CDCP1 on Dendritic Cells Contributes to the Development of a Model of Kawasaki Disease.

The etiology and pathology of Kawasaki disease (KD) remain elusive. Cub domain-containing protein 1 (CDCP1), a cell-surface protein that confers poor prognosis of patients with certain solid tumors, was recently identified as one of the most significantly upregulated genes in SARS-CoV-2-infected children who developed systemic vasculitis, a hallmark of KD. However, a potential role of CDCP1 in KD has not previously been explored. In this study, we found that CDCP1 knockout (KO) mice exhibited attenuated coronary and aortic vasculitis and decreased serum Candida albicans water-soluble fraction (CAWS)-specific IgM/IgG2a and IL-6 concentrations compared with wild-type mice in an established model of KD induced by CAWS administration. CDCP1 expression was not detectable in cardiomyocytes, cardio fibroblasts, or coronary endothelium, but constitutive expression of CDCP1 was observed on dendritic cells (DCs) and was upregulated by CAWS stimulation. CAWS-induced IL-6 production was significantly reduced in CDCP1 KO DCs, in association with impaired Syk-MAPK signaling pathway activation. These novel findings suggest that CDCP1 might regulate KD development by modulating IL-6 production from DCs via the Syk-MAPK signaling pathway.

Coronary Vasculitis Induced in Mice by the Cell Wall Mannoprotein of Candida krusei.

Kawasaki disease (KD) is an inflammatory disease that was identified by Professor Tomisaku Kawasaki in 1961. Candida albicans-derived substances, such as the hot water extract of C. albicans (CADS) and Candida water-soluble fraction (CAWS), induced coronary vasculitis similar to KD in mice. An increasing proportion of deep-seated candidiasis cases are caused by non-albicans Candida and are often resistant to antifungal drugs. We herein investigated whether the hot water extract of C. krusei, inherently resistant to fluconazole, induces vasculitis in mice. Three strains of C. krusei, NBRC1395, NBRC1162, and NBRC10737, were cultured in natural (Y) and chemically defined (C) media and cell wall mannoprotein (MN) fractions were prepared by autoclaving cells (CKY1395MN, CKC1395MN, CKY1162MN, CKC1162MN, CKY10737MN, and CKC10737MN). All MN fractions reacted strongly with Concanavalin A (Con A) and dectin-2 and induced anaphylactoid shock in ICR mice. MNs induced severe coronary vasculitis in DBA/2 mice, resulting in cardiac hypertrophy. MNs also induced coronary vasculitis in C57Bl/6 mice. These results suggest that the MNs of non-albicans Candida, such as C. krusei, induce similar toxicity to those of C. albicans.

A sphingosine 1-phosphate receptor agonist ameliorates animal model of vasculitis.

OBJECTIVES: Sphingosine 1-phosphate (S1P) is a bioactive lipid that binds to cell surface receptors (S1P1-5). In this study, we examined the effect of S1P1 agonist, ONO-W061, on murine Candida albicans water-soluble fraction (CAWS)-induced vasculitis. METHODS: Mice were administered ONO-W061, and the number of peripheral blood cells was counted. Vasculitis was induced by an intraperitoneal injection of CAWS. Expression of S1P receptors and CXCL1 was analyzed by quantitative RT-PCR. ONO-W061 was orally administered, and vasculitis was evaluated histologically. Number of neutrophils, macrophages and T cells in the vasculitis tissue was counted using flow cytometry. Production of chemokines from S1P-stimulated human umbilical vein endothelial cells (HUVECs) was measured by ELISA. RESULTS: Number of peripheral blood lymphocytes was decreased by ONO-W061. Expression of CXCL1 and S1P1 was enhanced in CAWS-induced vasculitis tissue. Vasculitis score, CXCL1 and number of neutrophils in the vasculitis tissue were lower in ONO-W061-treated mice. Treatment of HUVECs with S1P upregulated the production of CXCL1 and IL-8 in vitro, and this was inhibited by ONO-W061. CONCLUSIONS: ONO-W061 significantly improved CAWS-induced vasculitis. This effect may be partly exerted through the inhibited production of chemokines by endothelial cells, which in turn could induce neutrophil recruitment into inflamed vessels.

Am80, a retinoic acid receptor agonist, ameliorates murine vasculitis through the suppression of neutrophil migration and activation.

OBJECTIVE: Vasculitis is characterized by leukocyte infiltration in the vessel walls, with destructive damage to mural structures. Retinoids are compounds that bind to retinoic acid receptors and exert biologic activities similar to those of vitamin A, including modulatory effects on cell proliferation and differentiation. This study was undertaken to examine the therapeutic effects of a synthetic retinoid, Am80, in a murine model of vasculitis induced by Candida albicans water-soluble fraction (CAWS). METHODS: Vasculitis was induced in BALB/c mice by intraperitoneal injection of CAWS. Neutrophils were depleted by injection of antineutrophil antibody-positive serum. Am80 was administered orally once daily. Vasculitis was evaluated histologically. Migration of labeled adoptively transferred cells was quantified. Chemotaxis was assessed by cell mobility analysis. Production of reactive oxygen species (ROS) and phosphorylation of MAPKs were measured by flow cytometry. Concentrations of elastase were measured by enzyme-linked immunosorbent assay. RESULTS: Administration of CAWS induced vasculitis in the coronary arteries and aortic root, with abundant neutrophil infiltration. Depletion of neutrophils reduced CAWS-induced vasculitis. Treatment with Am80 led to a significant attenuation of the vasculitis score and inhibition of the migration of transferred neutrophils into the site of vasculitis. In vitro, Am80 suppressed fMLP-induced chemotaxis of human peripheral blood neutrophils. ROS production and elastase release by stimulated neutrophils were reduced by AM80 treatment, and Am80 also inhibited phosphorylation of ERK-1/2 and p38 in neutrophils stimulated with fMLP plus lipopolysaccharide. CONCLUSION: Am80 significantly suppressed CAWS-induced vasculitis. This effect was presumably exerted via inhibition of neutrophil migration and activation.

Analysis of the titer and reactivity of antibody/ies against fungal cell wall ß-glucans in human sera.

The aim of this work was to characterize an antibody response to ß-glucan (BG), a major component of the fungal cell wall, at each isotype in human sera. The titer and reactivity of the anti-human BG antibody were examined using enzyme-linked immunosorbant assay plates coated with Candida soluble cell wall ß-glucan as a standard antigen. The antibody was detected using anti-human immunoglobulin (Ig) G, IgM, and IgA. Its major class was IgG in all subjects. The antibody titer varied significantly. The anti-BG antibody showed greater reactivity to ß-glucans derived from pathogenic fungi than monoglycosyl-branched ß-glucans derived from mycelia culture medium. In addition, it was suggested that the anti-BG IgM antibody was bound relatively strongly to the ß1,3-glucan backbone and the anti-BG IgG antibody to ß1,6-glucan. The anti-BG antibody plays a variety of roles, according to class, in the host's response to fungi. We propose a new index of human response to ß-glucan that effects the understanding of the response to ß-glucan in humans.

Effect of Agaricus brasiliensis-derived cold water extract on Toll-like receptor 2-dependent cytokine production in vitro.

Agaricus brasiliensis (Agaricus blazei Murrill) is well known as a medicinal mushroom. Fruit body of A. brasiliensis is rich in ß-glucan and has shown benefits for various diseases. Both hot and cold water extraction are traditional methods for intake of this mushroom extract. In the present study, we prepared cold water extract of the fruit body of A. brasiliensis (ACWS). The 1,3-ß-glucan segment of this fraction was too small and did not interact with the 1,3-ß-glucan receptor, dectin-1. However, ACWS could induce production of various cytokines including IL-6 from murine splenocytes. Therefore, we aimed to identify the receptor that modulates IL-6 production using ACWS. We focused our attention on Toll-like receptors (TLRs) and examined them as follows. (i) The interaction between TLRs and ACWS was screened using HEK293 cells transfected with TLR plasmid. (ii) IL-6 production from splenocytes induced by ACWS was inhibited by treatment of anti-TLR antibodies. (iii) Direct binding activity between TLR protein and ACWS was assessed by ELISA-like assay. ACWS was found to activate HEK293 cells via TLR2, 4 and 5. However, only anti-TLR2 monoclonal antibody suppressed IL-6 production from splenocytes. In addition, ACWS has the ability to bind directly to TLR2 protein. Accordingly, we suggest that fruit body of A. brasiliensis has some water-soluble TLR ligand complexes, and TLR2 on splenocytes strongly induces IL-6 production.

Disruption of actin cytoskeleton enhanced cytokine synthesis of splenocytes stimulated with beta-glucan from the cauliflower medicinal mushroom, Sparassis crispa Wulf.:Fr. (higher Basidiomycetes) in vitro.

Beta-glucan (BG) is a representative pathogen-associated molecular pattern (PAMP) produced by pathogenic fungi. SCG is a BG obtained from Sparassis crispa, which stimulates splenocytes in DBA/2 mice to produce cytokines, such as GM-CSF, IFN-γ, and TNF-α. In the present study, we analyzed the molecular mechanism of SCG-mediated cytokine synthesis using cytocharasin D (CytD), an inhibitor of actin polymerization. It was found that GM-CSF and TNF-α synthesis of splenocytes stimulated with SCG, but not with lipopolysaccharide, was significantly enhanced in the presence of CytD. CRDO, partially hydrolyzed linear 1,3-BG curdlan, stimulated splenocytes of DBA/2 mice slightly to produce cytokines. CRDO, acting as an antagonist in the presence of SCG, changed to a strong agonist in the presence of CytD. CytD also enhanced cytokine synthesis of bone marrow-derived dendritic cells. Taken together, cytokine productivity of BG was significantly dependent on molecular weight, and CytD treatment is useful to enhance the sensitivity for analyzing the immunostimulating activity of BG in vitro.

Effect of Sasa veitchii extract on immunostimulating activity of ß-glucan (SCG) from culinary-medicinal mushroom Sparassis crispa Wulf.:Fr. (higher Basidiomycetes).

Fungal ß-glucan is a representative pathogen-associated microbial pattern (PAMP) from mushroom, yeast, and fungi, and stimulates innate as well as acquired immune systems. It is a widely used functional food to enhance immunity. Such plant extracts have been known as folk medicines and reported to show various biological activities beneficial to human health, such as anti-tumor, anti-allergic, and anti-inflammatory activities. In the present study, the cooperative effect of bamboo water-soluble methanol precipitation (BWMP), a macromolecular fraction of the hot-water extract of Sasa veitchii (Japanese folk medicine Kumazasa), and the ß-glucan from the medicinal mushroom Sparassis crispa (SCG) was analyzed in vitro using DBA/2 mice. The splenocytes from male DBA/2 mice were cultured with BWMP in the presence of SCG, and the responses were assessed by measuring cytokines. BWMP suppressed IFN-γ and GM-CSF production by SCG, but not TNF-α production. To analyze the specificity of the reaction, similar experiments were conducted with BWMP in the presence of bacterial lipopolysaccharide (LPS); however, none of the cytokines were inhibited. Cytokine production of splenocytes by SCG was suggested to be largely dependent on the binding of lymphocytes with dendritic cells. Functions of BWMP were also analyzed by mixed lymphocyte reaction, and IFN-γ production was suppressed. These findings suggested that BWMP modulated the cell-to-cell contact induced by SCG and inhibited cytokine production. It is strongly suggested that the plant extracts modulate the immunostimulating effects of medicinal mushrooms. Cooperative effects of plants and mushrooms would be an important issue for functional foods.

Beneficial effects of anti-apolipoprotein A-2 on an animal model for coronary arteritis in Kawasaki disease.

BACKGROUND: Kawasaki disease (KD) is usually treated with high-dose intravenous immunoglobulin (IVIg) as severe infectious and other diseases. Due to issues that are associated with immunoglobulin preparation, such as the risk of possible contamination by infectious agents and limited blood banking resources, recombinant immunoglobulins are required. We developed a novel recombinant antibody drug candidate, "VasSF," based on the therapeutic effects it exerted on a mouse spontaneous crescentic glomerulonephritis model (SCG/Kj). Apolipoprotein A-2 (ApoA2) has been identified as one of VasSF's target molecules. METHODS: Here, we tested the potential of anti-apolipoprotein A-2 antibodies (anti-ApoA2) as a new therapeutic drug against KD by examining its effect on a mouse model, in which KD was induced via Candida albicans water-soluble fraction (CAWS). CAWS (2 mg/mouse) was injected intraperitoneally into C57BL/6NCrSlc mice for five consecutive days. The incidence and histological severity of vasculitis in CAWS-induced coronary arteritis in mice administered anti-ApoA2 was examined. The following experimental groups were tested: solvent (only PBS (-) injection); anti-ApoA2 antibodies at dosages of 0.05 mg, 0.1 mg, and 0.5 mg/kg/day; human IgG at 0.1 mg/kg/day. RESULTS: The group treated with anti-ApoA2 0.5 mg/kg/day showed a lower incidence of panvasculitis induced by CAWS, less inflammation of the coronary arteries and aortic roots, and lower levels of serum IL-6, M-CSF, and MIP-1α and 32 cytokines/chemokines compared with those in the solvent group. CONCLUSIONS: The anti-ApoA2 treatment suppressed the development of coronary arteritis in an animal KD model and anti-ApoA2 shows potential as an effective therapeutic candidate for the treatment of KD vasculitis. The use of specific antibodies that display higher vasculitis-suppressing effects, such as anti-ApoA2, may attenuate KD as well as other infectious diseases, with less severe adverse side effects than treatment with IVIg.

IL-10 is a negative regulatory factor of CAWS-vasculitis in CBA/J mice as assessed by comparison with Bruton's tyrosine kinase-deficient CBA/N mice.

Candida albicans water-soluble fraction (CAWS), a mannoprotein-beta-glucan complex obtained from the culture supernatant of C. albicans NBRC1385, exhibits vasculitis-inducing activity (CAWS-vasculitis) in mice. The sensitivity to CAWS-vasculitis varies greatly among mouse strains. This study examined the factors contributing to or inhibiting CAWS-vasculitis using CAWS-vasculitis-resistant CBA/J mice and Bruton's tyrosine kinase-deficient CBA/N mice, which is a CAWS-vasculitis-sensitive strain that has the same origin as CBA/J mice. After stimulation with various kinds of pathogen-associated molecular patterns, the production of inflammatory cytokines IL-6 and IFN-gamma was induced in CBA/N mice, whereas that of immunosuppressive IL-10 was induced in CAWS-vasculitis-resistant CBA/J mice. Furthermore, the production of tissue inhibitor of metalloproteinase 1, an endogenous matrix metalloproteinase inhibitor, was observed in CBA/J mice. The results strongly suggest that the difference in the production of these cytokines is closely linked to the development of CAWS-vasculitis.

Characterization of blood beta-1,3-glucan and anti-beta-glucan antibody in hemodialysis patients using culinary-medicinal Royal Sun Agaricus, Agaricus brasiliensis S. Wasser et al. (Agaricomycetideae).

Beta-glucan is a major component of fungal cell walls and shows various immunopharmacological activities including antitumor activity. Previously, we detected anti-beta-glucan antibody in human sera. Anti-beta-glucan antibody participates in the immune response to fungal cell wall beta-glucan. Patients on dialysis are at high risk of infection including fungal infections. We examined the plasma beta-glucan level and the titer of anti-beta-glucan antibody in dialysis patients. We measured plasma beta-1,3-glucan concentrations with the limulus G test and anti-beta-glucan antibody titers by ELISA with Candida beta-glucan-coated plates. We also examined the influence of the period of dialysis and the kind of dialysis membrane. The patients were positive for beta-1,3-glucan in their plasma. The anti-beta-glucan antibody titer was lower in the dialysis patients than in healthy volunteers. Long-term dialysis patients showed lower anti-beta-glucan antibody titers than short-term dialysis patients. No significant difference was found between the kinds of dialysis membrane. The titer of anti-beta-glucan antibody as recognition molecule of beta-glucan was low in dialysis patients compared with healthy volunteers. This is likely to be one factor explaining the sensitivity to infection of the dialysis patients. An appropriate application of culinary-medicinal mushroom such as Agaricus brasiliensis has potential for the prevention of fungal infection in dialysis patients.

Administration of human immunoglobulin suppresses development of murine systemic vasculitis induced with Candida albicans water-soluble fraction: an animal model of Kawasaki disease.

We investigated the inhibitory effect of human immunoglobulin (h-Ig) on the development of coronary arteritis in a murine model of vasculitis induced with a Candida albicans water-soluble fraction (CAWS). CAWS was intraperitoneally injected to C57BL/6 mice for 5 days. Then h-Ig was administered according to various schedules. The animals were sacrificed in week 5, and the status of vasculitis in the coronary arteries and the aortic root was investigated histologically. The groups in which h-Ig was administered for 5 days from day 3 and from day 5 of the experiment showed a significant reduction in the incidence of panvasculitis. In addition, the scope and severity of the inflammation of the aortic root and the coronary arteries were reduced in both groups. In the group administered h-Ig for 5 days from day 1 and the group administered a high dose of h-Ig once on day 1 or day 3, no suppression of development of vasculitis was observed. The h-Ig acted by suppressing the generation and progression of vasculitis in this CAWS-induced murine vasculitis model.

Coronary Vasculitis Induced in Mice by Cell Wall Mannoprotein Fractions of Clinically Isolated Candida Species.

Kawasaki disease (KD) is an inflammatory disease that was identified by Professor Tomisaku Kawasaki in 1961. Candida albicans-derived substances (CADS) such as the hot water extract of C. albicans and Candida water-soluble fractions (CAWS) induce coronary vasculitis similar to KD in mice. An increasing proportion of deep-seated candidiasis cases are caused by non-albicans Candida and are often resistant to antifungal drugs. We herein investigated whether the mannoprotein fractions (MN fractions) of clinically isolated Candida species induce vasculitis in mice. We prepared MN fractions from 26 strains of Candida species by conventional hot water extraction and compared vasculitis in DBA/2 mice. The results obtained revealed that the induction of vasculitis and resulting heart failure were significantly dependent on the species; namely, death rates on day 200 were as follows: Candida krusei (100%), Candida albicans (84%), Candida dubliniensis (47%), Candida parapsilosis (44%), Candida glabrata (32%), Candida guilliermondii (20%), and Candida tropicalis (20%). Even for C. albicans, some strains did not induce vasculitis. The present results suggest that MN-induced vasculitis is strongly dependent on the species and strains of Candida, and also that the MN fractions of some non-albicans Candida induce similar toxicity to those of C. albicans.

Abrogation of lysophosphatidic acid receptor 1 ameliorates murine vasculitis.

BACKGROUND: Lysophosphatidic acid (LPA), generated by autotaxin (ATX), is a bioactive lipid mediator that binds to the receptors (LPA1-6), and serves as an important mediator in inflammation. Previous studies have demonstrated that LPA-LPA1 cascade contributes to arthritis and skin sclerosis. In this study, we examined the role of LPA signals in murine Candida albicans water-soluble fraction (CAWS)-induced vasculitis. METHODS: ATX and LPA receptor expressions were analyzed by immunohistochemistry and quantitative reverse transcription-polymerase chain reaction. Effects of LPA1 inhibition on CAWS-induced vasculitis were evaluated in LPA1-deficient mice or using an LPA1 antagonist, LA-01. Migration activity was assessed using a chemotaxis chamber. The number of migrated fluorescently labeled neutrophils, which were transferred into the vasculitis mice, was counted in the aortic wall. CXCL1 and IL-8 concentrations were determined by enzyme-linked immunosorbent assay. RESULTS: ATX and LPA1 were highly expressed in the inflamed region of CAWS-induced vasculitis. Severity of the vasculitis in LPA1-deficient mice was suppressed. The LPA1 antagonist, LA-01, also ameliorated the CAWS-induced vasculitis. LPA induced neutrophil migration, which was inhibited by LA-01 in vitro. Infiltration of transferred neutrophils from LPA1-deficient mice into the coronary arteries was suppressed. LA-01 also inhibited the infiltration of wild-type neutrophils. Expression of CXCL1 and IL-8 in human endothelial cells was enhanced by LPA, but was inhibited by LA-01. ATX and LPA1 expression levels were higher in the affected skin region of vasculitis patients than in healthy controls. CONCLUSIONS: These results suggest that LPA-LPA1 signaling contributes to the development of vasculitis via chemoattractant production from endothelial cells followed by neutrophil recruitment. Thus, LPA1 has potential as a novel target for vasculitis therapies.

Dectin-2-induced CCL2 production in tissue-resident macrophages ignites cardiac arteritis.

Environmental triggers, including those from pathogens, are thought to play an important role in triggering autoimmune diseases, such as vasculitis, in genetically susceptible individuals. The mechanism by which activation of the innate immune system contributes to vessel-specific autoimmunity in vasculitis is not known. Systemic administration of Candida albicans water-soluble extract (CAWS) induces vasculitis in the aortic root and coronary arteries of mice that mimics human Kawasaki disease. We found that Dectin-2 signaling in macrophages resident in the aortic root of the heart induced early CCL2 production and the initial recruitment of CCR2+ inflammatory monocytes (iMo) into the aortic root and coronary arteries. iMo differentiated into monocyte-derived dendritic cells (Mo-DC) in the vessel wall and were induced to release IL-1ß in a Dectin-2-Syk-NLRP3 inflammasome dependent pathway. IL-1ß then activated cardiac endothelial cells to express CXCL1 and CCL2 and adhesion molecules that induced neutrophil and further iMo recruitment and accumulation in the aortic root and coronary arteries. Our findings demonstrate that Dectin-2-mediated induction of CCL2 production by macrophages resident in the aortic root and coronary arteries initiates vascular inflammation in a model of Kawasaki disease, suggesting an important role for the innate immune system in initiating vasculitis.

[Preparation and Biological Characterization of Limulus Factor G-activating Substance of Aspergillus spp.]

Aspergillus is a medically important fungal genus that causes a life-threatening infection known as aspergillosis in immunocompromised patients. ß-1,3-Glucan is detected in the plasma of patients with aspergillosis and appears to be useful for the diagnosis of aspergillosis. In this study, we cultured Aspergillus spp. in a chemically defined liquid medium and prepared an Aspergillus water-soluble fraction (ASWS) from the culture supernatants. ASWS was found to be primarily composed of polysaccharides and proteins. Nuclear magnetic resonance analysis suggested that ASWS is a complex carbohydrate, consisting of α-1,3-glucan, ß-1,3-glucan, galactomannan, and protein. The ASWS from Aspergillus fumigatus showed limulus factor G activity, whereas zymolyase-treated ASWS did not. ASWS was eliminated from the blood more rapidly than Aspergillus solubilized cell wall ß-glucan. We analyzed the reactivity of human immunoglobulin towards ASWS by an enzyme-linked immunosorbent assay. Anti-ASWS antibodies were detected in human sera, with titers differing among individuals. This study demonstrated that the ASWS corresponds to the limulus factor G-activating substance found in the blood of patients with aspergillosis.

Cell to cell contact through ICAM-1-LFA-1 and TNF-alpha synergistically contributes to GM-CSF and subsequent cytokine synthesis in DBA/2 mice induced by 1,3-beta-D-Glucan SCG.

SCG is a major 6-branched 1,3-beta-D-glucan in Sparassis crispa Fr. showing antitumor activity. We recently found that the splenocytes from naive DBA/1 and DBA/2 mice are potently induced by SCG to produce interferon- gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin-12p70 (IL-12p70), and that GM-CSF plays a key biologic role among these cytokines. In this study, we investigated the contribution of cell-cell contact and soluble factors to cytokine induction by SCG in DBA/2 mice. Cell-cell contact involving intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) was an essential step for the induction of GM-CSF and IFN-gamma by SCG but not for the induction of TNF-alpha or IL-12p70 by SCG. SCG directly induced adherent splenocytes to produce TNF-alpha and IL-12p70. GM-CSF was required for the induction of TNF-alpha by SCG, and in turn, TNF-alpha enhanced the release of GM-CSF and thereby augmented the induction of IL-12p70 and IFN-gamma by SCG. Neutralization of IL-12 significantly inhibited the induction of IFN-gamma by SCG. We concluded that induction of GM-CSF production by SCG was mediated through ICAM-1 and LFA-1 interaction, GM-CSF subsequently contributed to further cytokine induction by SCG, and reciprocal actions of the cytokines were essential for enhancement of the overall response to SCG in DBA/2 mice.

Immunochemical Cross-Reactivity of ß-Glucan in the Medicinal Plant, Sasa veitchii (Japanese Folk Medicine Kumazasa), and Medicinal Mushrooms.

Fungal ß-glucan is a representative pathogen-associated molecular pattern from mushroom, yeast, and fungi and stimulates innate as well as acquired immune systems. This ß-glucan is widely applied in functional food to enhance immunity. Humans and animals generally become sensitized to this ß-glucan and gradually produce specific antibodies to ß-glucans. The extracts of plants have been used as folk medicine and are reported to possess various biological activities that are beneficial for human health, such as antitumor, antiallergic, and anti-inflammatory activities. In the present study, the immunochemical cross-reactivity of Sasa extract and fungal ß-glucan was analyzed. We found that the anti-ß-glucan antibody in human sera strongly cross-reacted with the Sasa extract. This result strongly suggested that plant extracts modulate the immunostimulating effects of medicinal mushrooms. The cooperative effects of plants and mushrooms may be an important issue for functional foods.

Role of anti-beta-glucan antibody in host defense against fungi.

We have recently detected an anti-beta-glucan antibody in normal human and normal mouse sera. The anti-beta-glucan antibody showed reactivity to pathogenic fungal Aspergillus and Candida cell wall glucan. Anti-beta-glucan antibody could bind whole Candida cells. It also enhanced the candidacidal activity of macrophages in vitro. The anti-beta-glucan antibody titer of DBA/2 mice intravenously administered either Candida or Aspergillus solubilized cell wall beta-glucan decreased remarkably dependent on dose. Moreover, in deep mycosis patients, the anti-beta-glucan antibody titer decreased, and this change correlated with clinical symptoms and other parameters such as C-reactive protein. It was suggested that the anti-beta-glucan antibody formed an antigen-antibody complex and participated in the immune response as a molecule recognizing pathogenic fungi.

Specificity of the Immunomodulating Activity of Sasa veitchii (Japanese Folk Medicine Kumazasa) to Fungal Polysaccharides.

Many plant extracts are used as well-known folk medicines and exhibit various biological activities that are beneficial to human health. These extracts contain polysaccharides, and some are pathogen-associated molecular patterns (PAMPs) that stimulate innate as well as acquired immune systems. In the present study, the cooperative effects of PAMPs and bamboo water-soluble methanol precipitation (BWMP) in a macromolecular fraction of the hot water extract of Sasa veitchii (in Japanese folk medicine, known as Kumazasa; family Poaceae) were analyzed in vitro using the spleen or bone marrow cells of mice. The splenocytes of male DBA/2 and C57BL/6 mice were cultured with BWMP in the presence or absence of PAMPs, and responses were assessed by measuring cytokines. BWMP inhibited the production of interferon gamma (IFN-γ) by not only toll like receptors (TLRs), but also the C-type lectin receptors (CLRs) dectin-1 and dectin-2. BWMP also inhibited the autologous production of IFN-γ in the splenocyte culture. These results suggested that BWMP may inhibit the signaling pathways of PAMPs, but not ligand-receptor interactions. In contrast, BWMP did not inhibit the production of cytokines by dendritic cells. These results indicated that the inhibition of IFN-γ by BWMP was mediated through the cell-to-cell interactions of splenic cells during cultivation.