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

An effective method was developed for the preparation of Brucella abortus native hapten by use of an ultrafiltration system. The membranes PM30 and YM5 were used to separate the lipopolysaccharide and the native hapten. The yield of the native hapten was higher than that obtained by a more complex procedure reported previously. This method is economical for the large-scale preparation of B. abortus native hapten. The effects of ultrafiltration were evaluated by a quick and sensitive high-performance liquid chromatographic technique.
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PMID:Preparation by ultrafiltration and control by high-performance liquid chromatography of the native hapten of Brucella abortus for use in radial immunodiffusion diagnostic test. 311 41

Immunoassays based on latex agglutination or enzyme labelling (ELISA) were devised for the detection of lipopolysaccharide (LPS) of Brucella abortus, or its degradation products, in biological fluids of infected mice. The agglutination of latex was measured by counting of the remaining non-agglutinated particles in an automated immunoassay analyser. LPS was assayed by agglutination with antibody-coated latex and by competitive inhibition of agglutination of LPS-coated latex by anti-LPS antiserum. The inhibition system was more sensitive for the detection of degradation products of LPS. Correlation between ELISA and agglutination inhibition immunoassay was excellent (r = 0.96). Degradation of LPS occurred during storage, particularly when the samples contained specific antibodies. It could be prevented by removing cells immediately after collecting blood samples and by heating or alkaline denaturation of plasma. CBA/H mice were infected with various doses [65-(65 x 10(6) cfu] of B. abortus biovar 3 cells and the course of infection followed by immunoassay of LPS-related antigens in serum and urine, and by titration of specific antibodies and non-specific circulating immune complexes. The concentration of LPS degradation products, assayed by the agglutination inhibition assay, was related to the severity of the infection, which was assessed by viable counts of B. abortus in the spleen. A close correlation was observed between the values of antigenaemia, the number of cfu (r = 0.97), and the inoculum size (r = 0.99 at day 28).
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PMID:Longitudinal study of brucellosis in mice by immunoassay of lipopolysaccharide-related antigens in blood and urine. 313 29

Purified Brucella abortus 1119-3 and Brucella melitensis 16M lipopolysaccharide O-chain polysaccharides were not precipitated in agar gel immunodiffusion by any of 24 sera from vaccinated cattle but were precipitated by 18 of 24 sera from infected cattle. This difference can be used to differentiate sera of cattle vaccinated with B. abortus S-19 from sera of some field-strain-infected cattle.
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PMID:Brucella abortus 1119-3 O-chain polysaccharide to differentiate sera from B. abortus S-19-vaccinated and field-strain-infected cattle by agar gel immunodiffusion. 313 89

Isolation and identification of Brucella antigenic determinants important to cellular responses have been difficult. In this study, bovine peripheral blood mononuclear (PBM) cells from cattle vaccinated with Brucella abortus 19 proliferated to extracted bacterial proteins blotted onto nitrocellulose. Proteins were extracted from gamma-irradiated B. abortus 19 with a sodium dodecyl sulfate extraction buffer. The extracted proteins were separated electrophoretically by sodium dodecyl sulfate-polyacrylamide gel electrophoresis prior to electroblotting onto nitrocellulose. Nitrocellulose sections corresponding to individual lanes of the gel (containing all separated proteins) were then cultured with the PBM cells. Primary and secondary stimulation responses of the PBM cells with the whole protein blots were similar kinetically to the responses of the PBM cells stimulated with whole irradiated B. abortus 19 or with whole irradiated B. abortus 19 blotted onto nitrocellulose. Although lipopolysaccharide was determined to be associated with the extracted proteins and transferred onto the blots, the lipopolysaccharide did not stimulate cellular proliferation, as indicated by the antigen-specific secondary responses. Stimulating PBM cells with portions of the blot containing high (greater than 45,000)-, medium (25,000 to 45,000)- or low (25,000)-molecular-weight proteins demonstrated that the responding cells were specific only to the proteins of corresponding molecular weights. These results indicate that cellular responses to individual proteins can be studied without cloning the bacterial genes or purifying the individual proteins.
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PMID:Determination of bovine lymphocyte responses to extracted proteins of Brucella abortus by using protein immunoblotting. 313 78

Smooth lipopolysaccharide (sLPS) of Brucella abortus, which is the most immunodominant component among the antigens of B. abortus isolated, has been used for diagnosis for decades. High yields of sLPS can be prepared by a modification of the procedures of Moreno et al. (J. Bacteriol. 138:361-369, 1979). Washed B. abortus cells can be disrupted by 21 freeze-quick thaw cycles and ultrasonication to separate non-membrane-bound material; then phenol extraction is performed 3 times and the phenol fraction is washed with H2O intensively. The membrane-bound sLPS can be fractionated into 3 to 5 groups according to the extent of dialysis and centrifugation. These membrane bound sLPS fractions show marked individual differences in their precipitin profile and chemical composition. Their protein content varies 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 indicates that these proteins associated with LPS may play important roles in the immunochemical interactions, solubility, and the heterogeneity of B. abortus lipopolysaccharides. Compared to previously published methods, a higher yield of sLPS, ranging from 3.6% to 7.7% of dried bacteria, is obtained. Group f5A, which has a standard bell shaped curve in the precipitin assay, is one of the major fractions in all three strains (1119.3, 19, 2308). The protein free sLPS (less than 1% of Lowry reactive component) can be prepared by pronase digestion. The immunochemical reactivity remains about the same before and after this treatment. The O-chains of the major fraction (f5A) of B. abortus (Strains 2308 and 19) membrane bound smooth lipopolysaccharide (sLPS) are obtained by hydrolysis of f5A native sLPS in 1% acetic acid at 100 degrees C for 2 hours. After hydrolysis, the O-chains are separated from the lipid A protein complex by centrifugation, and from small fragments by ultrafiltration of a molecular weight cut-off (MWCO) of 1.0 x 10(3). These carbohydrate haptens can be identified by precipitin-inhibition assay and further fractionated by both membrane filtration and dialysis. The size distributions of carbohydrate haptens of the endotoxins (f5A) ranged from several oligosaccharides up to 1.0 x 10(4) MWCO. Three major fractions of MWCO 8.0-10.0 x 10(3), 3.5-5.0 x 10(3), and less than 1.0 x 10(3) for both strains 2308 and 19 contain more than 85% of the total immunreactive materials.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Structural and immunochemical aspects of Brucella abortus endotoxins. 314 Jun 12

Studies of the serum bactericidal system in bovine brucellosis were undertaken to investigate the role of the humoral immune response in protection of cattle against the facultative intracellular parasite Brucella abortus. Fresh sera from normal control cattle, infected cattle, and cattle immunized with B. abortus cell envelopes were collected before treatment and during the course of immunization or infection. Normal fresh bovine serum or fresh agammaglobulinemic serum from colostrum-deprived calves was effective in killing smooth virulent B. abortus 2308, but rough strains RB51 (a rough mutant of strain 2308) and 45/20 were much more sensitive to serum. The difference in susceptibility to serum was shown to be correlated with differences in lipopolysaccharide chemotype, with the more resistant strain 2308 having O polysaccharide and the more susceptible strains 45/20 and RB51 lacking O side chains. By treatment of fresh serum with MgCl2 and EGTA [ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid] killing was shown to occur via the classical pathway of complement activation. When antibody to B. abortus was present, killing of strain RB51 increased but killing of smooth strain 2308 decreased. The earliest antibody response in serum from infected animals did not interfere with killing. When affinity-purified bovine immunoglobulins specific for B. abortus smooth lipopolysaccharide were added to fresh normal bovine serum, immunoglobulin G1 (IgG1) and IgG2 isotypes blocked killing but IgM and IgA isotypes did not. Thus, it appears that serum from previously unexposed animals or animals early during infection can kill smooth B. abortus, an appropriate defense mechanism before the organism becomes intracellular. At later stages of infection, blocking antibodies predominate.
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PMID:Killing of Brucella abortus by bovine serum. 314 Dec 87

A rough antigen (SRA) extracted from Brucella ovis in hot saline by Myers procedure, showed three precipitation lines when tested in immunodiffusion against sera from experimentally infected rams. The components responsible for the lines could be isolated by ultracentrifugation or gel filtration which gave 3 fractions, named PI, PII and PIII. The lipopolysaccharide (LPS) appeared in the pellet (SRA-pp) after ultracentrifugation as judged by the presence of lipids, sugar composition, 2 keto-2deoxyoctulosonic acid (KDO), and its characteristic immunoelectrophoretic and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns. SRA-pp contained the antigen responsible for one of the immunoprecipitation lines of SRA and the supernatant (SRA-sn) contained only antigens responsible for the other two. Gel filtration of SRA-pp showed the presence of PI, while SRA-sn gave PII with high protein content and PIII with high carbohydrate content. Immunological activity in gel diffusion (GD) of the Fraction PII and PIII was specific for sera of B. ovis infected rams. Sera from rams experimentally infected with smooth strains (Brucella abortus and melitensis), were not able to react with these antigens.
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PMID:Characterization of Brucella ovis surface antigens. 314 41

Facultative intracellular bacteria localize preferentially in reticulo endothelial system organs where they can either multiply or be destroyed, concomitantly or successively. Immunity may thus be estimated by counts of viable (surviving) bacteria at convenient time(s) after a standard challenge. When mice vaccinated with the living attenuated Brucella abortus strain 19 were intravenously challenged with the virulent B abortus strain 544, some mice exhibited unexpected high spleen counts. The vaccinal strain surviving at low level in some mice 30 days after a subcutaneous vaccination was reactivated by the virulent challenge as evidenced by a fast but temporary count increase. Reactivation was stronger in outbred OF 1 mice than in outbred CD-1 mice. Reactivation did not alter the normal course of the virulent infection as shown by comparison between mice already cured of the vaccinal infection or not, at time of challenge. Because reactivation was also induced by intravenous injection of either the brucellin allergen or the brucella lipopolysaccharide antigen, hypersensitivity reactions occurring inside the vaccinal granuloma foci may expel the surviving bacteria into the surrounding extracellular environment where a secondary growth may develop.
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PMID:Reactivation of a residual Brucella abortus 19 vaccine infection in mice by a virulent challenge or by injection of brucellin or of Brucella lipopolysaccharide. 314 91

Eighteen monoclonal antibodies were generated from mice immunized with Vibrio cholerae O1 serotype Inaba. Reactivities of these antibodies were investigated by slide agglutination, microdilution agglutination, and passive hemagglutination tests. Although all antibodies reacted to the Inaba-type cells, reactivity to Ogawa cells showed some variation. These antibodies were roughly subdivided into three groups by slide agglutination tests and microdilution agglutination tests by using type-specific standard strains. The first group showed almost identical reactivities to both the Ogawa- and the Inaba-type cells, while the second group reacted to Inaba-type cells but only very weakly reacted to Ogawa-type cells. The third group reacted only to Inaba-type cells; no agglutination was observed for Ogawa-type cells in either the slide agglutination or the microdilution agglutination tests. Most of the third group showed cross-reactivity to Brucella abortus and Yersinia enterocolitica O9. Results of passive hemagglutination tests showed that all 18 antibodies were to the lipopolysaccharide of V. cholerae O1.
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PMID:Monoclonal antibodies to Vibrio cholerae O1 serotype inaba. 323 65

Polysaccharide B was extracted from Brucella melitensis 16M and from a rough strain of Brucella abortus 45/20 by autoclaving or trichloroacetic acid extraction of whole cells and by a new method involving mild leaching of cells. The material obtained by either of the established procedures was contaminated by O polysaccharide. The new leaching protocol eliminated this impurity and provided a pure glucan, which was regarded as polysaccharide B. This polysaccharide was found by high-performance liquid chromatography separations, chemical composition, methylation, and two-dimensional homo- and heteronuclear magnetic resonance experiments to be a family of nonreducing cyclic 1,2-linked polymers of beta-D-glucopyranosyl residues. The degree of polymerization varied between 17 and 24. Polysaccharide B was essentially identical to cyclic D-glucans produced by Rhizobia, Agrobacteria, and other bacterial species. Pure polysaccharide B did not precipitate with Brucella anti-A or anti-M serum and did not inhibit the serological reaction of Brucella A or M antigen with either bovine or murine monoclonal Brucella anti-A or anti-M serum. Previously described serological reactions of polysaccharide B preparations with Brucella anti-A and anti-M sera are related in this study to the presence in crude extracts of contaminants with the antigenic properties of Brucella lipopolysaccharide O polysaccharides.
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PMID:Characterization of Brucella polysaccharide B. 335 61


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