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

Concanavalin A (Con A), in solution, induces mouse T cells, but not B cells, to proliferate. However, lectin concentrations which were optimal for the T cell response induced purified B cells to depolarize, to enlarge, and to display increased levels of Ia antigens. Furthermore, culturing B lymphocytes with Con A for 24 hr caused the cells to synthesize DNA more rapidly in response to subsequent stimulation by lipopolysaccharide, or anti-immunoglobulin antibodies. This priming effect did not appear to require either T cells or accessory cells. It was therefore concluded that Con A activates resting B lymphocytes, i.e. stimulates them to enter the cell cycle, even though it does not induce B cells to divide.
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PMID:Activation and proliferation signals in mouse B cells. IV. Concanavalin A stimulates B cells to leave G0, but not to proliferate. 633 19

A Mycoplasma arginini strain, found to contaminate a T-T hybridoma designated TUH-14, was the source of a lymphokine-like activity with an ability to stimulate B-blasts to proliferate. Maturation to immunoglobulin secretion induced by the mycoplasma alone was low compared with induction by lipopolysaccharide (LPS), but could reach the same levels achieved with LPS by the addition of a B-cell maturation factor obtained from lectin-activated EL-4 thymoma cells. The mitogenic effect on B-cells was found only in the strain isolated from TUS-14; three other M. arginini strains were negative. Both mitogenic and nonmitogenic mycoplasma membrane preparations displayed higher affinity for B-cells than for T-blasts. However, membranes from the mitogenic strain, the TUH-14 isolate, bound better to activated blasts than to small resting cells, in contrast to the nonmitogenic strain G-230.
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PMID:Lymphokine-like activity of a strain of Mycoplasma arginini. 633 70

The effects of sugars and glycoproteins that are known to bind to lectins of liver tissue on the clearance of cells of Escherichia coli from mouse blood was investigated. The administration of 100 mg per mouse of methyl-alpha-D-mannoside, methyl-alpha-D-glucoside, or methyl-alpha-D-fucoside, but not of methyl-alpha-D-galactoside or L-rhamnose, markedly inhibited the blood clearance of cells of E. coli 346. Clearance was similarly inhibited by 0.1 and 1.0 mg per mouse of asialofetuin or ovalbumin, respectively, whereas fetuin had no effect. The inhibitory effects of the sugars on blood clearance was abolished by pretreating the E. coli cells with antibodies against whole organisms. All of these effects were equal for fimbriated and nonfimbriated phenotypes of E. coli 346. Homogenates of mouse liver tissue coaggregated with nonfimbriated cells of E. coli. The aggregation was blocked by 100 mM solutions of methyl-alpha-D-mannoside, or methyl-alpha-D-glucoside, 1 mg of bacterial lipopolysaccharide per ml, or 10 mM EDTA but not by L-rhamnose. These results suggest that the mannose-N-acetylglucosamine hepatic lectin recognizes specific sugars on the surface of E. coli and may be centrally involved in the nonimmune clearance of nonfimbriated E. coli from the blood of the infected host.
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PMID:Inhibition of blood clearance and hepatic tissue binding of Escherichia coli by liver lectin-specific sugars and glycoproteins. 636 Aug 99

The chemical and immunochemical properties of lipopolysaccharides (LPS) isolated from pyocin 103-sensitive and -resistant Neisseria gonorrheae were investigated. Marked differences were found in immunochemical behavior of LPS from pyocin-sensitive gonococcal strain JW31 and its isogenic pyocin-resistant variant JW31R. JW31 LPS readily precipitated wheat-germ agglutinin, soybean lectin, and rabbit anti-Streptococcus faecalis or horse anti-type 14 pneumococcal antibody. In contrast, JW31R LPS precipitated only soybean lectin. The combining-site specificity of anti-S. faecalis cross-precipitated by JW31 LPS, or type 14 pneumococcal capsular polysaccharide, was examined by hapten inhibition, and lactose found to be the most potent inhibitor. Horse anti-pneumococcal type 14 antibodies, cross-precipitated by JW31 LPS and streptococcal lactose polymer, exhibited heterogeneity with respect to combining site specificity. Gel filtration of LPS-derived core oligosaccharide showed both strain JW31 and JW31 R to possess R-type lipopolysaccharide with cores having a Mr approximately 1800. JW31R LPS contains more galactose but less hexosamine than JW31 LPS. Both JW31 and JW31R core oligosaccharides possess D-glucosamine and D-galactosamine, probably N-acetylated, as the only nonreducing end-groups, and (1 leads to 4)-linked D-glucose residues. Chemical data support immunochemical findings which indicate that lactose units occur as a structural feature of JW31 gonococcal LPS.
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PMID:Chemical and immunochemical studies on lipopolysaccharides from pyocin 103-sensitive and -resistant Neisseria gonorrhoeae. 641 2

The specific interaction between the exopolysaccharide purified from a number of Pseudomonas aeruginosa isolates from cystic fibrosis patients and a rat lung heparin-lectin was assayed. The polysaccharide prepared from Homma serotypes M, B, I, and G did not act as hapten inhibitors of lectin activity, whereas the polymers prepared from ca. 80% of strains that did not type with Homma serum did act as hapten inhibitors. Inhibition was shown not to be due to lipopolysaccharide. The infrared spectrums of both inhibitory and noninhibitory polymers appeared very similar, although small amounts of glucose and an unidentified amino sugar were found only in the nontypable strains. This evidence suggests that rat lung lectin recognizes and distinguishes a specific type of alginate-like polymer prevalent on the Homma nontypable P. aeruginosa.
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PMID:Interaction of a rat lung lectin with the exopolysaccharides of Pseudomonas aeruginosa. 641 18

In this study we investigated whether interleukin 2 (IL-2) acts on B cell proliferation and whether activated B cells express IL-2 receptors. First, the functional activity of immunoaffinity-purified or recombinant human IL-2 was studied in a B blast assay using positively selected murine surface Ig-positive cells that had been activated by lipopolysaccharide (LPS) plus anti-Ig antibodies (anti-Ig). In this assay, T cells were not detected by fluorescence-activated cell sorter analysis. It was found that both IL-2 preparations led to optimal B cell proliferation compared with supernatants obtained from murine or human spleen cells or murine cloned T helper cells. Second, we observed that the IL-2 requirement in this assay was about the same as in a proliferation assay using lectin-activated polyclonal murine Lyt-2-positive T cells. Third, analysis of the binding of radiolabeled immunoaffinity-purified IL-2 to B cells indicated that LPS plus anti-Ig-activated B cells expressed a mean of 3,500 IL-2 receptors per cell with an apparent dissociation constant of 150 pM. However, neither nonactivated B cells nor B cells activated by LPS alone exhibited significant specific IL-2 binding. The functional and the receptor data are consistent with the conclusion that IL-2 is a growth factor not only for T cells but also for B cells.
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PMID:Activated B cells express receptors for, and proliferate in response to, pure interleukin 2. 643 89

Lectin-like molecules on the surface of murine peritoneal exudate macrophages induced by thioglycolate or an anti-tumor streptococcal preparation, OK-432, were investigated and isolated. Furthermore, their sugar-binding specificities and their role in macrophage-mediated tumor cytotoxicity were examined. A neoglycoprotein, D-galactose (Gal)-bovine serum albumin, bound to these murine peritoneal macrophages. This binding of Gal-bovine serum albumin was inhibited by D-galactose, and by complex-type oligosaccharides (unit B) and high mannose-type oligosaccharides (unit A) prepared from porcine thyroglobulin. When thioglycolate-elicited macrophages were activated by lipopolysaccharide and/or the culture supernatant of concanavalin A-activated mouse spleen cells, they became tumoricidal and the number of the lectin-like molecules on the macrophage surface was found to increase. Since the binding and cytotoxic activities of these tumoricidal macrophages toward tumor cells were partially inhibited by D-galactose, the D-galactose-binding lectin-like molecules on the surface of tumoricidal macrophages might play an important role in macrophage-mediated cytotoxicity. These lectin-like molecules were then isolated from solubilized murine peritoneal exudate cells labeled with pyridoxal 5'-phosphate and sodium [3H]borohydride by affinity chromatography on columns of asialo unit B oligosaccharide-Sepharose 4B and/or beta-D-galactose-Bio-Gel P-100. The proteins bound to the asialo unit B oligosaccharide-Sepharose 4B column and eluted specifically were found to have approximate molecular weights of 79 000 and 18 000, and the protein bound to and eluted from the beta-D-galactose-Bio-Gel P-100 column had an approximate molecular weight of 77 000. These isolated proteins bound to the surface of glutaraldehyde-fixed tumor cells, and their binding was inhibited by D-galactose and also by D-mannose. Since most of the 77 kDa protein bound to the asialo unit B oligosaccharide-Sepharose 4B, this protein was assumed to be identical with the 79 kDa protein. These results suggest that the lectin-like molecules on murine macrophages have wide specificity and that one lectin-like molecule can bind both D-galactose and D-mannose.
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PMID:Lectin-like molecules on the murine macrophage cell surface. 648 61

The effect of Sarcophaga lectin on mouse macrophage-like cell line J774.1 was studied. It was found that this lectin induced significant morphological changes and stimulated glucose consumption of J774.1 cells. A similar effect was observed when bacterial lipopolysaccharide was added to the culture medium. However, although cells treated with lipopolysaccharide were not cytotoxic to allogeneic tumor cells, those treated with Sarcophaga lectin were found to acquire cytotoxicity. The physiological significance of Sarcophaga lectin is discussed from the viewpoint of comparative immunology.
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PMID:Activation of murine macrophage-like cell line J774.1 by Sarcophaga peregrina lectin. 648 79

A lectin which we purified from the mucous of Ophidiidae Genypterus blacodes showed a potent mitogenic activity which was comparable to that of concanavalin A (con A). On the other hand, the lectin treated with 2-mercaptoethanol showed an anti-mitogenic activity against con A and lipopolysaccharide (LPS). Lymphocytes were separated into a T cell rich fraction and B cell rich fraction by soybean agglutinin. The mitogenic activity of G. blacodes lectin was examined using these cells. It was suggested that the mitogenic activity of G. blacodes lectin was based on the stimulation of T cells. The lectin was also subjected to both the sperm agglutination and the in vitro fertilization tests in mouse. It was demonstrated that: a) the lectin receptors were ubiquitous on sperm; b) in vitro fertilization of mouse ova was completely blocked by the binding of the lectin to the zona pellucida of the ova.
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PMID:Mitogenic activity and in vitro fertilization inhibitory activity of Genypterus blacodes lectin. 653 Jun 48

Vertebrate lectin purified from loach egg was tested for induction of tumor lysis mediated by macrophages. Loach egg lectin lysed tumor cells but not normal spleen cells in cooperation with BCG- or glucan (TAK)-elicited peritoneal macrophages of mice. Corynebacterium parvum-, OK432-, glycogen-, lipopolysaccharide-elicited or resident macrophages were not effective. Neither loach egg lectin nor BCG nor glucan macrophages alone had a cytolytic action on tumor cells. Thus, the vertebrate lectin from loach egg is a mediator in macrophage-mediated tumor lysis, inducing binding of macrophages to target cells. This lectin-dependent macrophage-mediated cytolysis (LDMC) was inhibited by galactose, N-acetylgalactosamine, fucose, or rhamnose. These results suggest that tumor cells can be recognized via glycoconjugates on cell membrane in addition to tumor-associated antigen and that some animal lectins participate in macrophage-mediated tumor lysis.
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PMID:Macrophage-mediated tumor lysis induced by loach egg lectin. 658 20


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