Relationship between the tissue distribution and antitumor activity of highly branched (1-->3)-beta-D-glucan, SSG

Distribution of 3H-labeled (1-->3)-beta-D-glucan([3H]SSG) obtained from the culture filtrate of Sclerotinia sclerotiorum IFO 9395, in various tissues in tumor-bearing mice was examined. [3H]SSG administered intra-peritoneally was mainly detected in liver, spleen, kidney and tumor masses. In contrast to i.p. administration, intra-lesionally administered [3H]SSG was not released from the tumor. Similarly, in a double grafted tumor system, [3H]SSG was located in the administered tumor and not distributed in the distant site tumor, in spite of the fact that significant antitumor effect was shown in both tumor sites in this system. Winn assay confirmed the activation of the systemic antitumor immunity. These results suggested that the distribution of glucans would be one important factor in determining their antitumor effects. However, this would not always be necessary if systemic immunity could be induced.

Expression of interleukin 1 family mRNAs by a highly branched (1-->3)-beta-D-glucan, OL-2

OL-2, a highly branched (1-->3)-beta-D-glucan, is an antitumor glucan showing strong hematopoietic activity with weaker adjuvant activity than schizophyllan (SPG), also an antitumor glucan and one which is clinically used. This paper deals with the gene expression of the interleukin 1 (IL-1) family in mice by OL-2 and SPG in order to characterize the immunopharmacological activity. Gene expression was examined by reverse transcriptase-polymerase chain reaction method. Intraperitoneal administration of OL-2 (250 micrograms/mouse) expressed all three genes of IL-1 alpha, beta, and IL-1 receptor antagonist (IL-1ra) in the peritoneal exudate cells, while SPG induced a strength of IL-1 alpha mRNA comparable to that by OL-2 but a weaker level of IL-1 beta mRNA. SPG did not induce IL-1ra. Similar patterns were seen in spleen and liver by OL-2 or SPG administration. These findings suggest that the immunopharmacological characteristics of (1-->3)-beta-D-glucan are regulated under the gene expression of the IL-1 family.

Application of limulus test (G pathway) for the detection of different conformers of (1-->3)-beta-D-glucans

The reactivity of factor G mediated coagulation pathway in limulus amebocyte lysate which is triggered by (1-->3)-beta-D-glucans is thought to depend on the structure of the glucans, especially on the ultrastructure: triple helix, single helix and random coil. We used Sonifilan (SPG) and grifolan (GRN) as parent compounds to compare the reactivities of these three conformers. Under a neutral condition, alkaline treated SPG (SPG-OH, single helix) and polycarboxylated SPG (PC-SPG, random coil) showed significantly stronger reactivity than untreated SPG (triple helix). After the alkaline treatment, all three conformers showed comparable reactivities. It is suggested that the pretreatment of the glucan preparations by sodium hydroxide is quite important to compare quantitatively the reactivity of the glucans by limulus test, and comparing the data of untreated and alkaline treated glucans would provide information about their conformations. Using this approach, it was found that after heat treatment at around 150 degrees C, the conformation of GRN was changed to rich in the triple helix, and that following sodium hydroxide treatment and dialysis of GRN, the conformation of GRN was changed to single helix rich conformer. About half of the single helix conformer was gradually changed to triple helix conformer over one week at 4 degrees C.

Inhibitory effect of beta-glucans on zymosan-mediated hydrogen peroxide production by murine peritoneal macrophages in vitro

Effects of the pretreatment of murine peritoneal macrophages with several polysaccharides on the production of H2O2 induced with unopsonized zymosan were examined. Pretreatment with most of (1-->3)-beta-D-glucans for 6 h at 37 degrees C inhibited the zymosan-mediated H2O2 production by macrophages. The phorbol myristate acetate (PMA)-mediated H2O2 production was not affected by the pretreatment. The pretreatment of macrophages with (1-->3)-beta-D-glucans decreased the ability to ingest unopsonized zymosan, but did not affect the ingestion of IgG-coated sheep red blood cells (IgG-SRBC). These results suggested that the pretreatment with (1-->3)-beta-D-glucans interfered with the interaction of macrophages to zymosan and that the occupation of the receptor for the (1-->3)-beta-D-glucans inhibited zymosan-mediated production of H2O2 by macrophages. Chemical modification by substitution with carboxymethyl groups or hydroxyethyl groups of a (1-->6)-branched (1-->3)-beta-D-glucan reduced the inhibitory effect of pretreatment on zymosan-mediated H2O2 production. The above results indicated the possibility that murine peritoneal macrophages possess certain receptors for beta-anomeric glucans, and one ligand specificity of the receptors is to restrict the intact (1-->3)-beta-D-glucosyl back bone.

Immunopharmacological characterization of a highly branched fungal (1-->3)-beta-D-glucan, OL-2, isolated from Omphalia lapidescens

The immunopharmacological activities of a fungal (1-->3)-beta-D-glucan, OL-2, isolated from "Leiwan" Omphalia lapidescens were examined. Intraperitoneal (i.p.) administration of OL-2 to ICR mice induced a significant number of peritoneal exudate cells (PEC) and white blood cells over the period of a few days. Spleen cell numbers were also increased by i.p. administration of OL-2 at about a week. These changes reverted to the normal level within a month. Responses of spleen cells and bone marrow cells (BM) to colony stimulating factors (CSF) were augmented by OL-2 administration assessed by cell proliferation assay. Sera from OL-2 administered mice contained an increased concentration of colony stimulating activity. Gene expressions of interleukin-1 beta, interleukin-6, and tumor necrosis factor alpha in the spleen were also increased. These results suggested the activation of hematopoietic responses, and would well relate to the incremental increase in PEC, white blood cell and spleen cell numbers. OL-2 also increased the serum concentration of fibronectin and complement component C-3. However, OL-2 did not show adjuvant activity to SRBC and antitumor activity against the solid form of Sarcoma 180 by i.p. administration. Yet, OL-2 did not interfere with the antitumor activity of SSG against the same tumor system. These facts suggested that OL-2 could enhance nonspecific host defense mechanisms by enhancing hematopoietic responses, but would not enhance or inhibit the specific immunity mediated by lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum components induce beta-D-glucan-inhibitable uptake of zymosan particles by murine peritoneal macrophages

Effects of murine serum (NMS) treatment on (1-->3)-beta-D-glucan inhibitable uptake of zymosan particles (ZYM) (GIZUP) by murine peritoneal macrophages (PM) and the structural specificity of the inhibition were examined. ZYM uptake by PM treated with NMS was enhanced in comparison with those treated with medium, and in a concentration- and incubation time-dependent manner. The enhanced ZYM uptake was significantly reduced by the pretreatment of PM with soluble (1-->3)-beta-D-glucans. These facts suggest that NMS enhances GIZUP. The effect disappeared by the treatment of NMS with gelatin-Sepharose which removed fibronectin (FN) from the serum, suggesting a significant contribution of FN on GIZUP. In addition, the administration of beta-glucan in vivo elevated the concentration of FN in serum by acute phase response and enhanced GIZUP, suggesting the positive contribution of acute phase responses on beta-glucan mediated immunopharmacological activities. Of particular interest, the inhibition was shown by both antitumor active and inactive glucans. These facts suggested that the recognition of beta-glucans by PM, which would proceed at a relatively early period of whole activation pathways, would not be enough to fully activate the host to show antitumor activity.

Binding of lysozyme to synthetic monosaccharide lipid A analogue, GLA60

Recent studies by our group suggested that lysozyme (LZM) has a high affinity for bacterial lipopolysaccharide (LPS) of both the smooth and rough forms, and inhibits various immunomodulatory activities of LPS. GLA60 is a synthetic monosaccharide analogue of bacterial lipid A, well-known as sharing large part of lipid A activities but with very low toxicity. In this study, we characterized the interaction of LZM with GLA60 in comparison to that with E. coli 0111 LPS (smooth form), taking a physicochemical approach. Using a dansylated lysozyme probe (DNS-LZM), LZM was found to bind to GLA60 in all 3 of its forms, free acid, triethylamine (TEA) salt and bovine serum albumin (BSA) complex of GLA60, as well as natural LPS. Compared with LPS, the complex formation of the TEA salt was weakly dependent on temperature and incubation time. LZM also bound to biologically inactive GLA analogues, GLA 64 and GLA69, at a high affinity, as well as to GLA 60. By using chemically modified LZM, it was found that the ionic as well as hydrophobic interactions are important for the complex formation.

Modification of immunopharmacological activities of synthetic monosaccharide lipid A analogue, GLA60, by lysozyme

Recent studies by our group suggested that lysozyme has a high affinity for bacterial lipopolysaccharide (LPS) of both the smooth and rough forms, and inhibits various immunomodulatory activities of LPS. GLA60 is a synthetic monosaccharide analogue of bacterial lipid A well known as having most of the activities of lipid A with very low toxicity. In this study, we characterized the interaction of lysozyme with GLA60 in comparison to that with Escherichia coli 0111 LPS (smooth form) by means of an immunopharmacological approach. Using dansylated lysozyme (DNS-LZM) as a probe, LZM was found to bind to GLA60. The mitogenic and polyclonal B-cell activating activities were significantly reduced by complex formation. However, there was no inhibitory effect on GLA60 induced production of IL-1 and TNF of macrophages. Interestingly, the activities of macrophages induced by the complex were found to be significantly higher than those induced by GLA60 itself. In contrast, the activities of 0111 LPS were significantly inhibited by LZM. Since the GLA60-LZM complex produced a turbid suspension but the 0111 LPS-LZM complex remained soluble, we consider that the activities of GLA60 alone were mediated by the common functional LPS receptor for dispersed form in both macrophages and B-lymphocytes, but activation of macrophages by the complex was mediated either by another LPS receptor not present in B-lymphocytes or through the phagocytic function of macrophages.

Heat induced conformational changes generate mitogenicity to splenocytes by sclerogen from Sclerotinia sclerotiorum IFO 9395

The fungal mitogen, sclerogen, obtained from sclerotia of Sclerotinia sclerotiorum IFO 9395 showed significant mitogenic activity to murine splenocytes after heat denaturation in relation to polymerization. To evaluate the conditions generating mitogenicity, we performed several chromatographic and spectral analyses. After heat denaturation of sclerogen, significant reduction of intrinsic fluorescence, significant changes on the ultraviolet absorption spectrum, significant changes on the circular dichroism spectrum, and an extreme change of the surface charge to anionic, were observed. These results strongly suggested that local as well as overall conformational changes of sclerogen associated with a high molecular mass and polyanionic charges are important in generating mitogenicity to murine splenocytes.

Physicochemical characteristics and antitumor activities of a highly branched fungal (1----3)-beta-D-glucan, OL-2, isolated from Omphalia lapidescens

Physicochemical properties and antitumor activities of a fungal (1----3)-beta-D-glucan, OL-2, isolated from Leiwan (Omphalia lapidescens) were examined. OL-2 showed sharp signals on carbon-13 nuclear magnetic resonance spectrum in dimethylsulfoxide-d6 as a solvent, and these signals were significantly reduced by the addition of distilled water to the concentration of 20%. This phenomenon is consistent with the general property of the gel forming (1----3)-beta-D-glucan. Binding of OL-2 to Congo red induced a significant change of lambda max to a longer wavelength, and the concentration to induce gel to sol transition was about 0.7 N; in contrast, the concentration was about 0.2 N in the cases of SPG and curdlan. These observations suggested that the gel structure would be significantly stabilized in the case of OL-2. OL-2 showed no or low antitumor activity against the solid form of Sarcoma 180 by intraperitoneal and intralesional administrations; however, it was effective on the ascites form of Sarcoma 180. Of interest, OL-2 also showed significant antitumor activity against the ascites form of MH-134 when administered with 5-fluorouracil. These results indicated that OL-2 showed characteristic features regarding its physicochemical properties and antitumor activity.

Intravenously administered (1----3)-beta-D-glucan, SSG, obtained from Sclerotinia sclerotiorum IFO 9395 augments murine peritoneal macrophage functions in vivo

Effect of intravenously (i.v.) or intraperitoneally (i.p.) administered (1----3)-beta-D-glucan, SSG, obtained from Sclerotinia sclerotiorum IFO 9395 on the murine peritoneal macrophage (PM) functions were examined. A single i.v. administration of SSG increased the number of PMs at a dose of 250 micrograms/mouse, and the peak appeared 4 d after administration. However, no special change was observed on peritoneal exude cell (PEC) populations. These PMs showed augmented lysosomal enzyme activity and the peaks appeared in 2 phases, on days 2 and 10. In contrast, SSG administered i.p. (250 micrograms/mouse) increased the number of PMs and enhanced the lysosomal enzyme activity of PMs from day 4, and a broad peak appeared until days 8--12. The populations of PECs were also changed by i.p. injection of SSG. Additionally, SSG administered i.v. enhanced phagocytic activity, H2O2 production and interleukin 1 (IL-1) production, and the kinetics of the activation differed depending on the activities. These data suggest that the effects of SSG on macrophage functions are different depending on administration routes, and there are some different mechanisms in the activation of macrophages in vivo by SSG.

Tissue distribution of intraperitoneally administered (1-->3)-beta-D-glucan (SSG), a highly branched antitumor glucan, in mice

Distribution of metabolically 3H-labeled (1-->3)-beta-D-glucan (3H-SSG) obtained from the culture filtrate of Sclerotinia sclerotiorum IFO 9395, in various tissues after intraperitoneal administration into ICR mice (250 micrograms/mouse) was examined. 3H-SSG was mainly detected in liver, spleen, and blood, and a negligible amount was excreted into the feces and excrement within 2 d. The significant amount of 3H-SSG remained in liver and spleen after 1 month. On the other hand, SSG was not incorporated effectively in vivo and in vitro by peritoneal exudate macrophages (0.5 microgram/1 x 10(6) M phi) Similarly in vivo, the majority of 3H-SSG distributed in spleen and liver were recovered from the non-cellular fraction and not from splenic macrophage and Kupffer cell fractions. These results suggested that (1-->3)-beta-D-glucans would not be easily incorporated by the host cells to degrade and exclude from the body even after the onset of the biological response modifier activity.

Enhancement of murine alveolar macrophage functions by orally administered beta-glucan

The effect of orally administered SSG, a beta-1,3-glucan obtained from the culture filtrate of the fungus Sclerotinia sclerotiorum IFO 9395, on alveolar macrophage (AM) functions of CDF1 mice was examined. SSG administered orally (20, 40, 80 or 160 mg/kg) for 10 consecutive days enhanced the lysosomal enzyme activity of AM. The greatest enhancing effect was observed at 80 mg/kg of SSG. Multiple oral administrations of SSG (10 consecutive days) were needed to induce significant enhancing effects. Phagocytic activity and interleukin-1 (IL-1) production of AM were also augmented by oral administration of SSG, and the kinetics of the activated state differed depending on the kind of activity. However, H2O2 production of AM was not affected by SSG. Orally administered SSG also (40 or 80 mg/kg, 10 consecutive days) increased the number of AM and the greatest increment was observed 14 days after the first administration. On the other hand, the supernatant of Peyer's patch (PP) cells from mice administered SSG (80 mg/kg) orally stimulated the lysosomal enzyme activity of AM in vitro, and enhanced colony stimulating activity (CSA) was detected from this supernatant. These results demonstrate that SSG given by the oral route can activate murine AM both qualitatively and quantitatively, and it would mediated, at least in part, by the activation of PP cells in the intestine.

Solubilization of limulus test reactive material(s) from Candida cells by murine phagocytes

Solubilization of limulus test reactive materials from Candida was examined in the presence or absence of phagocytic cells. Solubilized limulus test reactive materials (LTRM) were detected in culture supernatant, and hot water and sodium hydroxide extracts of the acetone dried cells of Candida parapsilosis. Suspensions of Candida cells also reacted with limulus test, and LTRM were released from the acetone dried cells by serum treatment. After treatment of the acetone dried cells with polymorphonuclear leucocytes (PMN) or macrophages (M phi), a significant amount of LTRM was solubilized. Significant amounts of LTRM were also released by PMN during treatment of live and growing C. parapsilosis. The reactivity of LTRM was completely inhibited by the addition of excess amount of purified (1----3)-beta-D-glucan, suggesting LTRM from Candida cells as described above would contain (1----3)-beta-D-glucan. These results suggested that LTRM during fungal infection would come from the extracellular water soluble polysaccharide fraction as well as the insoluble cell wall fraction solubilized by the action of phagocytes.

Activation of the complement system by (1----3)-beta-D-glucans having different degrees of branching and different ultrastructures

Activation of the alternative (APC) and classical (CPC) pathways of complement by fungal (1----3)-beta-D-glucans having different degrees of branching (DB) and different conformations were examined by using human serum and plasma. The glucans used in this study were curdlan (no branch; 0/1), grifolan (one branch in every third main chain unit; 1/3), schizophyllan (1/3), SSG (1/2), and OL-2(2/3). Triple or single helix conformer of these glucans were prepared by heating at 150 degrees C or dissolution in sodium hydroxide. Activation of APC by these glucans were dependent on incubation time, concentration, molecular weight, and DB. Interestingly, the triple helix conformer of all glucans tested activated APC stronger than a single helix one. The activity of branched glucans in plasma was weaker than those in serum. On the other hand, in the case of CPC, a single helix conformer activated CPC stronger than a triple helix one, and the activity was dependent on DB. Activation of CPC by a single helix conformer was thought to be dependent on the binding of beta-glucan to immunoglobulin in serum, because the complex was clearly detected by gel permeation chromatography only in the case of single helix one. From these results, it appears that the different conformers were recognized by the host complement systems in different ways. (1----3)-beta-D-Glucan is one of the major constituents of fungal cell wall and is thought to be clearly recognized by the host immune systems.(ABSTRACT TRUNCATED AT 250 WORDS)

Oral administration of a streptococcal agent OK-432 activates alveolar macrophages in mice

The effect of orally administered OK-432, a streptococcal preparation, on the functions of alveolar macrophages in mice was examined. The oral administration of OK-432 (1, 2 or 4 KE, four times every 3 days) augmented phagocytic activity, lysosomal enzyme activity and interleukin 1 (IL-1) production of murine alveolar macrophages recovered 5 days after the final administration while it did not augment H2O2 production. The number of alveolar macrophages was not affected by the same treatment. These results suggested that oral administration of OK-432 activates alveolar macrophages qualitatively to protect the lung from the metastasis of cancer cells and infectious diseases by pathogenic micro-organisms.

Structure and antitumor activity of the less-branched derivatives of an alkali-soluble glucan isolated from Omphalia lapidescens. (Studies on fungal polysaccharide. XXXVIII)

The structure and antitumor activity of Smith-type degradation products (OL-2-I, OL-2-II and OL-2-III) of an alkali-soluble glucan, OL-2, isolated from a crude fungal drug "Leiwan" (Omphalia lapidescens) were investigated. Methylation analysis suggested that OL-2-I was a (1----3)-beta-D-glucan with approximately one branch at every three main chain glucosyl units at each C-6 position; OL-2-II was a (1----3)-beta-D-glucan with approximately one branch at twenty four main chain glucosyl units at each C-6 position (number of all main chain glucosyl units is on average). OL-2-I, OL-2-II and OL-2-III which were Smith-type degradation products of OL-2, showed potent antitumor activity against the solid form of sarcoma 180 in ICR mice. These results indicated that the degree of beta-linked branching at position 6 was remarkably related to the antitumor activity.

Characterization of complex formation between lipopolysaccharide and lysozyme

The binding of lysozyme (LZM) to bacterial lipopolysaccharide (LPS) inhibited the biological activities of LPS as well as the enzymic activity of LZM. The mode of binding has been characterized by using dansylated LZM and enzyme inhibition. The binding of LPS to LZM significantly increased the fluorescence intensity (Fl-intensity) of the danyl group and was found to be time-dependent; the complex was produced gradually and became stabilized within 20 min at 37 degrees, 10 min at 50 degrees, and 1 min at 70 degrees. The maximum level of binding was also dependent on the reaction temperature, and more complex was formed at higher temperatures. Complexation was strongly dependent on the salt concentration and was not observed at greater than 0.5M NaCl. From collected evidence of the Fl-intensities of various dansyl derivatives and amphiphiles, it is concluded that LZM interacts with LPS by multiple binding-modes, the first being strongly related to the enzyme inhibition, the second being close to the Fl-intensity, and the third being dependent on the inhibition of immunopharmacological activities. For the amphiphiles used in this study, sodium dodecyl sulfate (SDS), 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS), 3-[(3-cholamidopropyl)dimethylammonio]-2-hydroxy-propanesulfonate (CHAPSO), decansulfonic acid, and cardiolipin have binding modes similar to that of LPS.

Inhibition of experimental pulmonary metastasis of Lewis lung carcinoma by orally administered beta-glucan in mice

The inhibitory effect on experimental pulmonary metastasis of Lewis lung carcinoma (3LL) of SSG, a (1----3)-beta-D-glucan obtained from the fungus Sclerotinia sclerotiorum IFO 9395, administered orally was examined in mice. Oral administration of SSG for 10 consecutive days just after the intravenous implantation of tumor cells significantly inhibited the experimental pulmonary metastasis of 3LL at a dose of 2000 micrograms. However, SSG administered orally involving other timings was less effective. In comparison with oral administration, SSG was effective when administered intraperitoneally for 10 consecutive days at a dose of 200 micrograms. These results suggest that SSG given by both parenteral and nonparenteral routes is effective in the inhibition of experimental pulmonary metastasis of tumors.

Isolation of mitogenic substance from sclerotia of Sclerotinia sclerotiorum IFO 9395 extracted with phosphate buffer

The buffer extracts (3S) of sclerotia of Sclerotinia sclerotiorum IFO 9395 contained mitogenic substance(s) to murine splenocytes (Shinohara et al. Chem. Pharm. Bull., 38, 2219 (1990)). Although the native 3S was slightly mitogenic, heating of 3S induced significant mitogenic activity. To isolate the mitogen, we separated 3S by ion-exchange and gel filtration chromatographies. The isolated mitogen, named sclerogen, has a molecular mass of 32 kilodaltons (kDa) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the isoelectric point (pI) of 5.9 by chromatofocusing. Sclerogen was significantly mitogenic in vitro against murine splenocytes after heat denaturation, and also showed the augmentation of the primary mixed lymphocyte reaction (MLR) in vitro. However, sclerogen did not show the activation of an alternative pathway of complement and hemagglutination activity. These results suggest that sclerogen is a unique mitogen which differs from lectins and shows mitogenicity after heat denaturation.

Preparation and biological activities of sulfated derivatives of (1----3)-beta-D-glucans

Sulfated derivatives of (1----3)-beta-D-glucans with different degree of branching (DB) i.e., curdlan (linear, DB 0), grifolan (6-O-substituted by beta-D-glucose at every third residue of the main chain, DB 1/3), and SSG (6-O-substituted by beta-D-glucose at every second residue, DB 1/2) having DS value (degree of substitution) lower than 0.6 were prepared. Biological activities [clotting of plasma, alternative pathway of complement (APC), proliferative response of murine spleen cells (mitogenic activity), and activation of murine peritoneal macrophages in vitro] of these derivatives were examined. Clotting of plasma was inhibited by the derivatives having DS above 0.2 APC was inhibited by incubation with derivatives and was strongly dependent on substitution. Inhibition of APC was the most significant in sulfated SSG having DS 0.6 [SSG(3)]. Mitogenic activity was observed by most of the derivatives and the highest activity was shown by SSG(1) (DS 0.2). Macrophage was also activated but SSG(1) would lose the capability to recognize the receptor for (1----3)-beta-D-glucans. From these results, it appears that the biological activities of (1----3)-beta-D-glucans were significantly modulated by sulfation and the effect was dependent on both DS and DB.

Distribution of the mitogenic protein, sclerogen, in extracts from Sclerotinia sclerotiorum IFO 9395 assessed by using immunochemical analysis

Sclerogen is a mitogenic protein isolated from the buffer extracts (3S) from sclerotia and shows significant mitogenic activity after heat denaturation accompanied with conformational changes. Experiments have been carried out to assess the distribution of sclerogen in several extracts from sclerotia and mycelia of this fungus by using the anti-serum against sclerogen. The anti-serum against the native- and heat denatured-sclerogen (anti-sclerogen-M and -MB serum, respectively) were prepared from Japanese white rabbits. These anti-sera showed different cross-reactivity to sclerogen-M and -MB from the results of immunoblotting after normal-polyacrylamide gel electrophoresis (normal-PAGE), suggesting that sclerogen-MB became to have different epitope(s) after heat denaturation of sclerogen-M. The result of immunoblotting after sodium dodecyl sulfate (SDS)-PAGE suggested that these anti-sera also recognized the random coil site(s) where the conformational specificity was not concerned, and that sclerogen (like substance(s] existed not only in mild extracts (e.g. phosphate buffer) but also in fractions extracted from mycelia of S. sclerotiorum IFO 9395. Taken together with the results of the mitogenic activity of the representative extracts from sclerotia, at least two kinds of the mitogenic substances would exist in sclerotia; one would be extracted by mild conditions, and the other would be difficult to extract and require drastic conditions such as hot water extraction.

Oxidative degradation of an antitumor (1-3)-beta-D-glucan, grifolan

A (1-3)-beta-D-glucan, grifolan (GRN), recovered from the peritoneal cavity after 1 d from i.p. injection contained a significant amount of anionic metabolite(s) having lower Mr than the parent GRN. In parallel with this observation, GRN induced peritoneal exudate cells exhibiting a higher level of oxidative burst than the non-stimulated, resident peritoneal cells. Chemical oxidation of GRN by active oxygen species such as (a) ascorbic acid-CuSO4, (b) hydrogen peroxide, (c) hydrogen peroxide-CuSO4, or (d) hypochlorous acid also produced anionic as well as lower Mr degradation products. Under these experimental conditions the structural changes were remarkable and in the order of a less than b less than c less than d. The products formed under the conditions (a) and (b) retained significant antitumor activity but those of (c) and (d) lost the activity. However, oxidation product(s) of curdlan, an antitumor inactive (1-3)-beta-D-glucan having no branch, by condition (d) induced significant antitumor activity. These results suggested that oxidative degradation of (1-3)-beta-D-glucans produced some temporary active metabolites and then gradually changed to the inactive form. However, these active metabolites contribute less than the parent glucan on the whole activation mechanisms of the host by (1-3)-beta-D-glucans.

Oral administration of SSG, a beta-glucan obtained from Sclerotinia sclerotiorum, affects the function of Peyer's patch cells

The effect of orally administered SSG, a beta-1,3-glucan obtained from the culture filtrate of a fungus, Sclerotinia sclerotiorum IFO 9395, on the function of Peyer's patch (PP) cells was investigated in comparison with that on spleen cells in mice. Oral administration of SSG enhanced the proliferative response of PP cells to a T-cell mitogen, concanavalin A (Con A), and a B-cell mitogen, lipopolysaccharide (LPS), although the response of spleen cells was not affected. Peyer's patch cells taken from mice which had received oral administration of SSG two days before, showed enhanced plaque-forming cell (PFC) response to sheep red blood cells (SRBC) after antigen (SRBC) stimulation for 5 days in vitro. These results suggest that oral administration of SSG can modulate the mucosal immune response.

Effect of intraperitoneally administered beta-1,3-glucan, SSG, obtained from Sclerotinia sclerotiorum IFO 9395 on the functions of murine alveolar macrophages

The effect of intraperitoneally (i.p.) administered SSG, a beta-1,3-glucan obtained from the culture filtrate of the fungus Sclerotinia sclerotiorum IFO 9395, on the functions of alveolar macrophages (AM) in CDF1 mice was examined. SSG administered i.p. increased the number of AM and enhanced several functions of murine AM (lysosomal enzyme activity, phagocytic activity, candidacidal activity, H2O2 production and interleukin 1 (IL-1) production) at a dose of 250 micrograms/mouse on days 1 and 8, especially on day 8. Furthermore, SSG (250 micrograms/mouse) administered i.p. for 10 consecutive days significantly inhibited the experimental pulmonary metastasis of Lewis Lung Carcinoma (3LL) on BDF1 mice.