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

Purified lipopolysaccharide-protein complex (LPS-PC) extracted by trichloroacetic acid from phase I Coxiella burnetii organisms induced in mice and rabbits fair levels of antibodies directed to antigen 1 and antigen 2, as detected by complement-fixation (CF), microagglutination (MA), opsonization-phagocytosis (OP) and serum protection (SP) tests. In guinea pigs only very low levels of MA antibodies against antigen 2 were demonstrated. In rabbit serum, MA antibodies directed to antigen 2 were found exclusively in the IgM fraction after the primary immunizing dose; the second dose was followed by gradual shift of MA antibodies to the IgG class. Two immunizing doses of the LPS-PC were more effective when testing antibody response in mice or protection of mice and guinea pigs against phase I virulent challenge.
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PMID:Immunological properties of the lipopolysaccharide-protein complex of Coxiella burnetii. 2 70

B lymphocyte function was assessed in outbred nude mice and nu/+controls infected with Trypanosoma brucei brucei. On day 10 of the infection in outbred nu/nu mice in which the initial wave of parasites was strongly controlled, B cell function was unaltered on enhanced compared with uninfected animals or infected nu/+. In other nu/nu mice unable to control the initial parasitaemia, thymidine incorporation and Ig secretion by spleen cells were increased on day 10 and their response to lipopolysaccharide in vitro negated. By day 15 however, even the spleen cells of infected nu/nu which controlled the initial wave of parasites were proliferating and secreting Ig on removal from the mice and they were unable to respond to LPS in vitro. These experiments confirm results of a previous study of B cell function in T cell-depleted mice (Askonas et al. 1979). T. b. brucei infection of mice causes both enhanced Ig production and suppression of the ability of B cells to respond to mitogen even in the absence of T cells, but the presence of T cells may accelerate the changes which occur in B lymphocytes following this infection.
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PMID:Trypanosoma brucei infection in nude mice: B lymphocyte function is suppressed in the absence of T lymphocytes. 4 25

One thymus-independent immunogen, trinitrophenylated lipopolysaccharide (TNP-LPS) has been studied in vivo and in vitro in C3H/He and C3H/HeJ strains of mice. C3H/HeJ mice have been shown to be low responders, and C3H/He mice high responders to this immunogen. This 'low responder' status of C3H/HeJ mice has been demonstrated to be consequent to an intrinsic defect present at least at the level of B cells. It was demonstrated that high responder cells or 'in vivo milieu' could not restore this deficit to C3H/HeJ cells. It is proposed that the adjuvanticity, mitogenicity and polyclonal activating capacity of LPS are all fundamental to its property of acting as a thymus-independent carrier for the TNP determinant. This observation is discussed from the point of view that the T-cell independence for an antigen cannot derive solely from its multivalency but must depend upon the intrinsic adjuvanticity of that molecule.
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PMID:The 'intrinsic adjuvanticity' and immunogenicity of trinitrophenylated lipopolysaccharide. 5 94

Modulation of the cyclical response in rabbits to aggregated human gamma globulin (AHuIgG) was investigated in order to study some of the parameters involved in self-regulation of the immune response. Several mitogens (lipopolysaccharide [LPS], phytohemagglutinin [PHA], and concanavalin A [Con A]), when injected simultaneously with antigen, have been shown to modulate the normal splenic plaque-forming cell (PFC) response in rabbits to a single intravenous injection of AHuIgG. This response to AHuIgG has previously been characterized by the initial appearance of PFC in the spleen 3 days later, with a peak of PFC at 5 days after injection. The number of PFC in the spleen then decreases and remains at a low level until a second increase begins on day 10, peaking on day 13. The 8-day cycle between peak PFC repeats, with a third peak appearing on day 21. In the present studies, injection of LPS with AHuIgG was shown to affect the PFC response by enhancing only the initial peak of PFC, PHA was shown to enhance both the initial and secondary peaks of PFC, while injection of Con A with AHuIgG resulted in a prolonged increase in PFC with no apparent cycling. Irradiation 24 h after injection of antigen resulted in PFC kinetics similar to those observed with PHA, although the increase in PFC was more marked with irradiation. Thus, although LPS, PHA, Con A, and irradiation markedly affected the immune response to AHuIgG, Con A was the only substance which altered the cyclical appearance of PFC to HuIgG. The cyclical nature of the PFC kinetics was shown to occur with either intravenous or intraperitoneal injection of antigen and in both primary and secondary responses, provided that the rabbits were primed with a low dose of antigen. Data were obtained that suggest that the response in distal lymph nodes may be regulated by immunological events occurring in the spleen. Cycling of PFC was not observed in the draining node after subcutaneous injection of AHuIgG in the hind foot. However, if the antigen was also injected intravenously at the same time as the subcutaneous injection, the response in the node became cyclical.
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PMID:Modulation of regulatory mechanisms operative in the cyclical production of antibody. 5 57

Mouse amniotic fluid (MAF) was shown to be capable of suppressing those antibody responses observed in euthymic or athymic mouse spleen cell cultures to the T-independent antigens dinitrophenylated Ficoll (DNP-Ficoll) and trinitrophenylated lipopolysaccharide (TNP-LPS) and to the polyclonal B-cell activators LPS and purified protein derivative of tuberculin (PPD). Titration experiments demonstrated that the suppressive capacity of MAF for either LPS or DNP-Ficoll responses was maintained up to a MAF dilution of 1:120. Preincubation of spleen cells obtained from athymic mice with MAF for 8 h significantly suppressed polyclonal B-cell activation of such cells induced by LPS, although suppression was greater when MAF was present during the entire culture period. In addition, the suppressive activity that MAF demonstrated for antibody production induced by DNP-Ficoll or LPS was not lost as a result of dialysis. MAF also suppressed the secondary in vitro proliferative responses of lymph node cells sensitized to the T-dependent antigen human gamma globulin (HGG). HGG-induced proliferation of such cells appeared to be more susceptible to suppression effected by MAF than concanavalin-A-induced proliferation.
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PMID:Suppression of immunological activities by mouse amniotic fluid. 7 67

CBA/N mice have an X-linked immune defect in B lymphocyte function which leads to their inability to respond to several thymus-independent antigens. We report here that these mice and immunologically defective F1 male (CBA/N X DBA/2N) mice can respond to Brucella abortus and to 2,4,6-trinitrophenyl derivatives of Brucella abortus (TNP-BA). These responses can be obtained in vivo and in vitro and are thymus-independent by the criteria that (a) they can be transferred to irradiated recipients by bone marrow cells and anti-Thy-1.2 and complement-treated spleen cells; (b) that nu/nu BALB/c spleen cells respond to TNP-BA in vitro; and (c) that anti-Thy-1.2 and complement-treated (CBA/N X DBA/2N)F1 male spleen cells respond to TNP-BA in vitro. B. abortus and TNP-BA are poor polyclonal B cell activators (PBA) and poor B cell mitogens, unlike lipopolysaccharide which is both a powerful PBA and B cell mitogen. These results therefore indicate that mice with the CBA/N B cell defect can respond to some thymus-independent antigens, namely TNP-BA, and as shown previously, TNP-LPS, although not to other thymus-independent antigens. This, in turn, suggests that thymus-independent antigens may be subdivided on the basis of their ability or inability to stimulate responses by CBA/N B lymphocytes.
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PMID:T-independent responses in B cell-defective CBA/N mice to Brucella abortus and to trinitrophenyl (TNP) conjugates of Brucella abortus. 9 20

The localisation of lipopolysaccharide-binding sites on erythrocytes with peroxidase-coupled LPS is described. LPS was isolated from Fusobacterium nucleatum (Fus MC-8) by phenol-water extraction. The LPS was coupled to horseradish peroxidase by the two-step method of Avrameas and Ternynck (1971). The biological and serological activities of the conjugated LPS were compared with those of the native material. Peroxidase could be coupled to LPS without significant loss of endotoxic or serological activity. The LPS-peroxidase conjugate could be demonstrated on erythrocytes by light and electron microscopy.
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PMID:Ultrastructural localisation of lipopolysaccharide-binding sites with peroxidase-conjugated lipopolysaccharides. 10 40

In an attempt to obtain pure and well characterized smooth lipopolysaccharide (S-LPS) and rough lipopolysaccharide (R-LPS), smooth and rough strains of Brucella abortus were extracted by two different modifications of the phenol-water method. S-LPS was obtained in the phenol phase, and R-LPS was obtained in the aqueous phase. Further purification was accomplished by treatment with enzymes, detergents, NaI as a chaotropic agent to separate non-covalently bound contaminants, and by gel filtration. The degree of purity of the molecules was determined by chemical and immunological analysis and by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels. Lipid identification by gas-liquid chromatography showed seven major fatty acids. Palmitic acid accounts for about 50%, stearic acid accounts for about 10%, and hydroxylated fatty acids account for less than 5% of total fatty acids. 2-Keto-3-deoxyoctonate but not heptose was detected in the sugar analysis. Protein was found to be firmly bound to S-LPS but not to R-LPS.
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PMID:Purification and characterization of smooth and rough lipopolysaccharides from Brucella abortus. 10 57

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 fluorescent antibody reagent (termed anti-LPS conjugate) was prepared from sera obtained from hens immunized with gonococcal R-type lipopolysaccharide. The reagent was absorbed with Formalin-treated cells of Neisseria meningitidis. The anti-LPS conjugate gave uniform brilliant staining of Neisseria gonorrhoeae with little background fluorescence, thus making interpretation and reading of fluorescence simple. The conjugate did not significantly stain cultures of N. meningitidis, Neisseria lactamica, nonpathogenic Neisseria species, or other gram-negative bacteria. Several preparations of the conjugate provided the same specificity and reproducibility of staining. The anti-LPS conjugate was compared with Difco Laboratories fluorescent antibody conjugate for staining of N. gonorrhoeae. Both conjugates stained cells of the light and dark variants of gonococcal colony types 1 and 2, as well as cells of colony types 3 and 4. When used for the confirmation of N. gonorrhoeae, the anti-LPS and Difco conjugates stained 426 of 431 (98.8%) and 210 of 213 (98.6%) of the gonococcal cultures, respectively. Absorption of the anti-LPS conjugate with R-type lipopolysaccharide removed the staining of gonococci. However, absorption of Difco conjugate with R-type lipopolysaccharide did not remove the staining of gonococci, suggesting that the majority of fluorescein-labeled antibody present in the Difco conjugate is directed to gonococcal cell surface components other than lipopolysaccharide. The results of this study indicate that fluorescein-labeled gonococcal lipopolysaccharide antibody should be a reliable fluorescent antibody reagent for the confirmation of N. gonorrhoeae.
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PMID:Hen fluorescein-labeled gonococcal lipopolysaccharide antibody in the delayed fluorescent antibody technique for the confirmation of Neisseria gonorrhoeae. 11 Aug 24


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