient mutant had a normal sulfonolipid content.
- Published
- 1990
- Full Text
- View/download PDF
45. Capnocytophaga spp. contain sulfonolipids that are novel in procaryotes.
- Author
-
Godchaux W 3rd and Leadbetter ER
- Subjects
- Chromatography, Thin Layer, Mass Spectrometry, Spectrophotometry, Infrared, Alkanesulfonates analysis, Alkanesulfonic Acids, Bacteria analysis, Membrane Lipids analysis
- Abstract
A group of unusual sulfonolipids was found in bacteria of the genus Capnocytophaga. One of these lipids, to which we have assigned the trivial name capnine, was isolated in 98% pure form and was identified, by infrared absorption spectrometry, high-resolution mass spectrometry, and other methods, as 2-amino-3-hydroxy-15-methylhexadecane-1-sulfonic acid. Another lipid appears to be an N-acylated version of capnine; after acid hydrolysis, its sulfur was recovered in a form chromatographically indistinguishable from that of capnine. The new lipids are related structurally to sphingosine and the ceramides, respectively, but differ markedly from those compounds in important respects, notably the presence of the sulfonate group. Some Capnocytophaga strains accumulated mostly capnine, whereas others accumulated mostly N-acylcapnine. All seven strains examined were found to contain the new lipids, in amounts ranging from 7 to 16 mumol/g of cells (wet weight). The lipids were found in isolated cell envelopes, where they were present in amounts ranging up to 400 mg/g of envelope protein; they are, accordingly, major cell components.
- Published
- 1980
- Full Text
- View/download PDF
46. Biosynthesis of a sulfonolipid in gliding bacteria.
- Author
-
Abbanat DR, Godchaux W 3rd, Polychroniou G, and Leadbetter ER
- Subjects
- Alkanesulfonates metabolism, Cysteic Acid metabolism, Cystine metabolism, Mass Spectrometry, Serine metabolism, Alkanesulfonic Acids, Cytophaga metabolism, Lipids biosynthesis
- Abstract
Gliding bacteria of the genus Cytophaga synthesize sulfonolipids (1,2) that contain capnine (1-deoxy-15-methylhexadecasphinganine-1-sulfonic acid). Studies of the incorporation of radiolabeled compounds by C. johnsonae show that cysteate is utilized preferentially to both cystine and inorganic sulfate as a precursor of capnine sulfur and to both cystine and serine as a precursor of carbons 1 and 2 of capnine. The results are consistent with a pathway in which capnine is formed by condensation of cysteate with a fatty acyl CoA. Cystine, added as the sole sulfur source in the presence of glucose, provides the sulfur but not the carbon for capnine. Hence, these cells form cysteate not by direct oxidation of cystine (or cysteine), but by transfer of its sulfur to a different carbon compound.
- Published
- 1985
- Full Text
- View/download PDF
47. Cysteine is not an obligatory intermediate in the biosynthesis of cysteate by Cytophaga johnsonae.
- Author
-
Gilmore DF, Godchaux W 3rd, and Leadbetter ER
- Subjects
- Alkanesulfonates metabolism, Cytophaga genetics, Cytophaga growth & development, Sulfates metabolism, Sulfur metabolism, Alkanesulfonic Acids, Amino Acids, Sulfur biosynthesis, Cysteic Acid biosynthesis, Cysteine biosynthesis, Cytophaga metabolism
- Abstract
A cysteine auxotroph of Cytophaga johnsonae was able to incorporate sulfur from sulfate into cysteate, and thus into sulfonolipid, in the absence of cysteine synthesis. This indicates that cysteine is not an obligatory intermediate of the cysteate biosynthetic pathway even though cysteine sulfur can be utilized for cysteate synthesis.
- Published
- 1989
- Full Text
- View/download PDF
48. Unusual sulfonolipids are characteristic of the Cytophaga-Flexibacter group.
- Author
-
Godchaux W 3rd and Leadbetter ER
- Subjects
- Cytophaga analysis, Alkanesulfonates analysis, Cytophagaceae analysis, Lipids analysis
- Abstract
Capnocytophaga spp. contain a group of unusual sulfonolipids, called capnoids (W. Godchaux III and E. R. Leadbetter, J. Bacteriol. 144:592-602, 1980). One of these lipids, capnine, is 2-amino-3-hydroxy-15-methylhexadecane-1-sulfonic acid; the others are, apparently, N-acylated versions of capnine. The lipids were found, in amounts ranging from 2.5 to 16 mumol of capnoid sulfur per g of cells (wet weight), in two Cytophaga spp. and also in several closely related organisms: several Capnocytophaga spp., Sporocytophaga myxococcoides, two Flexibacter spp., and two Flavobacterium spp. With the exception of the flavobacteria, all of these bacteria have been shown to exhibit gliding motility. The two Flavobacterium spp. belong to a subset of that genus that shares many other characteristics with the cytophagas. Only the Capnocytophaga spp. contained large quantities of capnine as such; in all of the others, most (and possibly all) of the capnoids were present as N-acylcapnines. Capnoid-negative bacteria included some gliding organisms that may not be closely related to the cytophagas: two fruiting myxobacters, a gliding cyanobacterium (Plectonema sp.), Beggiatoa alba, Vitreoscilla stercoraria, Herpetosiphon aurantiacus, and Lysobacter enzymogenes. Nongliding bacteria representing nine genera were also tested, and all of these fell into the capnoid-negative group.
- Published
- 1983
- Full Text
- View/download PDF
49. Comparative ultrastructure of selected oral streptococci: thin-sectioning and freeze-etching studies.
- Author
-
Holt SC and Leadbetter ER
- Subjects
- Cell Membrane ultrastructure, Cell Wall ultrastructure, Freeze Etching, Humans, Inclusion Bodies ultrastructure, Species Specificity, Streptococcus mutans ultrastructure, Streptococcus sanguis ultrastructure, Mouth microbiology, Streptococcus ultrastructure
- Abstract
The ultrastructure of Streptococcus mutans, serotypes a-e, S. sanguis, S. mitis, and S. salivarius HHT, were examined by the techniques of thin-sectioning and freeze-etching. The cell walls varied in width between 15 and 46 nm and were covered with an electron-dense fibrillar or fuzz layer. The cytoplasmic membrane was in close association with numerous mesosomes which were, in turn, either closely associated or in contact with the bacterial chromosome. In freeze-etch replicas, the outermost layer of the cell wall was fibrous, and the cytoplasmic membrane was covered with particles composed of several subunits. Both particle-clusters and particle-free areas occurred on the surfaces of the cytoplasmic membrane, as well as a crystalline array in the ground plasm of the cell.
- Published
- 1976
- Full Text
- View/download PDF
50. Increase of ornithine amino lipid content in a sulfonolipid-deficient mutant of Cytophaga johnsonae.
- Author
-
Pitta TP, Leadbetter ER, and Godchaux W 3rd
- Subjects
- Cell Membrane metabolism, Cytophaga metabolism, Lipids isolation & purification, Cytophaga genetics, Lipid Metabolism, Lipids genetics, Mutation, Ornithine metabolism
- Abstract
The gram-negative gliding bacterium Cytophaga johnsonae contains not only large quantities of unusual sulfonolipids but also, as we report here, a second class of unusual lipids. These lipids were detected and quantified by two-dimensional thin-layer chromatography of lipids from cells grown in the presence of [14C]acetate and shown by chemical studies to be alpha-N-(3-fatty acyloxy fatty acyl)ornithines. Like the sulfonolipids, these ornithine lipids were localized in the outer membrane (whereas phosphatidylethanolamine was the predominant lipid of the inner membrane). In a sulfonolipid-deficient mutant, the missing lipid was replaced, specifically, by an increased amount of ornithine lipid. Cells grown in liquid media contained predominantly ornithine lipids with nonhydroxylated residues in the O-fatty acyl position. In contrast, surface-grown cells contained a high proportion of ornithine lipids in which the O-fatty acyl group was 3-hydroxylated. The sulfonolipids and ornithine lipids are apparently coregulated in the sense that, regardless of perturbations caused by mutation or growth conditions, their total amounts remain constant at 40% of total cell lipid.
- Published
- 1989
- Full Text
- View/download PDF
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