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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It was initially reported that lipopolysaccharide (LPS)-unresponsive C3H/HeJ mice are refractory to LPS at the B-lymphocyte level, but more recently it has been shown that other cells are similarly unaffected. The current study was undertaken to study an in vivo LPS-modulated disease process involving macrophage-T cell interactions. Adult CBA/J and C3H/HeJ mice were used as spleen donors, and graft versus host reactions were induced in BALB/c neonates. Prior LPS treatment of CBA/J adults decreased the ability of their spleen cells to cause fatal graft versus host disease in BALB/c neonates, whereas no difference was found between injection of spleen cells from normal or LPS-treated C3H/HeJ mice. Similar results were obtained with these cell types when the mouse spleen mixed leukocyte culture system was used. In a carbon clearance assay for stimulation of the reticuloendothelial system with LPS, it was found that the rate of phagocytosis was significantly increased in BALB/c and CBA/J mice 72 h after inoculation of LPS. No stimulation was seen in rate of carbon uptake in the C3H/HeJ animals after treatment with phenol-extracted LPS or with butanol-extracted LPS. An LPS-induced protective serum factor was produced only in the LPS-responsive CBA/J mice and was specific for the syngeneic cells.
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PMID:Influence of lipopolysaccharide on graft versus host reactivity of lipopolysaccharide-unresponsive C3H/HeJ mice. 4 Aug 77

Interferon production stimulated by the active substance (neutral fraction) of the capsular polysaccharide of Klebsiella pneumoniae (neutral CPS-K) in BCG-infected mice was compared with that by bacterial lipopolysaccharide (LPS). Prior infection with BCG increased the responsiveness of mice to the lethal effect of neutral CPS-K as well as to that of LPS. Associated with this, BCG-infected mice showed a markedly enhanced ability to produce interferon after stimulation not only by LPS but also by neutral CPS-K. In addition, a cytotoxic factor (cytotoxin) was found to be released in the serum of BCG-infected mice after injection of these inducers. The kinetics of production of interferon and cytotoxin stimulated by neutral CPS-K were very similar to those stimulated by LPS. The time pattern of cytotoxin production was not in parallel with that of interferon production. Interferon reached a peak 2 hr and cytotoxin 3 hr after injection with these inducers. Interferon and cytotoxin produced by neutral CPS-K showed essentially the same stabilities to heating at 56 C and to treatment at pH 2 respectively as those produced by LPS. Interferon was inactivated by heating at 56 C more rapidly than cytotoxin. Cytotoxin was inactivated by treatment at pH 2 for 24 hr, whereas interferon activity was well preserved after this treatment. These results suggest that both activities are the result of different substances.
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PMID:Interferon and cytotoxic factor (cytotoxin) released in the blood of mice infected with Mycobacterium bovis BCG. I. Enhanced production of interferon and appearance of cytotoxin stimulated by capsular polysaccharide of Klebsiella pneumoniae or bacterial lipopolysaccharide. 4 Nov 63

Pili from Bacteroides nodosus were purified to greater than 99% homogeneity by precipitation at pH 4.0 and in MgCl2 followed by chromatography on BioGel A150. The pili were composed entirely of one type of polypeptide subunit, pilin. No carbohydrates, nucleic acid, lipid, lipopolysaccharide or phosphate could be detected in purified pili preparations. The molecular weight of pilin from B. nodosus strains 91B and 198 was 18,400 and from strain 80 was 19,300. The isoelectric points of pili from B. nodosus strains 91B and 80 were both 4.5. The buoyant densities of pili from strains 91B, 80 and 198 were 1.287, 1.284 and 1.286 g ml-1, respectively. The three strains of B. nodosus did not cross-react in K-agglutination tests and produced pili which did not cross-react in immunodiffusion tests. Antiserum to highly purified pili caused a characteristic K-type agglutination reaction. It was concluded that pili are the K-agglutinogen.
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PMID:Purification of pili from Bacteroides nodosus and an examination of their chemical, physical and serological properties. 4 54

Major surface antigens of Bactmbrane complex by gentle methods, purified, and characterized immunochemically. A lipopolysaccharide (LPS) was found to be chemically distinct from the LPS of facultative gram-negative bacteria in that it lacked two core sugars, 2-keto-3-deoxyoctonate and heptose, as well as beta-hydroxymyristic acid, the predominant fatty acid in the lipid A moiety. The LPS was further atypical in that it had a very low level of biologic activity. A capsular polysaccharide was demonstrated morphologically by electron microscopy with ruthenium red staining and a ferritin-labeled antibody technique. This antigen was shown to be subspecies-specific by indirect immunofluorescence. Antibody to the capsular polysaccharide was measured by an enzyme-linked immunospecific assay. The presence of a relatively impotent LPS and a surface capsular antigen may partly explain the rarity of bacteremia and septic shock due to B. melaninogenicus subspecies asaccharolyticus and the common association of this organism with abscess formation.
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PMID:Immunochemical characterization of surface antigens of Bacteroides melaninogenicus. 4 22

Recent taxonomic and anatomical studies of dental plaque associated with periodontal health and disease have demonstrated that differences in the microbial populations in plaque may be responsible for the initiation and progression of disease. The consistent isolation of large numbers of anaerobic and capnophilic bacteria from the depths of periodontal lesions has suggested an important role for these organisms. Bacteria that have been isolated include Capnocytophaga (Bacteroides ochraceus), other species of Bacteroides, Fusobacterium, Selenomonas, spirochetes, Campylobacter, Veillonella, Actinomyces, Propionibacterium, Peptococcus, and other genera. The periodontopathic potential of oral strains of Bacteroides melaninogenicus has been explored in a number of investigations because these organisms are consistently isolated from periodontal lesions. Studies of B. melaninogenicus have included purification of a capsular substance, characterization of the lipopolysaccharide and a variety of toxic substances and lytic enzymes, and ecologic aspects of its colonization. Understanding of the nature and pathogenic mechanisms of the oral microbiota may lead to control of this pandemic infection.
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PMID:The role of Bacteroides melaninogenicus and other anaerobes in periodontal infections. 4 23

B lymphocyte function was assessed in outbred nude mice and nu/+controls infected with Trypanosoma brucei brucei. On day 10 of the infection in outbred nu/nu mice in which the initial wave of parasites was strongly controlled, B cell function was unaltered on enhanced compared with uninfected animals or infected nu/+. In other nu/nu mice unable to control the initial parasitaemia, thymidine incorporation and Ig secretion by spleen cells were increased on day 10 and their response to lipopolysaccharide in vitro negated. By day 15 however, even the spleen cells of infected nu/nu which controlled the initial wave of parasites were proliferating and secreting Ig on removal from the mice and they were unable to respond to LPS in vitro. These experiments confirm results of a previous study of B cell function in T cell-depleted mice (Askonas et al. 1979). T. b. brucei infection of mice causes both enhanced Ig production and suppression of the ability of B cells to respond to mitogen even in the absence of T cells, but the presence of T cells may accelerate the changes which occur in B lymphocytes following this infection.
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PMID:Trypanosoma brucei infection in nude mice: B lymphocyte function is suppressed in the absence of T lymphocytes. 4 25

The fine structure of lipopolysaccharide isolated from Thermoplasma acidophilum was examined by electron microscopy. Negative staining of the lipopolysaccharide revealed long, ribbon-like structures with some branching. The average width of the lipopolysaccharide ribbons was 5 nm. Treatment of the lipopolysaccharide with 0.5% sodium dodecyl sulfate resulted in the dissociation of the ribbon-like structures to spherical- and vesicular-shaped particles and some short, rodlike structures. Results suggest that the lipopolysaccharide from T. acidophilum is morphologically similar to lipopolysaccharide isolated from gram-negative bacteria.
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PMID:Ultrastructure of lipopolysaccharide isolated from Thermoplasma acidophilum. 4 26

Bacterial lipopolysaccharide (LPS) was demonstrated to have the capacity in mice to enhance the response to soluble bovine serum albumin (BSA) and to interfere with the induction of tolerance to human gamma-globulin (HGG). These adjuvant activities were shown to occur under conditions in which LPS could also function as a B cell mitogen. This positive correlation was established by utilizing two experimental situations in which LPS was non-mitogenic for spleen cells. Thus, on the one hand, it was found that LPS did not function as an adjuvant in C3H/HeJ mice, a unique strain whose spleen cells were also unresponsive to LPS-induced mitogenesis. On the other hand, in strains which did respond to LPS mitogenically, LPS failed to function as an adjuvant when it was chemically altered to reduce its in vitro mitogenic activity. A correlation was also observed between mitogenesis and the capacity of LPS to function as a specific immunogen i mice. In contrast to the sustained and prolonged plaque-forming cell response that was observed in mice whose spleen cells were also responsive to LPS-induced mitogenesis, the response was relatively transient in the C3H/HeJ strain. These results are discussed in view of the possible in vivo modes of action of LPS.
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PMID:Immunologic properties of bacterial lipopolysaccharide (LPS): correlation between the mitogenic, adjuvant, and immunogenic activities. 4 49

Sensitivity to actinomycin D(AD) varies in Pseudomonas fluorescens cells grown in glucose or succinate minimal salts medium. Growth is inhibited in succinate minimal medium by much lower concentrations of AD than in glucose minimal medium. Uptake of selected radioactive metabolites is inhibited by AD in cells incubated for 2 h in succinate medium containing AD but glucose-grown cells were not sensitive. EDTA treatment promotes increased sensitivity to AD in succinate-grown cells but does not alter sensitivity in glucose-grown cells. Succinate-grown cells bound 2-3 times as much 3H-AD as glucose-grown cells. Glucose-grown cells had much higher lipopolysaccharide levels in the envelope than succinate-grown cells. It is proposed that the lipopolysaccharide masks the binding sites and, therefore, is responsible for the difference in binding of AD by the glucose- and succinate-grown cells. The availability of the binding sites is also reflected in the sensitivity of the cells to the antibiotic.
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PMID:Effect of carbon source during growth on sensitivity of Pseudomonas fluorescens to actinomycin D. 4 73

It has been reported previously that enriched populations of mouse thymus-dependent (T) lymphocytes could be prepared by the use of a column procedure that is believed to remove selectively cells with receptors for antigen-antibody complexes. In our hands, this procedure does not selectively remove B lymphocytes but rather masks the surface immunoglobulin. Analysis of the column-passed cells revealed an apparent decrease in the percentage of immunoglobulin-bearing cells but little decrease in either the percentage of complement receptor lymphocytes or the mitogenic response to lipopolysaccharide. Furthermore, rabbit immunoglobulin could be detected on the surface of 35 to 45% of the cells emerging from the columns prepared with rabbit anti-human gamma-globulin (HGG). After overnight incubation, 30 to 40% of the emerging cells reexpressed mouse immunoglobulin on their surfaces. Adsorption of the antisera used to make the columns with mouse gamma-globulin (MGG) diminished the depleting capacity of the columns. We conclude from these observations that antibodies in the anti-HGG sera, cross-reactive with mouse immunoglobulin, account for the spacious depletion of B lymphocytes observed when cells are passed over these antigen-antibody complex columns.
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PMID:Lack of B lymphocyte depletion from murine spleen cell populations by a human gamma-globulin, anti-human gamma-globulin column system. 4 52


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