Adjuvant effect of grifolan on antibody production in mice

The effects of grifolan (GRN), a gel-forming (1-->6)-branched (1-->3)-beta-D-glucan, on antibody production were examined. Sera from mice that were injected with GRN and trinitrophenyl ovalbumin (TNP-OVA) intraperitoneally showed a significantly increased level of anti-TNP IgG. However, injection of TNP-OVA alone showed a lower antibody level. Two hundred fifty microg of GRN and 10 microg of TNP-OVA gave the maximum production of anti-TNP antibody. Enhanced antibody production was also observed in the culture supernatant of splenocyte obtained from GRN-administered mice. The culture supernatant contained a significant amount of nitric oxide (NO) in the case of GRN-administered mice. To observe the effect of NO on the antibody production induced by GRN, N-monomethyl arginine (NMMA), an inhibitor of NO synthetase, was added to the splenocyte cultures. The antibody level of supernatants containing NMMA was higher than that of control supernatants. These results suggest that GRN can enhance antibody production and that NO induced by stimulation with GRN concomitantly with antibody production is a negative factor on the adjuvant activity. Inhibition of NO may increase the adjuvant effect of GRN.

Soluble mannan and beta-glucan inhibit the uptake of Malassezia furfur by human monocytic cell line, THP-1

The uptake of live and heat-killed Malassezia furfur HIC 3321, HIC 3343 and Candida albicans ATCC 10231 by human monocytic cell line, THP-1, was examined. THP-1 was differentiated by PMA for 7 days before use. The uptake of these yeasts by THP-1 was increased in a concentration-dependent manner of yeasts, and the uptake reached plateau level at the E/T (yeast/THP-1) ratio 5. In addition, a higher percentage of heat-killed cells than live cells was taken in THP-1. Yeast mannan and beta-1,3-glucan, random coiled conformer, inhibited the uptake of live and heat-killed M. furfur by THP-1, though dextran T-250, that is alpha-glucan, and schizophyllan (SPG), triple helix conformer of beta-glucan, did not. Interestingly, mannan inhibited the uptake of both types, live and heat-killed, of C. albicans, however, laminaran inhibited the uptake of heat-killed C. albicans alone. Opsonization of these yeasts with normal human serum enhanced the uptake of yeasts, although opsonization with heat-inactivated serum, the treatment at 56 degrees C for 30 min, did not enhance. These results suggested that live and heat-killed M. furfur was recognized by THP-1 through mannose receptor, beta-glucan receptor and complement receptor type 3 via the activation of alternative pathway of complement.

Immunotoxicity of soluble beta-glucans induced by indomethacin treatment

(1 --> 3)-Beta-D-Glucan (beta-glucan) is a biological response modifier that regulates host immune response. However, the side effects of this drug have not been extensively examined. In this study, we found that the combination of a beta-glucan and a nonsteroidal anti-inflammatory drug, indomethacin, induced lethal toxicity in mice. Lethal toxicity of orally administered indomethacin (multiple administration to ICR mice; once a day for 2 weeks) was 0/8 (2.5 mg kg(-1)) and 5/8 (5 mg kg(-1)) (death/total) over 2 weeks. The toxicity was enhanced to 3/8 and 8/8 in mice treated with a clinical beta-glucan preparation, sonifilan (250 microg/mouse, single i.p. administration on day 0). A similar effect was observed for other beta-glucans, including SSG, grifolan, zymosan A and zymocel. Enhanced lethal toxicity resulted from a single p.o. administration of indomethacin on day 5 to day 9 after multiple beta-glucans administration. Interferon-gamma, interleukin-6 and colony stimulating factor concentrations in sera of indomethacin/beta-glucan-treated mice were significantly elevated. These results strongly suggest that indomethacin/beta-glucan treatment induces lethality in mice by maladjusting the cytokine network.

Gradual solubilization of Candida cell wall beta-glucan by oxidative degradation in mice

Candida spp. is a medically important fungi which induces disseminated candidiasis and candidemia in hospitalized immunocompromised patients. The cell wall of Candida is mainly composed of two polysaccharides, mannan and beta-glucan, and at least part of beta-glucan is basically insoluble in H2O or NaOH. We became interested in when and how particulate beta-glucan changes to the soluble form. However, the fate of wall components has not been examined in detail. In this study, modification and solubilization of the cell wall beta-glucan were analyzed in vivo and in vitro. Cells of Candida, intravenously administered to mice (1 mg/mouse), were immediately deposited mainly in liver as determined by 3H-labeled cells. Beta-Glucans were detected in these mice for at least for 6 months by the beta-glucan specific assay. During this period, the insoluble cell wall beta-glucan was gradually solubilized in these organs, probably by oxidative stress of macrophages. Candida cells and particulate beta-glucans were also gradually solubilized in vitro using sodium hypochlorite solution, but part of the cell wall beta-glucan was still insoluble even after treatment with concentrated hypochlorite solution for one day at room temperature. These findings strongly suggested that the fungal cell wall beta-glucans were quite resistant to oxidative metabolism in vivo and in vitro, and thus deposited for quite long period in the host.

Effect of O-antigenic polysaccharide of Escherichia coli on endotoxin neutralizing activity of lysozyme

Endotoxemia is considered to be associated with the high mortality of gram-negative septic patients. Increasing evidence shows that beta-lactam antibiotics have a propensity to induce endotoxin release from the bacterial outer membrane while killing bacteria. We have recently found that egg white lysozyme (EW-LZM) shows strong inhibition of beta-lactam induced bacteriolysis and lipopolysaccharide (LPS) release from Escherichia coli O111, resulting in reduction of the LPS-initiated inflammatory response. In this study, we compared the effect of EW-LZM on E. coli J5, which possesses rough-type LPS (RaLPS), in order to demonstrate the effect of O-antigenic polysaccharide on endotoxin neutralizing activity of EW-LZM and on inhibition of beta-lactam induced lysis by LZM. Both of the beta-lactam induced bacterial lysis and subsequent LPS release were almost completely inhibited by EW-LZM. The effect was more potent than that of wild-type LPS as assessed by released LPS concentration and LPS induced cytokine syntheses. In addition, EW-LZM was effective against lethal infection of E. coli J5 in cyclophosphamide induced leukopenic mice. These facts strongly suggested that O-antigenic polysaccharide negatively modulates LPS neutralizing activity of EW-LZM.

Contribution of CR3 to nitric oxide production from macrophages stimulated with high-dose of LPS

The contribution of the complement receptor type 3 (CR3) to nitric oxide (NO) production from macrophages stimulated by LPS was investigated. When thioglycollate-elicited mouse peritoneal macrophages were stimulated with a high dose of LPS (10 micrograms/ml) in both the presence and absence of fetal calf serum, a source of LPS binding protein (LBP) necessary for the binding of LPS to CD14, NO production was observed. These findings suggest that CD14-dependent and CD14-independent signaling pathways for NO production are present in macrophages. Because binding and phagocytosis of bacteria by macrophages through the CR3 has been previously reported, we investigated whether the CR3 acts in CD14-independent signaling pathway for NO production. By flow cytometric analysis, the binding of FITC-labeled anti-CR3 monoclonal antibody (anti-CR3 mAb) to macrophages was inhibited by LPS. Anti-CR3 mAb induced iNOS protein and produced NO in a dose dependent manner. Further, NO production induced by anti-CR3 mAb was also inhibited by zymocel, beta-glucan with a high affinity to CR3. These results suggest that the CR3 molecule acts in a CD14-independent signaling pathway, and contributes to NO production by macrophages stimulated with high doses of LPS.

Activation of murine kupffer cells by administration with gel-forming (1-->3)-beta-D-glucan from Grifola frondosa

The effect of gel-forming (1-->3)-beta-D-glucan on the immunological activities of murine kupffer cells was examined. A branched type gel-forming (1-->3)-beta-D-glucan, GRN, was administered intravenously to mice. GRN associating to kupffer cells was detected by an immunohistochemical technique using anti-GRN antibody. A kinetic study of the activation of kupffer cells revealed that GRN could induce the enhanced production of cytokines and nitric oxide on 4 to 7 d after the administration. The activities are further augmented by adding GRN in the culture. The cytostatic activity of kupffer cells against murine lymphoma, EL-4, was also augmented by a time course similar to nitric oxide production. The cytostatic activity was reduced by adding an inhibitor of nitric oxide synthase, implying that the cytostatic activity of kupffer cells to EL-4 was dependent on nitric oxide. The administration of GRN increased the expression of CD11b, known as a beta-glucan receptor, on kupffer cells at day 7. The above data suggest that GRN could activate murine kupffer cells to enhance the production of cytokines and nitric oxide, and that the activation required 4 or 7 d, at least, after the administration with GRN.

Inactivation of a particle beta-glucan by proteins in plasma and serum

(1-->3)-beta-D-Glucans remained in the liver and spleen for long time, i.e. more than a month, without major structural changes/because there is no specific metabolic pathway for it in the body. However, biological activities, such as priming activity to LPS, triggered TNF-alpha synthesis, and antitumor activity was reduced more quickly. In this paper, we demonstrated the contribution of protein binding in inactivating beta-glucans. A particle beta-glucan preparation, zymosan, was treated with serum or plasma at 37 degrees C and their various biological activities were compared with zymosan alone. Such biological activities as antitumor activity, TNF-production, IL-6 production, complement activation and vascular permeability were significantly decreased by serum or plasma treatment. These results strongly suggested that the binding of serum or plasma protein(s) to beta-glucans would be a key step in inactivating a particle beta-glucan in the body.

Enhanced production of inducible nitric oxide synthase by beta-glucans in mice

We have already demonstrated that various activities including NO (nitric oxide) synthesis in vivo and in vitro significantly differ between triple helical (SPG) and single helical (alkaline-treated SPG, SPG-OH) beta-glucans. It was previously suggested that the single helical conformer of beta-glucan (SPG-OH) was dominant in cytokine production and subsequent NO synthesis in vitro. In this study, we analyzed production of inducible nitric oxide synthase (iNOS) induced by beta-glucans in vitro and in vivo. The iNOS production was enhanced in proteose peptone-induced peritoneal macrophages (PMs) cultured with SPG-OH in the presence of IFN-gamma for 24 h, and SPG-OH-induced PMs. Moreover, SPG-OH was effective for iNOS production not only in isolated macrophages but also in tissue macrophages, whereas SPG was less effective. These findings suggest that a single helical conformer is essential for iNOS production, and that NO synthesis by beta-glucans is closely related to iNOS production.

Different role of serum components and cytokines on alveolar macrophage activation by soluble fungal (1-->3)-beta-D-glucan

In this study, we investigated the mechanism of alveolar macrophage activation by systemic administration of SSG, a soluble highly branched (1-->3)-beta-D-glucan obtained from a fungus Sclerotinia sclerotiorum IFO 9395. Multiple i.v. administration (10 mg/kg; once daily for 10 consecutive days) of SSG enhanced some functions of alveolar macrophages, such as lysosomal enzyme activity and nitric oxide secretion, on day 1 after the last administration, and it also elevated the concentrations of serum protein, interferon gamma and SSG in bronchoalveolar lavage fluid on the same day. On the in vitro assay system, stimulation by SSG alone (500 microg/ml) slightly augmented the lysosomal enzyme activity of alveolar macrophages, but it had no effect on nitric oxide production of cells. Stimulation by serum (1 or 10% mouse serum) or serum components, such as fibronectin (25 microg/ml) and albumin (500 microg/ml), alone strongly augmented only the lysosomal enzyme activity of alveolar macrophages, but it had no effect on nitric oxide secretion from cells, and no synergism or additive-like effect was observed between serum components and SSG. In contrast, stimulation by crude lymphokine (5%) or recombinant murine interferon gamma (100 U/ml) alone did not induce augmentation of lysosomal enzyme activity and nitric oxide production of alveolar macrophages in vitro, but when cells were incubated together with crude lymphokine or recombinant murine interferon gamma and SSG (500 microg/ml), a significant combined effect was observed on both functions of alveolar macrophages. In addition, pretreatment of crude lymphokine or recombinant murine interferon gamma enhanced the expression of beta-D-glucan specific binding sites on the alveolar macrophage surface in vitro though pretreatment by serum components had no effect. Based on these findings, the enhancement of alveolar macrophage functions by systemic administration of SSG appears to be mediated, at least in part, by both the simple effect of serum components including fibronectin and albumin leaked from pulmonary peripheral blood into the alveoli and the synergistic effect between lymphokines released from activated pulmonary T cells and SSG itself entering the alveoli after SSG injection via the priming effect of lymphokines which enhances the expression of beta-D-glucan specific binding sites on the alveolar macrophage surface.

Nitric oxide synthesis in murine peritoneal macrophages by fungal beta-glucans

Fungal beta-glucans have abilities to induce NO (nitric oxide) synthesis by macrophages in vivo, and the intensity of NO synthesis significantly varied dependent on the structure of beta-glucans. The molecular mechanism of NO synthesis by beta-glucans, however, has not been clarified in detail. To determine beta-glucan-mediated NO production, we used various beta-glucans (SPG-OH, GRN; Grifolan, SSG, OL-2, ZYM; zymosan A and ZYC; zymocel), which could enhance NO synthesis in vivo, and stimulated peritoneal macrophages (MPs) in vitro in the presence of interferon-gamma (IFN-gamma). Using recombinant cytokines, a minimum concentration of the cytokines for NO induction was about 20 mg/ml in the presence of IFN-gamma under the experimental conditions. Of beta-glucans tested, only SPG-OH and GRN produced high concentrations of IL-6 in the culture supernatants. SSG also induced NO synthesis in vitro, but concentrations of inflammatory cytokines were low even in the presence of IFN-gamma. In addition, there are some beta-glucans which could induce NO synthesis in vivo but not in vitro (OL-2, ZYM, ZYC). These findings suggested that NO productivity of beta-glucans in vivo is regulated by several mechanisms.

Increases in hematopoietic responses caused by beta-glucans in mice

The effects of various (1-->3)-beta-D-glucans on hematopoietic responses of mice were investigated by measuring colony stimulating activity in sera and ascites of the mice administered glucan. We have demonstrated that the hematopoietic response was increased by various structures of (1-->3)-beta-D-glucans, i.e. soluble glucans (linear, branched, single helix, triple helix) and particulate glucans. From the viewpoint of structure and activity relationships, we found several characteristic features: i) hematopoietic response induced by the particulate glucan disappeared faster than that by the soluble glucans, ii) conformation of the glucans, single vs. triple helix, are relatively independent of the response, iii) linear glucan had a weaker response, and iv) there is a strong strain-dependency of the response. These results corresponded well with the fact that branched (1-->3)-beta-D-glucans, but not linear and not particulate, are often used as biological response modifiers for cancer patients.

Wide range of molecular weight distribution of mitogenic substance(s) in the hot water extract of a Chinese herbal medicine, Bupleurum chinense

In this study, we examined the contribution of lignin-like materials in lower molecular weight (MW) fractions from the hot water extract of Bupleuri Radix (Bupleurum chinense) (HWE-BR) for their immunopharmacological activities. Mitogenic activity was detected in all the fractions of MW ranges: lower than 1.0 kDa, 1.0-3.5 kDa, 3.5-10 kDa, and 10-50 kDa. After NaClO2 treatment of these subfractions, UV spectra, ESR spectra, mitogenic activities on murine B-cells, and the activity of inducing nitric oxide in RAW 264.7 cells were significantly reduced, suggesting that lignin-like polyphenolic substance(s) of various MW might take part in these activities. The intensity of ESR spectra and mitogenic activities were stronger in higher MW subfractions, thus the content of stable radical species and/or the degrees of polymerization would be important for their immunopharmacological activities.

Analysis of mitogenic substances in Bupleurum chinense by ESR spectroscopy

The polyphenolic substance(s) in the hot water extract of Bupleurum chinense (PSF) showed strong mitogenic activity. In this paper, we analyzed PSF by using ESR spectroscopy, and found that i) PSF showed a strong ESR signal on g = 2.005 which was similar to the commercially available lignin; ii) Sho-saiko-to, which contains an extract of B. chinense, also showed similar signals on ESR; iii) Powdered B. chinense also showed similar signals on g = 2.005. Peroxidase activity, essential for producing polyphenolic substances, was detected in the cold water extract of B. chinense. In addition, the signal intensity of the ESR spectrum of B. chinense was increased after boiling. The data of the ESR spectra of the model reactions using lignin, arginine, proline and maltose also strongly suggested that a certain chemical modification proceeded during the hot water extraction to increase the percentage of the stable free radical. These facts strongly suggested that the mitogenic substance in B. chinense is a polyphenolic substance extracted by hot water, and the structure was modified during the extraction to increase the stable free radical components.

Immunopharmacological activity of the purified insoluble glucan, zymocel, in mice

Although it has been established that soluble glucan in fungi is important to host defence against infection, the importance of insoluble glucans is not clear. We have examined the in-vivo immunopharmacological activity of the insoluble glucan, zymocel. Administration of zymocel increased peritoneal exudate cell number and spleen weight, and enhanced: phagocytic activity, hydrogen peroxide production, and nitric oxide production of peritoneal exudate cells; the extravascular release of Evans blue (which might reflect vascular permeability); lipopolysaccharide-triggered synthesis of tumour necrosis factor (TNF); and recovery of white blood cell number in cyclophosphamide-induced leukopenia. Zymocel also showed anti-tumour activity against sarcoma 180 in mice and also enhanced TNF synthesis and hydrogen peroxide production by macrophage-like cell line in-vitro, i.e. resulted in direct macrophage activation. These results show that zymocel shows varied immunopharmacological activity; it is suggested that the administration of insoluble glucan induces the inflammatory response, the subsequent activation of the immune systems via the cytokine network, and direct macrophage activation.

Architecture of alkaline-soluble and bioactive polysaccharide from the kernels of Prunus mume Sieb. et Zucc. assessed by anti P-1 antibody

P-1 was partially hydrolyzed with 0.01, 0.05, and 0.1 M trifluoroacetic acid (TFA), successively, and the dialyzable (E-1, E-2, and E-3) and non-dialyzable (I-1, I-2, and I-3) fractions were prepared and analyzed chemically and immunochemically. Either I-1 or E-1 reacted with anti P-1 serum as strongly as P-1 and were mitogenic. The cross-reactivity of I-2 and I-3 was less than I-1 with anti P-1 serum. However, they were as mitogenic as I-1. The cross-reactivity of E-2 and E-3 to anti P-1 serum was also very weak, and they were not mitogenic. The E-1 fraction had a similar sugar composition to I-1 and P-1. E-2 was a monosaccharide, all of Ara, and would be from the linkage of furanosyl residues in P-1. The composition of E-3 was free from Ara and the structure of E-3 was similar to that of I-3. E-3 would be considered to be deleted arabinofuranose from E-1. These results suggest that the mitogenic activity measured by the alkaline phosphatase assay is a property of the core part, I-3, but that P-1 contains several epitopes other than the core part by the immunochemical analysis.

Characterization of sodium hypochlorite degradation of beta-glucan in relation to its metabolism in vivo

Soluble (SSG, beta-1,3-D-glucan obtained from the culture filtrates of a fungus, Sclerotinia sclerotiorum IFO 9395) and particulate (zymosan) beta-glucans were oxidized by sodium hypochlorite (NaClO), and the oxidized products were analyzed by gel filtration and ion-exchange chromatographies and by limulus G-test to study the metabolism of beta-glucans in vivo. By oxidative degradation, SSG was gradually oxidized to anionic polymers, which decreased the molecular weight and reduced the content of the sidechain at the same time. Zymosan, a particle from fungi cell wall, was easily solubilized to a high molecular weight polysaccharide by oxidative degradation. The elution profiles on ion exchange columns and the limulus G-test reactivity of the products were similar to those of polysaccharides obtained by in vivo experiments using SSG and zymosan. These results suggest that oxidative degradation is the main metabolic pathway of beta-glucans in vivo, and that the sidechains would be oxidized faster than the main chain.

Conformation dependency of nitric oxide synthesis of murine peritoneal macrophages by beta-glucans in vitro

We have already demonstrated that various activities including NO (nitric oxide) synthesis in vivo were significantly different between triple helical (SPG) and single helical (alkaline-treated SPG, SPG-OH) beta-glucans, and beta-glucan-mediated NO synthesis was associated with increased gene of IFN-gamma. In this study, we analyzed beta-glucan-mediated NO production in vitro with the concomitant use of IFN-gamma. Proteose peptone-elicited peritoneal macrophages (PM) were collected from male C3H/HeJ mice and cultured with beta-glucans in the presence or absence of IFN-gamma for 24 h. It was found that SPG-OH, but not SPG, enhanced NO synthesis in vitro, especially in the presence of IFN-gamma. Concentrations of interleukin-1 alpha, -6 and TNF-alpha in the culture supernatant of SPG-OH were significantly higher than those in that SPG. Membrane-associated IL-1 alpha was also high with SPG-OH. Cytokine productivity of PMs, as well as NO synthesis, was elevated in the presence of IFN-gamma. These facts intensely suggest that the single helical conformer of beta-glucan (SPG-OH) is dominant in cytokine production and subsequent NO synthesis.

A water-soluble antitumor glycoprotein from Chlorella vulgaris

An active substance with antitumor activity (ARS2) was purified from the culture media of Chlorella vulgaris and found to be a glycoprotein with a molecular weight of 63,100 amu, as determined by matrix-assisted laser desorption/ ionization (MALDI) mass spectrometry. ARS2 contains 66.9% carbohydrate, mainly D-galactose, and 35.2% protein. The carbohydrate moiety has a beta-1,6-D-galactopyranose backbone, as determined by methylation analysis and 13C-NMR. Apparently, the protein moiety, whose 15 amino acid sequence at the NH2-terminus, we determined as DVGEAFPTVVDALVA, is necessary for the antitumor activity, as assessed by hydrazinolysis, periodate oxidation, and proteolysis.

Kupffer cells play important roles in the metabolic degradation of a soluble anti-tumor (1-->3)-beta-D-glucan, SSG, in mice

Metabolic degradation of a soluble highly branched (-->3)-beta-D-glucan, SSG, was examined in mice using a macrophage blocker, gadolinium chloride (GdCl3). Intraperitoneally administered SSG distributed in the liver was slowly degraded, and after 5 weeks about 30% of the SSG became anionic. In addition, it is suggested that the metabolites would contain fewer branching points as assessed by the reactivity to limulus factor G. On the other hand, in the spleen, the molecular weight and the degree of branching of SSG were not changed for at least 5 weeks. Blockade of Kupffer cells by GdCl3 did not significantly change the distribution ratio of SSG in the liver. However, the treatment significantly delayed the degradation of SSG. These results suggested that Kupffer cells play important roles, not in the distribution, but in the oxidative degradation of SSG in the liver. In addition, splenic macrophages did not significantly contribute to the metabolic degradation of SSG.

Conformation dependency of nitric oxide synthesis of murine peritoneal macrophages by beta-glucans in vitro

We have already demonstrated that various activities including NO (nitric oxide) synthesis in vivo were significantly different between triple helical (SPG) and single helical (alkaline-treated SPG, SPG-OH) beta-glucans, and that beta-glucan-mediated NO synthesis was associated with increased gene expression of IFN-gamma. In this study, we analyzed beta-glucan-mediated NO production in vitro with the concomitant use of IFN-gamma. Proteose peptone-elicited peritoneal macrophages (PM) were collected from male C3H/HeJ mice and cultured with beta-glucans in the presence or absence of IFN-gamma for 24 h. It was found that SPG-OH, but not SPG, enhanced NO synthesis in vitro, especially in the presence of IFN-gamma. Concentrations of interleukin-1 alpha, -6 and TNF-alpha in the culture supernatant of SPG-OH were significantly higher than those in that of SPG. Membrane-associated IL-1 alpha was also high with SPG-OH. Cytokine productivity of PMs, as well as NO synthesis, was elevated in the presence of IFN-gamma. These facts intensely suggest that the single helical conformer of beta-glucan (SPG-OH) is dominant in cytokine production and subsequent NO synthesis.

Effects of fungal beta-glucan and interferon-gamma on the secretory functions of murine alveolar macrophages

We investigated the effect of a fungal component, soluble beta-glucan, on secretory functions of murine alveolar macrophages (AMs) in vitro. Stimulation by beta-glucan (500 microg/mL) or interferon-gamma (IFN-gamma; 100 U/mL) alone had a slight effect on AM functions, but when AMs were incubated together with beta-glucan and IFN-gamma, the production and secretion of some immune mediators, such as nitric oxide, interleukin-1 (IL-1), IL-6, and tumor necrosis factor-alpha (TNF-alpha), were markedly augmented. This combined effect of beta-glucan and IFN-gamma was based on a priming effect of IFN-gamma, because prestimulation with IFN-gamma followed by beta-glucan induced high nitric oxide production of AMs, but reversal of the sequence of treatments had only a slight effect. We also found that preincubation of AMs with IFN-gamma enhanced the binding of fluorescein-labeled beta-glucan on the AM surface, and this increased binding was abrogated to the control level by the addition of three species of soluble unlabeled (1-->3)-beta-D-glucans but not by soluble alpha-glucan. These data imply that the priming effect of IFN-gamma on the AM response to beta-glucan was dependent, at least in part, on the enhancement of beta-glucan specific binding sites on the AM surface. It was suggested that IFN-gamma is one of the principal factors controlling the pulmonary immune system against both severe fungal infection and inflammation via AM activation at the alveoli.

Immunochemical characterization of alkaline-soluble polysaccharide, P-1, from the kernels of Prunus mume Sieb. et Zucc

Polyclonal antibodies against P-1, a pectic polysaccharide fraction extracted with 0.5 M NaOH from the kernels of Prunus mume and consisted of arabino-galacturonan, and I-3, the partial acid (0.1 M trifluoroacetic acid) hydrolysate of P-1, were prepared in Japanese white rabbits. Competitive ELISA experiments strongly suggested that anti P-1 and anti I-3 antibodies were different but P-1 and I-3 cross-reacted with each other to recognize a partly similar epitope structure. The reactivities of polysaccharide fractions from the raw flesh of P. mume, and the kernels of apricot and peach extracted with either water or sodium hydroxide were examined using both antisera by the indirect competitive ELISA method. The polysaccharide fractions extracted with sodium hydroxide solutions had the reactivities but not those extracted with cold and hot water. These facts suggested that the similar structure of polysaccharides to P-1 was present in the flesh of P. mume and the kernels of apricot and peach. However, neither pectin of apple nor citrus had reactivity with each antiserum. P-1 would be different in chemical structure from a commercially available pectin, a water-soluble polysaccharide from apple and citrus.

Effects of murine lysozyme on lipopolysaccharide-induced biological activities

We have demonstrated that egg-white lysozyme (EW-LZM) bound to lipopolysaccharide (LPS), reduced the lethal toxicity and the biological activity of LPS. In this study, the interaction of LPS with murine lysozyme (M-LZM) and the modulation of biological activities were investigated. M-LZM was prepared from the culture supernatant of the murine macrophage cell line RAW264.7 by ion-exchange and gel filtration chromatographies and dialysis. Two types of M-LZM, murine M lysozyme (MM-LZM) and murine P lysozyme (MP-LZM), were purified from the supernatant. The enzymatic activities of both MM-LZM and MP-LZM were inhibited by LPS and their effects were affected by the temperature and the ionic strength. TNF-alpha production from RAW264.7 by LPS was inhibited by mixing with MM-LZM and MP-LZM. MP-LZM inhibited TNF-alpha production stronger than MM-LZM. Considering these facts, we suggested that M-LZM, like EW-LZM, make a complex with LPS to reduce the toxicity of LPS together with inhibiting the enzymatic activity.