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)

A panel of monoclonal antibodies (MAb) has been raised against Brucella abortus cell surface antigens from mice immunized with either heat/phenol treated or UV killed bacterial suspensions of B. abortus. The hybridomas were screened by either a microagglutination procedure or by an indirect enzyme immunoassay (EIA) on sonicated bacterial preparations. From a large number of MAb generated by various procedures, two distinct types of MAb emerged. The most numerous type was capable of agglutinating B. abortus and reacting with a soluble preparation of lipopolysaccharide (LPS). A second type was not capable of agglutinating the bacterial suspensions or of binding to the soluble LPS preparation but reacted with an antigen present in bacterial sonicates. Two MAb of this type react differentially with sonicates prepared from virulent and avirulent strains of B. abortus. There appeared to be sufficient evidence from our analysis of the relative degree of cross reaction with antigens present on a range of B. abortus strains and Brucella and xenogenic bacterial species to conclude that each of the seven MAb was recognising a separate antigenic site on the B. abortus cell surface.
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PMID:Monoclonal antibodies directed against Brucella abortus cell surface antigens. 258 58

When preparations containing smooth Brucella abortus lipopolysaccharide (LPS) were used as antigen in an ELISA, strong positive reactions were obtained with sera from sheep infected with Brucella melitensis or with Brucella ovis. Oxidation of the LPS with sodium metaperiodate greatly reduced the extent of the cross-reactions with antisera to B. ovis, with little effect on the reactions with antisera to smooth B. melitensis. Periodate oxidation of hot saline extract (HSX) antigen of B. ovis markedly reduced its reactivity in ELISA with anti-B. ovis sera and eliminated cross-reactivity with anti-B. melitensis sera. The reactivity of HSX was maintained after treatment with proteinase K. A simple ELISA system, in which replicate samples from a single serum dilution were tested in parallel against both B. ovis HSX antigen and periodate-oxidised smooth phase B. abortus LPS, was evaluated. It was found to discriminate well between antibodies induced by vaccination or virulent infection with B. melitensis strains and those induced by infection with B. ovis.
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PMID:Discrimination between sheep antibodies to Brucella melitensis and to Brucella ovis. 280 Mar 7

A single vaccination of mice with a complex of porin and smooth lipopolysaccharide (porin-S-LPS) extracted from virulent Brucella abortus 2308 provided significant protection (P less than 0.01 to P less than 0.001) against challenge with the same strain, equivalent to that achieved by vaccination with living attenuated B. abortus 19. The porin-S-LPS vaccine given without adjuvant or in several adjuvants (trehalose dimycolate and muramyl dipeptide; the pluronic polymer L-121 and muramyl dipeptide; or complexed with Quil A in immunostimulating complexes) provided equivalent protection. In contrast, one vaccination with porin complexed with rough LPS (porin-R-LPS) from a rough mutant of strain 2308 provided no protection with any adjuvant tested. In one experiment, two inoculations with the porin-R-LPS resulted in a low level of protection, probably owing to priming of the animals for production of O-polysaccharide-specific antibodies. However, one vaccination with rough-strain porin covalently bound to purified O polysaccharide conferred protection equal to that obtained with natural complexes of porin-S-LPS or with living strain 19. A synthetic vaccine containing long chains of O polysaccharide was more effective than one prepared with short chains. Protective vaccines caused the formation of increased concentrations of circulating O-polysaccharide-specific antibodies, although there were individual exceptions to the quantitative association between O-polysaccharide-specific antibodies and protection. Antibodies specific for porin or R-LPS were found in negligible quantities in vaccinated mice. These results provide additional evidence that the O polysaccharide will constitute an essential component of an effective subcellular vaccine against B. abortus and that O-polysaccharide-specific antibodies play an important role in protective immunity in brucellosis.
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PMID:Effectiveness of natural and synthetic complexes of porin and O polysaccharide as vaccines against Brucella abortus in mice. 284 73

The phenol-phase soluble lipopolysaccharide isolated from Escherichia coli 0:157 by the hot phenol-water extraction procedure was shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, periodate oxidation, methylation, and 13C and 1H nuclear magnetic resonance studies to be an unbranched linear polysaccharide with a tetrasaccharide repeating unit having the structure: (formula; see text) The serological cross-reactivity of E. coli 0:157 with Brucella abortus, Yersinia enterocolitica (serotype 0:9), group N Salmonella, and some other E. coli species can be related immunochemically to the presence of 1,2-glycosylated N-acylated 4-amino-4, 6-dideoxy-alpha-D-mannopyranosyl residues in the O-chains of their respective lipopolysaccharides.
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PMID:Structure of the O-chain polysaccharide of the phenol-phase soluble lipopolysaccharide of Escherichia coli 0:157:H7. 300 86

These studies addressed the question of whether the Lyb-5 determinant on mouse B cells might represent a marker for a unique lineage of B cells as has been thought, or rather, a differentiation antigen. Previous studies have addressed this question by treating splenic B cells with anti-Lyb-5 + complement and then culturing them with various antigens. In this study, we first immunized in vivo or in vitro and then determined susceptibility to anti-Lyb-5. These studies demonstrate that a substantial proportion of antibody-forming cells produced in response to immunization with sheep red blood cells, trinitrophenyl (TNP)-keyhole limpet hemocyanin, TNP-Brucella abortus, TNP-lipopolysaccharide, as well as TNP-Ficoll, are eliminated by anti-Lyb-5 + complement treatment at the end of culture. Some generation of Lyb-5+ antibody-forming cells occurred in the last 24 hr of culture. These studies suggest that the Lyb-5 marker represents a differentiation antigen on relatively mature B cells.
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PMID:Evidence that Lyb-5 is a differentiation antigen in normal and xid mice. 308 May 20

Brucella abortus endotoxin preparations, containing approximately 5 to 6% protein, induce strong immune and adjuvant immunoglobulin G (IgG) responses as compared with Escherichia coli endotoxin preparations, with equivalent amounts of protein, which induce responses in which IgM antibody predominates. Using an enzyme-linked immunoassay with isotype-specific conjugates, we found that antibody of all four subclasses of IgG were evoked during the course of the immune responses of C3H/HeAu mice to B. abortus endotoxin. Secondary responses of endotoxin-hyporesponsive C3H/HeJ mice were similar to those seen in C3H/HeAu mice, although lower levels of antibody were produced during their primary responses. The primary responses of BALB/c athymic mice consisted almost entirely of IgG3, and IgG1 appeared following a second injection. The effects of lipopolysaccharide (LPS)-associated protein on the immunogenic properties of B. abortus endotoxin were examined by comparing responses to endotoxin with those to a purified B. abortus LPS containing less than 1% protein. The endotoxin evoked strong primary and secondary responses in which antibody directed to LPS determinants consisted mainly of IgG3 and those to the protein determinants were largely IgG1 antibody. Primary and secondary responses to purified LPS consisted mainly of IgG3 antibody. The potential mechanism of the contribution of protein to the immunogenic properties of the endotoxin as well as possible immune mechanisms involved in these responses are discussed.
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PMID:Influence of endotoxin-protein in immunoglobulin G isotype responses of mice to Brucella abortus lipopolysaccharide. 309 90

In three distinct chronic Ig-specific suppression systems in which suppression was initiated by injection of mice with anti-idiotype (Id) or anti-allotype sera, evidence has been presented by others that the differentiation of B cells bearing surface Ig with a target marker (Id or allotype) need not be totally disrupted. Normally "silent" Id+ B cells from Id-suppressed mice could be revealed by certain procedures, one of these being to make use of the powerful stimulatory properties of bacterial lipopolysaccharide. We have employed a similar strategy to determine whether cryptic CRIA+ B cells exist in significant numbers in hyperimmune, CRI-suppressed (HIS) A/J mice. Thus, following T cell removal, the Ar-specific B cell repertoire from HIS mice was probed using Ar- Brucella abortus as a T-independent Ag. No evidence for "silent" CRIA+ B cells was found. The results, taken in conjunction with those of others, suggests that there may exist multiple forms of long-term Ig-specific suppression.
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PMID:T-independent form of azophenylarsonate fails to reveal "silent" idiotype-positive B cells in idiotype-suppressed mice. 311 94

Smooth lipopolysaccharide (sLPS) of Brucella abortus was prepared and fractionated by a modification of the procedures of Moreno et al. (J. Bac. 138:361-369, 1979). Washed B. abortus cells were disrupted by 21 freeze-quick thaw cycles with ultrasonication to separate the non-membrane-bound material. Ultrasonicated bacteria were used for preparation of membrane-bound sLPS (approximately f5, the main crude sLPS fraction described by Moreno et al.). Phenol extraction was repeated 3 times and then washed with H2O 10 times to remove most of the chromogen, polysaccharides and nucleic acids, eliminating the need for enzyme treatment as described previously. The membrane-bound sLPS was fractionated into 3 to 5 groups according to the extent of dialysis and centrifugation, these fractions required only 80 ng for positive ELISA, about 0.2 ng for positive Limulus lysate tests, and reacted well with precipitating antibodies in the serum from a strain 2308 infected cow. They had marked differences in precipitin curves and chemical composition. The protein content varied from 16% to 42% as determined by dye binding test and 17 to 60% by Lowry phenol method using bovine serum albumin as the standard, which implies that the proteins associated with LPS may also play important roles in the complex for the immunochemical interactions and the heterogeneity of B. abortus lipopolysaccharide protein complex. As compared with previous reports, a higher yield of sLPS, ranging from 3.6% to 7.7% of dried bacteria, was obtained. Group f5A, which had a standard bell shaped curve in the precipitin assay, is one of the major fractions in all three strains (1119.3, 19 and 2308). The amount of other subfractions obtained varied with batches or strains of B. abortus. These results provide a new profile of the immunochemical reactivities and the heterogeneity on B. abortus smooth membrane-bound endotoxins.
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PMID:Immunochemical and partial chemical characterization of fractions of membrane-bound smooth lipopolysaccharide-protein complex from Brucella abortus. 311 18

An immune serum infused into mice prior to intravenous virulent Brucella abortus challenge may reduce initial colonization of the spleen on day 7 post-challenge and increase bacteriolysis in the spleen and liver, as evidenced on day 21. Three monoclonal antibodies (IgG1, IgG3 and IgG2a) directed toward the lipopolysaccharide-A epitope (LPS-A) of B. abortus were studied in this model and compared with three previously studied polyclonal immune sera. The three monoclonals restricted spleen infection on day 7 post-challenge and spleen and liver infections on day 21. These early and late effects were similar to those obtained with the two polyclonal sera of high anti-LPS-A titres, namely, serum from mice either infected by B. abortus or vaccinated with a cell-wall B. abortus fraction. In contrast, serum from mice vaccinated with LPS-M from B. melitensis, which had a high anti-LPS-M but a low anti-LPS-A titre, had lower activity, evidenced at day 7 only. Hence, immune serum protection was mediated by antibodies directed toward the LPS-dominant epitope of the challenge strain.
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PMID:Immunity conferred upon mice by anti-LPS monoclonal antibodies in murine brucellosis. 311 79

The 13C nuclear magnetic resonance spectrum of Brucella melitensis native polysaccharide hapten proved to be very similar to that generated by the O-specific chain (PS) isolated from B. melitensis lipopolysaccharide; that is, to a linear polymer in which the repeating unit is composed of five N-formylperosaminyl residues, one of them being substituted at position C-3 and the other four at position C-2. The serological analysis suggests that the so-called A determinant is present solely in Brucella abortus PS, the M determinant is only in B. melitensis PS, and the extensive cross-reaction observed is due to a determinant shared by both polysaccharides.
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PMID:Characterization of a native polysaccharide hapten from Brucella melitensis. 311 96


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