Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To identify molecular determinants of virulence, the proteins of Brucella abortus strains 2308 (virulent), S19 (vaccine) and lipopolysaccharide deficient rough mutants derived from each (RB51 and S19M3 respectively) were compared by 2-D gel electrophoresis. A total of 996 proteins were identified on autoradiographs of 2-D gels containing [35S]-labeled proteins from these four strains. Proteins differing qualitatively or quantitatively (greater than or equal to 10X) between 2308 and S19 are implicated in virulence and are identified by Mr and pI. Paired comparisons of proteins present in both 2308 and RB51 and missing in both S19 and M3 were used to make tentative identification of 14 putative virulence proteins representing primary expression of genetic differences between virulent and vaccine strains. 28 proteins and/or core lipopolysaccharide-protein complexes involved in the biosynthesis of lipopolysaccharide were identified by paired comparisons of proteins present in both smooth strains and missing in both rough strains.
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PMID:Virulence associated proteins of Brucella abortus identified by paired two-dimensional gel electrophoretic comparisons of virulent, vaccine and LPS deficient strains. 159 62

Clinical isolates of Escherichia hermannii which showed serological cross-reaction with polyclonal antisera to the O-polysaccharide portion of the lipopolysaccharide of E. coli O157 strains and with antisera to the O antigens of Brucella abortus and B. melitensis were found by chemical and nuclear magnetic resonance analyses to have lipopolysaccharide O chains composed of linear polymers containing 1,2- and 1,3-linked 4-acetamido-4,6-dideoxy-alpha-D-mannopyranosyl (alpha-D-Rhap4NAc) residues. Two O-antigen structures were identified; each had an unbranched pentasaccharide repeating unit, and one was composed of three 1,2- and two 1,3-linked alpha-D-Rhap4NAc residues and the other had two 1,2- and three 1,3-linked alpha-D-Rhap4NAc residues. The above-described cross-serological reactivities, which have led to false-positive identifications, are related to the common occurrence of epitopes involving the presence of N-acyl derivatives of 4-amino-4,6-dideoxy-D-mannopyranosyl residues in the O-polysaccharide portions of the respective lipopolysaccharides of the organisms. Strains of E. hermannii which did not show serological cross-reactions with E. coli O157 and Brucella antisera were found to have unique lipopolysaccharide O chains devoid of D-Rhap4NAc residues, demonstrating the existence of serotypes of E. hermannii that are distinct on the basis of their lipopolysaccharide components.
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PMID:Antigenic relationships of the lipopolysaccharides of Escherichia hermannii strains with those of Escherichia coli O157:H7, Brucella melitensis, and Brucella abortus. 169 Nov 46

A panel of monoclonal antibodies (MAbs) to seven Brucella outer membrane proteins were characterized. These antibodies were obtained by immunizing mice with sodium dodecyl sulfate-insoluble (SDS-I) fractions, cell walls, or whole bacterial cells of Brucella abortus or B. melitensis. Enzyme-linked immunosorbent assays were used to screen the hybridoma supernatants and to determine their binding at the surface of rough and smooth B. abortus and B. melitensis cells. The outer membrane proteins (OMPs) recognized by these antibodies were the proteins with molecular masses of 25 to 27 kDa and 36 to 38 kDa (porin) (major proteins) and the proteins with molecular masses of 10, 16.5, 19, 31 to 34, and 89 kDa (minor proteins). Surface exposure of these OMPs was visualized by electron microscopy by using the MAbs and immunogold labeling. Binding of the MAbs on whole rough bacterial cells indicates that the 10-, 16.5-, 19-, 25- to 27-, 31- to 34-, 36- to 38-, and 89-kDa OMPs are exposed at the cell surface. However, enzyme-linked immunosorbent assay results indicate a much better binding of the anti-OMP MAbs on rough strains than on the corresponding smooth strains except for the anti-19-kDa MAb. Immunoelectron microscopy showed that on smooth B. abortus cells only the 89- and 31- to 34-kDa OMPs were not accessible to the MAbs tested. Binding of the anti-31- to 34-kDa MAb at the cell surface was observed for the rough B. abortus cells and for the rough and smooth B. melitensis cells. These results indicate the importance of steric hindrance due to the presence of the long lipopolysaccharide O side chains in the accessibility of OMPs on smooth Brucella strains and should be considered when undertaking vaccine development.
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PMID:Identification of seven surface-exposed Brucella outer membrane proteins by use of monoclonal antibodies: immunogold labeling for electron microscopy and enzyme-linked immunosorbent assay. 170 17

The immunosuppressive effects of prodigiosin 25-C were studied in comparison with FK506. Both prodigiosin 25-C and FK506 suppressed T cell proliferation in response to concanavalin A (con A) or phytohemagglutinin (PHA) more significantly than that to lipopolysaccharide. However, prodigiosin 25-C inhibited con A-mediated mitogenic response more strongly than PHA-mediated one. FK506 showed no selectivity among those responses. In addition, when higher concentration of con A was used an inhibitory effect of prodigiosin 25-C became more evident whereas that of FK506 became less evident. Furthermore, prodigiosin 25-C affected neither interleukin-2 (IL-2) production nor IL-2 receptor (IL-2R) and transferrin receptor (TF-R) expression in vitro, though FK506 extensively inhibited IL-2 production and significantly suppressed IL-2R and TF-R expression. When comparing the effects of prodigiosin 25-C and FK506 in vivo by injecting antigens of different nature to a mouse, prodigiosin 25-C selectively inhibited cytotoxic T lymphocyte (CTL) activity induced by an allogenic mastocytoma, P815, without affecting production of antibody against a thymus dependent (TD) antigen, sheep red blood cell (SRBC). On the contrary, FK506 significantly inhibited both CTL induction and the antibody production. When Brucella abortus, a thymus independent (TI) antigen, and SRBC were simultaneously challenged to a mouse, neither prodigiosin 25-C nor FK506 affected antibody production against the TI antigen while the effect on the TD antigen were the same as described above. The present results revealed the unique immunosuppressive property of prodigiosin 25-C which was different from that of FK506.
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PMID:Selective immunosuppression of prodigiosin 25-C and FK506 in the murine immune system. 170 65

We have previously reported that chronic exposure of rats to cigarette smoke inhibits the antibody-forming cell (AFC) response to both T-dependent and T-independent antigens and may reflect B cell dysfunction. In this communication we extend these studies to show that T cell functions are normal in chronically smoke-exposed rats (SM) as judged by their responses to mitogens and "nominal" or alloantigens. While B cells from SM respond significantly to the B cell mitogen lipopolysaccharide (LPS), they fail to proliferate in response to anti-IgM (anti-mu) or to produce significant AFC response to sheep red blood cells. On the basis of the number of rosettes formed with trinitrophenylated (TNP) horse red blood cells; the frequency of TNP-binding cells (TNP-ABC) in the spleens of SM is comparable to sham control rats. However, the proliferation of TNP-ABC to TNP-Brucella abortus is significantly decreased in SM. These differences in SM B cell responses, i.e., between LPS and anti-mu/antigen, may to be related to the ability of LPS to bypass a portion of the membrane signal transduction cascade. These results suggest that cigarette smoke affects an early step(s) in the antigen-dependent B cell signal transduction pathway.
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PMID:Effects of cigarette smoke on the immune response. II. Chronic exposure to cigarette smoke inhibits surface immunoglobulin-mediated responses in B cells. 174 27

Fetuses of goats in their last trimester of pregnancy were experimentally infected with Brucella abortus strain RB51, a stable rough mutant deficient in the perosamine O-chain content of its lipopolysaccharide. RB51 maintained its rough phenotype in vivo and did not induce abortion. Infection with RB51 resulted in the production of significant levels of IgG type antibodies specific for B abortus cellular antigens distinct from the perosamine O-chain. These findings suggest that strain RB51 will be useful in the pregnant goat for studying the role of brucella antigens other than the lipopolysaccharide O-chain in the immune response to brucellosis.
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PMID:Experimental infection of goat fetuses in utero with a stable, rough mutant of Brucella abortus. 178 75

In view of its unique ability to stimulate human B cells, we have considered using Brucella abortus (BA) as a carrier for human vaccines. Recently we showed that HIV-1 coupled to BA, but not unconjugated HIV-1, was able to stimulate murine responses even in the relative absence of CD4+ T cells. This result suggested that HIV-BA may be useful in boosting the immunity of individuals infected with HIV-1 and who have impaired CD4+ T cell function. In order to refine this carrier we purified lipopolysaccharide (LPS) from BA and examined its effects on immune responses. Similar to LPS from E. coli (LPS-EC), LPS-BA was capable of stimulating mouse B cells to proliferate. In addition, LPS-BA could activate mouse spleen cells to secrete antibodies in vitro. Isotype analysis revealed that IgM and all the IgG subclasses were elicited. When comparing these responses to those of LPS-EC, LPS-BA induced a greater percentage of IgG2a and LPS-EC evoked more IgG3. IgG2a is probably important in protection against murine viral infection. LPS-BA was haptenated with trinitrophenol TNP-LPS (BA) and tested for carrier effect. Similar to TNP-BA and TNP-LPS (EC), TNP-LPS (BA) triggered anti-TNP antibody of the IgM and all IgG subclasses. In contrast, TNP-ficoll induced mainly IgM and only small amounts of IgG3. These results suggest that LPS-BA, like intact BA, behaves as a T-independent type 1 carrier, and as such may be advantageous as a carrier for human vaccines development.
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PMID:Immunogenicity of lipopolysaccharide derived from Brucella abortus: potential as a carrier in development of vaccines for AIDS. 180 68

A study was conducted to determine the immune (increased antibody) and protective (reduced colony-forming units) responses induced in mice by a: (i) single vaccinal inoculation, using various concentrations of Brucella cell surface protein (BCSP) or lipopolysaccharide (LPS); (ii) primary inoculation, using various concentrations of BCSP, followed by a secondary inoculation, using a standard concentration of BCSP; and (iii) primary inoculation, using 1 concentration of BCSP or LPS, followed by a secondary inoculation, using various concentrations of BCSP or LPS. Four weeks after the primary inoculation, mice were challenge exposed with approximately 1 x 10(4) colony-forming units of Brucella abortus strain 2308 and all mice were euthanatized at 6 weeks. Reduced splenic weights and reduced colony-forming units in the spleens of vaccinated mice, compared with nonvaccinated mice, were the criteria of protection. Increase in serum IgM and IgG was defined as immunity. Both BCSP and LPS induced protective and immune responses that were proportional to the dose given up to an optimal limit. However, concentrations higher than optimal decreased the protective and immune responses. This was true for mice given either 1 or 2 vaccinal inoculations. Enhanced secondary protective responses were seen only when suboptimal doses were used in the primary inoculation. Excessive or optimal doses in the secondary inoculations prevented or obscured the protectiveness and immunity by primary inoculations. The protective effects appeared to be additive when suboptimal doses were used in the primary and secondary inoculations.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Establishment of dose-response relationships in BALB/c mice, using Brucella cell surface protein and lipopolysaccharide. 190 65

A study was conducted to determine whether the protection induced in mice by a primary inoculation of lipopolysaccharide from Brucella abortus would be enhanced by a second inoculation given at different time intervals. Protection was challenged by exposure of the mice to a virulent culture of B. abortus strain 2308. Reduced mean viable count and/or splenic weights were the criteria of protection. There was no significant difference (P greater than 0.05) in the protective responses among mice given a single inoculation. Vaccinated mice were significantly (P less than 0.05) better protected than were nonvaccinated mice. Mice given vaccinal inoculations simultaneous with challenge exposure were less protected (P less than 0.001) than were mice vaccinated prior to challenge, but were better protected (P less than 0.010) than were nonvaccinated mice.
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PMID:Unresponsiveness of vaccinated BALB/c mice to a second inoculation of lipopolysaccharide from Brucella abortus strain 2308. 190 10

A rifampin-resistant mutant of Brucella abortus, designated RB51, was derived by repeated passage of strain 2308 on Trypticase soy supplemented with 1.5% agar and varying concentrations rifampin or penicillin. The RB51 colonies absorbed crystal violet and RB51 cell suspensions autoagglutinated, indicating a rough type colonial morphology for this strain. No O-chain component was detected in lipopolysaccharide (LPS) extracted from RB51 on SDS-PAGE gels stained with silver. Western blot analysis with the monoclonal antibody BRU 38, which is specific for the perosamine homopolymer O-chain of smooth Brucella LPS, indicated that the LPS of RB51 is highly deficient in O-chain when compared with the parenteral smooth strain 2308 or rough strain 45/20. Biochemically, RB51 resembles parental strain 2308 in its ability to utilize erythritol. Intraperitoneal inoculation of RB51 into mice results in a splenic colonization which is cleared within four weeks post infection. RB51 does not revert to smooth colony morphology upon passage in vivo (mice) or in vitro. Mice infected with RB51 produce antibodies against B. abortus antigens including class 2 and 3 outer membrane proteins but not against the O-chain. Furthermore, rabbits, goats and cattle hyperimmunized with sonicates of RB51 develop antibodies to B. abortus cellular antigens but do not develop antibodies specific for the O-chain. Immunization of mice with 1 x 10(8) viable RB51 organisms confers significant protection against challenge with virulent B. abortus strain 2308.
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PMID:Biological properties of RB51; a stable rough strain of Brucella abortus. 190 58


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