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

Effective immunization against infection with Pseudomonas aeruginosa is difficult to evaluate because agglutinin levels decline rapidly. Because fractionation of hyperimmune sera often yields more specific antibody than can be accounted for by direct agglutination tests, an immunoglobulin-specific assay based on antiglobulin augmentation was used to characterize antibody responses of C3H/HeJ mice vaccinated with P. aeruginosa type 2 lipopolysaccharide. Nonagglutinating antibodies, initially detected at 2 weeks post-primary vaccination, were predominantly immunoglobulin G after 5 weeks, and they remained elevated at levels usually 32-fold higher than the direct titer throughout the 4-month study period. The sequential production of immunoglobulin M, then immunoglobulin G, followed that found in orthodox immunological responses. Sera that contained nonagglutinating antibodies but not direct agglutinins (14 to 16 weeks) enhanced phagocytosis of P. aeruginosa type 2 by macrophages from unimmunized mice and passively immunized mice against lethal challenge doses; bactericidal activity of these sera was not demonstrated in the presence or absence of complement. When challenged with 1, 10, and 100 50% lethal doses at 16 weeks, survival rates of actively immunized mice were significantly higher than those of unvaccinated mice (P < 0.001). Thus, at a time when no direct agglutinins were detectable, the augmented system detected nonagglutinating antibodies that could confer protracted resistance in vaccinated mice to pseudomonas infection.
Infect Immun 1978 Sep
PMID:Role of nonagglutinating antibody in the protracted immunity of vaccinated mice to Pseudomonas aeruginosa infection. 10 67

The smooth lipopolysaccharide complex of the outer surface of smooth Brucella abortus cells is believed to be the antigenic component involved in serological tests routinely used for the diagnosis of brucellosis. Sera from cattle vaccinated or infected with B. abortus generally contain antibody directed toward the smooth lipopolysaccharide complex. The brucella organism contains a large number of other antigenically distinct components. The biological significance of some of these antigens has been demonstrated by showing that sera from infected cattle have precipitins to these components. These sera revealed up to seven distinct lines in immunoelectrophoresis with a protein-rich antigen mixture prepared from rough strain B. abortus 45/20, whereas sera from strain 19-vaccinated cattle did not reveal these lines at 4 or more months after vaccination. Monospecific antisera were prepared against six antigens in this mixture, and the purification of two of them by antibody affinity chromatography is described.
Infect Immun 1978 Sep
PMID:Antibody response to antigens distinct from smooth lipopolysaccharide complex in Brucella infection. 10 70

Mice peritoneal macrophages cultured in vitro release a prostaglandin-like activity as evaluated by a bio-assay using Rat stomach fundus. The prostaglandin release is greatly increased when macrophages are incubated with the supernatant of mixed lymphocyte cultures between recipient and donor of a skin allograft. This phenomenon was found in all strains of Mice tested except C3H/HeJ Mice, a strain already known for its defective responsiveness to bacterial lipopolysaccharide (LPS).
C R Acad Hebd Seances Acad Sci D 1978 Sep 25
PMID:[Effect of lymphokines produced in a grafted system on production of prostaglandins by macrophages]. 10 46

Artificial antigens were obtained on the basis of the polysaccharide component of P. aeruginosa complexed with an indifferent protein. Immunological study indicated that the specific polysaccharide of P. aeruginosa lipopolysaccharide contained two structures, high molecular and low molecular, having qualitative and quantitative differences in their hydrocarbon composition. Artificial complex antigens possessed serological and immunogenic properties, the low molecular polysaccharide fraction complexed with protein having less pronounced serological and immunogenic activity than polysaccharide and the high molecular fraction complexed with protein. Antificial complex antigens exerted no protective effect in generalized P. aeruginosa infection in rats.
Zh Mikrobiol Epidemiol Immunobiol 1979 Sep
PMID:[Immunologic study of artificial complex antigens obtained from P. aeruginosa lipopolysaccharides]. 11 86

This study shows that the capsular polysaccharide, protein, and lipopolysaccharide antigens from the outer membrane of Neisseria meningitidis group B serotype 2 may be identified by crossed immunoelectrophoresis. By using this technique, seven precipitates were resolved when outer membrane preparations were reacted against goat anti-whole cell group B type 2 antiserum. Most of these precipitates were identified by comparison with purified reference preparations. Different outer membrane preparations, reflecting different growth conditions, varied in their compositions of lipopolysaccharide, protein, and polysaccharide. Detergent treatment altered the protein and lipopolysaccharide precipitation patterns. In the presence of detergent, the lipopolysaccharide did not precipitate, and the electrophoretic migration of the protein antigens decreased. Crossed immunoelectrophoresis is a useful qualitative method for analysis of the antigenic components of the meningococcal outer membrane. The crossed immunoelectrophoresis with intermediate gel technique is presently being used to measure the human immune response to the different cell surface components.
Infect Immun 1979 Sep
PMID:Outer membrane antigens of Neisseria meningitidis group B serotype 2 studied by crossed immunoelectrophoresis. 11 91

The maturation level of the B-lymphocyte subpopulations involved in trinitrophenyl (TNP)-specific immunological tolerance in adult mice induced by the injection of trinitrobenzenesulfonic acid (TNBS) was investigated using in vitro antigen-specific and nonspecific polyclonal stimulation. The maturity of the B-cell subsets being studied was defined by the antigen or polyclonal activator which evoked a response. Thus, the thymic independent (TI-1) antigen TNP-lipopolysaccharide (TNP-LPS) and the polyclonal stimulant LPS were used to activate immature, neonatal-type B lymphocytes, whereas mature, adult-type B cells were responsive to the TI-2 antigen, TNP-Ficoll, and the nonspecific activator, purified protein derivative (PPD). Whereas unresponsiveness in TNP-LPS-reactive (immature) B cells 4 d after TNBS treatment was previously shown to be the result of functional deletion, partially reversible receptor blockade was detected in this study early after tolerogen treatment. By the 24-h point, tolerance was irreversible, as assessed by 24-h of antigen-free incubation and cocultivation of tolerant cells with control splenocytes. Tolerance was induced more rapidly in immature, TI-1 B cells than in mature TI-2 B lymphocytes. B lymphocytes reactive to TNP-Ficoll were also less susceptible to receptor blockade. Using LPS as a nonspecific probe for immature B cells, 60% tolerance in high affinity TNP-specific cells was induced within 12 h of TNBS treatment, and complete unresponsiveness by 24 h. In contrast, no significant decrease in response to the mature B-cell activator, PPD, occurred until day 2. Furthermore, the 50% tolerance level was achieved in TNP-specific LPS-reactive B cells by 100 times less tolerogen than required for PPD-responsive cells. Thus, TNBS-induced unresponsiveness in cells reactive to TNP-LPS is initially a result of reversible receptor blockade which leads within 4 d to functional deletion. Immature, TI-1 B lymphocytes, which give polyclonal responses to LPS and antigen-specific responses to TNP-LPS, are rendered tolerant to TNBS more rapidly and at lower tolerogen does than mature, TI-2 mouse B cells which react polyclonally to PPD and specifically to TNP-Ficoll. Moreover, these data show that both the immature and the mature B lymphocyts with these characteristic tolerance susceptibilities and specific and nonspecific immune response patterns are present in the adult mouse spleen.
J Exp Med 1979 Sep 19
PMID:The induction of hapten-specific immunological tolerance and immunity in B lymphocytes. VI. Differential tolerance susceptibility in adult spleen as a function of B-cell maturation level. 15 60

The effect of polymyxin on two sets of Salmonella mutants was studied by thin-section and scanning electron microscopy. Polymyxin (in increasing concentrations, starting just below bactericidal effect) caused the appearance of the previously described rodlike projections on the cell surface of wild-type (smooth, polymyxin-sensitive) bacteria. These projections seemed to involve the outer membrane of the cell wall. In rough mutants, which are deficient in lipopolysaccharide, the projections were much smaller and flat. Higher concentrations of polymyxin were required to produce morphological effects in polyxmin-resistant mutants of both smooth and rough forms. Furthermore, in these mutants polymyxin caused vesicle-like bulging of the total outer membrane quite different in appearance from the rodlike projections of the wild type.
J Bacteriol 1976 Sep
PMID:Effect of polymyxin on the ultrastructure of the outer membrane of wild-type and polymyxin-resistant strain of Salmonella. 18 75

Xenogeneic and allogeneic antisera to the major envelope glycoprotein (gp71) of murine leukemia viruses (NyLV) inhibited the mitogenic response of normal mouse splenic lymphocytes to phytohemagglutinin (PHA) and lipopolysaccharide (LPS). This inhibition was specific for gp71 as demonstrated by the inability of xenogeneic antisera to other viral glycoproteins or structural proteins to inhibit and by the ability of purified antigens to block specifically the inhibitory effect. The ability of antisera to gp71 to inhibit LPS responses, however, is highly dependent on the strain and age of mouse spleen cells used and appears correlated with the expression of endogenous viruses. Moreover, the preferential inhibition of LPS responses suggests that this expression may be predominately B cell specific. The results suggest that the inhibitory effect is mediated via antibody binding to lymphocytes and that expression of viral envelope antigens on the cell surface which bind immunoglobulins can block or interfere with the binding or uptake of mitogens. A variety of natural mouse immune sera and "tumor" sera, having antibodies directed against gp71, can similarly inhibit mitogen responses; and this inhibition can be specifically blocked with MuLV or gp71.
J Immunol 1976 Sep
PMID:Inhibition of normal mouse lymphocyte mitogen responses by xenogeneic or allogeneic antibodies to the MuLV glycoprotein gp71. 18 79

Immobilized antigen-antibody complexes are able to inhibit the mitogenic response of murine spleen cells to the B-cell mitogen 8-bromo-3',5'-cyclic guanosine monophosphoric acid. This this inhibition is dependent on intact Fc fragments in the immobilized complexes. Soluble complexes do not mediate this inhibition. When lipopolysaccharide (lps) activation of B cells was studied, it was found that the mitogenic response was inhibited at all times tested between 2 and 7 days of culture. Also, the LPS-induced mitogenesis of nude spleen cells was inhibited by immobilized complexes, indicating that suppressor T cells probably play no significant role in the inhibition. Immobilized complexes inhibit polyclonal antibody responses in a serum-free system and in the presence of normal mouse serum, but are unable to inhibit in the presence of fetal calf serum (FCS). If nu/nu spleen cells are used, however, the FCS does not block the ability of the complexes to inhibit the polyclonal response. It is suggested that that antigen-antibody complexes under appropriate conditions may bind to B lymphocytes via their Fc receptors and trigger a central "off" signal which blocks proliferation and consequently antibody production.
J Exp Med 1976 Sep 01
PMID:Fc receptor-mediated inhibition of murine B-lymphocyte activation. 18 99

Endotoxin was shown to depress neutrophil bactericidal activity while enhancing Nitro Blue Tetrazolium reduction and hexose monophosphate shunt activity. Separation of bactericidal action from oxidative metabolism suggests that the effect of endotoxin might involve the formation of reactive oxygen radicals such as superoxide. Chemiluminescence often accompanies metabolic activation of polymorphonuclear neutrophils (PMNs). However, human PMNs did not show chemiluminescence when challenged with endotoxin (lipopolysaccharide; LPS) or lipid A. Superoxide formation was also unaffected by endotoxin. In contrast, preincubation of PMNs with LPS for 30 min produced significant depression of chemiluminescence, oxygen consumption, and superoxide formation. Decreased chemiluminescence was not the result of complement consumption. In a cell-free system, superoxide was not scavenged by LPS, nor did LPS stimulate superoxide dismutase. Oxidase enzymes for reduced nicotinamide adenine dinucleotide or reduced nicotinamide adenine dinucleotide phosphate harvested from broken cells were not affected by LPS. The toxicity of LPS may reside in its ability to activate the PMNs while simultaneously blocking bactericidal capacity.
Infect Immun 1979 Sep
PMID:Endotoxin in vitro interactions with human neutrophils: depression of chemiluminescence, oxygen consumption, superoxide production, and killing. 22 88


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