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

In the present study in mice we used the Jerne plaque assay to compare the immunity enhancing potential of different Gram-negative bacteria with special regard to their endotoxin. The results confirm the recent finding that injection of Escherichia coli bacteria of various serotypes may enhance the IgG antibody response to the O antigen of a serologically unrelated E. coli strain injected subsequently, but may suppress the IgM antibody formation. The O antibodies formed were of low avidity but were antigen specific. Smaller amounts of antibodies were formed to a serologically unrelated antigen, E. coli O76, which had not been injected. Of the strains tested as primary stimuli E. coli O4 gave considerably greater enhancement than any other serotype including the homologous E. coli O6, when a short interval between the injections was used. The influence of O4 on the serologically unrelated anti-O6 response was stronger than on the response to the cross-reactive E. coli O18 antigen, suggesting that O antigen cross-reactivity is not the basis for the immunomodulation. Formalin-killed bacteria were more effective in this respect than boiled bacteria or purified lipopolysaccharide and rough mutants (E. coli R1--R4) and E. coli O4 were less effective than many of the other smooth E. coli. These findings suggest that shared determinants in the lipid, basic carbohydrate core or Kunin common antigen portions of the endotoxin do not play the major immunomodulating role in this system. Salmonella reading but not Pseudomonas aeruginosa affected the anti-E. coli O6 response in a similar manner. One explanation for the alterations in the immune response observed implies the presence of an antigen determinant shared by many Enterobacteriaceae in such a position in relation to the O antigen that it can be utilized for cellular co-operative events in the O antibody response. The protein portion of the endotoxin protein--lipid--carbohydrate complex is a possible location.
 ...
PMID:Alteration of the antibody response to Escherichia coli O antigen in mice by prior exposure to various somatic antigens. 5 29

Escherichia coli K100 produces an antigenic determinant similar to, or identical with, the capsular antigen of Haemophilus influenzae type b. Studies of the effects of heat on the immunogenicity, erythrocyte-modifying capacity, and antigenicity of this cross-reacting antigen (CRA) revealed the following findings. Immunization of rabbits with viable or formaldehyde-killed suspensions of E. coli K100, producing CRA, engendered CRA antibodies in significant titers, as demonstrated by hemagglutination of erythrocytes modified by H. influenzae type b antigen. Heating of the suspensions for 1 h at 56 or 100 degrees C destroyed the immunogenicity of CRA, and the heated suspensions did not prime for a secondary antibody response. Supernatants of heated suspensions also were non-immunogenic. Repeated freezing and thawing of heated suspensions of E. coli K100 or their supernatants did not restore immunogenicity. Heat also abolished the immunogenicity of H. influenzae type b. The loss of immunogenicity of CRA of E. coli K100 by heat was not due to alteration of the antigenic determinant, since heated suspensions and supernatants thereof modified erythrocytes for agglutination by H. influenzae type b antiserum. The latter supernatants also inhibited hemagglutination by H. influenzae type b antibodies and absorbed the latter. We conclude that striking differences exist in the effects of heat on CRA on the one hand and of enterobacterial common antigen and lipopolysaccharide O antigen of enteric bacteria on the other. Heating of the latter two antigens does not abolish their priming effect, and repeated freezing and thawing restores the immunogenicity of heated antigens.
 ...
PMID:Effect of heat on antigenicity and immunogenicity of the antigenic determinant shared by Haemophilus influenzae type b and Escherichia coli K100. 7 Dec 69

A fluorescent antibody reagent (termed anti-LPS conjugate) was prepared from sera obtained from hens immunized with gonococcal R-type lipopolysaccharide. The reagent was absorbed with Formalin-treated cells of Neisseria meningitidis. The anti-LPS conjugate gave uniform brilliant staining of Neisseria gonorrhoeae with little background fluorescence, thus making interpretation and reading of fluorescence simple. The conjugate did not significantly stain cultures of N. meningitidis, Neisseria lactamica, nonpathogenic Neisseria species, or other gram-negative bacteria. Several preparations of the conjugate provided the same specificity and reproducibility of staining. The anti-LPS conjugate was compared with Difco Laboratories fluorescent antibody conjugate for staining of N. gonorrhoeae. Both conjugates stained cells of the light and dark variants of gonococcal colony types 1 and 2, as well as cells of colony types 3 and 4. When used for the confirmation of N. gonorrhoeae, the anti-LPS and Difco conjugates stained 426 of 431 (98.8%) and 210 of 213 (98.6%) of the gonococcal cultures, respectively. Absorption of the anti-LPS conjugate with R-type lipopolysaccharide removed the staining of gonococci. However, absorption of Difco conjugate with R-type lipopolysaccharide did not remove the staining of gonococci, suggesting that the majority of fluorescein-labeled antibody present in the Difco conjugate is directed to gonococcal cell surface components other than lipopolysaccharide. The results of this study indicate that fluorescein-labeled gonococcal lipopolysaccharide antibody should be a reliable fluorescent antibody reagent for the confirmation of N. gonorrhoeae.
 ...
PMID:Hen fluorescein-labeled gonococcal lipopolysaccharide antibody in the delayed fluorescent antibody technique for the confirmation of Neisseria gonorrhoeae. 11 Aug 24

Four murine hybridoma clones secreting monoclonal antibodies (mAb) directed against lipopolysaccharide (LPS) antigen of S. newington, serogroup E1, were obtained after a fusion of spleen cells of mice immunized with formaldehyde-killed bacteria and mouse myeloma cells of the X63-Ag8.653 line. Antigen binding properties and specificity of the mAb were studied in bacterial agglutination tests, passive hemolysis and its inhibition, passive hemagglutination tests, passive hemolysis and its inhibition, passive hemagglutination and immunoenzyme tests (ELISA and immunoblotting). Three of the mAb (24E6, 29E1 and 45F6) were agglutinating and were active in all tests used, while mAb 31H12 did not agglutinate bacteria but revealed a high reactivity in the immunoenzyme reactions. It was found that the mAb reacted with LPS and Salmonella strains from serogroup E (E1, E2, E3 and E4) as well as from serogroups C (C1 and C4), F and S thus showing that the O3 antigen possesses more than one epitope, one of which is represented on the LPS antigens of the serovars from the cross-reacting groups mentioned. According to the known chemical the most probable recognized epitope consists of mannose with beta-linkage to the next monosaccharide residue in the LPS chain.
 ...
PMID:Monoclonal antibodies directed to the O antigen of Salmonella serogroup E cross-react with lipopolysaccharides of Salmonella serogroups C, F and S. 128 92

To test the importance of lipopolysaccharide (LPS) and adhesin as major antigens in vaccination against rabbit enteropathogenic Escherichia coli (EPEC)-like E. coli O103 infection, we used two nonpathogenic wild-type strains to immunize rabbits at weaning. One of these strains (C127) harbors the O103 LPS but does not express the 32,000-molecular-weight adhesin that characterizes the highly pathogenic O103 strains. The other (C6) belongs to the O128 serogroup, which does not cross-react with the O103 serogroup, but expresses the adhesin. These strains were administered orally, either live or after Formalin inactivation. After vaccination, the animals were challenged with highly pathogenic O103 strain B10. Compared with rabbits vaccinated with the Formalin-killed homologous strain, rabbits vaccinated with killed C127 or C6 showed partial but significant protection. When given live, these strains colonized more or less heavily the digestive tract of the animals and provided nearly complete (C127) or complete (C6) protection against challenge. They induced a quick local immune response, as judged by fecal immunoglobulin A anti-LPS kinetics. Furthermore, strain C6 induced an ecological effect of "resistance to colonization" against challenge strain B10. This effect may have been due to the adhesin that is shared by both strains and to the production of a colicin. Strain C6 could inhibit in vitro the growth of highly pathogenic O103 strains. On the whole, our results show that adhesins and LPS are important, although probably not exclusive, protection-inducing components in rabbit EPEC-like colibacillosis and provide insight into possible protection of rabbits against EPEC-like E. coli infection with live strains.
 ...
PMID:Oral vaccination of weaned rabbits against enteropathogenic Escherichia coli-like E. coli O103 infection: use of heterologous strains harboring lipopolysaccharide or adhesin of pathogenic strains. 135 80

Haemophilus ducreyi (H. ducreyi) strains, representing both reference strains and low-passage isolates, were investigated in terms of surface structures and enzymatic equipment. The interaction of these factors with host tissue was analysed using new in vitro- and in vivo-models. By electron microscopy studies there was no evidence of an extracellular capsule or surface appendages such as pili or flagella. Interaction of all isolates tested with the lectin Phaseolus vulgaris suggests N-acetyl-D-glucosamine units as common structural features of H. ducreyi cell envelope polysaccharide. In attachment to epithelial cells more than one hemagglutinin might be implicated as different haemagglutination patterns could be observed whereby the activity was not heat-labile, but was abolished by formaldehyde. Hydrophobic interactions might be of importance as well as strains showed a wide range of reactions from hydrophobic to hydrophilic, low hydrophobicity being more marked with the older strains. No elaboration of degradative enzymes based on the measurement of enzymatic activity using insoluble dye-protein complexes could be detected in case of H. ducreyi, using Azocoll and Remazol Brilliantblue hide powder for detection of proteolytic activity and elastinorcein for detection of elastase activity. In vitro studies using human keratinocytes and Vero cells did not show any morphological changes when incubated with H. ducreyi culture filtrates. In vivo studies with a new mouse model for H. ducreyi infection could confirm the results of the in vitro studies. Mere contact to undamaged skin both of whole cell organisms, live or heat-killed, and of culture filtrates did not lead to any reaction or even damage of mouse skin. However, when the outer epidermal layer was overcome by intradermal injection of shaved mice ulcers developed. Tissue necrosis production was not bound to live organisms as dead ones showed the same effect. There is great evidence that this tissue necrosis is associated with H. ducreyi lipopolysaccharide (LPS) because intradermal injection of purified H. ducreyi LPS lead to the same reaction pattern. For the first time a cell mediated immune response could be demonstrated in case of H. ducreyi infection as different antigen preparations of H. ducreyi isolates induced proliferation of lymphocytes isolated from healthy unexposed individuals and from a chancroid-sensitized male. In the latter case measured cell responses were much stronger. The dose-dependent phenomenon was associated with interleukin-2 production. In summary, H. ducreyi isolates do not exhibit cytotoxic effects on the epithelial cells of the skin.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Mechanisms of skin adherence, penetration and tissue necrosis production by Haemophilus ducreyi, the causative agent of chancroid. 163 61

Formalin-killed Legionella pneumophila bacterial cells, as well as a purified cell wall preparation (designated F-1 antigen) containing lipopolysaccharide (LPS), stimulated production of interferons (IFNs) in mouse spleen cell cultures. L. pneumophila whole-cell vaccine induced an IFN that was pH 2 labile and neutralized by anti-IFN-gamma indicating that IFN-gamma was the dominant form present. F-1 antigen induced a mixture of IFNs, depending upon the age of the culture and cell types present. In freshly prepared whole-spleen cultures and in 2-h adherent cultures, F-1 induced predominantly IFN-alpha/beta. In whole-spleen cultures that were allowed to age for 24 to 48 h before stimulation, F-1 was seen to induce mostly IFN-gamma, with low levels of IFN-alpha/beta present. Since only IFN-alpha/beta was produced in T-cell-depleted populations (at 2 h or at 48 h), it is suggested that T cells are responsible for IFN-gamma production in aged cultures. Additionally, heat-treated F-1, Escherichia coli LPS, and heat-treated E. coli LPS all induced similar levels of IFN-gamma in whole-splenocyte or nonadherent cell cultures which were incubated 48 h before stimulation. This suggests that LPS present in F-1 is responsible for IFN-gamma production and that an activated cell population is required. These results show that L. pneumophila antigens can induce the production of various types of IFN in mouse spleen cell cultures through several mechanisms.
 ...
PMID:Kinetics and characterization of interferon production by murine spleen cells stimulated with Legionella pneumophila antigens. 241 62

Monoclonal antibodies against 12 of the 17 IATS serotype strains of Pseudomonas aeruginosa were produced. Eighty-seven hybridoma clones were isolated, and the antibodies secreted were found to be reactive with both Formalin-fixed whole cells and purified lipopolysaccharide of homologous strains in enzyme-linked immunosorbent assays. Among these monoclonal antibodies, the predominant antibody class was immunoglobulin M (IgM) (76%), although antibodies of the IgG2a and IgG3 isotypes were also produced. The monoclonal antibodies could further be divided into two groups based on their ability to agglutinate whole cells of homologous strains. The agglutinating monoclonal antibodies were found to immunoblot with the O side chains of homologous lipopolysaccharide, while the nonagglutinating monoclonal antibodies were found to be reactive with outer membrane protein-associated lipopolysaccharide. The applicability of monoclonal antibodies for serotyping was examined, and several antibodies were found to agglutinate whole cells and immunoblot with the O antigen of corresponding serotypes of clinical isolates from cystic fibrosis patients. In conclusion, a set of monoclonal antibodies against the IATS serotype strains of P. aeruginosa have been produced. These antibodies represent a bank of invaluable immunological reagents which may have application in serotyping, epitope mapping, lipopolysaccharide structural determination, and studies of protection against P. aeruginosa.
 ...
PMID:Production and characterization of monoclonal antibodies against serotype strains of Pseudomonas aeruginosa. 243 30

Nine monoclonal antibodies to Ogawa-specific antigenic determinants of Vibrio cholerae O1 and seven monoclonal antibodies to the Ogawa-Inaba common antigenic determinants were obtained. Specificities and reactivities were examined by slide or microdilution agglutination methods, along with enzyme-linked immunosorbent assays and immunoblotting analysis. In both the Ogawa-specific and Ogawa-Inaba common groups, it was revealed that there were two types of antibodies. One type showed strong agglutination with both live cells and heat-killed (100 degrees C for 30 min) cells in the microdilution agglutination test and in the slide agglutination test (type 1), while the other showed rather weak agglutination with heat-killed cells, especially in the slide agglutination test (type 2). Electronic measurement of agglutinates from these antibodies revealed that the size of aggregates varied. In the case of the type 2 antibodies, the size of aggregates obtained with heat-killed cells was smaller than those obtained with Formalin-killed cells. Results of enzyme-linked immunosorbent assays and immunoblotting analysis showed that all 16 antibodies were to the lipopolysaccharide of V. cholerae O1.
 ...
PMID:Different types of monoclonal antibodies to Ogawa-specific and group-specific antigens of Vibrio cholerae O1. 244 33

Twenty two hybridoma strains producing monoclonal antibodies against Francisella tularensis ATCC 6223, var. tularensis, were characterized. In an enzyme-linked-immunosorbent-assay (ELISA) using formaldehyde fixed bacteria as antigens, neither cross-reactions with six different Brucella spp., with Yersinia enterocolitica 0:9 nor with two biotypes of Yersinia pseudotuberculosis could be detected. The antibodies gave comparable titres with the three strains of F.tularensis tested. ELISA binding studies indicated that fifteen of the antibodies bound with high affinities to their epitopes of the three Francisella strains, while the others each seemed to bind with low affinity to at least one of the antigens. Immunoblot analysis showed that six of the antibodies were directed to epitopes on the core moiety of the lipopolysaccharide molecule, while the other 16 antibodies bound to O side chain components.
 ...
PMID:Monoclonal antibodies reacting specifically with Francisella sp. 259


1 2 3 4 5 6 Next >>