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)

Malnutrition is frequently observed in patients with pulmonary tuberculosis. We have already reported the nutritional disturbance in those patients by comprehensive nutritional assessment. But the mechanism of this nutritional disturbance remains unclear. We anticipated that cytokines contributed to the nutritional disturbance. To elucidate this mechanism we measured the productions of interleukin-1 (IL-1) and tumor necrosis factor (TNF) by peripheral blood monocytes, and correlated them with nutritional parameters in those patients. These cytokines had been reported to mediate metabolic alterations in inflammatory process. Subjects were 45 patients with bacteriologically confirmed pulmonary tuberculosis and their controls matched by age and sex. Adherent monocyte at 0.5 x 10(6)/ml were stimulated by lipopolysaccharide (LPS), and the culture supernatant was measured by ELISA for IL-1 and TNF. In order to assess nutritional status we measured serum albumin, transferrin, prealbumin, retinol binding protein, branched chain amino acid (BCAA)/aromatic amino acid (AAA) ratio as amino acid imbalance index, % ideal body weight (%IBW), % arm muscle circumference (% AMC) as muscle mass index, % triceps skin fold thickness (% TSF), as fat store index. The results were as follows: (1) Patients with active pulmonary tuberculosis were confirmed to be malnourished in visceral proteins, plasma amino acid, and anthropometric indices. (2) In patients with moderate or mild nutritional depletion the production of IL-1 and TNF was higher than that in healthy controls, and significantly correlated inversely with the nutritional parameters. (3) In patients with severe nutritional depletion the production of IL-1 and TNF was lower than that in healthy controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Interaction between interleukin-1 and tumor necrosis factor productions by peripheral blood monocytes and nutritional disturbance in active pulmonary tuberculosis]. 189 Jul 90

To facilitate the production and purification of human monoclonal antibodies, we evaluated the ability of human hybridomas to adapt to chemically defined-serum free media. From a panel of human hybridomas secreting antibody against serotype specific lipopolysaccharide determinants of gram-negative bacteria, the growth and secretion properties of the two hybridomas producing antibodies against two strains of Pseudomonas aeruginosa, 4-8KH15 and 4-10KH139, were analysed. Both clones did not grow in protein-free medium. However, it was possible to adapt them to serum-free media consisting of a basal medium supplemented with insulin, transferrin, ethanolamine, and selenite. Antibody secretion rates were equal (4-8KH15: 26-31 micrograms IgM/10(6) cells/day) or higher (4-10KH139: 58-90 micrograms IgM/10(6) cells/day) in serum-free media as compared to conventional serum-supplemented medium. Our studies suggest that adaptation of the described hybridomas to selected serum-free media results in an antibody production which is very high as compared with reports in comparable systems. The establishment of these conditions will significantly facilitate the production of large amounts of human monoclonal antibodies which is a prerequisite for a therapeutical application.
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PMID:Optimization of growth and secretion of human monoclonal antibodies by hybridomas cultured in serum-free media. 191 51

We defined the acute phase behaviour of a number of rabbit plasma proteins in studies (in vivo) and studied the effects of monokine preparations on their synthesis by rabbit primary hepatocyte cultures. Following turpentine injection, increased serum levels of C-reactive protein, serum amyloid A protein, haptoglobin, ceruloplasmin, and decreased concentrations of albumin were observed. In contrast to what is observed in man, concentrations of alpha 2-macroglobulin and transferrin were increased. Co-culture of primary hepatocyte cultures with lipopolysaccharide-activated human peripheral blood monocytes or incubation with conditioned medium prepared from lipopolysaccharide-activated human or rabbit monocytes resulted in dose-dependent induction of serum amyloid A, haptoglobin, ceruloplasmin and transferrin and depression of albumin synthesis, while C-reactive protein synthesis and mRNA levels remained unchanged. A variety of interleukin-1 preparations induced dose-dependent increases in the synthesis and secretion of serum amyloid A, haptoglobin, ceruloplasmin and transferrin and decreased albumin synthesis. Human recombinant tumour necrosis factor (cachectin) induced a dose-dependent increase in synthesis of haptoglobin and ceruloplasmin. In general, human interleukin-1 was more potent than mouse interleukin-1 and tumour necrosis factor. None of the monokines we studied had an effect on C-reactive protein synthesis or mRNA levels. These data confirm that C-reactive protein, serum amyloid A, haptoglobin and ceruloplasmin display acute phase behaviour in the rabbit, and demonstrate that, in contrast to their behaviour in man, alpha 2M and transferrin are positive acute phase proteins in this species. While both interleukin-1 and tumour necrosis factor regulate biosynthesis of a number of these acute phase proteins in rabbit primary hepatocyte cultures, neither of these monokines induced C-reactive protein synthesis. Comparison of these findings with those in human hepatoma cell lines, in which interleukin-1 does not induce serum amyloid A synthesis, suggests that the effect of interleukin-1 on serum amyloid A synthesis may be indirect.
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PMID:Regulation of rabbit acute phase protein biosynthesis by monokines. 246 85

A fibroblast proliferation assay was developed for the detection of interleukin 1 (IL 1). Proliferation was measured by thymidine incorporation and by staining of cellular proteins with crystal violet. Response of fibroblasts was optimal at cell numbers of 4,000 to 9,000 cells/culture and an incubation period of four days. Serum content of the culture medium, ranging from 1 to 10% fetal calf serum (FCS), enhanced the proliferative response in a concentration-dependent manner, while higher concentrations of FCS did not lead to further increase. Both detection methods were equally suitable for the measurement of IL 1 biological activity in purified and crude preparations. In contrast to the conventional thymocyte comitogenic assay, the fibroblasts in this assay did not proliferate in response to IL 2 or IL 6. Fibroblasts were weakly stimulated by recombinant (rec) tumor necrosis factor (rec TNF-alpha); they did, however, not proliferate in response to mitogens, lipopolysaccharide, rec granulocyte-macrophage colony stimulating factor (rec GM-CSF), macrophage-CSF, rec interferon-gamma, insulin or transferrin. The detection of IL 1 activity by crystal violet staining of human dermal fibroblasts was easier and faster than by measurement of thymidine incorporation of fibroblasts or mouse thymocytes; without loss of sensitivity, the sample capacity of the IL 1 assay could be enhanced, and the use of experimental animals was avoided.
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PMID:Detection of interleukin 1 with human dermal fibroblasts. 247 29

The unassembled (soluble) and assembled (particulate) pools of clathrin in murine lymphocytes have been separated by centrifugation, and specifically quantified by immunoblotting of cellular extracts with an anticlathrin heavy chain monoclonal antibody. In resting spleen lymphocytes only 25-30% of the total cellular clathrin was found to be present in an assembled form. Upon activation of lymphocytes with B or T cell mitogens (lipopolysaccharide or concanavalin A), the levels of assembled clathrin increased to 60% of the total. These changes in the levels of assembled clathrin were not due to an increase in total cellular clathrin concentration following lymphocyte activation, but rather to changes in the steady state ratio of assembled to unassembled clathrin. The increase in assembled clathrin preceded the expression of transferrin receptors, as measured by the cell surface binding of an antitransferrin receptor monoclonal antibody, and maximal DNA synthesis, indicating that clathrin assembly occurs early after lymphocyte activation and precedes cell division. Immunofluorescence analysis of activated lymphocytes with an anti-clathrin heavy chain monoclonal antibody revealed a punctuate staining pattern characteristic of coated pits and vesicles. Activated B lymphocytes displayed particularly prominent staining in the perinuclear region compared to T cells, suggesting that clathrin assembly may be important for B cell functions such as immunoglobulin synthesis or secretion. These results suggest that in lymphocytes, clathrin assembly is a dynamic process that is triggered by mitogenic stimuli.
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PMID:Increased assembly of clathrin occurs in response to mitogenic activation of murine lymphocytes. 266 60

Administration of endotoxins is often followed within 12-24 h by marked hypoferremia. Because the hepatocyte is the major site of both iron storage and transferrin synthesis, we have investigated the effects of an Escherichia coli endotoxin (lipopolysaccharide, LPS) on these parameters on isolated hepatocytes from normal Wistar rats (ND), rats previously treated intraperitoneally with 2.5 mg/kg (LD) or 25 mg/kg (HD) LPS, and control rats injected intraperitoneally with sterile saline (CD). No effects were observed on iron uptake from transferrin by ND cells incubated in vitro with up to 350 micrograms LPS/10(7) hepatocytes. There was also no significant difference in iron uptake between CD, HD, and LD hepatocytes 1 h after LPS injection. However, hepatocytes isolated 24 h after LPS administration took up iron significantly faster than controls. The uptake of non-transferrin-bound iron was also increased in HD and LD hepatocytes at 24 h but only in HD cells at 1 h. Transferrin binding was not altered in LPS-treated cells from ND rats but was depressed in cells from LPS-treated rats both at 1 h and at 24 h after injection. Transferrin receptor recycling was significantly increased at 24 h in cells from both LD and HD rats. Transferrin and total protein synthesis were also depressed at 1 h in LPS-treated rats, returning to normal values at 24 h. Direct preincubation of ND cells, however, failed to increase synthesis except at the highest concentrations of LPS. We conclude that LPS has an immediate (although indirect) effect on protein synthesis by the hepatocyte but not on iron uptake.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of endotoxin on iron uptake by the hepatocyte. 267 34

Data obtained by in vitro experiments concerning the binding kinetics of the transferrin-endotoxin interactions are provided. The separation of protein-bound and free tritiated endotoxin of E. coli O 111:B4 is achieved by a simple precipitation method using ethanol. The main features of this reaction are the velocity of the saturation--saturation is reached after 2-3 min--and the requirement of divalent cations. EDTA (ethylenediaminetetraacetic acid) strongly inhibits the binding reaction of endotoxin to transferrin. The specificity of this interaction as well as the physiological importance can be demonstrated by the replacement of the radioactively labelled lipopolysaccharide preparation of E. coli 0 111:B4, by non-radioactive preparations of Salmonella minnesota, Serratia marcescens, E. coli 0 55:B5 and E. coli 0 111:B4. The described ethanol precipitation procedure for separating protein-bound and free endotoxin was applied to a commercially available immunoglobulin preparation. Although this preparation is known to exhibit high antibody titers against the lipid A moiety of lipopolysaccharides, no specific binding with the intact lipopolysaccharide can be found.
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PMID:Comparison of the endotoxin-binding capacity of human transferrin and a human applicable immunoglobulin preparation. 305 61

Many studies have shown that lactoferrin and transferrin have antimicrobial activity against gram-negative bacteria, but a mechanism of action has not been defined. We hypothesized that the iron-binding proteins could affect the gram-negative outer membrane in a manner similar to that of the chelator EDTA. The ability of lactoferrin and transferrin to release radiolabeled lipopolysaccharide (LPS) from a UDP-galactose epimerase-deficient Escherichia coli mutant and from wild-type Salmonella typhimurium strains was tested. Initial studies in barbital-acetate buffer showed that EDTA and lactoferrin cause significant release of LPS from all three strains. Further studies found that LPS release was blocked by iron saturation of lactoferrin, occurred between pH 6 and 7.5, was comparable for bacterial concentrations from 10(4) to 10(7) CFU/ml, and increased with increasing lactoferrin concentrations. Studies using Hanks balanced salt solution lacking calcium and magnesium showed that transferrin also could cause LPS release. Additionally, both lactoferrin and transferrin increased the antibacterial effect of a subinhibitory concentration of rifampin, a drug excluded by the bacterial outer membrane. This work demonstrates that these iron-binding proteins damage the gram-negative outer membrane and alter bacterial outer membrane permeability.
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PMID:Damage of the outer membrane of enteric gram-negative bacteria by lactoferrin and transferrin. 316 87

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 serum-free medium has been developed which is able to support primary antibody responses by cultured murine lymphocytes. This medium is based on RPMI 1640 that is supplemented with beta-cyclodextrin, insulin, transferrin, albumin, low density lipoprotein, putrescine and L-alanine as substitutes for fetal calf serum. Omission of anyone of these components resulted in a marked decrease of antibody responses. By employing the serum-free culture conditions, it was clearly demonstrated that polyamines such as putrescine, spermidine and spermine had positive effects on the development of antibody-forming cells. This serum-free medium supported the antibody response to sheep erythrocytes, trinitrophenyl (TNP)-Ficoll or TNP-lipopolysaccharide as efficiently as 10% fetal calf serum-containing medium. In addition, murine lymphocytes proliferated in response to an antigen or a mitogen equally well in these two types of medium.
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PMID:Development of a serum-free medium for in vitro immune responses by using beta-cyclodextrin. Demonstration of the requirements for polyamines. 341 28


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