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

Smooth lipopolysaccharide (sLPS) of Brucella abortus was prepared and fractionated by a modification of the procedures of Moreno et al. (J. Bac. 138:361-369, 1979). Washed B. abortus cells were disrupted by 21 freeze-quick thaw cycles with ultrasonication to separate the non-membrane-bound material. Ultrasonicated bacteria were used for preparation of membrane-bound sLPS (approximately f5, the main crude sLPS fraction described by Moreno et al.). Phenol extraction was repeated 3 times and then washed with H2O 10 times to remove most of the chromogen, polysaccharides and nucleic acids, eliminating the need for enzyme treatment as described previously. The membrane-bound sLPS was fractionated into 3 to 5 groups according to the extent of dialysis and centrifugation, these fractions required only 80 ng for positive ELISA, about 0.2 ng for positive Limulus lysate tests, and reacted well with precipitating antibodies in the serum from a strain 2308 infected cow. They had marked differences in precipitin curves and chemical composition. The protein content varied from 16% to 42% as determined by dye binding test and 17 to 60% by Lowry phenol method using bovine serum albumin as the standard, which implies that the proteins associated with LPS may also play important roles in the complex for the immunochemical interactions and the heterogeneity of B. abortus lipopolysaccharide protein complex. As compared with previous reports, a higher yield of sLPS, ranging from 3.6% to 7.7% of dried bacteria, was obtained. Group f5A, which had a standard bell shaped curve in the precipitin assay, is one of the major fractions in all three strains (1119.3, 19 and 2308). The amount of other subfractions obtained varied with batches or strains of B. abortus. These results provide a new profile of the immunochemical reactivities and the heterogeneity on B. abortus smooth membrane-bound endotoxins.
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PMID:Immunochemical and partial chemical characterization of fractions of membrane-bound smooth lipopolysaccharide-protein complex from Brucella abortus. 311 18

Smooth lipopolysaccharide (sLPS) of Brucella abortus, which is the most immunodominant component among the antigens of B. abortus isolated, has been used for diagnosis for decades. High yields of sLPS can be prepared by a modification of the procedures of Moreno et al. (J. Bacteriol. 138:361-369, 1979). Washed B. abortus cells can be disrupted by 21 freeze-quick thaw cycles and ultrasonication to separate non-membrane-bound material; then phenol extraction is performed 3 times and the phenol fraction is washed with H2O intensively. The membrane-bound sLPS can be fractionated into 3 to 5 groups according to the extent of dialysis and centrifugation. These membrane bound sLPS fractions show marked individual differences in their precipitin profile and chemical composition. Their protein content varies from 16% to 42% as determined by dye binding test and 17 to 60% by Lowry phenol method using bovine serum albumin as the standard, which indicates that these proteins associated with LPS may play important roles in the immunochemical interactions, solubility, and the heterogeneity of B. abortus lipopolysaccharides. Compared to previously published methods, a higher yield of sLPS, ranging from 3.6% to 7.7% of dried bacteria, is obtained. Group f5A, which has a standard bell shaped curve in the precipitin assay, is one of the major fractions in all three strains (1119.3, 19, 2308). The protein free sLPS (less than 1% of Lowry reactive component) can be prepared by pronase digestion. The immunochemical reactivity remains about the same before and after this treatment. The O-chains of the major fraction (f5A) of B. abortus (Strains 2308 and 19) membrane bound smooth lipopolysaccharide (sLPS) are obtained by hydrolysis of f5A native sLPS in 1% acetic acid at 100 degrees C for 2 hours. After hydrolysis, the O-chains are separated from the lipid A protein complex by centrifugation, and from small fragments by ultrafiltration of a molecular weight cut-off (MWCO) of 1.0 x 10(3). These carbohydrate haptens can be identified by precipitin-inhibition assay and further fractionated by both membrane filtration and dialysis. The size distributions of carbohydrate haptens of the endotoxins (f5A) ranged from several oligosaccharides up to 1.0 x 10(4) MWCO. Three major fractions of MWCO 8.0-10.0 x 10(3), 3.5-5.0 x 10(3), and less than 1.0 x 10(3) for both strains 2308 and 19 contain more than 85% of the total immunreactive materials.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Structural and immunochemical aspects of Brucella abortus endotoxins. 314 Jun 12

We here describe a form of 'noise' in the ELISA as commonly performed on antigen-coated microtiter trays that represents a major hindrance to the accurate enumeration of infrequent antibody-forming cell (AFC) precursors (AFCp) specific for epitopes on monomeric proteins. Supernatants from cultures of lipopolysaccharide-stimulated murine splenocytes, when split into aliquots and separately assayed, scored as positive in parallel on ELISA trays coated with unrelated proteins and on uncoated trays. Some properties of such coincident false positives (CFP) noted were: (1) optical density (OD) ranges for CFP and non-CFP overlapped; (2) different members of CFP triplets on differently coated assay trays usually had similar OD values; (3) CFP-generating culture supernatants did not contain unusually high immunoglobulin concentrations; and (4) numbers of CFP-forming supernatants increased with increasing input cells/culture consistent with causation by single AFCp present at an approximate mean frequency of 1 in 6600 CBA splenocytes. It is proposed that CFP are due to AFC clones that secrete antibody reactive with some epitope(s) present in the assay tray itself. Repertoire elements with such 'anti-plastic' characteristics are rarer than anti-keyhole limpet hemocyanin (KLH) AFCp, but at least as frequent as anti-bovine serum albumin (BSA) or anti-transferrin (TFN) AFCp.
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PMID:Analysis of the B lymphocyte repertoire by polyclonal activation. Hindrance by clones yielding antibodies which bind promiscuously to plastic. 325 11

A preliminary experiment showed that the supernatants of in vitro cultured peritoneal cells (rich in Ly-1 B cell subset shown to secrete most IgM autoantibodies against bromelain-treated mouse red blood cells (BrMRBC) and DNA) from different mouse strains did not contain any significant antibody activity against DNA and cytoskeleton proteins, although the presence of anti-BrMRBC antibodies was clearly evident. Therefore, we investigated comparative natural antibody (NAb) specificities against an antigen panel (DNA, cytoskeleton proteins, IgG, bovine serum albumin (BSA), BrMRBC, trinitrophenyl (TNP), and trimethylammonium (TMA) haptens) among Ig-secreting hybridoma collections from the splenic (158) and peritoneal (230) immune compartments of autoimmune New Zealand black (NZB) and lipopolysaccharide (LPS)-stimulated BALB/c mice. The data showed: (i) isotypic restriction (mu and gamma 3 only), predominance of TMA ion-reactive (including BrMRBC) but negligible anti-DNA-reactive antibody specificities, and lack of simultaneous polyspecific widespread reactivity (i.e. at least four or more antigens) against DNA and cytoskeleton proteins in the peritoneal cavity; (ii) predominance of simultaneous widespread polyspecific reactivity against DNA and cytoskeleton proteins but negligible or no TMA hapten-reactive antibody specificities in the spleen. These observations reflect certain differences in the B cell repertoire of peritoneal cavity (rich in Ly-1 B cells) compared with spleen. The NAb against BrMRBC and those reactive with DNA and cytoskeleton proteins, which have been suggested to be secreted by the Ly-1 B cell subset, are distinguishable on the basis of the presence of separate recurrent idiotypes and preferential localization of B lymphocytes directed against these autoantigens.
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PMID:Comparative analysis of natural antibody specificities among hybridomas originating from spleen and peritoneal cavity of adult NZB and BALB/c mice. 325 8

Oxamisole is a T-cell immunorestorative agent when administered by the oral (p.o.) route. It has little or no effect on the IgM or IgG responses to the T-dependent antigen, sheep erythrocytes (SRBC), in normal mice but augments antibody production in immunodeficient animals. Unlike the response to SRBC, the humoral immunocompetence of both normal and immunosuppressed animals sensitized with the T-independent antigen, trinitrophenyl-lipopolysaccharide (TNP-LPS) was unaffected by oxamisole. Oxamisole restored cellular immunocompetence, as evidenced by an increase in the in vitro proliferative response of normal murine splenocytes to T-cell mitogens, while decreasing B-cell mitogenic responses. This indicates that oxamisole may selectively restore T-cell function. However, oxamisole did not significantly modify the classical T-cell-mediated delayed hypersensitivity responses to either the protein antigen methylated bovine serum albumin or to the contact-sensitizing antigen oxazolone. When assayed in vitro, oxamisole enhanced macrophage chemotactic function but not phagocytic function, suggesting a potential stimulation of the reticuloendothelial system. In vivo studies failed to demonstrate any consistent significant activation of murine macrophage function following oral dosing with oxamisole.
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PMID:The immunological profile of a new immunomodulatory agent, oxamisole. 326 41

In the course of using the infant rat model to determine the ability of various rabbit antisera to protect against challenge by Haemophilus influenzae type b we made two unexpected observations. In these experiments 4-day-old rats were inoculated s.c. on the dorsum with either rabbit serum or physiological buffers (sham serum) and then were challenged the next day with H. influenzae type b injected i.p. Bacteremia, as a marker for disease, was measured 24 h later on day 6. We observed the following. (i) Pre-immune, i.e., normal rabbit serum, containing minimal levels of antibodies to outer membrane proteins and depleted of antibodies to capsule and lipopolysaccharide, nevertheless significantly (P less than 0.01) protected the rats from challenge with H. influenzae type b when compared to a sham inoculation of buffer; (ii) In the absence of a serum inoculation on day 4 (a buffer was used as a sham serum inoculation), the levels of bacteremia obtained after inoculation with bacteria on day 5 depended upon the composition of the buffer in which the H. influenzae inoculum was suspended. Use of phosphate buffered saline (PBS) resulted in higher levels of bacteremia than PBS containing 0.5% bovine serum albumin (PBS-BSA) (P less than 0.001), i.e. the BSA apparently acted to protect the rats from H. influenzae infection. In fact the use of PBS-BSA as an inoculum buffer masked the protective effect noted above of the absorbed normal rabbit serum.
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PMID:Unexpected effects of absorbed normal rabbit serum and bovine serum albumin on survival of Haemophilus influenzae type b in the infant rat. 326 78

Immune responses of mast cell-deficient WBB6F1-W/Wv mice and their mast cell-sufficient littermates (LM: WBB6F1-W/+, Wv/+ and +/+) were compared. After a single intravenous injection of sheep erythrocytes (SE), polyvinylpyrrolidone or bacterial lipopolysaccharide, the antigen-specific IgM plaque-forming cell (PFC) response of W/Wv mice was similar to or greater than the response of LM mice. When both primary and secondary injections of SE or chicken gamma-globulin were given to mice and antigen-specific IgG PFC responses quantified, the response of W/Wv again was similar to or greater than that of LM mice. Serum titers of antigen-specific IgE were higher in W/Wv than in LM mice after injections of ovalbumin in alum or infections of Nippostrongylus brasiliensis. Ovalbumin-sensitized W/Wv and LM mice developed active systemic anaphylaxis after ovalbumin challenge. The ability of W/Wv mice to be sensitized for and elicit contact sensitivity (CS) reactions was studied using picryl chloride or dinitrofluorobenzene as sensitizing and challenge agents and quantifying 24-hour reactions by change in ear thickness. SE or methylated bovine serum albumin was used to sensitize and challenge mice for delayed-type hypersensitivity (DTH) reactions which were quantified at 24 h by change in foot pad or ear thickness. CS and DTH reactions of W/Wv and LM mice were similar. No evidence of immune deficiency of W/Wv mice was found.
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PMID:Immune response potential of mast cell-deficient W/Wv mice. 351 77

In order to elucidate the dependency of pyrogenicity of lipopolysaccharide (LPS) on the lipid A structure, we investigated the pyrogenicity of both LPS and lipid A prepared from Mima polymorpha var. oxidans which is deficient in 3-hydroxymyristic acids linked to the 3-hydroxy group of other fatty acids. LPS and lipid A were also prepared as reference compounds from Escherichia coli UKT-B. Furthermore, the establishment of reliable indices for pyrogenicity was undertaken. The following results were obtained. The correlation in linearity was demonstrated between maximal increase in body temperature (delta Tmax) and dose of LPS or lipid A complexed with bovine serum albumin (BSA). The dose-response curves based on delta Tmax were more reliable statistically than the Fever Index-4h representing the area under fever curves for 4 h. The minimum pyrogenic dose (MPD) of E. coli LPS was 1.6 X 10(-3) micrograms/kg i.v. In contrast, the MPD of M. polymorpha LPS was 7.0 X 10(-3) micrograms/kg i.v. By intracisternal injection, the MPD of E. coli LPS was 2.5 X 10(-6) micrograms/kg and that of M. polymorpha LPS 1.0 X 10(-4) micrograms/kg. The end points of Limulus amoebocyte lysate gelation were 10(-5) micrograms/ml in E. coli LPS and 10(-3) micrograms/ml in M. polymorpha LPS. The MPDs of lipid A/BSA complexes by i.v. injection were 0.15 micrograms/kg in E. coli and 2.5 micrograms/kg in M. polymorpha. The rabbits immunized with E. coli lipid A/BSA complex acquired pyrogenic tolerance to the parent LPS but the cross tolerance to M. polymorpha LPS was not observed.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Characterization of the pyrogenicity of two different lipopolysaccharides and their lipid A-bovine serum albumin complexes. 354 Feb 73

Serum antibody responses of mice to repeatedly inhaled protein antigens such as bovine serum albumin and ovalbumin, plus or minus bacterial lipopolysaccharide (LPS) in the form of an aerosol were studied. Results showed that the levels of responses to inhaled protein antigens varied, depending on the mouse strain-antigen combination and that LPS inhaled simultaneously with the antigens definitely augmented the responses which were not otherwise very high. LPS extracted from Klebsiella O3 (LPS-K) but not LPS from Escherichia coli O55 (LPS-E), which was inhaled at the time of initial inhalation of antigen, significantly intensified the priming for the secondary antibody response to the antigen subsequently inhaled. Both LPS-K and LPS-E, however, definitely acted to augment the response when they were inhaled repeatedly together with the antigen. Oral administration of antigen or antigen plus LPS-K did not induce any detectable antibody response in our experiment, ruling out the possibility that the antigen and LPS stimulated the immune system via alimentary canal rather than via lung. Tissue distribution of the radioactivity soon after inhalation of 131I-labeled antigen and decay speed of the radioactivity were not significantly changed by LPS-K inhaled simultaneously. This suggested that the augmentation of responses was not mediated by the action of LPS to modulate the air-blood barrier against the entry of antigen via lung. All the results prove for the first time that inhaled LPS displays a definite adjuvant action on antibody responses to inhaled antigens.
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PMID:Augmentation of antibody responses of mice to inhaled protein antigens by simultaneously inhaled bacterial lipopolysaccharides. 354 12

Much clinical and experimental data suggest that infection and graft-versus-host disease (GVHD) are intimately associated, and that bacterial endotoxin (ET), a potent immunostimulant, influences the severity of GVHD. We have used a cell-wall-deficient mutant of Escherichia coli (E coli J5) to study the effect of active and passive immunization against ET in a murine model of GVHD induced by major histocompatibility antigens. CBA/Ca (H-2k) mice were irradiated and grafted with 1 X 10(7) bone marrow cells from C57BL/B6 (H-2b) donors. Groups of mice were immunized against J5: either actively immunized with killed J5 cells or pure J5 lipopolysaccharide, or passively immunized with rabbit anti-J5 antiserum (R alpha J5). Controls included irradiation controls, negative controls (syngeneic graft), positive controls (conventional mice receiving allogeneic graft), mice immunized with normal rabbit serum, Freund's adjuvant (FA), or human serum albumin (HSA) in FA. Active immunization with J5 exacerbated the effects of GVHD as indicated by increased weight loss (P = 0.002) and earlier death (P = 0.043). In contrast, immunization with HSA protected against weight loss (P = 0.028), and improved survival (P = 0.008). Passive immunization with J5 had no effect. These observations support the hypothesis that ET influences the pathogenesis of GVHD, and provide a useful model for studying the effects of ET in a well-defined immunological system.
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PMID:Influence of endotoxin on graft-versus-host disease after bone marrow transplantation across major histocompatibility barriers in mice. 355 64


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