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)

Female B6C3F1 mice were given i.p. injections with 1.5, 3.0 and 5.0 mg/kg N-nitrosodimethylamine (DMN) daily for 14 days and evaluated on day 15. The day 4 immunoglobulin M (peak day) antibody response to sheep red blood cells (sRBC) was inhibited by 20, 53 and 81%, respectively. The day 5 immunoglobulin G (peak day) antibody response to sRBC was only inhibited significantly (60%) at the highest dose. Recovery studies indicated that the IgM antibody response was still significantly inhibited (48%) 30 days after the completion of the exposure to 5 mg/kg of DMN. The peak response (day 3) to 100 micrograms of the B-cell mitogen, lipopolysaccharide, was inhibited by 15, 26 and 32%, respectively, indicating that a portion of the suppression of the antibody response by DMN may be due to an effect on the ability of the lymphocytes to proliferate. Concentrations of DMN up to 100 mM added directly to untreated spleen cell suspensions had no effect on the in vitro antibody responses to lipopolysaccharide and sRBC. Preincubating DMN (100 mM) with either phenobarbital-induced or 3-methylcholanthrene-induced liver proteins (postmitochondrial supernatant from a 9000 X g liver homogenate) was still ineffective. The activation of DMN by either preparation was verified by measuring formaldehyde production, which reflects demethylation. In contrast to the results with DMN added directly to untreated spleen cell suspensions, the most sensitive indicator of suppression by DMN was the in vitro antibody responses to lipopolysaccharide and sRBC by spleen cell suspensions from DMN-treated mice.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of N-nitrosodimethylamine on humoral immunity. 671 71

Antisera against isolated outer membrane (OM) proteins I and II of Escherichia coli O26 K60 were elicited in rabbits. Antisera obtained after intramuscular administration with Freund's complete adjuvant showed high titres of specific antibodies. Intravenous administration of the same preparations yielded a considerable antibody response against bacterial lipopolysaccharide, a minor contaminant of the protein preparations. Antibody titres against OM proteins I and II, lipopolysaccharide and murein-lipoprotein were determined by the enzyme-linked immunosorbent assay (ELISA) in these sera, and in antisera elicited against whole formaldehyde-fixed bacteria or isolated OM. Comparison of ELISA with single radial immunodiffusion and interfacial immunoprecipitation tests revealed that ELISA was not only the most uniformly applicable, but also the most specific and the most convenient method. In double diffusion tests no cross-reactivity between proteins I and II was seen. Antibodies against proteins I and II, lipopolysaccharide and lipoprotein could be specifically absorbed from the sera with the appropriate antigen preparations. Absorption experiments with intact E. coli O26 K60, Tris/EDTA-sheared bacteria and isolated OM revealed that antibodies against protein I were hardly absorbed at all probably because the antibody, evoked against denatured protein I, did not react with the protein in its native configuration. Antibodies against protein II and lipoprotein were absorbed by intact as well as by sheared bacteria, but to a much greater extent by isolated OM, which indicates that these OM components are accessible from the outside, but that they are situated relatively deep in the OM structure.
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PMID:Preparation and quantitative determination of antibodies against major outer mambranes proteins of Escherichia coli O26 K60. 677 43

A "new" polyclonal activator of human peripheral blood B cells, formaldehyde-fixed Salmonella paratyphi B, is described. This bacterium does not stimulate cell proliferation as measured by incorporation of tritiated thymidine but does stimulate a subpopulation of B cells to secrete large amounts of IgM, IgG, and IgA in 7-day cell cultures. The immunoglobulins (Ig) produced by cells responding to S. paratyphi B are not specific antibodies against the bacterial antigens. In comparison with other B cell activators (pokeweed mitogen, Staphylococcus aureus Cowan I, and lipopolysaccharide), S. paratyphi B stimulation produced greater amounts of IgM but less IgG than pokeweed mitogen (PWM) or S. aureus Cowan I; lipopolysaccharide failed to stimulate significant Ig production on day 7 in most cases. In addition, the response to S. paratyphi apparently did not require T cell collaboration. These results suggest that the B cell subpopulation(s) responding to S. paratyphi B may be more differentiated B cells than those responding to either PWM or S. aureus Cowan I. Peripheral blood mononuclear cells from five patients with common variable immunodeficiency without evidence of abnormal suppressor T cells or monocytes failed to respond to S. paratyphi B, whereas cells from two of the same patients responded well to S. aureus Cowan I and partially to PWM. Thus, S. paratyphi B appears to be superior to other B cell activators for studies of B cell function in normal and abnormal states.
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PMID:Polyclonal activation of human peripheral blood B lymphocytes by formaldehyde-fixed Salmonella paratyphi B. I. Immunoglobulin production without DNA synthesis. 697 34

The effects of heat and chemical inactivation on the antigenicity and immunogenicity of Vibrio cholerae 1418 in rabbits were studied. V. cholerae 1418 was inactivated with heat and chemical inactivants (phenol or Formalin) alone or in combination. Enzyme-linked immunoassay systems employing whole cells of V. cholerae 1418, lipopolysaccharide, or flagella as immobilized antigens were used to measure the antibody response (immunoglobulins G and M) after parenteral immunization of rabbits with various inactivated whole-cell preparations. The "classical" whole-cell vaccine, produced by phenol treatment, was found to be a comparatively poor immunogen. When Formalin was used instead of phenol, the antibody response to all three enzyme-linked immunosorbent assay antigens was greatly increased. Immunoglobulin G titers to intact V. cholerae cells were as much as 100-fold higher in rabbits immunized with the Formalin-inactivated preparation as compared to the classical phenol-inactivated vaccine. Furthermore, antibody produced against the Formalin-inactivated preparation was capable of recognizing antigenic determinants expressed on the cell surface of several heterologous strains of V. cholerae. These results indicate that the antigenicity and immunogenicity of V. cholerae are greatly affected by the inactivation conditions employed for vaccine production and that Formalin is much superior to phenol as an inactivant under the conditions employed in the present study.
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PMID:Effect of chemical and heat inactivation on the antigenicity and immunogenicity of Vibrio cholerae. 714 90

A recombinant 23-kDa amino-terminal fragment of human bactericidal/permeability-increasing protein (rBPI23), a potent lipopolysaccharide (LPS)-binding/neutralizing protein, was used as a probe to assess the role of endotoxin in the acute inflammatory responses elicited by gram-negative bacteria in rat subcutaneous air pouches. In initial experiments, rBPI23 prevented the Escherichia coli O111:B4 LPS-induced accumulation of polymorphonuclear leukocytes (PMN), tumor necrosis factor alpha (TNF-alpha), and nitrite (a stable end product of nitric oxide formation) in exudate fluids. Significant inhibition of TNF-alpha production was still evident when rBPI23 treatment was delayed for 30 min after LPS instillation. In subsequent experiments, rBPI23 also prevented the nitrite and early (2-h) TNF-alpha accumulation induced by three different strains of formaldehyde-killed gram-negative bacteria (E. coli O7:K1, E. coli O111:B4, and Pseudomonas aeruginosa 12.4.4) but did not inhibit the PMN or late (6-h) TNF-alpha accumulation induced by these bacteria. As with LPS challenge, a significant inhibition of early TNF-alpha production was still evident when rBPI23 treatment was delayed for 30 to 60 min after instillation of killed bacteria. The results indicate that in this experimental model the NO and early TNF-alpha responses to gram-negative bacterial challenge are mediated predominantly by endotoxin, whereas the PMN and late TNF-alpha responses may be mediated by other bacterial components. Moreover, the results indicate that rBPI23 can inhibit the bacterially induced production of certain potentially harmful mediators (TNF-alpha and NO) without entirely blocking the host defense, i.e., PMN response, against the bacteria.
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PMID:Role of endotoxin in acute inflammation induced by gram-negative bacteria: specific inhibition of lipopolysaccharide-mediated responses with an amino-terminal fragment of bactericidal/permeability-increasing protein. 780 73

We have investigated the interaction of Salmonella minnesota R595 lipopolysaccharide (ReLPS) depleted of Ca2+ and Mg2+ with both Kupffer and endothelial liver cells under serum-free conditions. Specific and saturable binding levels of 125I-ReLPS were similar in both types of cells with respect to divalent cation independence, susceptibility to proteases, and concanavalin A inhibition. By using partial structures of ReLPS, it was demonstrated that acidic 3-deoxy-D-manno-octulosonic acid residues and phosphoryl groups on lipid A are of primary importance in ReLPS binding. The role of ionic interactions in LPS recognition by the cells was further confirmed by susceptibility of the binding to competitive inhibition by polyanions. Both ReLPS and ReLPS partial structures inhibited the specific cellular binding of acetylated low-density lipoprotein (Ac-LDL) by Kupffer cells and Ac-LDL- and formaldehyde-treated albumin by endothelial cells whose cellular accumulation is mediated by a different type(s) of scavenger receptor(s). In contrast, 125I-ReLPS binding to Kupffer and endothelial cells was not competed by Ac-LDL or formaldehyde-treated albumin. Our results indicate the scavenger pathway of LPS uptake by Kupffer and endothelial cells and the primary role of LPS anionic properties in this process.
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PMID:Scavenger receptor pathway for lipopolysaccharide binding to Kupffer and endothelial liver cells in vitro. 786 58

This is the first documentation that Borrelia burgdorferi-specific T lymphocytes are involved in the pathogenesis of Lyme arthritis. We present direct evidence that T lymphocytes obtained from inbred LSH hamsters vaccinated with a whole-cell preparation of Formalin-inactivated B. burgdorferi sensu stricto isolate C-1-11 in adjuvant conferred on naive recipient hamsters the ability to develop severe destructive arthritis when challenged with B. burgdorferi sensu stricto isolates C-1-11 and 297. By contrast, recipients infused with normal T lymphocytes and challenged with B. burgdorferi sensu stricto isolates C-1-11 and 297 failed to develop severe destructive arthritis. The T lymphocytes transferred were obtained from the lymph nodes of vaccinated and nonvaccinated hamsters by depleting B lymphocytes by using monoclonal antibody 14-4-4s (< 1% B lymphocytes by flow cytometric analysis). The enriched T lymphocytes showed enhanced proliferation to stimulation with concanavalin A and failed to respond to lipopolysaccharide. Moreover, only the enriched T lymphocytes from vaccinated hamsters proliferated on exposure to a whole-cell preparation of B. burgdorferi sensu stricto isolate C-1-11 in the presence of mitomycin-treated syngeneic antigen-presenting cells. These results demonstrate that B. burgdorferi-specific T lymphocytes primed by vaccination with a whole-cell preparation of inactivated B. burgdorferi sensu stricto isolate C-1-11 in adjuvant are involved in the development of severe destructive arthritis. Additional experiments are needed to define the precise mechanism(s) responsible for the development of Lyme arthritis.
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PMID:Borrelia burgdorferi-specific T lymphocytes induce severe destructive Lyme arthritis. 789 Apr 2

In view of the controversy concerning the expression of chlamydial lipopolysaccharide (LPS) in the eukaryotic host cell, the presence of this molecule was examined in three cell types which were experimentally infected with Chlamydia trachomatis serotype E. LPS was detected in the McCoy cell line, human endometrial epithelium and human amniotic epithelium with two monoclonal antibodies. The appearance and distribution of LPS at the host cell surface during the chlamydial developmental cycle and its transmission to neighbouring cells were examined by immunofluorescence microscopy after air drying of the host cells. LPS distribution was not uniform; it was first observed on regions of the cell surface in close proximity to the chlamydial endosome (inclusion). Soon after, the antigen was also detected at points of contact with neighbouring uninfected cells. Immunofluorescent plaques of host cells contaminated with LPS were thus formed in the vicinity of infected cells. These plaques increased in size over 2 d before becoming smaller as host cell lysis occurred. The major outer-membrane protein (MOMP) was not visualized on the host cell surface after air drying. No cell-surface LPS antigen was observed in live cells or those fixed in formaldehyde without air drying. Conventional methanol fixation and immunolocalization of LPS and MOMP in parallel infected cultures stained these antigens within inclusions in the expected fashion. Radio-immunoassays were used to quantify LPS in confluent McCoy cell monolayers during the chlamydial developmental cycle. Cell-surface-associated and inclusion-associated LPS, measured by direct binding of 125I-labelled anti-LPS monoclonal antibodies to air-dried or methanol-fixed monolayers respectively, increased for up to 3 d then declined.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Lipopolysaccharide in cells infected by Chlamydia trachomatis. 792 Dec 50

Tumor necrosis factor (TNF) of hepatic origin is thought to play a pivotal role early in the genesis of the septic shock syndrome, regardless of microbial etiology. To determine if production of TNF by Kupffer cells varies with microbial taxonomic class, we measured TNF secretory responses in primary cultures of rat Kupffer cells to numerically equivalent gram-negative bacterial or fungal phagocytic challenges. After a 30-min exposure to media, latex beads, soluble Escherichia coli lipopolysaccharide (LPS; serotype 055:B5), live or Formalin-fixed E. coli (serotype 055:B5), live or Formalin-fixed yeast-phase Candida albicans, or live hyphal-phase Candida, samples of culture supernatant were assessed at 30, 60, 120, and 240 min and at 24 h for TNF bioactivity by L929 cell cytotoxicity. Compared with media and latex bead controls, TNF levels progressively increased for up to 240 min after either LPS and equivalently in live E. coli or Formalin-fixed E. coli groups (P < 0.05). Formalin-fixed yeast-phase and live extracellular hyphal-phase C. albicans failed to stimulate production of TNF at any time point (6.9 +/- 0.7 and 8.7 +/- 0.4 U/ml, respectively, at t = 240 min; P < 0.05 vs. E. coli). In contrast, internalization of live yeast-phase C. albicans with subsequent hyphal formation and growth within Kupffer cells was accompanied by a rise in supernatant TNF levels (14.5 +/- 1.8 U/ml at t = 240 min).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differential production of TNF by Kupffer cells after phagocytosis of E. coli and C. albicans. 807 22

Twelve hybridoma clones producing monoclonal antibodies to Afipia felis, a putative causative agent of cat scratch disease, were derived from BALB/c mice immunized with A felis. All 12 monoclonal antibodies were species-specific for A felis and reacted with lipopolysaccharide antigens of A felis. These monoclonal antibodies belong to immunoglobulin (Ig) G1, IgG2a, IgG2b, IgG3, and IgM isotypes. All monoclonal antibodies reacted with both agar-grown A felis and tissue culture-propagated A felis. Formalin fixation did not alter the reactivity of the antigen with the monoclonal antibodies. These monoclonal antibodies could be a useful tool for investigation of the disputed role of A felis in cat scratch disease.
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PMID:Monoclonal antibodies to Afipia felis--a putative agent of cat scratch disease. 817 67


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