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

The receptor of coliphage omega8 is the O-specific mannan of Escherichia coli O8 in which the trisaccharide alpha-mannosyl-1,2-alpha-mannosyl-1,2-mannose is joined through alpha-mannosyl-1,3-linkages. Coliphage omega8 produces an endo-alpha-1,3-mannosidase which destroys the receptor, liberating a series of oligosaccharides (repeating trisaccharide and multiples). The enzyme is an integral part of the phage particles and also occurs in a free form in the lysates. Phage particles hydrolyze alpha-1,3-mannosyl linkages in the lipopolysaccharide, the polysaccharide (mannan) moiety, and higher oligosaccharides with an efficiency decreasing in this order. No transmannosylation could be detected. Phage particles also degrade the receptor mannan on whole bacteria, as determined with 14C-labeled E. coli O8. The values of Km and Vmax were determined with omega8 particles and free enzymes using native lipopolysaccharide and its triethylammonium salt. The latter, which was obtained after electrodialysis, has a micellar weight of 2.5 X 10(5), whereas the native lipopolysaccharide forms supermicelles with micellar weights of several millions. With coliphage omega8 as enzyme and supermicellar lipopolysaccharide as substrate Km=5 X 10(-8) M was obtained. This, together with the fact that omega8 attaches irreversibly to E. coli O8, was used in proposing a hypothesis for the possible role of the enzyme in the first steps of infection with coliphage omega8.
J Virol 1976 Sep
PMID:Enzymatic action of coliphage omega8 and its possible role in infection. 0 21

A lipophilic thermostable lipopolysaccharide (LPS) complex was isolated by phenol extraction from purified suspensions of the typhus group rickettsiae. The LPS complex is antigenic and possesses some endotoxic properties such as toxicity for actinomycin D-treated mice, pyrogenicity for rabbits and guinea pigs, ability to elicit hypothermia in white rats and local Schwartzman reaction and active cutaneous anaphylaxis in rabbits.
Acta Virol 1977 Sep
PMID:Some biological properties of an endotoxic lipopolysaccharide from the typhus group rickettsiae. 2 40

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.
Immunology 1975 Sep
PMID:Alteration of the antibody response to Escherichia coli O antigen in mice by prior exposure to various somatic antigens. 5 29

We have shown previously that in the differentiation of fetal liver cells to mature B cells in irradiated hosts, these cells sequentially gain responsiveness to the polyclonal B-cell activators dextran-sulphate (DxS), lipopolysaccharide (LPS), and purified protein derivative from tuberculin (PPD), in that order. In this paper we show that both fetal liver cells and adult bone marrow cells responded with proliferation to DxS, but not to LPS OR PPD. However, neither fetal liver nor bone marrow cells gave rise to detectable numbers of high-rate antibody-secreting cells on short-term stimulation by polyclonal B-cell activators. The lack of LPS and and PPD responses of fetal liver and bone marrow cells could not be ascribed to the presence of inhibitory cells, and the DxS-induced response in these cell populations was not dependent on adherent cells. However, LPS could inhibit the DxS response of fetal liver cells, possibly indicating that DxS-responsive cells are precursors to B cells. Direct evidence was provided that DxS activated B-cell precursors in bone marrow. Thus, this cell population became responsive to LPS after DxS prestimulation, as measured by DNA synthesis. Bone marrow cells, sequentially stimulated with DxS and LPS, contained increased numbers of cells with surface immunoglobulin, although no significant increase in numbers of antibody-secreting cells was obtained. These data indicate that DxS had the capacity to increase the rate of differentiation of B-cell precursors. Finally, we show that the sequential appearance of responsiveness in B-cell differentiation to polyclonal B-cell activators is not due to lack of accessory cells during early stages in maturation.
Scand J Immunol 1975 Sep
PMID:Responsiveness of lymphoid precursors to polyclonal B-cell activators. 5 77

We have studied the effects of lipopolysaccharide (LPS) on the primary in vivo immune response to the hapten (4-hydroxy-3,5-dinitrophenyl)acetyl (NNP), with special reference to the avidity and affinity of the early appearing 19S and 7S antibodies. Comparisons were made of the immune response to NNP in groups of mice given either antigen alone, LPS alone, or antigen plus LPS. The avidity of antibodies induced by LPS plus antigen were similar to that found after injection of antigen alone, in spite of the fact that the antibodies were more numerous. However, when comparing the avidity of antibodies produced in animals given only LPS with those given LPS plus antigen, the latter group was often found to have fewer low-avidity 19S-antibody-producing cells. The affinity of 7S antibodies was also similar in the two groups given antigen or antigen plus LPS. Kinetic studies of the effect of LPS on the primary immune response to NNP showed that synergy was observed only before or after the peak response in groups given antigen alone. It is concluded that LPS under synergy conditions acts preferentially on specific antigen-sensitive cells, which are distinct from those that are activated to polyclonal antibody synthesis by LPS alone. Possible mechanisms for the adjuvant effect of LPS are discussed.
Scand J Immunol 1975 Sep
PMID:The effect of lipopolysaccharide on the primary immune response to the hapten NNP. 5 84

2-Amino-2-deoxygalacturonic acid was identified as a component of the lipopolysaccharide from Pseudomonas aeruginosa N.C.T.C. 8505. The compound probably occurs in the region of polysaccharide responsible for O-antigenic specificity.
Biochem J 1975 Sep
PMID:2-Amino-2-deoxygalacturonic acid in lipopolysaccharides from Pseudomonas aerugimosa. 5 64

In the course of the organic synthesis of model compounds similar in some features to the lipid moiety of endotoxic lipopolysaccharide (LPS), Nacylated-D-glucosamine derivatives were prepared. One of these, N-palmitoyl-D-glucosamine, has been previously found to be mitogenic for athymic nude mouse B cells. This and other N-acylated homologs were tested for adjuvant activity in the immune response to human gamma-globulin (HGG) and sheep red blood cells (SRBC) in mice. Comparable or superior enhancement of the immune response was obtained for these glycolipids when compared to LPS in assays measuring anti-SRBC or HGG hemagglutinin titers. In the determination of hemolytic plaque formation, considerable adjuvant effect was shown by the lauroyl derivative, and less but still significant enhancement was achieved by the N-palmitoyl-D-glucosamine. In the rosette formation assay, in addition to the above two glycolipids, N-oleyl-D-glucosamine showed good adjuvant effect. In the latter two assays, the LPS was a superior adjuvant as compared to the synthetic glycolipids. The radiation protective effect of some of the better synthetic adjuvants was also investigated in mice. It was found that although LPS was more effective in this assay, the N-myristoyl-D-glucosamine and N-decanoyl-D-glucosamine compounds gave a definite protection, since up to 40% of the lethally irradiated (700 R) mice survived.
J Immunol 1976 Sep
PMID:Synthetic glycolipid adjuvants. 6 Apr 50

By a series of chromatographic procedures involving precipitation by salt, gel filtration, anionic exchange, and hydroxyapatite elution, a protein--termed the lipopolysaccharide inactivator (LPS-I)--has been isolated from normal human serum. As a result of treatment of bacterial lipopolysaccharide (LPS) by LPS-I, the treated LPS loses its toxicity for mice and reactivity in the Limulus assay and appears to be irreversibly disaggregated. The inactivation of the LPS by the purified LPS-I is temperature and time dependent and is not blocked by the addition of irreversible inhibitors of serine esterases. The LPS inactivator migrates as an alpha-globulin in whole serum and has a sedimentation velocity of approximately 4.5S. Characteristics of the inactivated LPS are briefly described using internally labeled LPS.
Am J Pathol 1977 Sep
PMID:Isolation from human serum of an inactivator of bacterial lipopolysaccharide. 7 Jan 73

Mice that have been injected with Corynebacterium parvum have mononuclear-cell infiltrates in the liver lobules. In such mice a small dose of lipopolysaccharide endotoxin produced a lethal hepatitis, with high serum-transaminase concentrations, glycogen depletion, and hypoglycaemia. It is suggested that lipopolysaccharide triggers the release from the infiltrating mononuclear cells of factors toxic for hepatocytes. Similarly certain parasitic and virus infections and graft-versus-host reactions can sensitise mice to the induction of hepatitis by exposure to small doses of lipopolysaccharide. This model may be applicable to human hepatitis.
Lancet 1978 Sep 16
PMID:Role of mononuclear infiltrating cells in pathogenesis of hepatitis. 8 May 31

A comparison of the in vivo and in vitro antibody response capabilities of two marmoset species, Saguinus fuscicollis and Saguinus oedipus oedipus, revealed the former to be superior in elaborating humoral antibody. In vivo challenges with Escherichia coli lipopolysaccharide (LPS) and Salmonella typhi flagella consistently yielded higher antibody titres in S. fuscicollis; indeed, with LPS antigen, multiple inoculations of S.o. oedipus marmosets led ultimately to a decrease in antibody formation, in contrast to the anamnestic response of S. fuscicollis. This species differential in immune competence was also suggested in the in vitro stimulation of peripheral blood leucocytes (PBL) and spleen cells with sheep red blood cells (RBC). None of 55 S.o. oedipus PBL cultures and 49 of 89 (55%) S. fuscicollis cultures responded to the test antigen. A similar differential in response to sheep RBC was noted with the spleen cells of each species, although this report contrasts the antibody-forming potential of two marmoset species, a comparison of the immunological response profile of marmosets to those of other laboratory animals challenged with similar antigens suggests these primates may be relatively incompetent. The possible relationship between the haemopoietic chimerism of marmosets and a diminished immune competence is discussed.
Immunology 1978 Sep
PMID:Marmoset species variation in the humoral antibody response: in vivo and in vitro studies. 10 Apr 17


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