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

Human and mouse lymphoid cells, stimulated by phytohemagglutinin (PHA) or lipopolysaccharide W (LPS), release supernatant factor(s) which are mitogenic for mouse thymocytes and which potentiate their responses to PHA or concanavalin A (Con A), The term LAF (lymphocyte-activating factor) is proposed for this activity. LAF not only enhances the mitotic responses of the less dense thymus subpopulations (A, B, and C) separable on discontinuous bovine serum albumin (BSA) gradients but also gives substantial responses in the otherwise inert cells of the denser fractions D and P. LAF does not exert a potentiating stimulatory effect on the responses of unfractionated mouse spleen cells, but does act synergistically with PHA on nonadherent spleen cells and on spleen cells of mice of several strains 5 days after irradiation and injection of thymocytes. Similarly LAF, which has no visible effect on unfractionated human peripheral blood cells, strongly potentiates the PHA response of column-purified lymphocytes, when these are cultured at low concentration. We conclude that LAF stimulates both central and peripheral T lymphocytes and enhances their responses to other stimulants.
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PMID:Potentiation of the T-lymphocyte response to mitogens. I. The responding cell. 503 17

Oligosaccharide was isolated from the lipopolysaccharide of Neisseria gonorrhoeae P9 following partial acid hydrolysis. The exposed terminal keto-deoxyoctonic acid group of the oligosaccharide was convert into the reactive phenylisothiocyanato derivative by reaction with 2-(4-aminophenyl)-ethylamine followed by reduction with sodium cyanoborohydride and treatment with thiophosgene. This intermediate was used to prepare an oligosaccharide-protein conjugate with either bovine serum albumin or purified gonococcal pili. Immunisation of rabbits with protein conjugates produced antibodies reactive with both pure protein and intact lipopolysaccharide.
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PMID:Synthesis of immunogenic oligosaccharide-protein conjugates from the lipopolysaccharide of Neisseria gonorrhoeae P9. 612 Jan 97

Antigen binding was used as a probe in the definition of functional B cell heterogeneity. Unprimed, anti-Thy 1 and complement-treated spleen cells were stained with fluorescent trinitrophenylated bovine serum albumin (FL-TNP-BSA). These cells were sorted, fluorescence negative from fluorescence positive, by using a multiparameter cell sorter and assayed for precursor frequency in antibody responses to TNP by limiting dilution analysis. The cells that bound FL-TNP-BSA were demonstrated to be enriched for antibody-forming precursors to the antigens TNP-lipopolysaccharide (LPS), TNP-sheep red blood cells (SRBC), and TNP- or DNP-Ficoll, whereas the fluorescence negative cells were depleted for these responses. B cells that bound FL-TNP-BSA were then sorted into populations that bound a moderate or high amount of FL-TNP-BSA. The B cells responsive to TNP-LPS and TNP-SRBC were present in both the moderate and high binding populations. In contrast, the B cells responsive to TNP- or DNP-Ficoll were present only in the cells that bound a moderate amount of FL-TNP-BSA. These experiments suggest that there is a population of B cells in adult mouse spleen that binds large amounts of antigen, and that can respond to antigen carried on LPS or SRBC but not carried on Ficoll.
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PMID:Flow sorting of antigen-binding B cell subsets. 615 84

Several elements of the phenomenon of oral tolerance were examined. It was shown that whereas intragastric (i.g.) exposure of mice to the T-dependent antigens ovalbumin (OVA), bovine serum albumin, and human gamma globulin severely compromised the ability to respond to a subsequent challenge with the homologous antigen, i.g. treatment with T-independent antigens such as dinitrophenylated Ficoll, polyvinylpyrrolidone and bacterial lipopolysaccharide (LPS) did not induce anergy. Furthermore, mice parenterally primed to OVA were not only refractory to the induction of oral tolerance with OVA, but displayed an anamnestic response following i.g. treatment with the antigen. In a final line of investigation, it was shown that whereas mice administered OVA orally lost specific T cell functions such as the ability to (a) provide helper activity; (b) proliferate in response to antigen, and (c) mediate delayed-type hypersensitivity, such animals possessed OVA-specific functional B cells as evidenced by the ability to respond to OVA when the antigen was administered either linked to a recognizable carrier or in conjunction with LPS.
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PMID:Orally induced tolerance. Definition at the cellular level. 616 88

Several saccharides representative of the O-antigenic polysaccharide chain of Salmonella typhimurium (O antigens 4 and 12) were used as haptenic groups covalently linked to bovine serum albumin. The disaccharide abequose 1 --> 3 D-mannose was synthesized, and the [Formula: see text] tetra-, octa- and dodecasaccharides were isolated after cleavage of isolated S. typhimurium O-polysaccharide chains by using bacteriophage endo-glycosidases. Rabbits immunized with the saccharide-protein conjugates suspended in Freund complete adjuvant readily responded with O4 antibody titers as high, or almost as high, as those elicited by heat-killed bacteria. The octa- and dodecasaccharide conjugates also gave rise to O12 antibody titers. The antibody response in mice differed in two ways from that seen in rabbits: mice did not respond with measurable antibody production against the disaccharide haptens, and the highest S. typhimurium lipopolysaccharide antibody response elicited by the saccharide haptens was still approximately 50-fold lower than that elicited by heat-killed bacteria. The latter difference may be a consequence of the fact that the mouse preferentially produces antibodies against the galactose residue which is terminal in the hapten but not in the native O-antigenic polysaccharide chain. Antibodies elicited in rabbits against all saccharide-protein conjugates protected passively transferred mice against intraperitoneal challenge with 100 times the 50% lethal dose of S. typhimurium SH 2201 (O4, 12) but not against challenge with S. enteritidis SH 2204 (O9, 12). The antibodies elicited by the saccharide-protein conjugates protected as well as antibodies elicited by heat-killed bacteria.
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PMID:Artificial Salmonella vaccines: Salmonella typhimurium O-antigen-specific oligosaccharide-protein conjugates elicit protective antibodies in rabbits and mice. 616 55

Murine spleen and lymphoma cells were almost completely enucleated in suspension by centrifugation in discontinuous Ficoll gradients in the presence of cytochalasin-B. Viability of cytoplasts (cells lacking nuclei) and karyoplasts (nuclei) was over 90%. Pure fractions of cytoplasts or karyoplasts were then obtained by fractionation of the cytochalasin-B treated cells with unit gravity sedimentation in bovine serum albumin. Protein synthesis was seen in cytoplasts when they were stimulated with mitogens, such as lipopolysaccharide (LPS). This method can consistently yield pure fractions of morphologically and functionally intact karyoplasts or cytoplasts from normal lymphocytes with very low contamination of nucleated cells. Pure karyoplasts or cytoplasts obtained in this way could be extremely useful for subcellular analysis of lymphocyte activation.
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PMID:Purification of cytoplasts (enucleated cells) and karyoplasts (nuclei) from mouse splenic lymphocytes with cytochalasin-B. 616 67

The mechanism of influenza virus (INFV)-induced immunosuppression and the mode of inosiplex action against INFV infection were studied. INFV suppressed both anti-lipopolysaccharide and anti-sheep erythrocyte antibody production in mice. INFV infection caused viral mRNA synthesis and increased total RNA synthesis in lymphocytes, but total mRNA synthesis was decreased. The translational ability of INFV-infected lymphocytes was also suppressed. Thus, INFV seemed to cause suppression of both mRNA synthesis and the translational ability of lymphocytes, resulting in suppression of lymphocyte functions. Inosiplex potentiated antibody production against sheep erythrocytes but not against lipopolysaccharide in normal and INFV-infected mice. Adamantanamine did not produce such a potentiating effect. The lymphocytes obtained from INFV-immunized and inosiplex-treated mice conferred resistance against INFV infection. This resistance was partially inhibited by anti-Thy 1.2 antibody treatment of the lymphocytes. In an adoptive cell transfer system, inosiplex treatment of T-cell donors potentiated antibody production when a non-immunosuppressive carrier (human serum albumin) was used. When an immunosuppressive carrier (INFV) was used, inosiplex treatment of either B-cell donors or T-cell donors increased antibody production. Direct introduction of inosiplex into lymphocytes by a cell fusion technique stimulated anti-sheep erythrocyte antibody production more effectively than the addition of inosiplex to cultures. Inosiplex increased total RNA and total mRNA syntheses in phytohemagglutinin-treated lymphocytes. In INFV-infected lymphocytes, inosiplex decreased syntheses of total RNA, total mRNA, and viral mRNA and restored translational ability. From these results, we concluded that inosiplex penetrates into lymphocytes and suppresses viral RNA synthesis and that it supports lymphocyte functions by promoting RNA synthesis and translational ability, both of which are necessary for hosts.
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PMID:Mechanism of host defense suppression induced by viral infection: mode of action of inosiplex as an antiviral agent. 618 9

We prepared a dodecasaccharide, specific for the O-antigenic polysaccharide chain of Salmonella typhimurium (O-antigens 4 and 12), by the partial hydrolysis of the O-polysaccharide chain, utilizing bacteriophage 28B endo-alpha-L-rhamnosidase. The dodecasaccharide was shown by chemical and spectroscopical analyses to be totally devoid of lipid A and core oligosaccharide. By coupling this dodecasaccharide to human serum albumin, a glycoconjugate (DODECA-4809-ITC-HSA) was prepared and found to be (i) nonpyrogenic, (ii) unable to gelate a Limulus amoebocyte lysate, and (iii) unable to induce early-phase pyrogenic tolerance to endotoxin. Rabbits immunized either intravenously (with the glycoconjugate suspended in saline) or intrapopliteally (with the glycoconjugate suspended in Freund complete adjuvant) developed a significant although modest pyrogenic tolerance against challenge with the O-antigenic homologous S. typhimurium lipopolysaccharide (P less than 0.025 and P less than 0.01 for immunized and control rabbits, respectively). The evoked tolerance was O-antigen specific since no pyrogenic tolerance against challenge with lipopolysaccharide from S. thompson (possessing identical lipid A and core oligosaccharide structures but differing in the O-antigen polysaccharide chain) could be seen (P greater than 0.1). These results demonstrate that a nonpyrogenic O-antigenic polysaccharide hapten, when coupled to an immunogenic carrier protein, evokes immune responses which mediate significant, although modest, late-phase tolerance and is capable of partly reducing the pyrogenic activity of the O-antigenic homologous lipopolysaccharide.
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PMID:Induction of endotoxin tolerance with nonpyrogenic O-antigenic oligosaccharide-protein conjugates. 619 67

We investigated the pathogenesis of increased glomerular permeability in Balb/c mice after 5 weeks of administration of a polyclonal B cell activator (bacterial lipopolysaccharide). The glomerular transfer of anionic ferritin across the capillary walls and the urinary excretion of serum albumin served as probes of glomerular permeability; anionic groups of the glomerular basement membrane were assessed by the binding of cationized ferritin, and glomeruli were studied by light, immunofluorescence, and electron microscopy. The mice developed circulating immune complexes, proteinuria, and a proliferative glomerulonephritis, with mesangial and capillary loop deposits of immunoreactants. Increased transfer of anionic ferritin molecules occurred across capillary walls with and without demonstrable electron-dense deposits; detachments of visceral epithelium were not seen, and epithelial transport of anionic ferritin was negligible. Loss of anionic groups was extensive in glomerular capillary loops with and without associated electron-dense deposits. The findings indicate that an increase in glomerular permeability may precede the deposition of immunoreactants in the capillary wall; that filtration of macromolecules can occur across capillary walls with or without demonstrable immune deposits; and that loss of anionic groups of the glomerular basement membrane and enhanced filtration of macromolecules can occur in the absence of focal detachments of the visceral epithelium.
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PMID:Altered glomerular permeability in the early phase of immune complex nephritis. 622 69

We have compared two components of bacterial cell walls, muramyl dipeptide (MDP) and lipopolysaccharide (LPS), for their effects on bone resorption as measured by the release of previously incorporated 45Ca. MDP is the smallest active component of peptidoglycan, whereas LPS is the active component of endotoxin. Fetal rat long bones were cultured for 5 days in a chemically defined medium supplemented with bovine serum albumin (BSA) or serum. LPS increased 45Ca release at concentrations of 0.03-1.0 microgram/ml. LPS further purified by electrolytic dialysis (ED-LPS) was active at 0.01 microgram/ml. ED-LPS was ineffective at such low concentrations in the presence of serum. The response to MDP was more variable than that to LPS, but bone resorption was stimulated at concentrations of 10(-7)-10(-5) M. MDP was less effective or inactive in medium supplemented with serum. Stereoisomers of MDP that do not have adjuvant activity caused minimal stimulation of bone resorption, whereas 6-0-steroyl MDP stimulated resorption at 10(-8) M. The stimulation of bone resorption by LPS and MDP was not inhibited by indomethacin. Both LPS and MDP increased lysosomal enzyme release in proportion to their effects on 45Ca release. LPS also markedly increased collagenase activity in the medium, but MDP did not. These results indicate that chemically different products of bacterial cell walls can stimulate bone resorption in vitro. These products may be distinguished by differences in dose response curve, serum inhibition, and collagenase release.
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PMID:Effects of two bacterial products, muramyl dipeptide and endotoxin, on bone resorption in organ culture. 629 30


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