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)

Earlier studies, which indicated that high titers of O-specific antibody to the patient's infecting organism in acute-phase serum specimens were not associated with a decrease in the frequency of subsequent shock and death in bacteremia due to gram-negative bacilli, were reexamined for evaluation of the protective activity of specific IgG and IgM antibody. Titers of hemagglutination antibody and levels of IgM, determined by indirect immunofluorescent staining of the patient's infecting organism, as well as hemagglutination titers after reduction of serum with 2-mercaptoethanol and IgG levels, correlated closely (P less than 0.001). High titers of IgG antibody to the patient's infecting organism in acute-phase specimens were associated with a significant reduction in the frequency of shock and death in bacteremia. In contrast, high titers of IgG antibody were not associated with a diminution in the frequency of shock and death. The previously demonstrated protective activity of antibody to an antigen, Re lipopolysaccharide, shared by most gram-negative bacilli was reconfirmed and shown to be independent of the protective activity of O-specific IgG antibody.
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PMID:Effects of IgM and IgG antibody in patients with bacteremia due to gram-negative bacilli. 5 97

Lipopolysaccharide antigens were extracted from heated cell extracts of several serotypes of Pseudonomas aeruginosa. Indirect hemagglutination with the extracts indicated specific reactivity with sera from rabbits immunized with homologous serotypes of P. aeruginosa. Sera from healthy adults and patients infected with P. aeruginosa were studied subsequently and shown to possess antibodies against P. aeurginosa. In patients infected with P. aeruginosa type E, indirect hemagglutination antibody against type E was resistant to 2-mercaptoethanol (2-ME) and classified as immunoglobulin G. In patients infected with any other type of P. aeruginosa and in healthy adults, it was sensitive to 2-ME and classified as immunoglobulin M. The antibody in the seven patients infected with P. aeruginosa was titrated during the course of infection with lipopolysaccharide antigen prepared from the infecting strain. As a result, all patients either possessed 2-ME-resistant antibody or showed antibody rise to homotypic antigen during the infection. However, no patient showed 2-ME-resistant antibody against hetero-typic lipopolysaccharide antigens. In hospitalized patients, the incidence of anti body against type E, G, and I Pseudomonas strains was greater than that against type A. In particular, 2-ME-resistant antibody to all four serotypes was detected at a higher rate in hospitalized patients than in healthy adults.
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PMID:Type-specific indirect hemagglutinating antibody in patients with Pseudomonas aeruginosa Infection. 10 87

The immunogenic and mitogenic properties of Brucella abortus 1119-3 bacterin (BA) and biologically active B. abortus lipopolysaccharide (BA-LPS) were studied using normal and athymic (nude) BALB/c and C3H/HeJ mice. Although BA stimulated 2-mercaptoethanol-sensitive (2-ME-S) primary and secondary antibody responses in all mice, nude mice, in contrast to normal BALB/c and C3H/HeJ mice, did not make substantial 2-mercaptoethanol-resistant (2-ME-R) antibody responses. Similarly, all mice injected with BA-LPS made 2-ME-S primary responses, and the secondary response of thymus-bearing mice contained a substantial 2-ME-R component. Collectively, these observations suggest that although both BA and BA-LPS can stimulate thymus-independent 2-ME-S antibody synthesis, thymus-derived cells are required for optimal immune responses containing a 2-ME-R component. The antibody responses of normal BALB/c and C3H/HeJ mice to BA and BA-LPS were qualitatively and quantitatively similar. Both BA and BA-LPS were mitogenic for spleen cells from normal and nude BALB/c and C3H/HeJ mice but not for thymus cells from normal BALB/c or C3H/HeJ mice, suggesting that both preparations are B-cell mitogens.
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PMID:Immune and mitogenic responses by BALB/c, C3H/HeJ, and nude mice to Brucella abortus bacterin and lipopolysaccharide. 11 Jun 98

A number of polyacrylamide gel systems and solubilization procedures were studied to define the number and nature of "major" polypeptide bands in the outer membrane of Pseudomonas aeruginosa. It was shown that five of the eight major outer membrane proteins were "heat modifiable" in that their mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis was determined by the solubilization temperature. Four of these heat-modifiable proteins had characteristics similar to protein II of the Escherichia coli outer membrane. Addition of lipopolysaccharide subsequent to solubilization caused reversal of the heat modification. The other heat-modifiable protein, the porin protein F, was unusually stable to sodium dodecyl sulfate. Long periods of boiling in sodium dodecyl sulfate were required to cause conversion to the heat-modified form. This was demonstrated both with outer membrane-associated and purified lipopolysaccharide-depleted protein F. Furthermore, lipopolysaccharide treatment had no effect on the mobility of heat-modified protein F. Thus it is concluded that protein F represents a new class of heat-modifiable protein. It was further demonstrated that the electrophoretic mobility of protein F was modified by 2-mercaptoethanol and that the 2-mercaptoethanol and heat modification of mobility were independent of one another. The optimal conditions for the examination of the outer membrane proteins of P. aeruginosa by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis are discussed.
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PMID:Outer membrane of Pseudomonas aeruginosa: heat- 2-mercaptoethanol-modifiable proteins. 11 60

Normal human serum was shown to inhibit the mitogenic effects of bacterial lipopolysaccharide and Con A on mouse spleen lymphocytes and reduce the in vitro antibody response to SRBC by these cells. Furthermore, it was demonstrated that immune suppression occurred without loss of lymphocyte viability. Fractionation of normal human serum resulted in isolation of several immunoenhancing and immunoinhibitory fractions. Electrophoretic analysis of the immunoinhibitory fractions revealed a complex array of serum proteins. The most prominent proteins on polyacrylamide electrophoresis stained for both proteins and carbohydrate. The heterogeneity of immunoinhibitory fractions were further substantiated by their differential susceptibility to trypsin, periodate, and 2-mercaptoethanol treatment. Heterogeneity of the fractions was also shown to be related to difference in their biologic activity as expressed in their effects on mitogenicity and immunogenicity of LPS in mouse splenic cultures. This study lends evidence to the consideration that normal human serum contains several immunoregulatory factors with differing biochemical characteristics and cellular sites of action.
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PMID:Isolation and characterization of immunoregulatory factors from normal human serum. I. Preliminary biochemical and biological characterization of immunosuppressive factors. 19 Mar 15

Selective growth and clonal proliferation of human T lymphocytes can be achieved by using a single-phase semi-solid methylcellulose system without the requirement of preincubation with lectins. Significant proliferation, however, depends upon the continued presence of Con A or PHA, but not pokeweed mitogen or lipopolysaccharide within the methylcellulose. This procedure eliminates nonspecific agglutination by lectins and allows for direct visualization of colonies and their specific removal and subsequent cloning in liquid phase. Optimal growth and production of colonies greater than 40-cell size require 3 to 9 days. Individual cells can be identified on the basis of E rosette formation and absence of surface immunoglobulin or ability to phagocytize latex particles. Moreover, proliferation is inhibited by antithymocyte but not anti-B cell sera and can be demonstrated with peripheral blood T and MOLT-4 cells, but not with B or Raji cells. Finally, colony formation is not enhanced by the presence of 2-mercaptoethanol. The clonal proliferation of human T lymphocytes has wide application in the study of both antigen recognition and lymphocyte alterations in specific diseases.
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PMID:Select growth of human T lymphocytes in single phase semisolid culture. 30 80

A functional subpopulation of murine B lymphocytes proliferate in semisolid agar culture in the presence of 2-mercaptoethanol to form colonies. The effects of diffusible macrophage-derived factors on this focal proliferation was investigated using a two-layer culture system which prevented macrophage-lymphocyte contact and permitted B-cell activation to be critically assessed under conditions of extremely low cell densities. Adherent peritoneal macrophages incorporated within underlayers of spleen or lymph node cell cultures potentiated both the number and size of developing B-cell colonies. These effects were most striking when low numbers of spleen or lymph node cells, or macrophage- depleted lymphoid cell suspensions were used. Thus, macrophage-depleted lymph node ceils gave rise to virtually no colonies, but colony-forming ability was restored by the presence of an optimal number of macrophages. When the number of macrophages exceeded that required for optimal stimulation, colony formation was suppressed; an effect which was largely prevented by indomethacin, an inhibitor of prostaglandin synthesis. Under these conditions, stimulation and inhibition of B-cell activation by macrophages could be dissociated, indicating that each signal is selectively controlled by individual molecules elaborated by the macrophage. With an appropriate number of macrophages required for B-cell activation, and sufficient indomethacin to inhibit the accumulation of macrophage-derived prostaglandin, B-lymphocyte clonal proliferation was a linear function of the number of B cells placed in culture. In the absence of macrophages, B-cell colony formation was potentiated by both lipopolysaccharide and intact sheep erythrocytes through a mechanism different from that of the macrophage-derived stimulatory factor. In addition to their direct stimulatory effect on B-cell proliferation, lipopolysaccharide and sheep erythrocytes were each capable of modulating the production and/or release of B-cell stimulatory and inhibitory factors by the macrophage. Parallel studies of conventional mitogen- stimulated lymphocyte cultures did not show a requirement for macrophages and confirm that the semisolid assay is uniquely suited to studies on the regulatory role of the macrophage in B-cell activation.
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PMID:Regulation of B-lymphocyte clonal proliferation by stimulatory and inhibitory macrophage-derived factors. 30 81

Antibody-forming cells with specificities against syngeneic and allogeneic thymocytes are detected in the spleens of normal mice after activation in vitro or in vivo with lipopolysaccharide (LPS). The activity of such cells was measured in a complement-dependent plaque assay employing trypan blue dye to assess zones of lysis. Plaques were rarely seen in the absence of LPS treatment. Anti-immunoglobulin added to the plaque assay abrogated the appearance of plaques, but the addition of LPS had no effect. Furthermore, plaque formation was 2-mercaptoethanol sensitive indicating that the antibody responsible was of the IgM class. Plaque forming cells (PFC) were also detected against syngeneic and allogeneic lymph node cells and to a much lesser extent against splenocytes. The numbers of PFC found against syngeneic, allogeneic, or a mixture of thymocytes was similar and ranged from 1000 to 3000 PFC/10(8) viable spleen cells tested. All murine strains tested, including congenitally athymic nude mice, exhibited anti-thymocyte PFC after LPS activation. C3H/HeJ mice, genetically unresponsive to LPS, did not respond mitogenically to LPS and no anti-thymocyte plaques were observed. These findings suggest that clones of autoreactive B cells are present in normal mice and can be activated by LPS.
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PMID:Autoreactive antibody-forming cells directed against thymocytes and thymus-derived lymphocytes. 30 19

The mechanism by which B and T lymphocytes interact synergistically in the proliferative response to 2-mercaptoethanol (2-ME) as a mitogen was investigated in cultures of C3H/St spleen cells. The interaction between these cells required physical contact between the collaborating cell types, and was not mediated by the release of a soluble factor into the culture supernate. Sonicates of spleen cells which had been activated with optimal concentrations of 2-ME for 24 h and then washed extensively, stimulated the uptake of tritiated thymidine and morphological blast transformation of fresh, unstimulated cells. This activity was found to reside within the soluble fraction of the activated cells, and to activate cells optimally at a ratio of 1 naive cell: 1 activated cell-equivalent. This reciprocally-acting lymphocyte proliferation helper (RALPH) activity was produced by B cells as well as by T cells, with a kinetic peak at 48 h of culture. RALPH activity was produced by viable but not by nonviable cells incubated with 2-ME, and was nondialyzable. It could not be induced by the B-cell mitogens lipopolysaccharide, polyinosinic-polycytidilic acid, or purified protein derivative of tuberculin, or by the T-cell mitogen concanavalin A. RALPH isolated from T cells activated B cells exclusively, while that from B cells acted predominantly upon T cells, possibly with a nonspecific effect on B cells. A model for the cellular interactions involved in the amplification of the proliferative response to 2-ME is described.
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PMID:Nonspecific activation of murine lymphocytes. VI. Mediation of synergistic interaction between T and B lymphocytes by a cell-associated, reciprocally acting lymphocyte proliferation helper. 31 12

Antibodies directed against the protein constituents of the outer envelope membrane of Escherichia coli O26 K60 were demonstrated in antisera elicited in rabbits against three different preparations of the bacterium. Outer membraned solubilized by sodium dodecyl sulphate were applied to the antisera in an interfacial precipitin test, followed by polyacrylamide gel electrophoretic analysis of the resulting immunecomplexes. Protein profiles showed a complete outer membrane protein pattern, indicating the antigenic character of these proteins. Antisera containing antibodies against outer membrane proteins and free of reactive antibodies against lipopolysaccharide showed relatively low agglutinating activities against the bacteria. The antibodies against the protein constituents of the outer membrane belong mainly to the 7S class immunoglobulins, as indicated by 2-mercaptoethanol treatment of the antisera.
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PMID:Antibodies against outer membrane proteins in rabbit antisera prepared against Escherichia coli O26 K60. 34 33


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