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)

In vitro and in vivo host reponses to lipopolysaccharide (LPS) and various immunostimulants were compared in C3h low-and highresponder mice, their F1, F2 and backcross hybrids. In contrast to the responsiveness of a congeneic high responder subline, LPS is unable to stimulate thymidine incorporation by splenocytes of the low-responder subline and to protect these mice against an unrelated bacterial infection, Moreover, although endotoxin extracted by trichloroacetic acid was mitogenic in these low-responder mice, it was still unable to increase their resistance against an infectious challenge; in addition, the LD50 of both endotoxin preparations was about 3,500 fold greater than in the high-responder mice. For this latter assay, mice were adrenaloctomized since it is well established that mouse's susceptibility to LPS is dramatically enhanced in the absence of glucocorticoids. Inheritance of susceptibility to lethal effect of endotoxin and of LPS-induced non-specific resistance to infection was also tested in both sublines, their hybrids and backcross progeny. The present findings are consistent with the hypothesis that these LPS host-responses may be determined by a single autosomal dominant gene.
 ...
PMID:[Non-specific responses of C3H/He low responder mice to LPS and to TCA-extracted endotoxin]. 84 8

The immunochemistry and structure of enteric bacterial porins are critical to the understanding of the immune response to bacterial infection. We raised 41 monoclonal antibodies (MAbs) to Salmonella typhimurium OmpD and OmpC porin trimers and monomers. Enzyme-linked immunosorbent assays, immunoprecipitations, and/or Western immunoblot techniques indicated that 39 MAbs (11 anti-trimer and 28 anti-monomer) in the panel are porin specific and one binds to the lipopolysaccharide; the specificity of the remaining MAb probably lies in the porin-lipopolysaccharide complex. Among the porin-specific MAbs, 10 bound cell-surface-exposed epitopes, one reacted with a periplasmic epitope, and the remaining 28 recognized determinants that are buried within the outer membrane bilayer. Many of the MAbs reacting with surface-exposed epitopes were highly specific, recognizing only the homologous porin trimers; this suggests that the cell-surface-exposed regions of porins tends to be quite different among S. typhimurium OmpF, OmpC, and OmpD porins. Immunological cross-reaction showed that S. typhimurium OmpD was very closely related to Escherichia coli NmpC and to the Lc porin of bacteriophage PA-2. Immunologically, E. coli OmpG and protein K also appear to belong to the family of closely related porins including E. coli OmpF, OmpC, PhoE, and NmpC and S. typhimurium OmpF, OmpC, and OmpD. It appears, however, that S. typhimurium "PhoE" is not closely related to this group. Finally, about one-third of the MAbs that presumably recognize buried epitopes reacted with porin domains that are widely conserved in 13 species of the family Enterobacteriaceae, but apparently not in the seven nonenterobacterial species tested. These data are evaluated in relation to host immune response to infection by gram-negative bacteria.
 ...
PMID:Structural relatedness of enteric bacterial porins assessed with monoclonal antibodies to Salmonella typhimurium OmpD and OmpC. 131 35

Bacterial lipopolysaccharide (LPS) is a potent and pleiotropic stimulus of immune cells. LPS has important clinical relevance because it has a direct role in the pathogenesis of Gram-negative bacterial infection. The lipid A moiety of LPS is responsible for the toxic effects of LPS. The identification of structural analogs and precursors of lipid A, which are apparently competitive antagonists of the biological actions of LPS, is strong evidence that the actions of LPS are mediated by a specific LPS receptor or family of receptors. Identification and analysis of these LPS receptors with LPS antagonists should help to define the pathways of cellular activation by LPS and lead to the development of novel anti-LPS strategies in the therapy of bacterial diseases.
 ...
PMID:Lipopolysaccharide antagonists. 138 55

Fumonisin-B1 (FB1) is one of the recently discovered metabolites of Fusarium moniliforme (Sheldon) occurring naturally in infected corn. It is hepatocarcinogenic and causes death in several animal species including rats, horses, swine, and ducklings. In the present study, chicken peritoneal macrophages (PM) and a chicken macrophage cell line, MQ-NCSU, were exposed in vitro to various doses of FB1. Exposure to .5, 5, and 10 micrograms FB1/mL caused significant cytotoxicity in PM after 2 and 4 h of exposure. Morphological alterations induced by FB1 in PM included cytoplasmic blebing or nuclear disintegration or both, which were maximal in cultures treated with 20 micrograms FB1/mL. Significant depression in the phagocytic potential of PM occurred after 4 h treatment with 20, 40, and 100 micrograms FB1. However, exposure to FB1 alone, as well as after stimulation with lipopolysaccharide, induced secretion of a cytolytic factor by MQ-NCSU cells. These findings, which showed that FB1 exposure induced morphological and functional alterations in chicken macrophages, imply that FB1 exposure may result in increased susceptibility of chickens to bacterial infection.
 ...
PMID:Effect of fumonisin-B1 exposure on chicken macrophage functions in vitro. 153 10

The etiology and the physiopathology of acute anterior uveitis (AAU) is not well understood yet. However, two major predisposing factors have been identified: a bacterial infection especially with gram negative organisms (functioning as a trigger) and a genetic background, in particular the expression of HLA B-27 tissue antigen. We report the case of a young woman returning from travel to the Far East with her partner. Both presented simultaneously a gastrointestinal infection with fever and diarrhea. Despite extensive investigations, the infectious agent was never identified because of early empirical antibiotic therapy. A few days later, the patient developed AAU of a moderate grade in both eyes. HLA B-27 testing was positive for her, but not for her partner. Experimental research, based on a animal model such as endotoxin-induced uveitis (EIU), gives us some insight into the possible pathogenic mechanisms of AAU. Footpad injection of endotoxin (lipopolysaccharide component of the wall of gram negative), produce an acute anterior uveitis in rats. Extensive histologic analysis of other organs shows that the anterior segment of the eye is the only structure involved. Intensity of inflammation varies in different rat strains, stressing the importance of the genetic background. The similarity of the animal model to AAU will contribute to orient clinical research towards identifying more thoroughly the possible infectious agent at the origin of AAU and possibly to develop a prophylactic therapy.
 ...
PMID:[Acute anterior uveitis: para-infectious hypothesis in predisposed individuals]. 161 44

Granulocyte colony-stimulating factor (G-CSF) plays an essential role in granulopoiesis during bacterial infection. Macrophages produce G-CSF in response to bacterial endotoxins such as lipopolysaccharide (LPS). To elucidate the mechanism of the induction of G-CSF gene in macrophages or macrophage-monocytes, we have examined regulatory cis elements in the promoter of mouse G-CSF gene. Analyses of linker-scanning and internal deletion mutants of the G-CSF promoter by the chloramphenicol acetyltransferase assay have indicated that at least three regulatory elements are indispensable for the LPS-induced expression of the G-CSF gene in macrophages. When one of the three elements was reiterated and placed upstream of the TATA box of the G-CSF promoter, it mediated inducibility as a tissue-specific and orientation-independent enhancer. Although this element contains a conserved NF-kappa B-like binding site, the gel retardation assay and DNA footprint analysis with nuclear extracts from macrophage cell lines demonstrated that nuclear proteins bind to the DNA sequence downstream of the NF-kappa B-like element, but not to the conserved element itself. The DNA sequence of the binding site was found to have some similarities to the LPS-responsive element which was recently identified in the promoter of the mouse class II major histocompatibility gene.
 ...
PMID:Regulatory elements responsible for inducible expression of the granulocyte colony-stimulating factor gene in macrophages. 169 38

Abnormal parturition can be followed by a persistent endometritis which can have deleterious effects on the cow's subsequent reproductive performance. Normal and active uterine defense mechanisms have been reported to be very important for the exclusion of bacterial infection from the uterus and recovery from endometritis developing after parturition. Despite the widespread use of local or systemic antibiotics, antiseptics, sulfonamides and hormones, rates of recovery from endometritis and the cow's subsequent fertility have not increased appreciably. Furthermore, the cost of any treatment, the frequency of its administration and the milk disposal after treatment make their use uneconomic. Alternative therapies which stimulate the natural uterine defense mechanisms have been suggested as treatments of bovine endometritis. These include: (I) Endotoxins such as lipopolysaccharide of E. coli, (II) serum, plasma or hyperimmune serum, (III) polymorphonuclear leucocyte (PMN) extracts and components and (IV) granulocyte-macrophage colony stimulating factors (G-M CSF).
 ...
PMID:Bovine endometritis: current and future alternative therapy. 177 86

The Tn5-containing fragment from a non-nodulating mutant of Bradyrhizobium japonicum, strain ML142, was introduced into B. japonicum strain 61A101c by marker exchange to construct strain JS314. Strain JS314 failed to nodulate several soybean varieties tested. However, on a few varieties nodulelike structures were induced to a frequency of 54% of the plants inoculated. The ultrastructure of these nodules was studied in detail by light and electron microscopy. The nodules were devoid of internal bacteria, possessed central vascular tissue (unlike the lateral vascular tissue of a normal nodule), and exhibited localized cell death of epidermal cells. Study of the cell surface polysaccharides of strain JS314 revealed that the exopolysaccharide of this strain was identical to that of the wild type. However, the lipopolysaccharide (LPS) of strain JS314 showed gross differences from that isolated from the wild-type strain. Specifically, the LPS of strain JS314 appeared to lack the high molecular weight LPS I form, strongly suggesting that the LPS lacks the O-chain. Glycosyl-composition analysis showed that the LPS of mutant JS314 lacked 2,3-di-O-methylrhamnose, 3-O-methylrhamnose, fucose, and quinovosamine. These results indicate that LPS I in B. japonicum is essential for bacterial infection of soybean, but is not required to initiate plant cortical cell division, an early plant response to infection.
 ...
PMID:A lipopolysaccharide mutant of Bradyrhizobium japonicum that uncouples plant from bacterial differentiation. 179 97

Actinobacillus pleuropneumoniae produces several hemolysins/cytotoxins that may be important in the pathogenesis of acute lesions. Little is known, however, about the role of these virulence factors in chronic disease or the carrier state. We investigated the effects of live bacterial infection and transthoracic injection of a sterile culture supernatant on primary lymphoid organs and lymphocyte populations. Transthoracic inoculation of mice or intranasal inoculation of pigs with virulent A. pleuropneumoniae serotypes 1 and 7 induced thymic cortical lymphoid necrosis. These lesions were reproduced in mice by transthoracic injection of a concentrated sterile culture supernatant. The cytotoxic effect of this culture supernatant was also demonstrated in vitro by using a tetrazolium dye reduction assay. Both porcine and murine thymic lymphocytes as well as splenic T lymphocytes were susceptible to the toxin. Porcine convalescent serum, but not preimmune serum, prevented thymic lesions and neutralized the in vitro cytotoxic effect of the culture supernatant on murine thymic lymphocytes. Thymic lesions also were reproduced in mice by using purified lipopolysaccharide (LPS) from Escherichia coli O111:B4; however, LPS had no in vitro cytotoxic effect on either porcine or murine thymic lymphocytes. These results suggest that secreted A. pleuropneumoniae toxin(s) is capable of affecting host T-lymphocyte populations and may affect host immune function.
 ...
PMID:Actinobacillus pleuropneumoniae-induced thymic lesions in mice and pigs. 187 15

Monoclonal antibodies (MAb) directed against bacterial lipopolysaccharide (LPS) and tumor necrosis factor-alpha (TNF) provide partial protection in experimental models of septic shock. To determine if additional benefit accrues from a combination of anti-TNF and anti-LPS MAb in the treatment of septic shock, a neutropenic rat model was developed to study active infection with Pseudomonas aeruginosa 12.4.4. Animals were treated intravenously with an irrelevant MAb (group 1); anti-TNF MAb (group 2); MAb directed against P. aeruginosa 12.4.4 LPS (group 3); or a combination of anti-TNF and anti-LPS MAb (group 4). None of the control animals in group 1 survived the 7-d period of neutropenia (0/16). In contrast, the survival rate was 44% in group 2 (P less than 0.02); 37% in group 3 (P less than 0.05); and 75% in group 4 (P less than 0.0002). The combination of monoclonal antibodies provided greater protection than either MAb given alone (P less than 0.05). Serum TNF levels during infection were significantly greater in groups 1 and 3 (20.1 +/- 3.3 U, mean +/- SE) than in groups 2 and 4 (0.9 +/- 0.8 U, P less than 0.0001). These results indicate that a combination of monoclonal antibodies to LPS and TNF have additive benefit in experimental Pseudomonas aeruginosa sepsis. This immunotherapeutic approach may be of potential utility in the management of serious, gram-negative bacterial infection in neutropenic patients.
 ...
PMID:Efficacy of antilipopolysaccharide and anti-tumor necrosis factor monoclonal antibodies in a neutropenic rat model of Pseudomonas sepsis. 188 75


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