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)

A fraction extracted from BCG and designated MY-1, which was composed of 70.0% DNA and 28.0% RNA, was previously reported to possess strong antitumor activities against various syngeneic mouse and guinea pig tumors. An intraperitoneal injection of MY-1 (100 micrograms) 1 day before rendered mouse peritoneal cells cytotoxic to YAC-1 cells. The effector cells were nonadherent to plastic dishes, and the activity was destroyed by treatment with anti-asialo GM1 antiserum plus complement or carrageenan in vitro, but not with carbonyl-iron or anti-Thy 1.2, suggesting that the cells are natural killer (NK) cells. In vivo augmentation of NK activity was dependent on MY-1 dose, and reached the peak 1 day after MY-1 injection. Since NK activity in lipopolysaccharide (LPS)-nonresponder mice could be augmented by MY-1, the possibility that LPS contaminated the MY-1-augmented NK was excluded. MY-1 digested preliminarily with DNase lost its NK-inducing activity, suggesting that the DNA entity of MY-1 was essential for the activity. When mice were pretreated with anti-asialo GM1 or carrageenan, MY-1 could not render the peritoneal cells cytotoxic. Antitumor activities of MY-1 were also abolished if the animals were pretreated with anti-asialo GM1 antiserum or carrageenan, suggesting that the activities can be ascribed mainly to activated NK cells.
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PMID:In vivo augmentation of natural killer cell activity with a deoxyribonucleic acid fraction of BCG. 242 98

Naturally elaborated membrane bleb material is frequently observed in cultures of Neisseria gonorrhoeae. This material was purified and analyzed for protein, lipopolysaccharide, and nucleic acid content. The electrophoretic protein profiles of two bleb-rich fractions, called BI and BII, were distinct, with only BII containing lipopolysaccharide and outer membrane proteins I and III. Both fractions contained RNA, circular DNA, and linear DNA. Exogenous pancreatic DNase I appeared to hydrolyze all bleb-associated DNA in fraction BI and the linear DNA in fraction BII. The circular DNA molecules associated with fraction BII resisted digestion. Electron microscopy of the bleb fractions verified their DNA content. Fixing blebs with glutaraldehyde before mounting them for microscopy prevented release of internal DNA. Such fixation produced little change in the micrographs of BI; however, only traces of DNA were observed in fixed BII preparations. Incubation of wild-type gonococci in mixtures of DNase and blebs purified from antibiotic-resistant strains resulted in efficient exchange of penicillinase-specifying R plasmids. Recipients incorporated plasmids independently of endogenous and exogenous chromosomal streptomycin resistance markers. These in vitro results suggest that bleb formation by N. gonorrhoeae may serve to transfer plasmids intercellularly in vivo, perhaps constituting a previously unexplored genetic exchange mechanism in these bacteria.
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PMID:Export and intercellular transfer of DNA via membrane blebs of Neisseria gonorrhoeae. 249 8

To detect nuclear proteins that might be involved in induction of cellular mitogenesis, we examined the effect of various mitogens on early changes in synthesis of nuclear proteins in murine B lymphocytes. Using two-dimensional gel electrophoresis, we found that activation of B cells by mitogens (anti-immunoglobulin antibody, lipopolysaccharide, phorbol 12-myristate 13-acetate (PMA)/A23187) was associated with a rapid and prominent (5-20-fold) increase in the synthesis of a 40-kDa/pI 5.0 nuclear protein, here termed numatrin. Numatrin was found to be absent from the cytosol (soluble fraction) of resting as well as activated B cells and was markedly resistant to DNase/RNase digestion and 2 N NaCl extraction, indicating that this protein is tightly bound to the nuclear matrix. Kinetic studies showed that the increase in synthesis of numatrin was detected 60-120 min following mitogen activation, reached a peak at 16 h, and declined to almost control level by 48 h, correlating with the peak of cellular DNA synthesis. The increase in synthesis of numatrin in normal B cells was found to be associated exclusively with cellular commitment for mitogenesis because activation of B cells by stimuli such as B cell stimulating factor 1, PMA alone, and calcium ionophore A23187, which do not stimulate an increase in DNA synthesis, also failed to induce an increase in the synthesis of numatrin. Inhibition of anti-Ig-induced proliferation (by PMA pretreatment) was associated with a 63% inhibition in the synthesis of numatrin. Addition of 8-mercaptoguanosine to these PMA-treated cells was associated with restoration of the increase in synthesis of numatrin, concomitant with induction of proliferation. Elevated synthesis of numatrin was also detected in the malignant B lymphoma cells: Raji, BAL-17, and WEHI-231. Taken collectively, these results suggest that numatrin, a tightly bound nuclear matrix protein, is a growth-regulated protein which might have an important role in regulation of cellular mitogenesis in normal and malignant B lymphocytes.
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PMID:"Numatrin," a nuclear matrix protein associated with induction of proliferation in B lymphocytes. 330 55

A lipopolysaccharide (LPS) fraction was extracted from Nichols, nonpathogenic Treponema pallidum by the hot, phenol-water procedure. The LPS was freed of nucleic acids and water-soluble proteins by successive exposures to ribonuclease, deoxyribonuclease, and Pronase. Purified LPS responded positively in a colorimetric assay for lipopolysaccharide. Electron microscope examination of the LPS both before and after purification demonstrated a heterogeneous mixture of forms including spheres, doughnuts, and ribbons. The trilaminar nature of the ribbon forms was observed by both negative staining and thin sectioning. Lyophilization of the LPS caused an increase in the number and length of ribbon forms seen. Results suggest that the surface layers of treponemes are similar to those of gram-negative bacteria.
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PMID:Ultrastructure of lipopolysaccharide isolated from Treponema pallidum. 412 67

Ribosomal preparations obtained from Salmonella typhimurium by differential centrifugation and sodium dodecyl sulfate (SDS) treatment of the bacillary lysate were found to be immunogenic in F(1) hybrid (C(3)H/HeJ x DBA/2J) and albino Swiss mice, as determined by progressive host survival. The immunity obtained was independent of the need for adjuvant and dependent on the dosage of immunogen given. Immunizations with the ribosomal preparations induced an immune response comparable to that obtained by vaccination with living organisms and significantly greater than that obtained by immunization with heat-killed salmonellae, purified lipopolysaccharide, or crude and SDS-treated endotoxin preparations. No effect on the immunogenicity of the ribosomal fraction was observed by enzymatic treatment with trypsin, Pronase, deoxyribonuclease, and pancreatic ribonuclease. Linear sucrose density gradient resolution of the preparations showed that the immunogenicity of the ribosomal fraction was not unique to any one of its subcomponents. Ethyl alcohol-precipitated, crude ribonucleic acid preparations obtained from the ribosomal and sucrose density-resolved ribosomal preparations were found to induce an immune response comparable to that obtained by immunization with the entire ribosomal fraction. Dialysis in doubly distilled demineralized water slightly reduced the immunogenicity of the preparation; however, comparable dialysis in 10(-4)m MgCl(2)-phosphate buffer did not. Chemical assays of the preparations found to be immunogenic were performed.
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PMID:Isolation and partial characterization of an immunogenic moiety obtained from Salmonella typhimurium. 489 82

The transcriptional activity of the kappa immunoglobulin genes in a B-cell lymphoma line, 7OZ/3 was measured before and after stimulation by lipopolysaccharide (LPS). Analyses of accumulated nuclear RNA components and of nascent transcripts showed that LPS induces transcription of both the productively rearranged (kappa+) and the unrearranged (kappa) allele in these cells. This pattern of transcriptional activation correlates well with the LPS induced appearance of a DNAase I hypersensitive site on both alleles in the vicinity of a putative enhancer element (Parslow and Granner, Nucl. Acids Res. 11, 4775, 1983). However, the transcriptional activation is not accompanied by detectable hypomethylation at Hha I and Hpa II sites which are normally undermethylated when kappa genes are constitutively expressed. These findings have enabled us to evaluate the relative importance of various structural parameters to the transcriptional competence of the kappa locus.
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PMID:Lipopolysaccharide-induced transcription of the kappa immunoglobulin locus occurs on both alleles and is independent of methylation status. 632 27

Following our previous demonstration that both viable and heat-killed Mycoplasma orale induce selective tumor cell killing by murine peritoneal macrophages, further investigations reported here showed that also macrophages from a continuously proliferating cell line established from long-term cultures of murine bone marrow explants can effectively be induced by the heat-killed mycoplasmas to express cytolysis. The use of single-cell suspensions of M. orale from a 0.45-micron filtrate or following either sonication or treatment with DNase did not significantly affect the level of cytolysis. Minute quantities of M. orale acted synergistically with ineffectively low levels of either lymphokines (LK) or lipopolysaccharide (LPS) to produce killing. The exceptional resistance of M109 lung adenocarcinoma cells to macrophage-mediated killing induced by LK and LPS, as previously reported by us, could not be overcome by the addition of M. orale. These data appear to indicate a mechanism of macrophage activation by M. orale similar to that caused by LPS.
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PMID:Studies on the mechanism of macrophage-mediated tumor cell lysis induced by Mycoplasma orale. 651 64

To determine whether the existence of anti-dsDNA producing lymphocyte clones is limited to autoimmune strains of mice, spleen cells derived from autoimmune mice (NZB, NZB X NZW F1, MRL) and from normal strains (BALB/c, DBA/2, C57BL/6, C3H/eb) were cultured with E. coli lipopolysaccharide (LPS). DNase-treated supernatants from these cultures were assayed for anti-dsDNA antibodies by employing a sensitive solid-phase radioimmunoassay with poly (dA-dT) as the antigen. All tested spleen cells secreted a small yet significant amount of anti-dsDNA upon stimulation with LPS. There was no difference in the amount or in the heavy chain type of anti-dsDNA secreted by cells from normal and autoimmune strain cells. Evidence of clonal expansion in unstimulated cells was observed only in cultures prepared from older autoimmune animals. Removal of T cells from the spleen cell preparations had no marked effect on the spontaneous or stimulated antibody secretion. Anti-dsDNA antibodies could also be induced in vivo by i.p. injection of LPS into young normal animals. Splenocytes from all tested strains spontaneously secreted anti-ssDNA and anti-TNP antibodies in culture, and these were present at relatively high levels in the serum of unstimulated animals. Stimulation with LPS increased secretion of anti-ssDNA and anti-TNP in all strains in vitro and in five of seven strains in vivo as well. It can be concluded that a) the existence of anti-dsDNA-producing clones is not limited to autoimmune strains, and b) these clones are expanded in old but not in young autoimmune mice. They are not expanded in normal mice at any age.
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PMID:The in vitro and in vivo induction of anti-double-stranded DNA antibodies in normal and autoimmune mice. 697 78

We investigated the ability of various polyclonal B-cell activators (PBA) to induce immunoglobulin synthesis, circulating immune complexes, and rheumatoid-factor-like autoantibodies. We found that, following the injection of a PBA--bacterial lipopolysaccharide, dextran sulfate, polyriboinosinic-polyribocytidilic acid, or purified protein derivative of tubercle bacteria--a transitory formation of circulating immune complexes occurred simultaneously with an increase in immunoglobulin production. The presence of circulating immune complexes after PBA administration was documented by the 125I-Clq-binding assay and the conglutinin-binding assay, and a partial characterization of this material was achieved. Although the kinetic properties, size, and composition of the immune complexes tested varied with the PBA used, the complexes detected in each group were inactivated by mild reduction and alkylation with 2-mercaptoethanol and were unaffected by DNase treatment. In the mice injected with bacterial lipopolysaccharide, the induction of circulating immune complexes correlated significantly with the presence of rheumatoid-factor-like antibodies, suggesting that this autoantibody may be present within the detected immune complexes. In tissues, glomerular deposits of IgM, IgG, and C3 were observed in a pattern compatible with the deposition of immune complexes. These deposits were progressively associated with marked glomerular abnormalities in mice chronically injected with LPS during 1 year. These data suggest that the induction of polyclonal antibody synthesis, which occurs in a variety of infectious or autoimmune diseases, may be responsible for the high incidence and persistence of immune complexes in these diseases. Such complexes would involve primarily autoantigens and corresponding autoantibodies, such as rheumatoid factor IgG complexes, without the participation of any specific bacterial, viral, or parasitic antigen.
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PMID:Induction of circulating immune complexes and their renal localization after acute or chronic polyclonal B-cell activation in mice. 698 26

Treatment of Pseudomonas aeruginosa with metal ion chelators, especially ethylenediaminetetraacetic acid (EDTA), causes both release of protein-lipopolysaccharide complexes and cell death. We have examined the effect of EDTA on P. aeruginosa and found that EDTA does not induce the rapid solubilization of the peptidoglycan sacculus and complete lysis as previously thought; the decrease in optical density of cultures incubated with EDTA is primarily due to the loss of the outer membrane. Of the other potential solubilizers examined, only ethylene-bis(oxyethylenenitrilo)tetraacetic acid (EGTA) resulted in some decrease in optical density. The lytic effect of EDTA on 12 strains of P. aeruginosa was examined and was found to vary greatly between strains; the sensitivity to EDTA varies from between 96% and 10% of the decrease in optical density resulting from incubation of cells with both EDTA and lysozyme. Sensitivity to EDTA is not constant during the growth of P. aeruginosa; in the early exponential phase of growth, cells treated with EDTA exhibit a 82% decrease in optical density after 30 min while in the stationary phase the optical density decreases by only 40%. Nucleic acids were observed to leak from cells following treatment with EDTA and this was greatly facilitated by DNase and RNase. The release of genetic material was much reduced when cells were incubated at 4 degrees C, supporting an enzymatic role in cell wall solubilization. We propose that only small areas of the sacculus become hydrolysed via specific peptidoglycan hydrolases, or autolysin(s), which are activated or de-regulated by EDTA.
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PMID:Role of autolysins in the EDTA-induced lysis of Pseudomonas aeruginosa. 800 62


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