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

Sheep in five age groups (two weeks, 10 weeks, 18 weeks, six months and four years old) were immunised systemically, twice, with ovalbumin or Brucella abortus (live or killed) and antibody responses in blood were measured. The animals were also infected with the nematode parasites Trichostrongylus colubriformis and Haemonchus contortus and faecal egg counts and serum antibody responses to larval antigens were measured. The experiments were designed so that, as far as possible, the effect of age per se could be dissociated from the combined effects of age and prior exposure to antigen. The effects of the age of sheep were more marked for antibody responses to Brucella abortus lipopolysaccharide than to ovalbumin. Older animals had much greater resistance to infection with internal parasites, as shown by the magnitude of the faecal egg count. In contrast to older lambs, neonatal lambs (infected with H contortus at two weeks old) had consistently declining concentrations of anti-H contortus antibody in their serum, mounted no detectable autogenous anti-H contortus antibody response in blood and appeared to develop no resistance to the parasite. Post natal ontogeny of immune responses was different for the various antigens/pathogens.
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PMID:Post natal ontogeny of immunological responsiveness in Merino sheep. 191 Feb 2

Transposon mutants offer a unique way to evaluate the role of lipopolysaccharide (LPS) by producing a theoretical single-gene difference between the original strain and the transposon mutant strain. Comparative survival of Brucella abortus smooth strain 2308, rough RB51, smooth strain 19, and two transposon mutant strains (rough strain 2308::Tn5 Lac Z [m106] and rough strain 19::Tn5 Lac Z [m3], was tested in restrictive bovine mammary macrophages that were able to effectively reduce the percentage of intracellular bacterial survival and permissive bovine mammary macrophages that were unable to control the intracellular replication of B. abortus. The theoretical single-gene difference between strain 19 and strain 19::Tn5 lac Z [m3] and between smooth virulent strain 2308 and rough transposon mutant 2308::Tn5 lacZ [m106] is likely related to differences in LPS content or structure. Significant (P less than 0.05) reduction in the survival of rough strain 19::Tn5 Lac Z [m3] with no significant reduction in the rough transposon mutant strain 2308::Tn5 lacZ [m106] indicated that at least one factor other than LPS contributes to the intracellular survival of B. abortus in bovine macrophages.
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PMID:Survival of smooth, rough and transposon mutant strains of Brucella abortus in bovine mammary macrophages. 196 14

Sera from calves immunized with Yersinia enterocolitica serotypes O:9 or O:16 were tested by indirect enzyme linked immunosorbent assay (ELISA) using lipopolysaccharide (LPS) preparations from Brucella abortus or Y. enterocolitica O:9 or O:16 for their antibody content of the IgG1 or IgG2 subclasses. High IgG1 responses were present with the three antigens in both groups although some individual variations between animals were noted. The IgG2 responses were modest and in some cases not above background 'noise'. Thus IgG2 antibody was not measurable in sera from serotype O:9 injected calves when using serotype O:16 LPS or in serotype O:16 injected calves when using B. abortus or serotype O:9 LPSs. A competitive ELISA using B. abortus O-polysaccharide and a monoclonal antibody to B. abortus LPS (initially designed to differentiate the antibody responses of cattle naturally infected with B. abortus from those vaccinated with strain 19) was used on sera from both groups of calves. Using this test, no antibody was detected in the group immunized with serotype O:16 and except for one animal in the serotype O:9 immunized group, only low levels of antibody were transiently in evidence. One animal in this group responded with quite high levels of competing antibody which, however, declined towards the end of the test period. The competitive ELISA may prove a useful serological tool for differentiating vaccinal and field infection titers to B. abortus and also to eliminate cross-reactions observed with Y. enterocolitica serotypes.
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PMID:The serological response of cattle immunized with Yersinia enterocolitica O:9 or O:16 to Yersinia and Brucella abortus antigens in enzyme immunoassays. 211 Oct 58

Five groups of heifers were immunized with various subcellular fractions of Brucella abortus and tested for their responsiveness in lymphocyte proliferative responses in vitro. The five subcellular fractions used as immunogens were: (1) a mixture of recombinant outer membrane proteins fused to Escherichia coli beta-galactosidase, (2) a mixture of outer membrane proteins BaomI, BaomIIB1, and BaomIII1, (3) a mixture of outer membrane proteins 7.5 kDa and 8.8 kDa, (4) a complex of smooth lipopolysaccharide and proteins, and (5) a complex of outer membranes and peptidoglycan (OM-PG complex) from a rough strain. All immunogens were emulsified in adjuvant and administered twice at a 61-day interval. Two other groups of cows were included; one immunized with strain 19 and the other with adjuvant only. Strain 19 and the rough OM-PG complex induced responsiveness in lymphocyte proliferation assays in a high percentage of immunized cows. The smooth lipopolysaccharide-protein complex induced responsiveness in fewer cows. The lowest frequencies of responding cows were found in groups that received either recombinant proteins or purified protein mixtures. Based on these results, we concluded: (1) cellular immunity, as measured by in vitro lymphocyte proliferative responses, can be induced with subcellular fractions of B. abortus and (2) the more complex the immunogen, the greater the frequency of responding cows.
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PMID:Immunogenicity of subcellular fractions of Brucella abortus: measurement by in vitro lymphocyte proliferative responses. 211 87

B lymphocytes from the pulmonary lymphoid tissues were stimulated with a variety of thymus-independent (TI) antigens by intratracheal (i.t.) immunization. Immune responses in the lungs and hilar lymph nodes (HLN), which are part of the localized lymphoid tissue, as well as in the spleen, the systemic lymphoid organ, were studied. Thus, primary i.t. immunization of mice with the TI-1 antigen trinitrophenyl-lipopolysaccharide (TNP-LPS) elicited both antigen-specific and polyclonal plaque-forming cell responses from HLN, lung, and splenic B lymphocytes. These responses appeared as early as 3 days after immunization and declined by day 7. Similar immunization with another TI-1 antigen, TNP-Brucella abortus, resulted in anti-TNP responses in both pulmonary and systemic lymphoid tissues, although the kinetics of the antibody response were different than those to TNP-LPS. Interestingly an i.t. immunization with a TI-2 antigen, TNP-Ficoll, failed to induce an anti-TNP PFC response from HLN and lung B cells, although there was good antibody formation from splenic B cells. Antibody response to TNP-Ficoll was restored in pulmonary tissues when mice were immunized with TNP-Ficoll mixed with unconjugated B. abortus. In conclusion, our results indicate that TI-1 and TI-2 antigens differ in their ability to induce antibody responses in the pulmonary lymphoid tissues. The inability of TNP-Ficoll to elicit an antibody response in pulmonary lymphoid tissues has significance in the development of vaccines containing bacterial polysaccharides.
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PMID:Primary antibody responses to thymus-independent antigens in the lungs and hilar lymph nodes of mice. 211 56

A study was conducted to determine whether subcomponent proteins (previously identified as BCSP20, BCSP31, and BCSP45, and the corresponding recombinant proteins rBCSP20, rBCSP31, and rBCSP45) that were recovered from the cell surface of Brucella abortus strain 19 were immunogenic and protective for mice when compared with Brucella cell surface protein (BCSP) and with a proteinase K-treated lipopolysaccharide (PKLPS) extracted from B abortus strain 2308. Protection was evaluated after challenge exposure with a virulent culture of B abortus strain 2308, using CD-1 or BALB/c mice or both inoculated with vaccines of various combinations and concentrations, with and without PKLPS or BCSP. Protection was assessed by enumeration of splenic colony-forming units, reduced mean splenic weight relative to controls, and the relative serologic responses (immune response) in an ELISA. The general results indicate that BCSP, PKLPS, BCSP20, and BCSP31 are immunogenic or protective or both. Protectiveness was not observed for each of the recombinant proteins; however, results from the combined recombinant protein vaccine study suggest the immunogenicity of the recombinant proteins. The apparent immune-inducing properties of BCSP20 and BCSP31 are thought to be attributable to the presence of an immunogenic and protective BCSP fraction (possibly lipopolysaccharide) still associated. Serologic results support our conclusion that each of the recombinant protein vaccines did not induce a protective response comparable to that of BCSP or PKLPS, even when the subcomponents were combined. Although the results suggest that the subcomponents of BCSP apparently induced partial protection, they are thought to be only a part of the antigens contained in BCSP that influence the serologic response.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Immunogenicity of Brucella-extracted and recombinant protein vaccines in CD-1 and BALB/c mice. 211 44

Smooth (S)-lipopolysaccharide (LPS) preparations from reference and field strains of several biovars of Brucella abortus, B. melitensis, and B. suis were prepared by (i) the hot phenol-water method, (ii) hot sodium dodecyl sulfate extraction and proteinase K digestion, or (iii) dimethyl sulfoxide extraction. These S-LPS-enriched fractions were further analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining after periodate oxidation. Immunoblots were developed by using either monoclonal antibodies specific for Brucella A or M antigens or polyclonal polyspecific or monospecific sera from rabbits, cattle, and goats. The specificity of monoclonal antibodies reactive with Brucella unique (A or M) epitopes was demonstrated by enzyme-linked immunosorbent assay, LPS latex agglutination, or agglutination inhibition. The most-represented subunits of S-LPS ranged in Mr from 30,000 to 70,000 relative to marker proteins. According to A or M immunodominance, two sodium dodecyl sulfate-polyacrylamide gel electrophoresis banding patterns were clearly distinguished among biovars, whatever the fraction tested: a close succession of regularly spaced narrow bands for A greater than M strains and regularly spaced triplets of bands including either (i) a first thin band followed by two thick bands for B. abortus M greater than A strains or (ii) one thick band between two thin bands for B. melitensis or B. suis M greater than A strains. Moreover, A and M specificities were reaffirmed by sandwich enzyme immunoassay and latex agglutination inhibition with monoclonal antibodies and polyclonal sera.
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PMID:Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting analysis of smooth-lipopolysaccharide heterogeneity among Brucella biovars related to A and M specificities. 222 39

The indirect hemolysis test (IHLT) for the diagnosis of brucellosis uses a lipopolysaccharide (LPS) antigen obtained by dimethyl sulfoxide extraction of Brucella abortus. We showed that a non-LPS antigen can be obtained as a by-product of the IHLT antigen preparation. The antigen was purified to homogeneity by a combination of gel-filtration chromatography and ion-exchange chromatography. The substance contained 8% protein and about 65% carbohydrate. The molecular weight of the primary unit was 19,750, when analyzed by polyacrylamide gel electrophoresis under denaturing conditions. The non-LPS antigen, which is serologically identical to B. abortus smooth LPS O antigen, did not bind to cell membranes. However, it could be used to detect specific antibodies by complement fixation, precipitation in agarose gels, and inhibition of the IHLT.
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PMID:Purification of nonlipopolysaccharide antigen from Brucella abortus during preparation of antigen used for indirect hemolysis test. 242 88

In an enzyme-linked immunosorbent assay (ELISA), purified Brucella abortus and Escherichia coli peptidoglycan-linked lipoproteins gave a strong cross-reaction with sera from rabbits hyperimmunized with the heterologous lipoprotein. When smooth E. coli cells were used as ELISA antigens, the immunological cross-reaction was not observed unless the cells were treated to remove lipopolysaccharide and other outer membrane components. In contrast, intact cells from smooth strains of B. abortus and Brucella melitensis bound anti-lipoprotein immunoglobulin G, and the controls performed by ELISA showed that this reaction was not due to antibodies to the lipopolysaccharide, group 3 outer membrane proteins, or porins. Electron microscopy of cells labeled with antilipoprotein serum and protein A-colloidal gold showed specific labeling of smooth cells from both B. abortus and B. melitensis, even though unspecific labeling by nonimmune serum was observed with rough B. abortus. These results confirm the close similarity between E. coli and Brucella peptidoglycan-linked lipoproteins and show that, in contrast to E. coli, the lipoprotein of B. abortus and B. melitensis is partially exposed on the surface of smooth cells.
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PMID:Brucella outer membrane lipoprotein shares antigenic determinants with Escherichia coli Braun lipoprotein and is exposed on the cell surface. 243 14

Purified O chain of Brucella abortus was passively attached to polystyrene to differentiate antibody responses of cattle vaccinated with B abortus strain 19 from those of naturally infected cattle. In the indirect assay, using O polysaccharide as antigen, a single serum dilution was used and mouse monoclonal antibody to bovine L chain conjugated with horseradish peroxidase was the detection reagent. Measurable antibody was not found in sera of vaccinated cattle, except for 3 sera from cattle that were persistently infected with strain 19. Sera from 25 cattle infected with pathogenic strains contained antibody on the basis of results of indirect enzyme immunoassay, using smooth lipopolysaccharide or O chain as antigens, or results of competitive enzyme immunoassay, using the O-chain antigen. Results in sera from calves with experimentally induced Yersinia enterocolitica serotype 0:9 infection or inoculated with a low dose of B abortus strain 2308 were comparable with those in sera of cattle that were vaccinated with strain 19. The data correlated with those from competitive enzyme immunoassay, using one serum dilution and horseradish peroxidase-conjugated mouse monoclonal antibody to smooth lipopolysaccharide. On the basis of results of the indirect enzyme immunoassay, all sera (except those samples obtained before inoculation) contained antibody to smooth lipopolysaccharide.
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PMID:Enzyme-linked immunosorbent assay for differentiation of the antibody response of cattle naturally infected with Brucella abortus or vaccinated with strain 19. 246 11


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