[A cross-reactivity of Candida albicans at the serum IgE level to the other yeast species].
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Publications and source records attributed to T Kanbe.
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We previously reported that the immunoglobulin M (IgM) monoclonal antibody (MAb) B6.1 protects mice against disseminated candidiasis, whereas the IgM MAb B6 does not. Both MAbs are specific for an adhesin fraction isolated from the cell surface of Candida albicans, but their epitope specificities differ. In the present study, we examined the surface locations of both epitopes and obtained structural information regarding the B6.1 epitope. Immunofluorescence confocal microscopic analysis of C. albicans yeast forms showed that epitope B6.1 is displayed rather homogeneously over the entire cell surface, whereas epitope B6 appears to have a patchy distribution. Both antibodies were essentially nonreactive with the surfaces of mycelial forms of the fungus, indicating that neither epitope is expressed on the surfaces of these forms. For isolation of the B6.1 epitope, the adhesin fraction consisting of cell surface phosphomannan was subjected to mildly acidic (10 mM HCl) hydrolysis and was fractionated into acid-labile and acid-stable portions by size exclusion chromatography. Antibody blocking experiments showed that the B6.1 epitope is an acid-labile moiety of the phosphomannan and that the B6 epitope is located in the acid-stable fraction. The B6 epitope appeared to be mannan because it was stable to heat (boiling) and protease treatments but was destroyed by alpha-mannosidase digestion. The B6.1 epitope eluted from the size exclusion column in two fractions. Mass spectroscopic analyses showed that one fraction contained material with the size of a mannotriose and that the other was a mixture of mannotriose- and mannotetraose-size substances. Dose response inhibition tests of the fractions indicated that the B6.1 epitope is associated with the mannotriose. Nuclear magnetic resonance (NMR) spectroscopic analysis of the epitope yielded data consistent with a beta-(1-->2)-linked mannotriose. The fine structure of the B6 epitope is under investigation. Information derived from these investigations will be useful both in understanding protective versus nonprotective antibody responses to C. albicans and in improving anti-Candida vaccine formulations.
We investigated the effects of endothelin-1 on nitric oxide synthesis in vascular smooth muscle cells. We measured the production of nitrite, a stable metabolite of nitric oxide, and the expression of inducible nitric oxide synthase mRNA and protein in cultured rat vascular smooth muscle cells. Incubation of the cultures with interleukin-1 beta (10 ng/mL) for 24 hours caused a significant increase in nitrite production. Endothelin-1 significantly decreased the interleukin-1 beta-induced nitrite production by vascular smooth muscle cells in a dose-dependent manner (10(-11) to 10(-8) mol/L). Incubation with interleukin-1 beta for 24 hours induced expression of inducible nitric oxide synthase mRNA and protein in vascular smooth muscle cells, whereas endothelin-1 showed a suppressive effect on their expressions. Addition of the endothelin type A receptor antagonist BQ-485, but not the endothelin type B receptor antagonist BQ-788, dose-dependently inhibited the effect of endothelin-1. After protein kinase C activity was functionally depleted by treatment of cells with phorbol 12-myristate 13-acetate for 24 hours, the effect of endothelin-1 was abolished. These results indicate that endothelin-1 acts on endothelin type A receptors and inhibits nitric oxide synthesis in interleukin-1 beta-stimulated vascular smooth muscle cells at least partially through a protein kinase C-dependent pathway.
BACKGROUND: Candida albicans crossreacts with Saccharomyces cerevisiae or Pityrosporum ovale at the IgE level. However, the extent of crossreactivity of C. albicans with other yeast species is not known. OBJECTIVE: The crossreactivity at the immunoglobulin E (IgE) level of Candida albicans with other pathogenic Candida species and to the airborne yeast species Cryptococcus and Rhodotorula was studied by immunoblot analysis. METHODS: Crude antigens, designated as heat extract, were prepared from 13 different yeast species and a dot blot test was performed to detect IgE antibodies against each of the heat extracts in 349 patients with allergies who were positive for IgE antibodies against C. albicans in a CAP system. RESULTS: In the dot blot test, most of the sera reacted with the heat extracts of not only C. albicans but also those prepared from the other yeast species. The sera of 41 of the 349 patients (11.7%) reacted with the heat extracts of all 13 yeast species. The extent of the binding of IgE antibodies to multiple yeast species correlated with both the fluorescence intensities measured in the CAP system and the intensities of dots generated by the heat extract of C. albicans in the dot blot test. In an inhibition dot blot test, mannoproteins, but not proteins, of C. albicans strongly inhibited the subsequent binding of IgE antibodies to all yeast species. CONCLUSION: Our data suggest that the C. albicans mannoproteins are responsible for the crossreactivity among these yeast species at the IgE level.
BACKGROUND: Plasma levels of adrenomedullin are increased in patients with congestive heart failure, but there has been no report concerning the effects of adrenomedullin on the heart. We investigated the effects of adrenomedullin on NO synthase activity in cardiac myocytes. METHODS AND RESULTS: We measured the production of nitrite, a stable metabolite of NO, in cultured neonatal rat cardiac myocytes with the Griess reagent. Inducible NO synthase mRNA and protein expression were assayed by Northern and Western blotting, respectively. Incubation of the cultures with interleukin-1 beta (10 ng/mL) for 24 hours caused a significant increase in nitrite accumulation. Adrenomedullin significantly augmented nitrite production by interleukin-1 beta-stimulated but not by unstimulated cardiac myocytes in a dose-dependent manner (10(-10) to 10(-6) mol/L). The adrenomedullin-induced nitrite production by interleukin-1 beta-stimulated cells was accompanied by increased inducible NO synthase mRNA and protein expression. In the presence of dibutyryl cAMP, the interleukin-1 beta-induced nitrite accumulation was increased further, but the stimulatory effect of adrenomedullin on nitrite production was abolished. Adrenomedullin dose-dependently increased intracellular cAMP levels in cardiac myocytes. Addition of the calcitonin gene-related peptide (CGRP) receptor antagonist CGRP[8-37] to the culture dose-dependently inhibited both cAMP and NO generation stimulated by adrenomedullin. CONCLUSIONS: These results indicate that adrenomedullin acts on cardiac myocytes and augments NO synthesis in these cells under cytokine-stimulated conditions, at least partially through a cAMP-dependent pathway.
Daunomycin is an antitumor antibiotic known to inhibit DNA replication and transcription. Although the inhibition is assumed to be caused by a direct interaction of the drug with DNA, the exact effect of daunomycin on the higher order DNA structure remains uncertain. We studied the effect of daunomycin on DNA compacted states using fluorescence and electron microscopies. Structural changes in individual DNA molecules were examined under the following conditions. T4 phage DNA (166 kbp) was first compacted by spermidine followed by the addition of daunomycin to the compacted DNA. A direct observation of individual single duplex DNAs by fluorescence microscopy indicated that daunomycin induced unfolding of the compacted DNA. Electron microscopic observation of the morphological changes of the higher order DNA structure supported the results obtained by fluorescence microscopy. We discuss here the mechanisms of the unfolding of the compacted structure following intercalation of daunomycin into DNA particularly in terms of the free energy.
Dioctadecylamidoglycylspermine (DOGS) is a cationic lipid vector capable of efficiently introducing DNA into various eukaryotic cells. We investigated the higher-order structure of the DNA/DOGS complex using fluorescence and electron microscopy. Our results show that the DNA/DOGS complex exhibits a nucleosome-like structure in which DNA wraps around an aggregate of DOGS molecules. In addition, DNA/DOGS complexes tend to associate with each other to form network structures. The resulting network assembly may play a role in effective gene transfection.
We investigated the effects of cilostazol, a cAMP phosphodiesterase inhibitor, on nitric oxide (NO) synthesis in cultured rat vascular smooth muscle cells. Incubation of the cultures with interleukin-1 beta (10 ng/ml) for 24 h caused a significant increase in the accumulation of nitrite, a stable metabolite of NO. Although cilostazol itself showed no effect on nitrite accumulation, it stimulated interleukin-1 beta-induced nitrite accumulation in a concentration-dependent manner (10(-8)-10(-5) M). This effect of cilostazol was completely abolished in the presence of NG-monomethyl-L-arginine, actinomycin D or dexamethasone. The cilostazol-induced nitrite production was accompanied by increased inducible NO synthase protein expression. In the presence of dibutyryl-cAMP, interleukin-1 beta-induced nitrite accumulation was further increased, but the stimulatory effect of cilostazol on nitrite accumulation was blunted. The effect of cilostazol was also abolished in the presence of Rp-8-bromoadenosine-3',5-cyclic monophosphorothioate, a competitive inhibitor of protein kinase A. Addition of cilostazol to the cultures significantly increased intracellular cAMP levels of vascular smooth muscle cells. These results indicate that cilostazol increases NO synthesis in interleukin-1 beta-stimulated smooth muscle cells, at least partially through a cAMP-dependent pathway.
We investigated the effects of alpha 1-adrenergic stimulation on nitric oxide (NO) production by cardiac myocytes. Incubation of cultured neonatal rat cardiac myocytes with interleukin-1 beta (IL-1 beta) caused a significant increase in the production of nitrite, a stable metabolite of NO. Addition of phenylephrine significantly augmented nitrite production by IL-1 beta-stimulated but not by unstimulated myocytes in a dose-dependent manner. The effect of phenylephrine was completely abolished in the presence of NG-monomethyl-L-arginine (L-NMMA) or actinomycin D. Northern blotting revealed increased inducible NO synthase mRNA accumulation in cardiac myocytes treated with IL-1 beta and phenylephrine compared with those treated with IL-1 beta alone. After protein kinase C activity was functionally depleted by treating cells with phorbol 12-myristate 13-acetate for 24 h, phenylephrine did not augment IL-1 beta-induced NO production. The effect of phenylephrine was also abolished in the presence of protein kinase C inhibitor calphostin C. These observations suggest that alpha 1-adrenergic stimulation causes an upregulation of cytokine-induced NO production by cardiac myocytes, which is mediated at least partially via activation of protein kinase C.
The effects of dietary highly hydrogenated soybean oil (HSO) upon the changes caused by dietary polychlorinated biphenyls (PCBs) were examined in rats. Six groups of rats were fed the following diets for 30 d: a 20% soybean oil-containing diet (control diet), a diet in which a half of soybean oil was substituted with HSO (HSO-A diet), a diet in which cellulose powder was replaced with HSO (HSO-B diet) and these diets supplemented with 100 ppm PCBs (control + PCBs, HSO-A + PCBs and HSO-B + PCBs diets). Hepatic concentration of PCBs and relative liver weight were markedly decreased in rats fed with the HSO-A + PCBs diet compared with those fed with the other diets containing PCBs. Liver lipids and liver cholesterol were considerably decreased with a reciprocal increase in fecal sterol excretion by rats fed the HSO-A + PCBs and the HSO-B + PCBs diets compared with those fed with the control + PCBs diet. The fatty acid composition in hepatic phospholipids showed an independent increase of the saturated fatty acid content induced by dietary HSO and PCBs. Dietary PCBs also caused decreases in the amounts of monounsaturated and n-3 polyunsaturated fatty acids. These results suggest that dietary HSO prevents accumulation of PCBs in the liver and promotes the excretion of lipids stimulated by PCBs, accompanied by a change in fatty acid metabolism.
The effect of a potent and long-acting bradykinin B2-receptor antagonist (HOE140) on acute pancreatitis induced by retrograde infusion of trypsin and taurocholate into the pancreatic duct was studied in rats. HOE140 was administered subcutaneously immediately before and 3 h after the induction of pancreatitis and the systemic blood pressure, ascites volume, serum amylase, 24-h survival rate, and pathology of the pancreas were evaluated. Plasma concentrations of bradykinin increased significantly 15 min after the induction of pancreatitis and decreased to basal levels at 90 min. HOE140 (0.1 mg/kg) alleviated hypotension developing immediately after the induction of pancreatitis and reduced the ascites volume. The 24-h survival rate in rats treated with 0.1 mg/kg HOE140 (70.3%) was significantly higher than that in controls (35.6%). Treatment with 0.01, 0.3, 1.0, and 3.0 mg/kg of HOE140, however, had no beneficial effect on the survival rate. Ascites volume, serum amylase, and pathology of the pancreas at 24 h were not improved by treatment with HOE140. These data suggest that HOE140 may improve the survival rate by maintaining hemodynamics in the early stage of experimental acute pancreatitis.
Two cases of protothecosis caused by Prototheca wickerhamii have been reported from Nagoya in a 12 year period in both cases the infection presented on the cheeks of otherwise healthy women. Biopsies showed numerous PAS positive staining organisms with the distinctive mulberry like endosporulation in the dermis. Prototheca wickerhamii was identified on sugar assimilation tests of colonies isolated from tissue on Sabouraud agar. Case 1 responded to 11 months of oral ketoconazole therapy. Case 2 might not respond to itraconazole. The source of the infections has not been identified.
To determine the major antigenic component of Candida albicans against immunoglobulin E (IgE) antibodies in the sera of patients with allergies who were positive for IgE antibodies to C. albicans crude antigen in a CAP system, phosphomannoproteins (CAMP/A or CAMP/B for serotype A or B strain, respectively) and their acid-stable portions (CAMP-S/A or CAMP-S/B) were isolated from beta-mercaptoethanol (2-ME) extracts of C. albicans cells of serotypes A and B, and IgE antibodies against these components were compared with those against protein complex and enolase (CAE) fractions isolated from C. albicans cells. The dot blot test, which was used to detect IgE antibodies to the C. albicans antigens, showed that IgE antibodies to the 2-ME extract and phosphomannoprotein fractions were present in the sera of 98.0% (2-ME extract), 96.8% (CAMP/A), 93.2% (CAMP-S/A), 97.2% (CAMP/B), and 81.5% (CAMP-S/B) of the patients, whereas IgE antibodies to the protein complex and CAE fractions were found in the sera of 73.6 and 48.8% of the patients, respectively. The extent of IgE binding to the 2-ME extract and phosphomannoproteins was well correlated with the fluorescence intensities estimated with the CAP system. Furthermore, the results obtained from the inhibition experiment with the CAP system indicated that the binding of IgE antibodies to Candida antigens is strongly inhibited by the phosphomannoprotein fraction and is an indication that the serum of the patients contained IgE antibodies specific to the cell wall phosphomannoproteins of C. albicans. Finally, an initial chemical analysis indicated that the epitopes for IgE antibodies on the phosphomannoproteins is a carbohydrate portion, since the ability of CAMP/A to inhibit the binding of IgE antibodies to the homologous CAMP/A was destroyed after oxidation by sodium periodate but not after digestion with proteinase K.
We investigated the effects of adrenomedullin on nitric oxide synthesis by measuring the production of nitrite, a stable metabolite of nitric oxide, in cultured rat vascular smooth muscle cells. Incubation of cultures with interleukin-1beta (10 ng/mL) for 24 hours caused a significant increase in nitrite generation. The interleukin-1beta-induced nitrite production by vascular smooth muscle cells was significantly increased by adrenomedullin in a dose-dependent manner (10(-10) to 10(-6) mol/L). This effect of adrenomedullin was significantly inhibited in the presence of Ng-monomethyl-L-arginine. The adrenomedullin-induced nitrite production by interleukin-1beta-stimulated cells was accompanied by increased inducible nitric oxide synthase mRNA accumulation. In the presence of the phosphodiesterase inhibitor isobutylmethylxanthine, interleukin-1beta-induced nitrite accumulation was further increased, but the effect of adrenomedullin was not additive or synergistic. Adrenomedullin dose dependently increased intracellular cAMP levels of vascular smooth muscle cells. These results indicate that adrenomedullin augments nitric oxide synthesis in interleukin-1beta-stimulated vascular smooth muscle cells, at least partially through a cAMP-dependent pathway.
We investigated the effects of aldosterone on nitric oxide (NO) synthesis in vascular smooth muscle cells. We measured the production of nitrite, a stable metabolite of NO, and the expression of inducible NO synthase mRNA and protein in cultured rat vascular smooth muscle cells. Incubation of the cultures with interleukin-1 beta (10 ng/ml) for 24 h caused a significant increase in nitrite generation. The interleukin-1 beta-induced nitrite production by vascular smooth muscle cells was significantly inhibited by aldosterone in a dose (10(-9) approximately 10(-6) M)-dependent manner. Incubation with interleukin-1 beta for 12 approximately 24 h caused inducible NO synthase mRNA expression in vascular smooth muscle cells, whereas aldosterone had a suppressive effect on its expression. Aldosterone also decreased interleukin-1 beta-induced NO synthase protein accumulation. These results indicate that aldosterone inhibits NO synthesis under interleukin-1 beta-stimulated conditions in vascular smooth muscle cells.
Incubation of cultured rat vascular smooth muscle cells with interleukin-1 beta caused a significant increase in the production of nitrite, a stable metabolite of nitric oxide (NO), in time- and dose-dependent manners. Addition of ouabain to the culture further enhanced interleukin-1 beta-induced nitrite production. Similarly, interleukin-1 beta produced a significant increase in the cellular level of guanosine 3',5'-cyclic monophosphate, and the increase was significantly enhanced by coincubation with ouabain. The calcium ionophore ionomycin also significantly enhanced interleukin-1 beta-induced nitrite generation. These findings indicate that ouabain enhances NO synthesis in vascular smooth muscle cells induced by interleukin-1 beta, presumably through an increase in intracellular calcium ion concentrations.
We investigated the relationship between dietary highly hydrogenated soybean oil (HSO) and cholesterol transport in rats. In the first study, to examine the effects on cholesterol transport of different concentrations of HSO in dietary oil, rats were given one of the three diets containing 0, 25, or 50% HSO in dietary oil with cholesterol (5 g/kg diet) or a diet without HSO and cholesterol for 22 d. Feeding the high concentration of HSO prevented the increase in plasma total cholesterol, hepatic total lipids, and cholesterol and the decrease in high-density lipoprotein-cholesterol, which were caused by dietary cholesterol. Moreover, HSO increased the fecal excretion, fecal lipids, and steroids in a dose-dependent manner. In the second study, to examine the effects on cholesterol transport of redistribution of steric acid in the triacylglycerol species contained in HSO, rats were given one of the six diets containing HSO (distearoylmonoacylglycerol and tristearoylglycerol)-rich, monostearoylglycerol-rich, or palmitic acid-rich oil with/without cholesterol (5 g/kg diet), for 30 d. Whereas the accumulation of cholesterol in the body was reduced, cholesterol excretion was enhanced effectively in rats given the HSO-rich diet compared with rats given the monostearoylglycerol-rich diet. These results suggested that not only the high concentration of stearic acid but also its uneven distribution in HSO-triacylglycerol contributed to the reduction in intestinal cholesterol absorption in rats.
Candida albicans 46 kDa protein, a glycolytic enolase enzyme, is an important allergen of the yeast. The purpose of the study was to detect circulating IgE and IgG antibodies against C. albicans enolase (CAE). We isolated CAE using sequential DEAE Sephacel and P11 column chromatography from spheroplasts of C. albicans, and detected IgE and IgG antibody against CAE by immunoblotting. Crossreactivity of enolase of C. albicans and Saccharomyces cerevisiae was also examined by immunoblotting and immunoblot inhibition test. Among 54 sera with positive IgE RAST to C. albicans, IgE antibody against CAE was detected in 20 sera (37%) and IgG antibody in 27 sera (50%). The allergenic potency of CAE was confirmed using a skin-prick test in three patients. Simultaneous IgE binding to S. cerevisiae enolase was only observed in four out of 20 sera reacting to CAE. Pre-treatment of sera with CAE completely inhibited IgE binding to S. cerevisiae enolase. Whereas the latter only partially inhibited IgE binding to CAE. These results suggest that CAE shares some crossreacting epitopes with S. cerevisiae enolase, representing minor components of CAE but dominant segments of S. cerevisiae enolase.