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)

Human plasma alpha 1-acid glycoprotein (orosomucoid) and derivatives of this protein produced by sequential enzymatic cleavage of the glycosidic residue (sialic acid, galactose, N-acetylglucosamine, mannose) were tested for the ability suppress a number of immune functions of mouse spleen cells in vitro at physiological concentrations. alpha 1-Acid glycoprotein and especially the agalacto/asialo derivative suppressed (i) the mitogenic responses to concanavalin A, lipopolysaccharide, and alloantigens, (ii) antibody responses to sheep erythrocytes, and (iii) induction of cell-mediated lympholysis against allogeneic target cells. The native protein and its derivative did not inhibit the proliferation of EL-4 lymphoma cells and did not suppress the lysis of YAC-1 lymphoma cells by natural killer cells. The enhanced potency of the agalacto/asialo derivative indicates that the nature of the carbohydrate moiety exposed on the protein determines the effectiveness of the glycoprotein and its deglycosylated derivatives may function to regulate immune responses in various physiological and pathological conditions.
 ...
PMID:Immunosuppression by human plasma alpha 1-acid glycoprotein: importance of the carbohydrate moiety. 693 36

A single intraperitoneal injection of bacterial lipopolysaccharide (LPS) or its lipid A component induced high levels of glycoprotein, gp70, in sera of several strains of mice within 24 h. This serum gp70 response induced by LPS was independent of the activation of B cells and the presence of T cells. However, serological and immunohistochemical studies demonstrated the production of gp70 by hepatic parenchymal cells and its subsequent release into the circulating blood. The expression of gp70 in the serum was enhanced not only by LPS but also other inducers of acute phase reactants (APR) such as turpentine oil or polyriboinosinic-polyribocytidylic acid. Further, the serum gp70 response was kinetically identical to those of APR. These results strongly suggest that (a) the liver may be the major source for serum gp70, (b) serum gp70 behaves like an APR, (c) its expression may be controlled by a mechanism similar to that for other APR, and (d) this glycoprotein apparently behaves as a normal host constituent and not a product of a viral genome.
 ...
PMID:Murine serum glycoprotein gp70 behaves as an acute phase reactant. 705 39

Human peripheral blood lymphocytes (PBL) were cultured for various time periods (up to 8 d) in the presence of pokeweed mitogen (PWM), lipopolysaccharide, or Epstein-Barr virus. Cell-free supernates were fractionated on a standardized ultrogel AcA 22 column and the proportion of polymeric and monomeric IgA was determined by radioimmunoassay. The results demonstrate that PBL stimulated with these mitogens produce IgM and IgG with molecular characteristics identical to those found in serum, but that the IgA produced is predominantly of the polymeric type. To prove that this IgA represented disulfide bond-linked polymers rather than aggregated monomers, we have demonstrated that the high molecular weight IgA (a) maintains its polymeric form upon treatment with acidic buffers, (b) contains J chain, a glycoprotein associated only with polymeric immunoglobulins, and (c) dissociates to the monomeric form upon reduction of disulfide bonds. After 1 wk in culture, approximately 60% of the PWM-stimulated cells that contained IgA were positive for IgA2, whereas 40% were IgA1 positive as determined by immunofluorescence. Therefore, peripheral blood contains a population of lymphocytes with the potential to display, after appropriate stimulation and differentiation, characteristics similar to IgA cells found in external secretory tissues. The demonstration of the presence of such cells in the peripheral circulation suggests that these cells are precursors of IgA-producing plasma cells with the potential to populate mucosal tissues.
 ...
PMID:Production of predominantly polymeric IgA by human peripheral blood lymphocytes stimulated in vitro with mitogens. 743 Sep 51

Angiotensinogen has been assumed to be an acute-phase protein, because some forms of acute inflammation, eg, the injection of lipopolysaccharide or cellite or partial hepatectomy, increased the hepatic synthesis of angiotensinogen. In addition, the well-characterized nephrectomy-induced stimulation of angiotensinogen was thought to represent an acute-phase reaction. To evaluate this hypothesis, we examined changes in angiotensinogen secretion by the isolated perfused rat liver after the systemic administration of turpentine or lipopolysaccharide as well as in response to nephrectomy or sham nephrectomy. Comparison was made with the secretion of two typical acute-phase proteins, alpha 1-acid glycoprotein and alpha 2-macroglobulin, and with the secretion of the negative acute-phase protein albumin. All forms of experimental surgery stimulated the secretion of both control acute-phase proteins several-fold. In contrast, the response of angiotensinogen was not uniform; lipopolysaccharide and bilateral nephrectomy stimulated secretion twofold to threefold, sham nephrectomy had no effect, and turpentine decreased the secretion to 30% of the control level. A similar inhomogeneity was found in an additional experiment performed to analyze the direct effects of interleukin-1 or interleukin-6 on the secretion of angiotensinogen by freshly isolated hepatocytes. Interleukin-6 increased but interleukin-1 decreased the mRNA and secretion of angiotensinogen, whereas both cytokines increased the secretion of both acute-phase proteins. Because of this nonuniform behavior of angiotensinogen, it is premature to classify angiotensinogen as an acute-phase protein until a specific function for angiotensinogen during acute inflammation is known.
 ...
PMID:Angiotensinogen: an acute-phase protein? 750 96

To clarify the mechanism involved in regulating the secretion of albumin and alpha 1-acid glycoprotein by rat hepatocytes, we studied hepatocyte culture and cocultures of hepatocyte and liver nonparenchymal cells. The secretion of alpha 1-acid glycoprotein by hepatocytes was stimulated and that of albumin was inhibited by combinations of dexamethasone and monokines, especially by dexamethasone and interleukin-6. The secretion of these proteins was equally inhibited during stimulation by lipopolysaccharide in cocultures. The inhibitory effect of sinusoidal endothelial cells was smaller than that of Kupffer cells. This inhibition was partially abolished by blocking the nitric oxide synthase pathway in cocultured cells and was completely abolished by dexamethasone. In conclusion, the secretion of albumin and alpha 1-acid glycoprotein by hepatocytes was regulated by monokines, dexamethasone, and the inducible nitric oxide synthase pathway in hepatocytes and liver nonparenchymal cells in vitro.
 ...
PMID:Regulation of hepatocyte albumin and alpha 1-acid glycoprotein secretion by monokines, dexamethasone, and nitric oxide synthase pathway: significance of activated liver nonparenchymal cells. 751 18

Female bonnet monkeys Macaca radiata (n = 8, four per group) were immunized with purified 55 kDa glycoprotein from porcine zona pellucida (ZP3) and ZP3 conjugated to the beta subunit of human chorionic gonadotrophin (beta hCG) using adjuvants permissible for human use (alum, muramyl dipeptide and sodium phthalyl derivative of lipopolysaccharide). The animals were monitored for anti-ZP3 antibody titres, biweekly progesterone concentrations, menstrual cyclicity and status of fertility. All the animals generated a good anti-ZP3 antibody response, continued to have ovulatory cycles, remained infertile in the presence of high anti-ZP3 antibody titres and showed no disturbance in cyclicity (except summer amenorrhoea). Examinations by laparoscope showed normal ovaries with developing follicles or corpora lutea on the surface. Fifty per cent of the animals conceived after a decline in antibody titres. Ovaries of animals that failed to regain fertility were examined for changes in morphology at times when anti-ZP3 antibody titres in the circulation were low and following a booster when titres were high. None of the ovaries showed any sign of inflammation or lymphocytic infiltration. Follicles at different stages of development were seen in all of the ovaries. No significant reduction in the number of follicles, except in one monkey (MRA 178), was observed. There was no increase in the numbers of atretic or degenerating follicles. The results showed that ZP3 immunization with permissible adjuvants could be used for immunocontraception without obvious ovarian changes.
 ...
PMID:Antifertility effects of porcine zona pellucida-3 immunization using permissible adjuvants in female bonnet monkeys (Macaca radiata): reversibility, effect on follicular development and hormonal profiles. 752 78

CD14 is a 55-kDa glycoprotein which binds lipopolysaccharide (LPS) and enables LPS-dependent responses in a variety of cells. In order to identify the domains in CD14 required for function, we deleted increasing amounts of CD14 from the C terminus. Truncated CD14 cDNA sequences were transfected into COS-7 cells and serum-free conditioned medium was analyzed for mutant CD14 expression and bioactivity. Mutant CD14s containing as few as 152 amino acids were found to have activity equivalent to full-length sCD14. To further characterize the mutant CD14, we constructed a stable Chinese hamster ovary cell line expressing sCD14(1-152) and purified the protein to homogeneity. sCD14(1-152) bound radioactive LPS, enabled U373 cells to synthesize interleukin 6 in response to LPS, and enabled human neutrophils to respond to smooth LPS. In all of these assays, the behavior of sCD14(1-152) was quantitatively similar to full-length sCD14. We also found that two neutralizing anti-CD14 antibodies (3C10 and MEM-18) bound and neutralized sCD14(1-152). We conclude from these experiments that the N-terminal 152 amino acids of CD14 are sufficient to bind LPS and confer essentially wild-type bioactivity in vitro.
 ...
PMID:Soluble CD14 truncated at amino acid 152 binds lipopolysaccharide (LPS) and enables cellular response to LPS. 753 Jul 12

The soluble glycoprotein sCD14 binds lipopolysaccharide, a complex that activates endothelial cells and that may be crucial in gram-negative sepsis. Therefore, serum sCD14 was analyzed in 54 patients with gram-negative septic shock and in 26 healthy controls. sCD14 was tested by ELISA and Western blotting. Patients had higher sCD14 concentrations than controls (median, 3.23 vs. 2.48 micrograms/mL, P = .002). Increased levels were associated with high mortality (median, 4.2 micrograms/mL in nonsurvivors vs. 2.8 micrograms/mL in survivors, P = .001). sCD14 was found in two isoforms (49 and 55 kDa) in monocyte cultures. In sera only one of either form was detectable. Controls had the 49-kDa form, and patients had either the 49- or 55-kDa form, but patients with high levels of sCD14 had only the 55-kDa form. Twenty-one (53%) of 39 with the 55-kDa form and 8 (57%) of 14 with the 49-kDa form died. Thus, the level of sCD14 but not its biochemical form had a prognostic value in patients with gram-negative septic shock.
 ...
PMID:Increased circulating soluble CD14 is associated with high mortality in gram-negative septic shock. 753 99

CD14 is a 55-kDa glycoprotein which binds lipopolysaccharide (LPS) and enables LPS-dependent responses in a variety of cells. Recent limited proteolysis studies have implicated a region in CD14 between amino acids 57 and 64 as being involved in LPS interaction. To specifically assess the importance of this region with respect to LPS binding, we constructed a mutant sCD14 (sCD14 delta 57-64) lacking amino acids 57-64. sCD14 delta 57-64 was isolated from the serum-free conditioned medium of this cell line, and, in all assays, the purified protein failed to recognize LPS or enable LPS-dependent responses in cells. We also demonstrated that the region between amino acids 57 and 64 is required for binding of a neutralizing CD14 mAb, MEM-18. Native polyacrylamide gel electrophoresis assays were used to demonstrate that MEM-18 and LPS compete for the same binding site on CD14. These data strongly suggest that the region spanning amino acids 57-64 binds LPS and that formation of sCD14.LPS complex is required in order for sCD14-mediated responses to occur.
 ...
PMID:Identification of a lipopolysaccharide binding domain in CD14 between amino acids 57 and 64. 753 91

1. Smoking exerts an inflammatory stimulus on lung macrophages, and smokers generally have low intakes of antioxidant micronutrients. This study was performed to investigate the relationship between whole-blood tumour necrosis factor production, plasma interleukin-6 and acute-phase protein concentration and antioxidant vitamins in smokers and non-smokers. 2. Measurement of tumour necrosis factor was conducted in whole blood stimulated with endotoxin (lipopolysaccharide), and interleukin-6 concentrations were measured in the plasma of smokers and non-smokers. Enzyme and dietary antioxidant concentrations and acute-phase proteins were determined in the two groups. 3. Tumour necrosis factor production and plasma interleukin-6 concentrations were 38% (P = 0.01) and 16% (P = 0.07) greater, respectively, in smokers than in non-smokers. Plasma vitamin A and E concentrations were unaffected by smoking; however, a 21% lower plasma vitamin C (P = 0.04) concentration was observed in smokers, than in non-smokers despite a similar intake of this vitamin by the two groups. 4. Concentrations of the acute-phase proteins alpha 1-acid glycoprotein, caeruloplasmin and alpha 2-macroglobulin were increased in the plasma of smokers compared with non-smokers by 39%, 28% and 12% respectively (P < 0.01). Our studies indicate that smokers have a compromised antioxidant status and elevated concentrations of tumour necrosis factor and interleukin-6 as a consequence of smoking. 5. These observations may provide some insight into the biological mechanisms underlying the pathology associated with smoking.
 ...
PMID:Cigarette smoking influences cytokine production and antioxidant defences. 754 May 25


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