Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Highly distinctive aspects of the exponentail-phase Rhizobium japonicum cell were disclosed by means of thin sections, freeze etching, fluorescent antibodies, and ruthenium red staining. Polarity was expressed in the form of reserve polymer distribution near one end of the cell and as cytoplasmic localization near the opposite end. In addition, exocellular polysaccharide (EPS) accumulated preferentially around the cytoplasmic end, and the feature described previously as an "immunofluorescent polar tip" was seen clearly as an extracellular polar body (EPB) on the tip of the cell at the reserve polymer end. Compartmentalization of cytoplasm and reserves were consistent features of nearly all exponential cells of the two strains studied; strain 31, however, formed little EPS and had a high incidence of a large, tightly bound EPB, while strain 138 formed EPS extensively and had a low incidence of EPB. Extracellular polysaccharides of strain 138 reacted with soybean lectin in gel diffusion tests, so that the EPS seen in electron micrographs is tentatively considered to include the lectin-binding material. Extracellular polar bodies were accumulations of granular and fibrillar material with properties consistent with the presence of polysaccharide and lipopolysaccharide. The role of EPB in cell to cell attachment was confirmed by electron microscopy.
Can J Microbiol 1977 Sep
PMID:Polarity in the exponential-phase Rhizobium japonicum cell. 90 20

The primary response of the popliteal node to Salmonella lipopolysaccharide was studied in the sheep. All three classes of immunoglobulin IgG1, igG2, and IgM were produced by both free-floating cells in the lymph and by cells within the pymph node throughout the immune responce which extended over a period of at least 20 days.. Most of the immunoglobulins were found to be nonspecific for the antigen when tested by a binding assay. It was calculated from the binding assay that far more antigen-specific IgG molecules were produced than IgM molecules. The proportion of IgM and IgG1 which showed affinity for Salmonella organisms increased throughout the response. IgG2 had no affinity for the antigen until around 480 h after challenge. When a hemagglutination assay was used to measure antibody production, most of the specific antibody produced during the response was found to be IgM. Blast cells produced most of the immunoglobulin during the first 4 days of the response, and these cells were responsible for almost all of the IgM production. Differences were observed in the relative amounts of IgG and IgM produced by the cells within the node and by free-floating cells in the efferent lymph. The free-floating cells in lymph synthesized and secreted relatively more IgM and relatively less IgG than did cells within the lymph node. Both populations of cells, however, secreted much more IgG than IgM.
J Exp Med 1976 Sep 01
PMID:The synthesis and secretion of immunoglobulins by lymphoid cells in the sheep. The primary response to salmonella lipopolysaccharide. 95 26

The stimulation of the D-(1-14C)glucose and D-(6-14C)glucose metabolism in pig leucocytes during the phagocytosis of bacteria and inert particles was studied. The following results were obtained: 1. The magnitude of phagocytosis-stimulated glucose oxidation is directly related to the nature and number of particles added. 2. Live bacteria stimulate the glucose metabolism to a greater extent than do a similar number of heat-killed organisms. As to the extent of the stimulation the species of bacteria offered for phagocytosis is crucial. 3. After in vitro addition of a lipopolysaccharide a stimulating effect is observed, a depression has been shown after the addition of hydrocortisone.
Z Immunitatsforsch Immunobiol 1976 Sep
PMID:Factors influencing the phagocytosis-stimulated glucose oxidation in porcine leukocytes. 96 Sep 72

Lipolysaccharide was isolated from Chromatium vinosum by phenol/water extraction. The lipopolysaccharide is found exclusively in the phenol phase and can be cleaved into a sugar moiety and a lipid A fraction by hydrolysis in 10% acetic acid at 100 degrees C for 3-4 h. The sugar moiety contains the neutral sugars 3-O-methyl-D-ribose, D-ribose, L-arabinose, mannosamine and glucose, and smaller quantities of D-rhamnose, D-glycero-D-manno-heptose (tentatively identified), quinovosamine and 2-keto-3-deoxyoctonate. L-glycero-D-manno-heptose was not detected. The 2-keto-3-deoxyoctonate linkage in C. vinosum lipopolysaccharide is more resistant to acid hydrolysis than that of Escherichia coli. The lipid A fraction contains glucosamine, mannose and the fatty acids of the lipopolysaccharide. The major fatty acid is beta-hydroxymyristic acid, with smaller amounts of lauric and palmitic acids as well as 14-carbon mono-unsaturated fatty acid, also being present. The phosphorus content of the C. vinosum lipopolysaccharide was found to be approximately 0.1%. Erythrocytes sensitized with alkali-treated C. vinosum lipopolysaccharide were agglutinated by antisera prepared against heat-killed cells. Untreated or heat-treated lipopolysaccharide did not sensitize erythrocytes. The lethal toxicity to mice of the C. vinosum lipopolysaccharide is about one-tenth as that from Salmonella abortus equi.
Eur J Biochem 1976 Sep 15
PMID:Isolation and characterization of the lipopolysaccharide of Chromatium vinosum. 97 62

Strain differences in susceptibility to the development of thyroiditis following adult thymectomy and repeated sublethal X-irradiation (4 X 200 rad) were investigated in the rat. Marked strain variation was noted, with AUG and PVG/c rats having the highest incidence and severity of lesion (100 and 80% respectively) whilst CAM rats had a low incidence (9%). WAG and LIS rats occupied an intermediate position. The incidence of autoantibodies to thyroglobulin correlated closely with the strain incidence of thyroiditis (r = 0-87). Fractionation of the sera from thymectomized and irradiated rats by gel filtration chromatography indicated that the bulk of the antibodies to thyroglobulin were of the IgG class. Freund's complete adjuvant, but not lipopolysaccharide, enhanced the rate of development of thyroiditis in thymectomized rats given a shortened series of irradiations. It was not found possible to induce thyroiditis in thymectomized rats by substituting antilymphocyte serum for irradiation as a T cell-depleting agent, despite the fact that the treated rats had markedly reduced responses to phytohaemagglutinin. A combination of thymectomy, three doses of 200 rad, and a development period of 8 weeks were found to be the optimum conditions for induction of severe thyroiditis together with high antibody titres to thyroglobulin. These findings add support for the role of thymus-derived cells in the regulation of autoimmune responses and further suggest that thymectomy, combined with a series of sublethal irradiations, causes a selective depletion of those T cells specifically involved in the suppression of autoimmune reactivity to thyroid components, whilst leaving autoreactive helper T cells unimpaired.
Clin Exp Immunol 1975 Sep
PMID:Thyroiditis in T cell-depleted rats. Influence of strain, radiation dose, adjuvants and antilymphocyte serum. 108 32

The in vivo adjuvant effect of lipopolysaccharide (LPS) in mice was investigated with the soluble synthetic polypeptide antigen (T, G)-A--L, the antibody response to which is determined by the Ir-1A gene. With this specific antigen it can be demonstrated that the LPS adjuvant effect has the following modes of action: a) a T cell-dependent enhancement of primary and secondary IgM antibody response; b) a T cell-dependent enhancement of IgG secondary andibody response; and c) a T cell-dependent induction of switchover from IgM to IgG andibody in some strains of Ir-1A low responders. Although T cells are necessary for some aspects of the adjuvant effect, these data do not distinguish between a mechanism involving a direct interaction between LPS and T cells or a direct interaction of LPS and B cells with a general requirement for T cells for expression of IgG antibody.
Eur J Immunol 1976 Sep
PMID:T cell requirements for the expression of the lipopolysaccharide adjuvant effect in vivo: evidence for a T cell-dependent and a T cell-independent mode of action. 108 42

Cultured cells from mouse thoracic duct, spleen, lymph node, Peyer's patches, and bone marrow gave rise to cells containing large amounts of cytoplasmic IgM, IgGl, and IgG2 when stimulated by bacterial lipopolysaccharide (LPS). Differntiation of IgA producers occurred in bone marrow only, and to a lesser extent than other classes. Significant IgM responses preceded development of cells containing other classes. The differentiation of IgG and IgA producers did not appear to depend on T cells, since cultures from nu/nu or thymectomized-irradiated, bone marrow-protected mice responded as well as normals. Cultures from mice rendered deficient in B cells by anti-mu treatment responded normally to T cell mitogens, but did not proliferate or give rise to immunoglobulin-secreting cells when stimulated with LPS. Bone marrow cultures gave relatively meager proliferative responses to LPS, but generated as many or more immunoglobulin-secreting cells as did other tissues.
J Immunol 1975 Sep
PMID:B lymphocyte differentiation induced by lipopolysaccharide. I. Generation of cells synthesizing four major immunoglobulin classes. 109 25

Both the synthesis of lipopolysaccharide O-antigen and the synthesis of peptidoglycan in Salmonella typhimurium proceed via membrane-bound glycosylated lipid intermediates. The first enzyme of each pathway transfers a sugar phosphate from a nucleotide sugar to the glycosyl carrier lipid (P-GCL). Each enzyme catalyzes an exchange reaction between the reaction product urine monophosphate, and the nucleotide sugar substrate. Several strains of S. typhimurium defective in lipopolysaccharide synthesis accumulate glycosylated lipid intermediates under appropriate conditions. In addition, strains lysogenic for phage P22 synthesize a glucose derivative of the carrier lipid. These strains were used to demonstrate the P/GCL requirement of the exchange reaction catalyzed by galactose-diphosphoglycosyl carrier lipid (GCL-PP-Gal) synthetase, the first enzyme of O-antigen synthesis. Enzyme activity is greatly reduced when glycosylated P-GCL accumulates on the cytoplasmic membrane. The exchange reaction catalyzed by the first enzyme of peptidoglycan synthesis is unaffected by the accumulation of O-antigen fragments on the carrier lipid and may interact with a different pool of P-GCL within the membrane. GCL-PP-Gal synthetase activity cannot be detected in the membranes of two rfa mutants that synthesize incomplete lipopolysaccharide core. Either the synthesis of GCL-PP-Gal synthetase or the stable integration of the enzyme into the membrane structure may be disrupted in the rfa mutants. Peptidoglycan synthesis is unaffected by the mutations affecting the core glycosyltransferases.
J Bacteriol 1975 Sep
PMID:Membrane-associated nucleotide sugar reactions: influence of mutations affecting lipopolysaccharide on the first enzyme of O-antigen synthesis. 109 85

In Escherichia coli and Salmonella typhimurium, the cell wall that contains both the outer membrane layer and the peptidoglycan layer acts as a barrier of the molecular sieve type for the penetration of uncharged saccharides (G. Decad, T. Nakae, and H. Nikaido (1974) Fed. Proc. 33, 1240). Here we examined which of the layers of the cell wall limited the size of the penetrating molecules, by studying the penetration of saccharides into (a) cells whose peptidoglycan layer had been destroyed by lysozyme treatment or growth in the presence of penicillin and (b) isolated outer membrane vesicles. We found that peptidoglycan-defective cells were similar to intact, plasmolyzed cells in that they allowed a partial penetration of stachyose (molecular weight 666), but essentially excluded saccharides with molecular weights higher than 900 to 1000. We also found that the isolated outer membrane acted as a penetration barrier for saccharides. These observations led us to conclude that the outer membrane, rather than peptidoglycan, sets the size limit for the penetration of uncharged, hydrophilic molecules through the E. coli or S. typhimurium cell wall. The isolated outer membrane, however, had an exclusion limit much higher than that found in intact cells. This "leakiness" could be decreased either by the use of mutants producing extremely deficient lipopolysaccharide, or by trypsin treatment of the isolated membrane followed by heating and slow cooling in the presence of Mg2+. We feel that these observations are consistent with the hypothesis that the resealing of the ruptured outer membrane during the isolation procedure is often incomplete, and that cracks and holes thus generated are responsible for the "leakiness" of the isolated membrane vesicles.
J Biol Chem 1975 Sep 25
PMID:Outer membrane as a diffusion barrier in Salmonella typhimurium. Penetration of oligo- and polysaccharides into isolated outer membrane vesicles and cells with degraded peptidoglycan layer. 110 Jun 25

The polyclonal B-cell activators (PBA) lipopolysaccharide (LPS), type III pneumococcal polysaccharide (SIII), dextran, dextran sulphate, pentosan sulphate, and polyvinylpyrrolidone (PVP) were found to cause an increased DNA synthesis in mouse fibroblast monolayer cultures in the presence of calf serum, provided the background cpm were within certain values. The same PBA suppressed DNA synthesis when the cultures showed high background [corrected] cpm. Since the PBA did not activate DNA synthesis in serum-free cultures, it was concluded that PBA could be directly activate fibroblasts but rather influenced factors responsible for regulation of DNA synthesis in fibroblasts. In contrast PBA directly trigger lymphocytes.
Scand J Immunol 1975 Sep
PMID:Effect of polyclonal B-cell activators on DNA synthesis in fibroblasts. 110 69


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>