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

Selective growth and clonal proliferation of human T lymphocytes can be achieved by using a single-phase semi-solid methylcellulose system without the requirement of preincubation with lectins. Significant proliferation, however, depends upon the continued presence of Con A or PHA, but not pokeweed mitogen or lipopolysaccharide within the methylcellulose. This procedure eliminates nonspecific agglutination by lectins and allows for direct visualization of colonies and their specific removal and subsequent cloning in liquid phase. Optimal growth and production of colonies greater than 40-cell size require 3 to 9 days. Individual cells can be identified on the basis of E rosette formation and absence of surface immunoglobulin or ability to phagocytize latex particles. Moreover, proliferation is inhibited by antithymocyte but not anti-B cell sera and can be demonstrated with peripheral blood T and MOLT-4 cells, but not with B or Raji cells. Finally, colony formation is not enhanced by the presence of 2-mercaptoethanol. The clonal proliferation of human T lymphocytes has wide application in the study of both antigen recognition and lymphocyte alterations in specific diseases.
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PMID:Select growth of human T lymphocytes in single phase semisolid culture. 30 80

Endothelial cell activation antigens may play important roles in immune responses and in inflammation. This report describes the identification and characterization of a monoclonal antibody, named EAA-B, which reacts specifically with human umbilical vein endothelial (HUVE) cells pre-treated with tumour necrosis factor-alpha (TNF-alpha) but not with untreated cells. The expression of the EAA-B antigen on HUVE cells could also be induced by interleukin-1 (IL-1), bacterial lipopolysaccharide (LPS), and phorbol esters but not by interferon-gamma (IFN-gamma). By contrast, EAA-B antigen expression on neonatal foreskin and rheumatoid synovial fibroblasts, whether pre-treated with TNF-alpha or not, was not detectable. Peripheral blood leucocytes and the leukaemic cell lines U937, HL-60, Raji and Molt 4 showed no detectable expression of the EAA-B antigen. Kinetic studies demonstrated that the EAA-B antigen was rapidly expressed, peaked at 6 hr and declined to basal level by 24 hr. Western blotting revealed that monoclonal antibody EAA-B recognized a polypeptide of approximately 80,000-90,000 MW. EAA-B partially blocked the augmented adhesion of HL-60 cells to TNF-treated HUVE cells. However, it failed to inhibit the enhanced binding of peripheral blood leucocytes, U937, Raji and Molt 4 Cells to TNF-treated HUVE cells. In situ, the EAA-B antigen was detected on some vascular endothelium in tonsils, lymph nodes, psoriatic skin and rheumatoid synovium but not in normal non-lymphoid tissues. Interestingly EAA-B antigen is also expressed by B lymphocytes in germinal follicle centres (GFC) of lymphoid tissues. The co-expression of this endothelial activation antigen by GFC B lymphocytes may have significant implications for immune responses and in B-lymphocyte differentiation.
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PMID:Identification of a human endothelial cell activation antigen that is co-expressed by germinal follicle centre B lymphocytes. 139 50

The minimal region of the human tumor necrosis factor alpha (TNF-alpha) gene promoter necessary for its transcriptional induction by phorbol esters (PMA) in human T and B lymphocyte cell lines has been localized between -52 and +89 nucleotides (nt) relative to the gene's transcriptional start site. Comparison of these sequences to those required to mediate virus or lipopolysaccharide (LPS) induction of the gene reveal significant differences, and thus, the sequence requirements for PMA induction are distinct from those that mediate induction by virus or LPS. Although three sites in the TNF-alpha promoter (kappa 1, kappa 2, and kappa 3) specifically bind the transcription factor NF-kappa B in lymphoid nuclear extracts, TNF-alpha mRNA induction by PMA does not correlate with NF-kappa B binding activities displayed by different T and B cell lines. Moreover, kappa 1-kappa 3 can each be deleted from the TNF-alpha promoter with little effect on the gene's inducibility by PMA. Therefore, TNF-alpha mRNA induction by PMA, like its induction by virus and LPS, is not primarily mediated by NF-kappa B, but rather is mediated through other sequences and protein factors. Surprisingly, multimers of kappa 1-kappa 3 can confer PMA inducibility on a heterologous promoter in a B (Raji), but not a T (HUT78) cell line. However they are not functional on a truncated TNF-alpha promoter, indicating that promoter context and cell type specificity influence the PMA inducible function of these NF-kappa B binding sites.
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PMID:Human tumor necrosis factor alpha gene regulation in phorbol ester stimulated T and B cell lines. 205 82

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

Chronic respiratory infection with Pseudomonas aeruginosa is a leading clinical problem among patients with cystic fibrosis. Because antimicrobial agents are usually ineffective in eradicating these infections, additional therapeutic or prophylactic measures should be considered. In this study, an experimental guinea pig model of chronic Pseudomonas aeruginosa bronchopneumonia was utilized to determine whether active immunization with lipopolysaccharide (LPS) P. aeruginosa antigen may favorably influence the course of this infection. Experimental pneumonia was established by tracheobronchial instillation of suspensions of microscopic agar beads, which were impregnated with viable P. aeruginosa. After 4 wk of infection, the geometric mean (reciprocal) passive hemagglutinating Pseudomonas antibody titer was 185+/-1.3, and lungs contained 16.8+/-4 x 10(3) colony-forming units Pseudomonas/ml of lung homogenate. Pseudomonas immunization, given prior to a 4-wk infection, resulted in significantly higher passive hemagglutinating titers (474+/-1.4; P < 0.05), lower numbers of viable Pseudomonas in lung tissues (2.4+/-0.6 x 10(3); P < 0.01), and reduced histopathology in lungs. In contrast, providing Pseudomonas immunization to animals 2 wk after pulmonary infection was established, offered no apparent benefit. Likewise, no protection was afforded by prophylactic immunization with a non-Pseudomonas LPS antigen (Escherichia coli J5 vaccine). Using a Raji cell assay, modified to detect circulating immune complexes in vaccinated and infected guinea pig sera, there was no evidence that active immunization increased the frequency of circulating immune complexes in infected guinea pigs. It is concluded that prophylactic immunization with Pseudomonas LPS antigen may confer protection from subsequent Pseudomonas bronchopneumonia, but that immunization during established infection is not beneficial.
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PMID:Active immunization with lipopolysaccharide Pseudomonas antigen for chronic Pseudomonas bronchopneumonia in guinea pigs. 679 29

Tumor necrosis factor alpha (TNF alpha) is a central mediator of the immunological response and the location of the gene within the major histocompatibility complex (MHC) has prompted much speculation about the role of TNF alpha alleles in inflammatory and MHC-associated autoimmune diseases. A G to A transition polymorphism at position -308 of the TNF alpha promoter/enhancer region has been described. The uncommon -308A allele was shown to be strongly associated with human leukocyte antigen (HLA)-DR3, known to be related to a TNF alpha "high producer" phenotype. In support for a clinical relevance, the -308A allele is implicated in susceptibility for cerebral malaria. In this study, we determined the junctional consequences of the TNF -308 polymorphism. Therefore, we analyzed both allelic forms (TNF alpha(-308G) and TNF alpha(-3O8A)) of the TNF alpha enhancer/promoter region (-598/+108) in a transient transfection system, using chloramphenicol acetyltransferase (CAT) as reporter gene. The T cell line Jurkat and the B cell line Raji served as hosts in these experiments. The results showed no differences in the level of inducible reporter gene expression between the TNF(-3O8G)/CAT and the TNF(-308A)/CAT constructs. These data were confirmed by allele specific TNF alpha transcript quantification (ASTQ) analysis, which demonstrated that both TNF alleles contribute equally to the total amount of mRNA in peripheral blood mononuclear cells (PBMCs) stimulated with phorbol 12-myristate 13-acetate (PMA)/anti-CD3. In analogy, no difference between the level of transcription of the -308A and -308G alleles was observed in lipopolysaccharide (LPS)-stimulated peripheral blood monocytes. This study indicates that the TNF alpha -308 G to A transition is not responsible for differential TNF alpha production induced by standard in vitro stimuli.
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PMID:Relevance of the tumor necrosis factor alpha (TNF alpha) -308 promoter polymorphism in TNF alpha gene regulation. 883 66

Binding of ligand to receptor, in various types of cells, results in changes in calcium concentration, which is an important factor in cellular signal transduction. Lymphocytes receive signals from the parasympathetic nervous system through the cholinergic receptors. Cholinergic receptors mediate response to stimuli through changes of the IP3, or cAMP level and Ca2+ mobilization in various types of cells. The aim of this work was to measure changes in calcium concentration in cytosol of lymphocytes stimulated with acetylcholine agonists - carbachol (analogue of acetylcholine) or nicotine. Human peripheral blood mononuclear cells (PMBC) and lymphocytes from the leukemic cell lines Jurkat and Raji were used. Immune cells were preactivated with mitogen phytohemagglutinin (PHA) for PBMC and Jurkat cells or lipopolysaccharide for Raji cells. Two methods of measurement of calcium concentration were used. With the first, calcium concentration was measured in the suspension of cells loaded with the fluorescent dye Fura-2AM. With the other method, calcium concentration was assessed in single cells loaded with the fluorescent dye Indo-1AM. Using the method of single cell investigation, we observed an increase in the level of calcium concentration induced by carbachol and nicotine. The method of measuring the Ca2+ concentration in a cell suspension was found to be not sensitive enough for this purpose. The increase in calcium concentration resulted both from the stimulation of Ca2+ influx and from the release of Ca2+ from intracellular stores, most likely due to the increase in the concentration of IP3. In conclusion, we suggest that the lymphocytes activated with PHA respond to cholinergic stimulation with an increase in their free cytoplasmic Ca2+ concentration.
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PMID:Effect of cholinergic stimulation on free intracellular Ca2+ concentration in human lymphocytes. 909 47

The presence of two different signaling molecules is essential to induce opsonin-independent phagocytosis of particulate activators of the human alternative complement pathway by human monocytes. In addition to the involvement of a low M(r) peptide cytokine or phagocytosis inducing factor (PIF), we have now established that the participation of bacterial lipopolysaccharide is also required. PIF has been demonstrated to be present in human cell lines of different origins, e.g., WISH cells, Raji cells, U937 cells, HL-60 cells and M21 cells. PIF has been purified to apparent homogeneity from the U937 cell line by anion-exchange chromatography on DEAE-Sephacel followed by gel filtration chromatography on Sephadex G-50. On the basis of Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the apparent molecular mass has been estimated to be approximately 1,600 Da. PIF also plays an important role in the regulation of cell-substratum adherence.
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PMID:Purification and characterization of a phagocytosis inducing factor: role in cell-substratum adherence. 948 Aug 53

Nucleoside transport systems and their regulation in human B-lymphocytes have been characterized using the cell lines Raji and Bare lymphoma syndrome-1 (BLS-1) as experimental models. These cells express at least three different nucleoside transport systems as follows: a nitrobenzylthioinosine-sensitive equilibrative transport system of the es-type, which appears to be associated with hENT1 expression, and two Na+-dependent transport systems that may correspond to N1 and to the recently characterized N5-type, which is nitrobenzylthioinosine-sensitive and guanosine-preferring. B cell activators such as phorbol 12-myristate 13-acetate and lipopolysaccharide (LPS) up-regulate both concentrative transport systems but down-regulate the equilibrative es-type transporter, which correlates with lower hENT1 mRNA levels. These effects are dependent on protein kinase C activity. Phorbol 12-myristate 13-acetate and LPS also induce an increase in tumor necrosis factor-alpha (TNF-alpha) mRNA levels, which suggest that this cytokine may mediate some of the effects triggered by these agents, since addition of TNF-alpha alone can increase N1 and N5 transport activities by a mechanism that also depends on protein kinase C activation. Interestingly, TNF-alpha down-regulates es activity, but this effect cannot be abolished by inhibiting protein kinase C. This study reveals differential regulation of nucleoside transport systems following activation of human B-lymphocyte cell lines by agents of physiological relevance such as TNF-alpha and LPS. Moreover, it indicates that the recently characterized N5 transport system can also be regulated following B cell activation, which may be relevant to lymphocyte physiology and to the treatment of lymphocyte malignancies.
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PMID:Regulation of nucleoside transport by lipopolysaccharide, phorbol esters, and tumor necrosis factor-alpha in human B-lymphocytes. 975 42

The authors have previously demonstrated that the tumour necrosis factor (TNF) -308 G/A polymorphism affects the binding of transcription factors. In transient transfection assays in PMA stimulated U937 monocytes and Jurkat T cells, the A-containing TNF2 promoter has a 2-3-fold greater transcriptional activity than the TNF1 promoter in the presence of the TNF 3'UTR. In this study it was found that a difference in TNF1 and TNF2 promoter activities was only observed in U937 and Jurkat cells, and not in Raji (B cell line), HeLa (epithelial carcinoma cell line), HepG2 (hepatoma cell line) or THP-1 (monocyte), suggesting cell-type specific transcription factors or modifications may be involved in the formation of the -308 protein/DNA complex. Physiological stimulators, TNF and interferon gamma (IFN-gamma) did not cause differential promoter activity between TNF1 and TNF2, but LPS did with only the TNF2 promoter/3'UTR construct being significantly responsive to lipopolysaccharide (LPS) in U937 cells. In U937 cells, the -308 polymorphism affected transcription following differentiation by phorbol myristate acetate (PMA), retinoic acid, PMA plus LPS and PMA plus retinoic acid with an increase in nuclear factor binding to both TNF1 and TNF2 in the -323 to -285 region being observed. The greatest difference between TNF2 and TNF1 promoter activities (5-fold) was observed following PMA plus retinoic acid treatment of transfected U937 cells for 48h. During this time, U937 differentiated into cells with a macrophage-like morphology. An understanding of the cell type and stimuli specific requirements for differential expression of the -308 polymorphism may help elucidate the role the TNF -308 polymorphism plays in diseases where elevated TNF levels are thought to be important.
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PMID:Effects of stimulus and cell type on the expression of the -308 tumour necrosis factor promoter polymorphism. 1067 Dec 95


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