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)

The effect of graded amounts of dietary lactalbumin (L) and casein (C) hydrolyzates on the immune responsiveness of C3H/HeN and DBA/2 strain mice has been investigated by measuring both the specific humoral immune response to sheep red blood cells (SRBC) and the nonspecific splenic cell responsiveness to phytohemagglutinin, concanavalin A and Escherichia coli lipopolysaccharide after stimulation with Mycobacterium bovis, strain BCG. The nutritional efficiency of these diets was similar at both 12 and 28% amino acid levels. The immune responses of mice fed the L diets were found to be significantly greater than those of mice fed the corresponding C diets, especially at the 28% level. Furthermore in the mice fed L diet, increasing the concentration of amino acid in the diet from 12 to 28% greatly enhanced immune responsiveness by both parameters measured. In the C-fed mice, a comparable enhancement of mitogen responsiveness with increasing amino acid level of diet was seen, but there was no change in the humoral immune response. The enhancement of immune responsiveness observed in mice fed the 28% L diet was moderately reduced by the addition of phenylalanine to the diet, indicating that the lower level of this amino acid in the L protein may be of some significance. These dietary effects on immune responsiveness were remarkably similar in both mouse strains tested.
 ...
PMID:Influence of dietary proteins on the immune system of mice. 705 Mar 21

The susceptibility of inbred strains of mice to pulmonary blastomycosis was studied to derive information relevant to host resistance and genetic background. Initial studies with eight strains with various H-2 backgrounds revealed the C3H/HeJ strain to be highly susceptible and DBA/1J mice to be resistant. These observations were confirmed with various challenge inocula. These differences were not dependent on the size of the challenge, the strain of Blastomyces dermatitidis, host age, or ability of the challenge to penetrate to the lower airways. Differences between the susceptible and resistant strains in lymphocyte proliferation in vitro and delayed-type hypersensitivity in vivo after nonlethal subcutaneous infection were not demonstrated; the susceptible strain made a significantly greater antibody response to blastomyces antigens as determined by an enzyme-linked immunosorbent assay. The resistance of the C3H/HeN strain of mice, which differs from the C3H/HeJ in sensitivity to lipopolysaccharide and lacks the macrophage cytotoxicity defect of the latter, suggests that the susceptibility of C3H/HeJ mice is not related to their C3H background or the H-2 locus. As the A/HeJ strain, which also has a macrophage cytotoxicity defect, was found in this study to be the second most susceptible strain, this also suggests macrophages as the subject for further study with respect to the mechanism of genetic resistance to this infection.
 ...
PMID:Susceptibility differences of inbred strains of mice to blastomycosis. 721 83

B cells are induced to antibody production by antigens or by mitogens, such as lipopolysaccharide (LPS). We observed a mutually antagonistic relationship between activation through the antigen-receptor (AgR) and LPS-receptor (LPSR) in vitro. Prior exposure of B cells to AgR-ligating antibody prevented antibody forming cell (AFC) production induced by LPS, but not that induced by specific antigen (SRBC, TNP-Ficoll, or TNP-LPS). AFC production induced by antigen could be abrogated by concomitant exposure to LPS; the shutdown of the antigen-driven response was apparent when LPS-induced AFC were prevented by pre-exposure to antibody against the AgR. The ability of signaling through the AgR to inhibit antibody production stimulated by LPS was seen in DBA/2 and BALB/c mouse strains, and not in the New Zealand Black (NZB) strain. The results suggest that mutual antagonism is distinct from other forms of immune hyporesponsiveness, and that defects in antagonism may be a factor in the development of autoimmune disease.
 ...
PMID:Mutual antagonism between antigen- and lipopolysaccharide-induced antibody production. 750 85

In early embryo loss, the fetus may be considered to be an allograft and, therefore, may be rejected by maternal immunocytes. However, the cytotoxic mechanisms involved are still poorly understood. We have previously shown the involvement of natural killer (NK) cells and mononuclear cells expressing Mac-1 (CD11b) and F4/80 in resorbing compared to nonresorbing embryos. In this study, the role of nitric oxide (NO) in the mechanism of early embryo loss was studied. Pregnant CBA/J females mated with DBA/2 males (20-30% early embryo loss) and CD1 females mated with CD1 males (5-10% early embryo loss) were studied on days 8, 10, and 12 of gestation. Cells from the implantation sites of individual embryos were tested for the production of nitrite and nitrate with or without in vitro challenge with lipopolysaccharide (LPS) to determine whether decidual macrophages were primed in situ. On day 12 of gestation, when resorption was clearly visible, resorbing embryos showed more than a fivefold increase in both basal- and LPS-induced nitrite and nitrate production compared to nonresorbing embryos in both mouse strains tested, indicating that the decidual mononuclear cells were primed. Furthermore, more than 20% of CBA/J embryos showed a significant nitrate release on days 8 and 10 of gestation before any signs of embryo cytopathology. This percentage corresponded to the spontaneous resorption rate seen in CBA/J female X DBA/2 male matings. Similarly, 4% of the embryos from pregnant CD1 mice on days 8 and 12 of gestation produced a significant amount of nitrate, which again correlated with the low incidence of resorption observed in these mice. Using immunohistochemistry, the presence of inducible nitric oxide synthase (iNOS) was detected at implantation sites. Furthermore, decidual cells positive for both iNOS and the macrophage marker Mac-1 were demonstrated in implantation sites by double immunostaining. This strongly suggests that decidual macrophages could be the cellular source of NO production. Aminoguanidine, a selective inhibitor of the iNOS, inhibited the in vitro production of nitric oxide by cells isolated from individual implantation sites, and more strikingly, significantly reduced early embryo losses in CBA/J females mated by DBA/2 males when given orally or parenterally to the gravid females starting on day 6 of gestation. In addition, aminoguanidine-treated pregnant mice showed a significant increase in average litter size when the pregnancies were allowed to proceed to term.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Early embryo loss is associated with local production of nitric oxide by decidual mononuclear cells. 756 87

This study compared the ability of highly purified resting and activated DBA/2 mouse peritoneal macrophages to survive treatment with the photosensitizer benzoporphyrin derivative (BPD, verteporfin) and light. Culture of macrophages with recombinant murine interferon-gamma (rIFN-gamma, 100 U/mL) for 72 h imparted a phenotypic and functional activation by dramatically increasing cell surface expression of major histocompatibility complex Class II (Ia) molecules and the formation of nitric oxide. The rIFN-gamma-activated macrophages were significantly (P < 0.05) more sensitive (lethal dose to cause a 50% reduction in cell survival, LD50 = 14.4 +/- 1.1 ng/mL) to photodynamic killing with BPD and light (10 J/cm2) than cells (LD50 = 18.2 +/- 2.0 ng/mL) cultured in medium alone. In contrast, macrophages treated with different concentrations of bacterial lipopolysaccharide (LPS) were as resistant or more resistant to photodynamic killing than cells cultured in medium alone. No cytotoxic effect of BPD was detected in cultures containing the drug but protected from light. Comparable amounts of BPD were taken up in vitro by unactivated and rIFN-gamma-activated macrophages, as detected by flow cytometric analysis. However, cells cultured with LPS (10 micrograms/mL) took up more BPD than macrophages cultured in medium alone or with rIFN-gamma. The DBA/2 P815 mastocytoma cells took up greater amounts of the drug and were subsequently more vulnerable to treatment with BPD and light (LD50 = 6.9 ng/mL) than macrophages cultured under any condition. The explanation for the increased vulnerability of rIFN-gamma-activated macrophages and the greater resistance of LPS-activated macrophages, relative to medium-cultured macrophages, to photodynamic killing with BPD is uncertain.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Sensitivity of activated murine peritoneal macrophages to photodynamic killing with benzoporphyrin derivative. 774 88

Ligation of surface immunoglobulin on resting or activated nonautoimmune B cells inhibited lipopolysaccharide (LPS)-induced total IgM production. B cells from NZB, (NZB x NZW)F1, and BXSB mice were relatively resistant, but B cells from NZW or MRL/lpr mice were inhibited. The resistance occurs in B cells from young and old NZB mice, and in both resting and activated splenic NZB B cells. Anti-ssDNA responses induced by lipopolysaccharide occur in the presence of antigen-receptor-ligating antibody in NZB, but not in DBA/2, B cells. Antagonism in signaling between the antigen and LPS receptor is not a general B cell hyporesponsiveness, but defects in antagonism specifically between antigen and LPS signaling may be a predisposing factor to autoimmune disease in some autoimmune strains of mice.
 ...
PMID:Lipopolysaccharide-induced IgM production is not suppressed by antigen receptor ligation in B cells from some autoimmune strains of mice. 789 58

An enzyme-linked immunosorbent assay (ELISA) was developed to detect IgM and IgG antibodies specific for trinitrophenyl-lipopolysaccharide (TNP-LPS). Treatment of C57BL/6 and DBA/2 mice with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other aryl hydrocarbon (Ah) receptor agonists followed by immunization with TNP-LPS resulted in a dose-dependent decrease in serum IgM which paralleled the decrease in the splenic PFC response. The ED50 values for the IgM and splenic PFCs in C57BL/6 mice for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3',4,4',5-pentachlorobiphenyl (pentaCB) and 3,3',4,4',5,5'-hexaCB were 2.8 and 1.6, 11 and 14, and 25 and 20 micrograms/kg, respectively; in the less Ah-responsive DBA/2 mice, the ED50 values were 8.5 and 10, 61 and 69, and 73 and 71 micrograms/kg, respectively. In addition, treatment of C57BL/6 mice with TCDD resulted in alterations of serum IgG relative to IgM and a delay of isotype switching was observed after immunization and boosting with TNP-LPS. This ELISA may prove to be a useful tool in monitoring immune function during long-term exposure of mice to TCDD and related compounds and exploring the mechanism of Ah receptor-mediated immunosuppression.
 ...
PMID:An enzyme-linked immunosorbent assay (ELISA) specific for antibodies to TNP-LPS detects alterations in serum immunoglobulins and isotype switching in C57BL/6 and DBA/2 mice exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin and related compounds. 794 May 57

The antifungal activity of nonactivated resident murine peritoneal macrophages for Cryptococcus neoformans was studied. Macrophages from five of six mouse strains tested had significant (40 to 80%) fungistatic activity, depending on the inoculum size, in a 24-hr coculture system. Macrophages from two outbred (SW and ICR) and three inbred (BALB/c, C57Bl/6, and DBA/2J) strains were fungistatic. Only macrophages from outbred CD-1 mice lacked fungistatic activity. Heat-inactivated and C5-deficient sera did not support phagocytosis or fungistasis by resident BALB/c or DBA/2 macrophages. Fungistasis correlated with contact, complement, and phagocytosis. Macrophages were studied in a Lab-Tek chamber slide system where noningested cells were washed away. Fungistasis in this system was similar to that found with a microtest plate coculture method where a smaller inoculum was cultured continuously with macrophages. After ingestion of yeast cells, CD-1 macrophages could be activated for fungistasis (70%) with interferon-gamma plus lipopolysaccharide. Activated BALB/c macrophages had increased fungistasis but were not fungicidal. NG-Monomethyl-L-arginine (200 microM), which inhibited the fungistatic activity of activated CD-1 macrophages, did not inhibit inherent fungistatic activity of BALB/c macrophages. The fungistatic mechanism of BALB/c macrophages resembled that reported for resident human macrophages.
 ...
PMID:Anticryptococcal activity of macrophages: role of mouse strain, C5, contact, phagocytosis, and L-arginine. 803 40

In order to determine the contribution of suppressive factors secreted from macrophages to the age-associated decline in T-cell mediated mitogenic responses, experiments were conducted to characterize eicosanoid and H2O2 production, total cellular fatty acid, and vitamin E composition of splenocytes isolated from young (4 mo) and old (24 mo) C57BL/6NIA mice. An age-related increase was observed in Ca++ ionophore A23187-stimulated ex-vivo production of prostaglandin (PG) E2, leukotriene (LT) B4, and LTC4 (p < .01), and in concanavalin A (ConA)-stimulated PGE2 production (p < .01). No age-related difference was observed in ex-vivo production of 12- and 15-hydroxyeicosatetranoic acid (HETE). The age-related increase in PGE2 production was also observed in lipopolysaccharide-stimulated peritoneal macrophages of C57BL/6NIA mice and ConA and phytohemagglutinin (PHA)-stimulated splenocytes isolated from DBA mice. Inhibition of cyclooxygenase with indomethacin resulted in increased ConA-stimulated proliferation of splenocytes from old mice (p < .01), while 5-lipoxygenase inhibition did not have an effect on mitogen induced proliferation. Furthermore, PGE2 addition to purified splenic T-cells decreased their proliferation. No age-related differences were observed in total cellular fatty acid composition, vitamin E level, or ex-vivo production of H2O2 from splenocytes stimulated with 10 or 100 ng phorbol myristate acetate (PMA). These data indicate that aging is associated with increased production of PG and LT from activated splenocytes. Inhibition of PGE2 but not LT production enhances mitogenic responses of old mice, suggesting a contributory role for PGE2 in the age-associated decline of T-cell responsiveness to polyclonal mitogens.
 ...
PMID:Age differences in eicosanoid production of mouse splenocytes: effects on mitogen-induced T-cell proliferation. 805 32

Partial resorption or abortion (depending upon the stage of gestation) can be induced with lower doses of lipopolysaccharide (LPS) (DIFCO) and human R-TNF than previously demonstrated. As can be expected, the abortion-prone CBA x DBA/2 and B10 x B10.A mating combinations are the most sensitive to such low doses. LPS synergizes with low doses of IL-2, gamma interferon, poly(I).poly(C) 12U. Treatment by GM-CSF, IL-3, or anti-natural killer antiserum decreases both TNF levels and abortion rates. Similar prevention of induced resorptions are obtained with either a neutralizing polyclonal rabbit anti-TNF antiserum or with pentoxyfilline, which has been shown to reduce resorption rates in CBA x DBA/2 pregnancies. More important, abortions induced by low doses of LPS or R-TNF can be prevented by alloimmunization. During late gestation, on the contrary, LPS- or TNF-induced delivery cannot be counteracted by alloimmunization nor by a progesterone-induced blocking factor, at least in the regimens employed by us. Therefore, although resorptions and parturition share common pathways consisting of immune mediators, they are not regulated similarly by the maternal immune system.
 ...
PMID:Synergy of lipopolysaccharide and inflammatory cytokines in murine pregnancy: alloimmunization prevents abortion but does not affect the induction of preterm delivery. 806 21


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