Effect of water-soluble proteoglycan isolated from Agaricus blazei on the maturation of murine bone marrow-derived dendritic cells

Anti-phytopathogenic-bacterial fatty acids from the mycelia of the edible mushroom Agaricus blazei

Five compounds including a new compound (1) were isolated from mycelia of a mushroom-forming fungus Agaricus blazei. Compound 2 was isolated from nature for the first time. Their structures were determined by the interpretation of spectroscopic data. In the bioassay examining growth inhibitory activity against phytopathogenic bacteria Clavibacter michiganensis, Burkholderia glumae, and Peptobacterium carotovorum, all the compounds showed inhibition effects on C. michiganensis. Compounds 3 and 4 also showed weak inhibitory activity against growth of B. glumae.

Antrodia cinnamomea Galactomannan Elicits Immuno-stimulatory Activity Through Toll-like Receptor 4

Antrodia cinnamomea (A. cinnamomea) is a medicinal fungus used in traditional Chinese medicine to treat different kinds of ailments, including liver diseases, abdominal pain, drug intoxication, diarrhea, itchy skin, hypertension, and cancer. Polysaccharides have been identified as one of the major pharmacologically active ingredients present in A. cinnamomea. The present study aims to investigate the immunoenhancing activity of galactomannan isolated from A. cinnamomea. The cold water-soluble polysaccharide (galactomannan-repeated; MW>70 kDa; named ACP) of A. cinnamomea was isolated, and immunostimulatory properties were studied through different immune cell models including mouse macrophages and human dendritic cells. Through Toll-like receptor 4, ACP stimulated tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in J774A.1 mouse macrophages, mouse peritoneal macrophages and human dendritic cells. It was further identified that ACP elicited its immunostimulatory activity through protein kinase C-α (PKC-α) and mitogen activated protein kinases (MAPK) phosphorylation. Furthermore, ACP exerted the endotoxin tolerance-like effect through NF-κB inhibition. These findings demonstrate the potential of A. cinnamomea galactomannan as an immunostimulator or an adjuvant in immunotherapy and vaccination.

Sinulariolide suppresses LPS‑induced phenotypic and functional maturation of dendritic cells

The dendritic cell (DC) maturation process is essential for the development of T cell responses and immune tolerance. Accordingly, DCs are considered a major target in the development of immunomodulating agents. In the present study, the effect of sinulariolide, an active compound isolated from the cultured soft coral Sinularia flexibilis, on lipopolysaccharide (LPS)‑induced murine bone marrow‑derived DCs was evaluated. The different phenotypes, cytokine secretion and the mix‑lymphocyte reaction of DCs were detected using flow cytometry and ELISA. The experimental results revealed that the phenotypic and functional maturation of DCs stimulated by LPS were markedly reduced by sinulariolide in a concentration‑dependent manner, including the expression of co‑stimulatory molecules (CD40, CD80 and CD86). In addition, sinulariolide reduced the release of tumor necrosis factor‑α, interleukin (IL)‑6, IL‑12 and nitric oxide from the LPS‑activated DCs, decreased their abilities to stimulate allogeneic T cell proliferation, and inhibited LPS‑induced nuclear factor‑κB pathways. These findings offer novel insight into the immunopharmacological function of sinulariolide and its effects on DCs.

Physical Interaction of T Cells with Dendritic Cells Is Not Required for the Immunomodulatory Effects of the Edible Mushroom Agaricus subrufescens

Mushrooms are well known for their immunomodulating capacities. However, little is known about how mushroom-stimulated dendritic cells (DCs) affect T cells. Therefore, we investigated the effect of mushroom compounds derived from seven edible mushroom species on DCs, their fate in DCs, and the effect of the mushroom-stimulated DCs on T cells. Each mushroom species stimulated DCs in a different manner as was revealed from the DC’s cytokine response. Assessing DC maturation revealed that only one mushroom species, Agaricus subrufescens, induced complete DC maturation. The other six mushroom species upregulated MHC-II and CD86 expression, but did not significantly affect the expression of CD40 and CD11c. Nevertheless, mushroom compounds of all investigated mushroom species are endocytosed by DCs. Endocytosis is most likely mediated by C-type lectin receptors (CLRs) because CLR binding is Ca²⁺ dependent, and EGTA reduces TNF-α secretion with more than 90%. Laminarin partly inhibited TNF-α secretion indicating that the CLR dectin-1, among other CLRs, is involved in binding mushroom compounds. Stimulated DCs were shown to stimulate T cells; however, physical contact of DCs and T cells is not required. Because CLRs seem to play a prominent role in DC stimulation, mushrooms may function as a carbohydrate containing adjuvant to be used in conjunction with anti-fungal vaccines.

Herbal preparation (HemoHIM) enhanced functional maturation of bone marrow-derived dendritic cells mediated toll-like receptor 4

Background

HemoHIM, which is an herbal preparation of three edible herbs (Angelicam gigas Nakai, Cnidium offinale Makino, and Peaonia japonica Miyabe), is known to have various biological and immunological activities, but the modulatory effects of this preparation on dendritic cells (DCs)-mediated immune responses have not been examined previously. DCs are a unique group of white blood cells that initiate primary immune responses by capturing, processing, and presenting antigens to T cells.

Results

In the present study, we investigated the effect of HemoHIM on the functional and phenotypic maturation of murine bone marrow-derived dendritic cells (BMDCs) both in vitro and in vivo. The expression of co-stimulatory molecules (CD40, CD80, CD86, MHC I, and MHC II) and the production of cytokines (IL-1β, IL-6, IL-12p70, and TNF-α) were increased by HemoHIM in BMDCs. Furthermore, the antigen-uptake ability of BMDCs was decreased by HemoHIM, and the antigen-presenting ability of HemoHIM-treated mature BMDCs increased TLR4-dependent CD4⁺ and CD8⁺ T cell responses.

Conclusions

Our findings demonstrated that HemoHIM induces TLR4-mediated BMDCs functional and phenotypic maturation through in vivo and in vitro. And our study showed the antigen-presenting ability that HemoHIM-treated mature BMDCs increase CD4⁺ and CD8⁺ T cell responses by in vitro. These results suggest that HemoHIM has the potential to mediate DC immune responses.

Dietary supplementation with white button mushrooms augments the protective immune response to Salmonella vaccine in mice

We previously showed that dietary white button mushrooms (WBMs) enhanced natural killer cell activity and that in vitro WBM supplementation promotes maturation and function of dendritic cells (DCs). The current study investigated whether WBM consumption would enhance pathogen-specific immune response using a Salmonella vaccination and infection animal model. C57BL/6 mice were fed diets containing 0%, 2%, or 5% WBM for 4 wk before oral vaccination with live attenuated Salmonella typhimurium SL1479. Four weeks after immunization, mice were orally infected with virulent Salmonella typhimurium SL1344. Immunization increased animal survival and, among immunized mice, the 2% WBM group had a higher survival rate than the other groups. Next, we fed mice 2% WBMs to determine the immunological mechanism underlying the WBM-potentiated protective effect. We found that WBM supplementation increased Salmonella-specific blood immunoglobulin (Ig) G and fecal IgA concentrations. WBM-fed mice also had a higher IgG2a and unchanged IgG1 production, leading to an elevated IgG2a:IgG1 ratio and indicating an enhanced T helper 1 response. Consistent with these results, WBM-fed mice had higher interferon-γ, tumor necrosis factor (TNF)-α, and interleukin (IL)-17A production and unchanged IL-4 production in their splenocytes after polyclonal (anti-CD3/CD28) or antigen-specific stimulation. Furthermore, WBM-fed mice had more DCs in the spleen, and these DCs expressed higher levels of activation markers CD40 and major histocompatibility complex-II. These mice also produced more IL-12 and TNF-α postimmunization. Together, these results suggest that WBMs may improve Salmonella vaccine efficacy through an enhanced adaptive immune response.

Agaricus subrufescens: A review

Medicinal mushrooms have currently become a hot issue due to their various therapeutic properties. Of these, Agaricus subrufescens, also known as the "almond mushroom", has long been valued by many societies (i.e., Brazil, China, France, and USA). Since its discovery in 1893, this mushroom has been cultivated throughout the world, especially in Brazil where several strains of A. subrufescens have been developed and used as health food and alternative medicine. This article presents up-to-date information on this mushroom including its taxonomy and health promoting benefits. Medicinal properties of A. subrufescens are emphasized in several studies which are reviewed here. In addition, safety issues concerning the use of this fungus will be discussed.

Immunomodulatory activity of polysaccharide-protein complex of longan (Dimocarpus longan Lour.) pulp

The immunomodulatory function of longan pulp polysaccharide-protein complex (LP3) was investigated in immunosuppressed mice models. Compared with the model control, peroral administration of 100 mgkg⁻¹d⁻¹ LP3 could significantly increase/enhance antibody production against chicken red blood cell (CRBC), concanavalin A (ConA)-induced splenocyte proliferation, macrophage phagocytosis, NK cell cytotoxicity against YAC-1 lymphoma cell, and interferon-gamma (INF-γ) and interleukin-2 (IL-2) secretion in serum (P < 0.05). The immunomodulatory effects, except for those on splenocytes and macrophages (P > 0.05), were also observed in mice administered with 50 or 200 mgkg⁻¹d⁻¹ LP3 (P < 0.05). The beneficial effects of 50–200 mgkg⁻¹d⁻¹ LP3 were comparable to those of 50 mgkg⁻¹d⁻¹ ganoderan. The strong immunomodulatory activity of LP3 confirmed its good potential as an immunotherapeutic adjuvant.

Pro-inflammatory effects of the mushroom Agaricus blazei and its consequences on atherosclerosis development

PURPOSE

Extracts of the mushroom Agaricus blazei (A. blazei) have been described as possessing immunomodulatory and potentially cancer-protective activities. However, these effects of A. blazei as a functional food have not been fully investigated in vivo.

METHODS

Using apolipoprotein E-deficient (ApoE(-/-)) mice, an experimental model of atherosclerosis, we evaluated the effects of 6 or 12 weeks of A. blazei supplementation on the activation of immune cells in the spleen and blood and on the development of atherosclerosis.

RESULTS

Food intake, weight gain, blood lipid profile, and glycemia were similar between the groups. To evaluate leukocyte homing and activation, mice were injected with (99m)Tc-radiolabeled leukocytes, which showed enhanced leukocyte migration to the spleen and heart of A. blazei-supplemented animals. Analysis of the spleen showed higher levels of activation of neutrophils, NKT cells, and monocytes as well as increased production of TNF-α and IFN-γ. Circulating NKT cells and monocytes were also more activated in the supplemented group. Atherosclerotic lesion areas were larger in the aorta of supplemented mice and exhibited increased numbers of macrophages and neutrophils and a thinner fibrous cap. A. blazei-induced transcriptional upregulation of molecules linked to macrophage activation (CD36, TLR4), neutrophil chemotaxy (CXCL1), leukocyte adhesion (VCAM-1), and plaque vulnerability (MMP9) were seen after 12 weeks of supplementation.

CONCLUSIONS

This is the first in vivo study showing that the immunostimulatory effect of A. blazei has proatherogenic repercussions. A. blazei enhances local and systemic inflammation, upregulating pro-inflammatory molecules, and enhancing leukocyte homing to atherosclerosis sites without affecting the lipoprotein profile.

Physicochemical characteristics and immunomodulatory activities of three polysaccharide-protein complexes of longan pulp

Three polysaccharide-protein complexes of longan pulp (LP1-3) were isolated in this work. Their physicochemical characteristics and immunomodulatory effects on splenocytes, natural killer (NK) cells and macrophages in vitro were investigated. The carbohydrate portions of LP1-3 were principally composed of glucose, arabinose and mannose. LP3 displayed the maximal moisture absorption, and the thermal stability of LP2 was obviously higher than that of LP1 and LP3. All of them showed the characteristic polysaccharide and protein bands in the Fourier Transform Infrared (FTIR) spectrum. For a certain dose, all the fractions could significantly stimulate splenocyte proliferation, macrophage phagocytosis against neutral red, and NK cell cytotoxicity against YAC-1 lymphoma cell (P < 0.05). The results demonstrated that the polysaccharide-protein complexes of longan pulp have medical potential as immunotherapeutic adjuvants due to their immunomodulatory activities.

Agaricus blazei Extract Induces Apoptosis through ROS-Dependent JNK Activation Involving the Mitochondrial Pathway and Suppression of Constitutive NF-κB in THP-1 Cells

Agaricus blazei is widely accepted as a traditional medicinal mushroom, and it has been known to exhibit immunostimulatory and anti-cancer activity. However, the apoptotic mechanism in cancer cells is poorly understood. In this study, we have investigated whether A. blazei extract (ABE) exerts antiproliferative and apoptotic effects in human leukemic THP-1 cells. We observed that ABE-induced apoptosis is associated with the mitochondrial pathway, which is mediated by reactive oxygen species (ROS) generation and prolonged c-Jun N-terminal kinase (JNK) activation. In addition, the ABE treatment resulted in the accumulation of cytochrome c in the cytoplasm, an increase in caspase activity, and an upregulation of Bax and Bad. With those results in mind, we found that ABE decreases constitutive NF-κB activation and NF-κB-regulated gene products such as IAP-1 and -2. We concluded that ABE induces apoptosis with ROS-dependent JNK activation and constitutive activated NF-κB inhibition in THP-1 cells.

Proteoglycans regulate the chemotaxis of dendritic cells derived from human peripheral blood monocytes

Dendritic cells (DCs) are a type of antigen-presenting cell which play an essential role in the immune system. The transition from immature DC (iDCs) to mature DCs (mDCs) requires appropriate maturation stimuli, such as pro-inflammatory cytokines or pathogen-derived components. Proteoglycans (PGs), which are composed of core proteins and the glycosaminoglycans that bind to them, are one of the main components of the extracellular matrix around pathogens such as bacteria. This study investigated the effects of PG extracted from the nasal septum cartilage of whale (W-PG) on the maturation of DCs derived from human peripheral blood monocytes. iDCs were prepared from human monocytes using granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4). The iDCs were stimulated by W-PG alone. In another type of experiment, the iDCs were stimulated by MIX (tumor necrosis factor-alpha (TNF-alpha), IL-1beta, IL-6 and prostaglandin E(2) (PGE(2))) or a combination of MIX plus W-PG. The stimulation of W-PG alone did not induce the phenotypic maturation from iDCs. However, W-PG promoted the up-regulation of chemokine receptor CCR7-surface expression and the chemotactic responsiveness to CCR7 ligand macrophage inflammatory protein-3beta on MIX-stimulated mDCs although W-PG did not influence matrix metalloproteinase-9 activity which is an important factor in DC migration through the extracellular matrix. The findings that W-PG can selectively regulate the chemotactic activity of DCs in vitro under inflammatory conditions therefore indicate that the interaction of PGs with immune cells including DCs plays an important role in the immune response under the milieu of innate immunity.

Dendritic cell activation by glucan isolated from umbilicaria esculenta

Background

Lichen-derived glucans have been known to stimulate the functions of immune cells. However, immunostimulatory activity of glucan obtained from edible lichen, Umbilicaria esculenta, has not been reported. Thus we evaluated the phenotype and functional maturation of dendritic cells (DCs) following treatment of extracted glucan (PUE).

Methods

The phenotypic and functional maturation of PUE-treated DCs was assessed by flow cytometric analysis and cytokine production, respectively. PUE-treated DCs was also used for mixed leukocyte reaction to evaluate T cell-priming capacity. Finally we detected the activation of MAPK and NF-κB by immunoblot.

Results

Phenotypic maturation of DCs was shown by the elevated expressions of CD40, CD80, CD86, and MHC class I/II molecules. Functional activation of DCs was proved by increased cytokine production of IL-12, IL-1β, TNF-α, and IFN-α/β, decreased endocytosis, and enhanced proliferation of allogenic T cells. Polymyxin B, specific inhibitor of lipopolysaccharide (LPS), did not affect PUE activity, which suggested that PUE was free of LPS contamination. As a mechanism of action, PUE increased phosphorylation of ERK, JNK, and p38 MAPKs, and enhanced nuclear translocation of NF-κB p50/p65 in DCs.

Conclusion

These results indicate that PUE induced DC maturation via MAPK and NF-κB signaling pathways.

Does the Agaricus blazei Murill mushroom have properties that affect the immune system? An integrative review

There has been a significant increase in the use of mushrooms for therapeutic and medicinal purposes, in particular, use of the species Agaricus blazei Murrill, a basidiomycota of Brazilian origin. The objective of this study was to identify scientific evidence regarding the influence of A. blazei Murrill on the immune system. We undertook an integrative review of indexed publications published between 2000 and 2009, using the following question as a guideline: "What evidence can be found in the literature regarding the influence of A. blazei Murrill on the immune system?" Fourteen studies verified that there is in vitro and in vivo research demonstrating this mushroom's influence on the immune system. All research was characterized as evidence level 7 (preclinical study [animals/in vitro]). The research shows that A. blazei Murrill functions through bioactive compounds via mechanisms that are not yet entirely clear, although it has been shown that they promote action on the innate and adaptive immunological response, activation of the complement system, and synthesis of pro- and anti-inflammatory cytokines and even aid in diapedesis. Despite broad scientific evidence demonstrating relevant immunomodulatory properties of A. blazei Murrill, randomized clinical trials with human subjects are still needed in order for the mushroom to be put into clinical practice.

A polysaccharide extracted from Grifola frondosa enhances the anti-tumor activity of bone marrow-derived dendritic cell-based immunotherapy against murine colon cancer

We previously isolated the novel heteropolysaccharide maitake Z-fraction (MZF) from the maitake mushroom (Grifola frondosa), and demonstrated that MZF significantly inhibited tumor growth by inducing cell-mediated immunity. In this study, we demonstrated that MZF upregulated the expression of CD80, CD86, CD83, and MHC II on bone marrow-derived dendritic cells (DCs) and significantly increased interleukin-12 (IL-12) and tumor necrosis factor-alpha production by DCs in a dose-dependent manner. MZF-treated DCs significantly stimulated both allogeneic and antigen-specific syngenic T cell responses and enhanced antigen-specific interferon-gamma (IFN-gamma) production by syngenic CD4(+) T cells; however, MZF-treated DCs did not affect IL-4 production. Furthermore, the enhancement of IFN-gamma production in CD4(+) T cells, which was induced by MZF-treated DCs, was completely inhibited by the addition of an anti-IL-12 antibody. These results indicate that MZF induced DC maturation and antigen-specific Th1 response by enhancing DC-produced IL-12. We also demonstrated that DCs pulsed with colon-26 tumor lysate in the presence of MZF induced both therapeutic and preventive effects on colon-26 tumor development in BALB/c mice. These results suggest that MZF could be a potential effective adjuvant to enhance immunotherapy using DC-based vaccination.

Effects of proteoglycan extracted from nasal cartilage of salmon heads on maturation of dendritic cells derived from human peripheral blood monocytes

Dendritic cells (DCs) play an essential role in the immune system. The transition from immature DC (iDCs) to mature DCs (mDCs) requires appropriate stimuli such as pro-inflammatory cytokines. Proteoglycans (PGs) are one of the main components of extracellular matrix, and some types of PGs are known to induce maturation of murine DCs. Recent studies have investigated the potential benefits of PG from nasal cartilage of salmon head (S-PG). This study investigated the effects of S-PG on maturation of human monocyte-derived DCs. iDCs were prepared from human monocytes using the appropriate cytokines and then stimulated by S-PG alone. In another experiment, iDCs were stimulated by a combination of pro-inflammatory cytokines (MIX) plus S-PG. Although the stimulation of S-PG alone did not induce phenotypic maturation from iDCs, CD40 expression on DCs stimulated by S-PG alone was lower than that of iDCs. In contrast, the phenotypic and functional characteristics of DCs stimulated by MIX+S-PG were similar to those of DCs stimulated by MIX alone. As a result, S-PG did not demonstrate a significant effect with regard to maturation of human monocyte-derived DCs.

Induction of dendritic cell maturation by β-glucan isolated from Sparassis crispa

Sparassis crispa is a medicinal mushroom containing high 6-branched 1,3-β-D-glucan (sparan) content, which exhibits immune-mediated antitumor activity. In the present study, we investigated the stimulating effect of sparan on phenotypic and functional maturation of dendritic cells (DCs). Phenotypic maturation was confirmed by the elevated expressions of CD40, CD80, CD86, and MHC-I/II molecules. Functional activation was proved by increased cytokine production of IL-12, IL-1β, TNF-α, and IFN-α/β, enhanced IL-2 production and proliferation of allogenic T cells, and decreased endocytosis. The role of toll-like receptor 4 (TLR4) as a membrane receptor of sparan was proved by the impaired maturation of DCs generated from bone marrow cells of tlr4⁻/⁻ knock-out mice and TLR4-mutated C3H/HeJ mice, and by using anti-MD-2/TLR4 neutralizing antibody. Sparan increased phosphorylation of ERK, p38, and JNK, and enhanced nuclear translocation of NF-κB p50/p65 in DCs. These results indicate that sparan activates DCs via MAPK and NF-κB signaling pathways, which are signaling molecules downstream of TLR4.

An extract based on the medicinal mushroom Agaricus blazei Murill stimulates monocyte-derived dendritic cells to cytokine and chemokine production in vitro

The edible mushroom Agaricus blazei Murill (AbM), which has been used in traditional medicine against a range of diseases and possess immunomodulating properties, probably due to its high content of beta-glucans. Others and we have demonstrated stimulatory effects of extracts of this mushroom on different immune cells. Dendritic cells are major directors of immune function. We wanted to examine the effect of AbM stimulation on signal substance release from monocyte-derived dendritic cells (MDDC). After 6d incubation with IL-4 and GM-CSF, the cells were true MDDC. Then the cells were further incubated with up to 10% of the AbM-based extract, AndoSan, LPS (0.5 microg/ml) or PBS control. We found that the AbM extract promoted dose-dependent increased levels of IL-8, G-CSF, TNFalpha, IL-1beta, IL-6 and MIP-1beta, in that order. The synthesis of IL-2, IL-8 and IFNgamma were similar for the AbM extract and LPS. However, AndoSan induced a 10- to 2-fold higher production than did LPS of G-CSF, TNFalpha and IL-1beta, respectively. AbM did not induce increased synthesis of Th2 or anti-inflammatory cytokines or the Th1 cytokine IL-12. We conclude that stimulation of MDDC with an AbM-based extract resulted in increased production of proinflammatory, chemotactic and some Th1-type cytokines in vitro.

Immunomodulatory activity of the seeds of Plantago asiatica L

ETHNOPHARMACOLOGICAL RELEVANCE

The seeds of Plantago asiatica L. were often used as a traditional Chinese medicine for some immunologically weak patients suffering from chronic illness. These uses could be related to immunomodulatory properties of the plant.

AIM OF THE STUDY

In this study, effects of extract of the seeds of Plantago asiatica L. (ES-PL) were investigated on the maturation of dendritic cells (DCs), which play significant role in primary immune system.

MATERIALS AND METHODS

The phenotypes of DCs were analyzed by using flow cytometry while phagocytosis was assessed by the uptake of FITC-dextran. Antigen presenting ability to allogeneically naïve or syngeneically primed T lymphocytes was examined by the lymphocyte proliferation of mixed lymphocyte reaction (MLR). In addition, the level of chemokine receptor CCR7 mRNA was determined by RT-PCR.

RESULTS

DCs treated with ES-PL expressed higher levels of MHC class II molecules and major costimulatory molecules such as CD80 and CD86. Functional maturation of DCs treated with ES-PL was confirmed by decreased mannose receptor-mediated endocytosis and increased antigen presenting abilities to allogeneically naïve or syngeneically primed T lymphocytes. The CCR7 mRNA expression in DCs treated with ES-PL was also enhanced.

CONCLUSIONS

These results indicated that ES-PL could induce the maturation of murine DCs.

The immunobiology of mushrooms

There has been enormous interest in the biologic activity of mushrooms and innumerable claims have been made that mushrooms have beneficial effects on immune function with subsequent implications for inhibition of tumor growth. The majority of these observations are anecdotal and often lack standardization. However, there remains considerable data on both in vitro and in vivo effects that reflect on the potential of mushroom compounds to influence human immunity. A number of these effects are beneficial but, unfortunately, many responses are still characterized based on phenomenology and there is more speculation than substance. With respect to tumor biology, although many neoplastic lesions are immunogenic, tumor antigens frequently are self antigens and induce tolerance and many patients with cancer exhibit suppressed immune responses, including defective antigen presentation. Therefore, if and when mushroom extracts are effective, they more likely function as a result of improved antigen presentation by dendritic cells than by a direct cytopathic effect. In this review we attempt to place these data in perspective, with a particular focus on dendritic cell populations and the ability of mushroom extracts to modulate immunity. There is, at present, no scientific basis for the use of either mushrooms or mushroom extracts in the treatment of human patients but there is significant potential for rigorous research to understand the potential of mushrooms in human disease and thence to focus on appropriate clinical trials to demonstrate effectiveness and/ or potential toxicity.

White button mushroom enhances maturation of bone marrow-derived dendritic cells and their antigen presenting function in mice

Mushrooms have been shown to enhance immune response, which contributes to their antitumor property. White button mushrooms (Agaricus bisporus) (WBM) constitute 90% of the total mushrooms consumed in the United States; however, the health benefit of this strain in general is not well studied. Furthermore, little is known about WBM's immunologic effects. Dendritic cells (DC) are the most potent antigen presenting cells and play a pivotal role in immune response by linking innate and adaptive immune responses. In this study, we investigated the effect of in vitro supplementation with WBM on maturation of bone marrow-derived DC (BMDC) of C57BL mice. BMDC were differentiated in the presence of whole mushroom concentrate at 50, 100, or 200 mg/L. Results showed that mushroom supplementation dose dependently increased the expression of maturation markers CD40, CD80, CD86, and major histocompatibility complex-II. Consistent with the changes in the phenotypic markers, functional assay for DC maturation showed that mushroom supplementation decreased DC endocytosis and increased intracellular interleukin (IL)-12 levels. Furthermore, using a syngeneic T cell activation model, we found that WBM-supplemented DC from BALB/c mice presented ovalbumin antigen to T cells from DO11.10 mice more efficiently as demonstrated by increased T cell proliferation and IL-2 production. In conclusion, WBM promote DC maturation and enhance their antigen-presenting function. This effect may have potential in enhancing both innate and T cell-mediated immunity leading to a more efficient surveillance and defense mechanism against microbial invasion and tumor development.

Effects of Agaricus blazei Murill extract on sensitivity to chemotherapeutic agents in HeLa cells and its resistant sublines

Agaricus blazei Murill (ABM; Japanese name: Kawahiratake or Agarikusutake) extract is a widely used dietary supplement. However, limited information is available on the effects of the extract on the effectiveness of the chemotherapeutic agents. In this study, we examined the effects of ABM extract (Kyowa Wellness Co., Ltd.) on sensitivity to chemotherapeutic agents, paclitaxel and doxorubicin as MDR1/P-glycoprotein substrates, and cisplatin and 5-fluorouracil as non-substrates, in human cervical carcinoma HeLa cells, and paclitaxel-resistant and cisplatin-resistant derivatives (HeLa/TXL and HeLa/CDDP, respectively). The extract had no growth inhibitory effects on HeLa and the resistant cells at concentrations ranging from 7.6 × 10(-4) μ g/ml to 8.0 × 10(2)μ g/ml, indicating no remarkable cytotoxic activity in vitro. In the presence of 0.1, 0.5, and 1 μ g/ml of ABM extract, sensitivity to paclitaxel, cisplatin and 5-fluorouracil did not change in HeLa, HeLa/TXL and HeLa/CDDP cells. However, the extract reduced sensitivity to doxorubicin in HeLa/TXL and HeLa/CDDP cells in a concentration-dependent manner. In conclusion, the concomitant use of ABM extract minimally affected sensitivity to various chemotherapeutic agents in HeLa cells and resistant sublines in vitro.

Bcl-2 and caspase-3 are major regulators in Agaricus blazei-induced human leukemic U937 cell apoptosis through dephoshorylation of Akt

Agaricus blazei is a medicinal mushroom that possesses antimetastatic, antitumor, antimutagenic, and immunostimulating effects. However, the molecular mechanisms involved in A. blazei-mediated apoptosis remain unclear. In the present study, to elucidate the role of the Bcl-2 in A. blazei-mediated apoptosis, U937 cells were transfected with either empty vector (U937/vec) or vector containing cDNA encoding full-length Bcl-2 (U937/Bcl-2). As compared with U937/vec, U937/Bcl-2 cells exhibited a 4-fold greater expression of Bcl-2. Treatment of U937/vec with 1.0-4.0 mg/ml of A. blazei extract (ABE) for 24 h resulted in a significant induction of morphologic features indicative of apoptosis. In contrast, U937/Bcl-2 exposed to the same ABE treatment only exhibited a slight induction of apoptotic features. ABE-induced apoptosis was accompanied by downregulation of antiapoptotic proteins such as X-linked inhibitor of apoptosis protein (XIAP), inhibitor of apoptosis protein (cIAP)-2 and Bcl-2, activation of caspase-3, and cleavage of poly(ADP-ribose)polymerase (PARP). Ectopic expression of Bcl-2 was associated with significantly induced expression of antiapoptotic proteins, such as cIAP-2 and Bcl-2, but not XIAP. Ectopic expression of Bcl-2 also reduced caspase-3 activation and PARP cleavage in ABE treated U937 cells. Furthermore, treatment with the caspase-3 inhibitor z-DEVD-fmk was sufficient to restore cell viability following ABE treatment. This increase in viability was ascribed to downregulation of caspase-3 and blockage of PARP and PLC-gamma cleavage. ABE also triggered the downregulation of Akt, and combined treatment with LY294002 (an inhibitor of Akt) significantly decreased cell viability. The results indicated that major regulators of ABE-induced apoptosis in human leukemic U937 cells are Bcl-2 and caspase-3, which are associated with dephosphorylation of the Akt signal pathway.

d-pinitol inhibits Th1 polarization via the suppression of dendritic cells

d-pinitol has been demonstrated to exert insulin-like and anti-inflammatory effects. However, the effects of the maturation and immunostimulatory functions of dendritic cells (DC) remain to be clearly elucidated. In this study, we have attempted to determine whether d-pinitol regulates surface molecule expression, cytokine production, endocytosis capacity, and underlying signaling pathways in murine bone marrow-derived DC. We also attempted to ascertain whether d-pinitol could influence Th1/Th2 immune response in vivo. The DC used in this study were derived from murine bone marrow cells, and were used as immature or LPS-stimulated mature DC. The DC were then assessed with regard to surface molecule expression, dextran-FITC uptake, cytokine production, capacity to induce T-cell differentiation, and underlying signaling pathways. d-pinitol was shown to significantly inhibit CD80, CD86, MHC class I, and MHC class II expression in the LPS-stimulated mature DC. The DC also evidenced impaired IL-12 expression and IFN-gamma production. The d-pinitol-treated DC were found to be highly efficient in regards to Ag capture via mannose receptor-mediated endocytosis. d-pinitol was also demonstrated to inhibit LPS-induced MAPKs activation and NF-kappaB nuclear translocation. Moreover, the d-pinitol-treated DC manifested impaired induction of Th1 responses, and normal cell-mediated immune responses. These novel findings provide new insight into the immunopharmacological role of d-pinitol in terms of its effects on DC. These findings also broaden current perspectives concerning our understanding of the immunopharmacological functions of d-pinitol, and have ramifications for the development of therapeutic adjuvants for the treatment of DC-related acute and chronic diseases.

Rosmarinic acid inhibits indoleamine 2,3-dioxygenase expression in murine dendritic cells

Indoleamine 2,3-dioxygenase (IDO), a key enzyme that catalyses the initial and rate-limiting step in the degradation of the tryptophan, is simultaneously expressed in murine dendritic cells and macrophages stimulated with interferon-gamma (IFN-gamma). In the present study, we investigated whether rosmarinic acid (RA), which is suggested to exhibit anti-oxidant and anti-cyclooxygenase properties, could suppress the functional expression of IDO in murine bone marrow-derived dendritic cells (BMDCs) stimulated with IFN-gamma. Treatment with RA reduced intracellular expression of IDO both in IFN-gamma-activated BMDCs in vitro and in CD11c(+)CD8alpha(+) DCs in vivo tumor-bearing mice model. Consequently, we obtained evidence that RA suppresses the functional activity of IDO and blocks the IDO-dependent T cell suppression. In IFN-gamma-mediated induction of IDO transcription, activation of the signal transducer and activator of transcription 1 (STAT1) is important to be express IDO in IFN-gamma-stimulated BMDCs. In this study, we demonstrated that the RA could also suppress IFN-gamma-induced STAT1 activation. These novel findings provide a new insight into that RA as a pharmacological and transcriptional inhibitor of IDO is worthy of clinical application as well as further investigation for IDO regulation.

p-Coumaric acid inhibits indoleamine 2, 3-dioxygenase expression in murine dendritic cells

Indoleamine 2, 3-dioxygenase (IDO), a key enzyme that catalyses the initial and rate-limiting step in the degradation of the tryptophan, is simultaneously expressed in murine dendritic cells and macrophages stimulated with interferon-gamma (IFN-gamma). In the present study, we investigated whether p-Coumaric acid (CA), which is suggested to exhibit antioxidant properties, could suppress the functional expression of IDO in murine bone marrow-derived dendritic cells (BMDCs) stimulated with IFN-gamma. Treatment with CA reduced intracellular expression of IDO mRNA and protein levels in IFN-gamma-activated murine BMDCs in vitro and in CD11c(+)CD8alpha(+) DCs of tumor-draining lymph node (TDLN) of tumor-bearing mice in vivo. Consequently, we obtained evidence that CA suppresses the functional activity of IDO, which catalyses oxidative catabolism of tryptophan, and significantly recovers the IDO-dependent T cell suppression. Activation of the signal transducer and activator of transcription 1 (STAT1) is important to be express IDO in IFN-gamma-stimulated murine BMDCs. To determine whether these inhibitory effects of CA are associated with the alteration of the signal transducer and activator of transcription 1 (STAT1) and IFN-gamma-inducible, dsRNA-activated serine/threonine protein kinase (PKR), BMDCs were pretreated with various concentrations of CA. We found that CA inhibited the activation of STAT1 in response to IFN-gamma. Based on our results, this study may account that CA could inhibit IDO expression by down-regulation of STAT1 activation in IFN-gamma-stimulated murine DCs.

Angelan isolated from Angelica gigas Nakai induces dendritic cell maturation through toll-like receptor 4

During the evolution of neoplastic diseases, dendritic cell (DC) functions are usually attenuated, and this presents a problem to DC-based immunotherapies against cancer. Here, we investigated the effects of angelan, an acidic polysaccharide isolated from Angelica gigas Nakai, on DC maturation. Angelan efficiently increased the maturation of tlr4(+/+) DCs from C57BL/6 and C3H/HeN mice, but not tlr4(-/-) DCs from C3H/HeJ mice. Phenotypic maturation was confirmed by the elevated expressions of CD80, CD86, and MHC-class II molecules, and functional maturation by increased IL-12 production, enhanced allogenic T cell stimulation, and decreased endocytosis. Angelan was found to activate ERK and NF-kappaB, which are signaling molecules down-stream of toll-like receptor-4 (TLR4) receptors. Angelan-treated mature DC more effectively inhibited B16F10 tumor growth than immature DCs in syngenic murine tumor model. These results indicate that angelan induces DC maturation via TLR4 signaling pathways and suggest the possible use of angelan in DC-based immunotherapies.

Apigenin Inhibits Immunostimulatory Function of Dendritic Cells: Implication of Immunotherapeutic Adjuvant

Apigenin, one of the most common flavonoids, has been shown to possess anti-inflammatory, anticarcinogenic, and free radical-scavenging properties. However, the influence of apigenin on the immunostimulatory effects and maturation of dendritic cells (DC) remains, for the most part, unknown. In this study, we have attempted to ascertain whether apigenin influences the expression of surface molecules, dextran uptake, cytokine production, and T-cell differentiation as well as the signaling pathways underlying these phenomena in murine bone marrow-derived DC. In the presence of apigenin, CD80, CD86, and major histocompatibility complex class I and II molecules, expressions on DC were significantly suppressed, and lipopolysaccharide (LPS)-induced interleukin (IL)-12 expression was impaired. The DC proved highly efficient at antigen capture, as evidenced by the observation of mannose receptor-mediated endocytosis in the presence of apigenin. The LPS-induced activation of mitogen-activated protein kinase, the nuclear translocation of its nuclear factor-kappaB p65 subunit, and the induction of the T-helper 1 response were all impaired in the presence of apigenin, whereas the cell-mediated immune response remained normal. These findings provide new insight into the immunopharmacological functions of apigenin and its effects on DC, and they may also prove useful in the development of adjuvant therapies for individuals suffering from acute or chronic DC-associated diseases.

Water Extract of Cordyceps militaris Enhances Maturation of Murine Bone Marrow-Derived Dendritic Cells in Vitro

Water extract (WE) of Cordyceps militaris has been reported to produce antitumor and immunomodulatory activities in vivo and in vitro. However, the therapeutic mechanism has not been known. In this study, we investigated whether water extract of C. militaris induces the phenotypic and functional maturation of dendritic cells (DC). It profoundly increased CD40, CD54, CD80, CD86, and MHC class II expression in murine bone marrow (BM)-derived myeloid DC. Endocytosis was assessed by the uptake of FITC-dextran and FITC-albumin. The ability of unstimulated DC (UT-DC) to uptake dextran and albumin was higher than that of WE- or LPS-stimulated DC (LPS-DC). Also, UT-DC secreted a low concentration of IL-12, while WE- or LPS-DC secreted higher levels of IL-12 than UT-DC. WE not only formed morphologically mature DC and clusters, but also induced predominantly functional maturation. Moreover, WE is shown to promote the cytotoxicity of specific-cytotoxic T lymphocyte (CTL) induced by DC which were pulsed with P815 tumor-lysate during the stage of antigen presentation. These results suggest that DC maturation by WE can play a critical role in the improvement of the immunoregulatory function in patients with impaired host defense.