• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of immunologyLink to Publisher's site
Immunology. Jun 2007; 121(2): 197–206.
PMCID: PMC2265935

Interleukin-12- and interferon-γ-mediated natural killer cell activation by Agaricus blazei Murill

Abstract

Dried fruiting bodies of Agaricus blazei Murill (A. blazei) and its extracts have generally used as complementary and alternative medicines (CAMs). Here, we report that the oral administration of A. blazei augmented cytotoxicity of natural killer (NK) cells in wild-type (WT) C57BL/6, C3H/HeJ, and BALB/c mice. Augmented cytotoxicity was demonstrated by purified NK cells from treated wild-type (WT) and RAG-2-deficient mice, but not from interferon-γ (IFN-γ) deficient mice. NK cell activation and IFN-γ production was also observed in vitro when dendritic cell (DC)-rich splenocytes of WT mice were coincubation with an extract of A. blazei. Both parameters were largely inhibited by neutralizing anti-interleukin-12 (IL-12) monoclonal antibody (mAb) and completely inhibited when anti-IL-12 mAb and anti-IL-18 mAb were used in combination. An aqueous extract of the hemicellulase-digested compound of A. blazei particle; (ABPC) induced IFN-γ production more effectively, and this was completely inhibited by anti-IL-12 mAb alone. NK cell cytotoxicty was augmented with the same extracts, again in an IL-12 and IFN-γ-dependent manner. These results clearly demonstrated that A. blazei and ABPC augmented NK cell activation through IL-12-mediated IFN-γ production.

Keywords: Agaricus blazei, NK cells, IFN-γ, IL-12, cytotoxicity

Introduction

Agaricus blazei Murill (A. blazei), a Brazilian native edible mushroom, has been used as a health food or a non-prescription remedy in traditional medicine for preventing cancer, diabetes, hyperlipidaemia, arteriosclerosis and chronic hepatitis in Brazil.1 A. blazei and the hemicellulase-digested component of A. blazei particle compound (ABPC) have recently been used as one of the common complementary and alternative medicines (CAMs).13 Oral intake of extracts of A. blazei has been reported to improve the living quality of cancer patients particularly undergoing chemotherapy.2,4 The antitumour effect of A. blazei has been demonstrated in several transplantable mouse tumour models.1,511 In addition, some reports suggested that augmentation of cellular immune responses is a critical mechanism for their antitumour effect.5 Particularly, natural killer (NK) cells, which play an important role in innate immunity against infection and tumour development1215 have been reported to be activated by A. blazei in vivo and in vitro.5,10,1618 The administration of the extract of A. blazei has been reported to restore NK cell activity in tumour bearing mice or cancer patients treated with chemotherapy.4,18 However, the precise mechanisms of NK cell activation by A. blazei have still not been clearly revealed, especially in oral administration models using experimental mice. Here we examined the effect of A. blazei and ABPC on NK cell cytotoxicty using gene-targeted mice, and demonstrated that A. blazei and ABPC induced interleukin-12 (IL-12)-mediated interferon-γ (IFN-γ) production and augmented NK cell cytotoxicity on a per cell basis.

Materials and methods

Mice

Wild-type (WT) male C57BL/6 (B6), C3H/HeJ, and BALB/c mice, 6 weeks of age, were purchased from Charles River Japan Inc. (Yokohama, Japan). IFN-γ-deficient (IFN-γ–/–) and Rag-2-deficient (RAG-2–/–) B6 mice were derived as described previously.19 All mice were maintained under specific pathogen-free conditions and used in accordance with the institutional guidelines of Juntendo University.

Reagents

Powdered dried fruiting bodies of A. blazei Murrill (H1) (A. blazei) and the hemicellulase-digested component of A. blazei particle (ABPC)20 were kindly provided from Japan Applied Microbiology Research Institute Ltd (Yamanashi, Japan). These are orally administered into mice as a suspension in the distilled water (500 µl). Extracts were prepared with distilled water at 37° for 1 hr at 200 mg/ml, and supernatants were passed through a 0·22 µm filter (Millipore Co., Bedfold, MA) after centrifugation at 2000 g for 15 min. The approximate content of β-glucan as estimated by a colorimetric analysis using G-test (Medical & Biological Laboratories, Nagoya, Japan) was 380 ng/ml in A. blazei extract and 820 ng/ml in the ABPC extract. Endotoxin was not detected in either extract by an analysis using an endotoxin-specific chromogenic Limulus test (Wako Biochemicals, Osaka, Japan). Eschericha coli-derived lipopolysaccharide (LPS) and polymixin B were purchased from Sigma Chemical (St Louis, MO). Neutralizing anti-mouse IL-12 monoclonal antibody (mAb) (C17.8) was purchased from eBioscience (San Diego, CA), and neutralizing anti-mouse IL-18 mAb (93-10C) was purchased from Medical & Biological Laboratories. Anti-mouse IL-12 mAb (C17.8) was also prepared and purified from ascites using protein G column in our laboratory for in vivo usage as previously described.

Cytotoxicity assay and purification of NK cells

Liver mononuclear cells (MNCs) were prepared as previously described.21 In some experiments, freshly isolated liver MNCs were incubated with anti-DX5 microbeads (Miltenyi Biotec, Bergisch Glabach, Germany), and DX5+ cells were enriched or eliminated by auto-magnetic-activated cell sorting (Miltenyi Biotec) according to the manufacturer's instructions. Flow cytometric analysis demonstrated more than 90% pure NK cell populations and less than 2% of NK cells in the NK cell-depleted population. Cytotoxic activity of MNCs and purified liver NK cells was assessed against the NK cell-sensitive target, YAC-1 cells, by a standard 51Cr release assay.21

Flow cytometric analysis

After preincubation with anti-mouse CD16/32 mAb (2.4G2) to avoid non-specific binding of mAbs to Fcγ receptors, cell surface molecules were stained with fluoroscein isothiocyanate-conjugated anti-mouse CD3 mAb (145-2C11) and phycoerythin-conjugated anti-NK1.1 mAb (PK136) and analysed using a FACS Caliber (BD Bioscience, San Jose, CA).21 All reagents were purchased from eBioscience.

In vitro culture of splenic MNCs with an extract of A. blazei

Dendritic cell (DC)-rich splenic MNCs or splenic DCs were prepared according to reported procedures.22,23 Briefly, spleen cells were digested with collagenase (400 U/ml, Wako Biochemicals) in the presence of 5 mm EDTA in Ca2+-free media, and red blood cells were lysed. In some experiments, DCs were purified by cell density from DC-rich splenocytes. Peritoneal macrophages were isolated using the previously reported method.22 Cells (1 × 105 cells/200 µl) were cultured with titrated extract of A. blazei or ABPC in RPMI-1640 medium supplemented with 10% heat-inactivated fetal calf serum, 2 mm l-glutamine, and 25 mm NaHCO3 in humidified 5% CO2 at 37° on 96-well flat-bottom culture plate (Costar, Cambridge, MA). Cell-free supernatants were harvested 72 hr later. In some experiments cells were cultured in the presence of anti-IL-12 mAb and/or anti-IL-18 mAb (10 µg/ml). In some experiments, extracts and LPS were incubate with 10 µg of polymixin B for 1 hr before culture.

Enzyme-linked immunosorbent assay (ELISA)

IFN-γ or IL-12 p40 levels in the culture supernatants were evaluated by using a highly sensitive mouse IFN-γ specific ELISA kit (Ready-SET-Go!; eBioscience) or IL-12 p40-specific ELISA kit (OptEIA; BD PharMingen) according to the manufacturer's instruction.

Statistical analysis

Data were analysed by a two-tailed Student t-test. P-values less than 0·05 were considered significant.

Results

Augmentation of NK cell cytotoxic activity by oral administration of A. blazei

To investigate the effect of A. blazei administration on the cytotoxic activity of mouse MNCs in a model possibly analogous to the usage of A. blazei in humans, we orally administered a suspension of powdered dried fruiting bodies of A. blazei into mice. Daily administration of 32 mg of A. blazei into WT B6 mice for 2 weeks, but not 1 week, augmented cytotoxicity of liver MNCs against the NK cell-sensitive target, YAC-1 (Fig. 1a). Daily administration of 32 mg or 64 mg of A.blazei significantly augmented the cytotoxic activity of liver MNCs, although daily intake of 16 mg of A. blazei did not augment cytotoxic activity (Fig. 1b). To exclude the contribution of LPS, which possibly contaminates powdered dried fruiting bodies of A. blazei, we also administered the A. blazei suspension into Toll-like receptor (TLR)-4-defective C3H/HeJ mice.24 Oral administration of A. blazei augmented the NK cell cytotoxicity of liver MNCs in C3H/HeJ mice as well as in BALB/c mice (Fig. 1c). The NK cell activity of spleen MNCs was also increased by oral administration of A. blazei in all strains of mice tested (data not shown). However augmentation of NK cell cytotoxicity in spleen MNCs was weaker compared with that of liver MNCs, which might be caused by a reduced proportion of NK cells in spleen compared with liver. In spite of the significant augmentation of NK cell cytotoxicity by the oral administration of A. blazei, neither MNC numbers nor populations of NK cells significantly increases in liver and spleen (Figs 2a, b and data not shown). No signs of hepatotoxicity with significantly elevated serum transaminases [alanine aminotransferase (ALT) and aspartate aminotransferase (AST)], or systemic toxicity as estimated by body weight, gross appearance, or behaviour was observed in all mice orally administered with a suspension of powdered dried fruiting bodies of A. blazei (data not shown). These results showed that NK cell cytotoxicity, but not NK cell number, was increased independent of TLR-4 when A. blazei were orally administered daily for 2 weeks.

Figure 1
Activation of NK cell cytotoxicity by oral administration with A. blazei. (a) B6 mice were administered daily with A. blazei suspension (32 mg/500 µl/head) (open circle) or water (500 µl/head) (open square) for 1 or 2 weeks. Then, liver ...
Figure 2
MNC numbers and NK cell percentage after A. blazei oral administration for 2 weeks. Two weeks after daily oral administration of A. blazei suspension (32 mg/500 µl/head) into WT B6 mice, spleen and liver MNCs number (a) and populations of liver ...

Requirement of IFN-γ but not T cells or NKT cells, in A. blazei-induced NK cell activation in vivo

To investigate the contribution of T cells, NKT cells, and IFN-γ to A. blazei-induced cytotoxicity in vivo, we next orally administered A. blazei into RAG-2–/– or IFN-γ–/– mice. NK cells purified from liver MNCs, isolated from WT and RAG-2–/– mice 2 weeks after daily administration of A. blazei, displayed augmented cytotoxicity (Fig. 3), suggesting that NK cells were the cytotoxic effector cells. Alternatively, the cytotoxicity of NK cells purified from IFN-γ–/– mice was not augmented (Fig. 3), indicating a critical role for IFN-γ in the augmentation of NK cell activity by A. blazei in vivo. Similar results were obtained in the experiments using whole liver or spleen MNCs or when ABPC was orally administered into these mice (data not shown). These results clearly indicated that oral administration with A. blazei augmented NK cell cytotoxicity on a per cell basis and this was dependent on IFN-γ but not T or NKT cells.

Figure 3
IFN-γ dependent NK cell activation by oral administration of A. blazei. WT, RAG-2–/–, and IFN-γ–/– B6 mice were orally administered daily with A. blazei (32 mg/500 µl/head) (open circle) or water ...

IFN-γ production by DC-rich spleen MNC stimulated in vitro with an extract of A. blazei or ABPC

To further examine the mechanisms of NK cell activation and IFN-γ production induced by A. blazei, we used in vitro culture experiments employing the extract from A. blazei or ABPC. Aqueous extract of A. blazei induced IFN-γ production by DC-rich spleen MNCs after 72 hr incubation, and the peak of IFN-γ production was observed when cells were cocultured with a 1/1000 diluted extract (Fig. 4a). ABPC extract induced similar amount of IFN-γ production when cells were cocultured with a 1/2000 diluted (Fig. 4a). Both extracts induced IFN-γ production from DC-rich spleen MNCs isolated from B6 mice and TLR-4-defective C3H/HeJ mice24 (Fig. 4a). Even when DC-rich spleen MNC were stimulated with the extract of A. blazei or ABPC in the presence of LPS-inactivating polymixin B25 a similar amount of IFN-γ was detected in culture supernatants (Fig. 4b). Polymixin B almost completely diminished IFN-γ production (less than 10 pg/ml) induced by in vitro stimulation with 5 µg/ml of LPS (Fig. 4c). IFN-γ was detected in the supernatants of DC-rich spleen MNCs prepared from RAG-2–/– mice when stimulated with either extract in vitro; however, IFN-γ was not detected when DC-rich spleen MNCs were stimulated after NK cell depletion (Fig. 4d). Thus, these results clearly suggested that the extract of A. blazei or ABPC induced IFN-γ production from NK cells independently of LPS and TLR-4 in vitro.

Figure 4
IFN-γ induction in vitro by an extract of A. blazei or ABPC. (a) DC-rich spleen MNCs isolated from B6 or C3H/HeJ mice were coincubated with an extract of A. blazei (open square) or ABPC (open circle) at the indicated concentrations for 72 hr. ...

Dominant role of IL-12 in IFN-γ production by DC-rich spleen MNC stimulated with an extract of A. blazei or ABPC

We examined IL-12 production from DCs and macrophages, because it has been reported that IL-12 was produced by CD14+ human monocytes/macrophages stimulated in vitro with the extract of ABPC.20 IL-12 was detected in the culture supernatants of splenic DCs stimulated with 0·1% of A. blazei extract or 0·05% of ABPC extract (Fig. 5a). In addition, the amount of IL-12 produced by peritoneal macrophages stimulated with either extract was extract dose dependent (Fig. 5b). To confirm the contribution of IL-12 to IFN-γ production, we examined IFN-γ production from DC-rich spleen cell cultured with the extract in the presence of a neutralizing anti-IL-12 mAb. As shown in Fig. 6(a), neutralization of IL-12 completely inhibited IFN-γ production when cells were stimulated with the extract of ABPC. Alternatively, a small amount of IFN-γ was still produced by DC-rich spleen cells stimulated with 0·1% of A. blazei extract even in the presence of anti-IL-12 mAb (Fig. 6a); however, this IFN-γ production was completely inhibited by coincubation with anti-IL-12 mAb and anti-IL-18 mAb (Fig. 6b). These results suggested that IL-12 plays the predominant role in IFN-γ induction by both extracts; however, IL-18 also contributes to IFN-γ induction by the A. blazei extract.

Figure 5
IL-12 production by DC or purified peritoneal macrophages stimulated with an extract of A. blazei or ABPC. (a) DCs were coincubated with an extract of A. blazei (0·1%) or ABPC (0·05%) for 72 hr. Cell free culture supernatants were then ...
Figure 6
IL-12- and IL-18-dependent IFN-γ induction by A. blazei. (a) DC-rich spleen MNCs isolated from B6 mice were coincubated with an extract of A. blazei or ABPC at the indicated concentration in the presence (open circle) or absence (open square) ...

IL-12- and IFN-γ-dependent NK cell activation in DC-rich spleen MNC stimulated with an extract of A. blazei or ABPC in vitro

We then examined NK cell cytotoxic activity 72 hr after coincubation of DC-rich spleen MNC with the extracts of A. blazei or ABPC. When DC-rich splenocytes derived from WT mice were coincubated with 0·1% of A. blazei extract or 0·05% of the ABPC extract, NK cell cytotoxicity was significantly augmented (Fig. 7a), although NK cell proportions were not increased (data not shown). Cytotoxicity was not augmented when DC-rich spleen MNC isolated from IFN-γ-deficient mice were stimulated with extract of A. blazei or ABPC (Fig. 7b), although IL-12 was detected in the supernatants (data not shown). Moreover, cytotoxic activity was not augmented when NK cells were depleted or when DC-rich spleen MNC were coincubated with the extracts in the presence of anti-IL-12 mAb (Fig. 7c). These results clearly indicated that the extracts of A. blazei or ABPC induced IL-12, and this was critical for IFN-γ-dependent augmentation of NK cell cytotoxicity in vitro.

Figure 7
IL-12 mediated IFN-γ-dependent NK cell cytotoxicity induced by an extract of A. blazei or ABPC in vitro. (a) Augmentation of NK cell cytotoxicity by an extract of A. blazei or ABPC. DC-rich spleen MNC isolated from B6 mice were cultured with an ...

IL-12-dependent NK cell cytotoxic activation by oral administration of A. blazei or ABPC extract

We finally analysed NK cell cytotoxicity in B6 mice administered orally with the extract of A. blazei or ABPC for 2 weeks. Serum IL-12 was not detected during entire period of the administration of either extract (data not shown). However NK cell cytotoxicity of liver MNCs was augmented in the mice treated with either extract, and the augmentation of NK cell cytotoxicity was almost completely diminished by in vivo anti-IL-12 mAb treatment (Fig. 8a). Moreover, NK cell activation was not observed in IFN-γ–/– mice treated with extract of A. blazei or ABPC for 2 weeks (Fig. 8b). These data clearly showed that NK cell activation by oral administration of the extracts of A. blazei or ABPC is dependent on IL-12 and IFN-γ, consistent with the data obtained in in vitro experiments.

Figure 8
IL-12-mediated activation of NK cell cytotoxicity induced by an extract of A. blazei or ABPC in vivo. (a) WT B6 mice were administered daily with A. blazei extract (500 µl/head) (square), ABPC extract (250 µl/head)(circle) or water (500 ...

Discussion

In this study, we explored the activation of NK cell cytotoxicity by A. blazei or ABPC, utilizing RAG-2–/– mice, IFN-γ–/– mice and neutralizing mAbs. In RAG-2–/– mice but not in IFN-γ–/– mice, oral consumption of A. blazei augmented NK cell cytotoxicity as potently as in WT mice. Consistently, coincubation of DC-rich spleen MNC with an extract of either A. blazei or ABPC augmented NK cell cytotoxicity dependent upon IFN-γ. IFN-γ induction was mostly mediated by IL-12, although IL-18 partly contributed to IFN-γ production induced by the extract of A. blazei. Moreover, oral administration of either A. blazei or ABPC extract induced NK cell activation; however, it was not observed in anti-IL-12 mAb-treated WT mice or IFN-γ–/– mice. This is the first report clearly showing that A. blazei or ABPC augment NK cell cytotoxicity mainly through IL-12-mediated IFN-γ production using gene-targeted mice and neutralizing mAbs.

A. blazei has been taken orally as one of the most common CAMs for cancer and other diseases.13 To examine the effector mechanisms possibly induced by A. blazei in humans, we used a mouse experimental model employing oral administration of A. blaze or either extract. The results obtained in vivo experiments were consistent with those obtained in vitro. Thus, the presented results strongly suggest that the in vivo NK cell activation mechanisms of A. blazei in human would likely be quite similar to that revealed in vitro experiments.

NK cells and IFN-γ are recognized as critical for immune surveillance for tumour and pathogen.1215,26,27 IL-12 and IL-18 have been reported to activate NK cells through the induction of IFN-γ production2830 and IFN-γ and IL-12 induction by the extract of A. blazei has been reported previously.10,17,20 In the present study, we demonstrated oral administration of A. blazei augmented NK cell cytotoxicity, which is commonly believed to be the major effector mechanism of NK cells against tumours and microbes.14,15,31,32 In contrast, it was also reported that IFN-γ produced by IL-12-activated NK and/or NKT cells induced NO-mediated cytotoxicity and/or antiangiogenic chemokines, and these pathways played a substantial role in the antitumour effect of IL-12.28,3335 IFN-γ has been suggested to play a substantial role in the immunomodulatory effect of A. blazei.5,10,17 Direct induction of tumour apoptosis, inhibition of tumour cell proliferation, and inhibition of tumour-induced neovascularization have been reported as the possible mechanisms of the antitumour effect of A. blazei.1,8,11,16 Nevertheless the contribution of IFN-γ to these effects has not been examined. It was also reported that A. blazei induced several cytokine and chemokine genes (including IL-1 and IL-8) in a human monocyte cell line (THP-1).36 Thus, several mechanisms could contribute to the antitumour effect of A. blazei as well as NK cell-mediated direct cytotoxicity against tumour cells.

Here we demonstrated that IL-12-mediated IFN-γ induction by A. blazei or ABPC is TLR-4 independent. It was suggested that β-glucan might be the effector component that induces immune responses by A. blazei and ABPC,57,37 although we do not have any evidence showing β-glucan as the effector component inducing IL-12 and IFN-γ-mediated NK cell activation and we have not yet identified the structure of β-glucans contained in A.blazei or ABPC. Dectin-1 was recently reported as the receptor for β(1→3)- and/or β(1→6)-linked glucan- and zymosan-inducing IL-12 production.38 Complement receptor 3, lactosylceramide, and scavenger receptors are also reported as β-glucan receptors inducing immune responses.39 TLR-2- and TLR-6-mediated signals are reported to be required for optimal β-glucan-induced and dectin-1-mediated immune responses;40,41 however, ligands of TLR-2 or TLR-6 are not still identified in β-glucans or zymogen. Thus, dectin-1, TLR-2, and TLR-6 would co-operate in recognition of β-glucans and activate immune responses.39 Complex signalling mechanisms would underlie immune activation by β-glucans; however, further investigations to identify the receptors and signalling mechanisms involved in the recognition of β-glucans are required. This will not only elucidate immune activation mechanisms against fungal pathogens but also improve the therapeutic benefit of mushroom-derived CAMs.

We now have reported that IL-18 partly contributes to A. blazei-induced, but not ABPC-induced, IFN-γ production, and ABPC demonstrated a two times higher efficacy in IL-12-mediated IFN-γ induction compared with A. blazei. These results suggested that ABPC preparations may have retained effective components inducing IL-12 production, but lost those inducing IL-18 production. However, the enhancement of NK cell cytotoxicity and the amount of IFN-γ induced by A. blazei or ABPC was significantly less than that triggered by recombinant IL-12 in vitro and in vivo, suggesting limited production of IFN-γ-inducing cytokines (IL-12 and/or IL-18) after A. blazei or ABPC treatment. We reported that IFN-γ-induced perforin-dependent NK cell cytotoxicity is the critical for the antimetastatic effect of recombinant IL-12.42 Thus, the NK cell cytotoxicity-dependent antimetastatic effect might be less after A. blazei or ABPC treatment compared with that induced by exogenous recombinant IL-12 treatment. However, it is possible that the amount of IL-12 and IFN-γ induced by A. blazei or ABPC might be sufficient to play a role in the surveillance for tumour development. Alternatively, IFN-γ independent antitumour mechanisms might play a role together with the IFN-γ-mediated antitumour effects of A. blazei. IL-12, IL-18, and IFN-γ were reported to induce hepatotoxicity and act as critical cytokines in the Shwartzman reaction43,44 suggesting that continuous production of large amounts of these cytokines might be toxic. Moreover, the tumour promotion effect of some other commercial products of A. blazei was recently reported by the Food Safety Commission of Japan, although the products used here were proved as safe (data not shown). Thus, further precise studies to identify the effective components of A. blazei and ABPC that induce IL-12 and/or IL-18, their downstream mechanisms activating immune responses against tumours, and toxicity are required to improve their therapeutic effects.

Acknowledgments

We thank Dr Mark J. Smyth for reading the manuscript and helpful suggestions. This work was supported by the Ministry of Education, Science, and Culture, Japan. Authors thank Mishima Kaiun Memorial Foundation for a financial support of the 2004 and the Danone Institute of Japan for a financial support of the 2005 DIJ research Grant.

Abbreviations

A. blazei
Agaricus blazei Murill
CAM
complementary and alternative medicine
NK
natural killer
WT
wild type
IFN
interferon
DC
dendritic cell
IL
interleukin
mAb
monoclonal antibody
ABPC
Agaricus blazei particle compound
MNC
mononuclear cell
ELISA
enzyme-linked immunosorbent assay
TLR
Toll-like receptor

References

1. Takaku T, Kimura Y, Okuda H. Isolation of an antitumor compound from Agaricus blazei Murill and its mechanism of action. J Nutr. 2001;131:1409–13. [PubMed]
2. Yoshimura K, Ueda N, Ichioka K, Matsui Y, Terai A, Arai Y. Use of complementary and alternative medicine by patients with urologic cancer: a prospective study at a single Japanese institution. Support Care Cancer. 2005;13:685–90. [PubMed]
3. Takeda K, Okumura K. CAM and NK cells. Evid Based Complement Alternat Med. 2004;1:17–27. [PMC free article] [PubMed]
4. Ahn WS, Kim DJ, Chae GT, et al. Natural killer cell activity and quality of life were improved by consumption of a mushroom extract, Agaricus blazei Murill Kyowa, in gynecological cancer patients undergoing chemotherapy. Int J Gynecol Cancer. 2004;14:589–94. [PubMed]
5. Itoh H, Ito H, Amano H, Noda H. Inhibitory action of a (1→6)-β-d-glucan–protein complex (FIII-2-b) isolated from Agaricus blazei Murill (‘himematsutake’) on Meth A fibrosarcoma-bearing mice and its antitumor mechanism. Jpn J Pharmacol. 1994;66:265–71. [PubMed]
6. Ohno N, Furukawa M, Miura NN, Adachi Y, Motoi M, Yadomae T. Antitumor β glucan from the cultured fruit body of Agaricus blazei. Biol Pharm Bull. 2001;24:820–8. [PubMed]
7. Oshiman K, Fujimiya Y, Ebina T, Suzuki I, Noji M. Orally administered β-1,6-d-polyglucose extracted from Agaricus blazei results in tumor regression in tumor-bearing mice. Planta Med. 2002;68:610–4. [PubMed]
8. Kobayashi H, Yoshida R, Kanada Y, et al. Suppressing effects of daily oral supplementation of β-glucan extracted from Agaricus blazei Murill on spontaneous and peritoneal disseminated metastasis in mouse model. J Cancer Res Clin Oncol. 2005;131:527–38. [PubMed]
9. Lee YL, Kim HJ, Lee MS, Kim JM, Han JS, Hong EK, Kwon MS, Lee MJ. Oral administration of Agaricus blazei (H1 strain) inhibited tumor growth in a sarcoma 180 inoculation model. Exp Anim. 2003;52:371–5. [PubMed]
10. Takimoto H, Wakita D, Kawaguchi K, Kumazawa Y. Potentiation of cytotoxic activity in naive and tumor-bearing mice by oral administration of hot-water extracts from Agaricus brazei fruiting bodies. Biol Pharm Bull. 2004;27:404–6. [PubMed]
11. Kimura Y, Kido T, Takaku T, Sumiyoshi M, Baba K. Isolation of an anti-angiogenic substance from Agaricus blazei Murill: its antitumor and antimetastatic actions. Cancer Sci. 2004;95:758–64. [PubMed]
12. Yokoyama WM, Scalzo AA. Natural killer cell activation receptors in innate immunity to infection. Microbes Infect. 2002;4:1513–21. [PubMed]
13. Biron CA, Brossay L. NK cells and NKT cells in innate defense against viral infections. Curr Opin Immunol. 2001;13:458–64. [PubMed]
14. Talmadge JE, Meyers KM, Prieur DJ, Starkey JR. Role of NK cells in tumour growth and metastasis in beige mice. Nature. 1980;284:622–4. [PubMed]
15. Smyth MJ, Hayakawa Y, Takeda K, Yagita H. New aspects of natural-killer-cell surveillance and therapy of cancer. Nat Rev Cancer. 2002;2:850–61. [PubMed]
16. Fujimiya Y, Suzuki Y, Oshiman K, et al. Selective tumoricidal effect of soluble proteoglucan extracted from the basidiomycete, Agaricus blazei Murill, mediated via natural killer cell activation and apoptosis. Cancer Immunol Immunother. 1998;46:147–59. [PubMed]
17. Zhong M, Tai A, Yamamoto I. In vitro augmentation of natural killer activity and interferon-γ production in murine spleen cells with Agaricus blazei fruiting body fractions. Biosci Biotechnol Biochem. 2005;69:2466–9. [PubMed]
18. Kaneno R, Fontanari LM, Santos SA, Di Stasi LC, Rodrigues Filho E, Eira AF. Effects of extracts from Brazilian sun-mushroom (Agaricus blazei) on the NK activity and lymphoproliferative responsiveness of Ehrlich tumor-bearing mice. Food Chem Toxicol. 2004;42:909–16. [PubMed]
19. Takeda K, Hayakawa Y, Smyth MJ, et al. Involvement of tumor necrosis factor-related apoptosis-inducing ligand in surveillance of tumor metastasis by liver natural killer cells. Nat Med. 2001;7:94–100. [PubMed]
20. Kasai H, He LM, Kawamura M, et al. IL-12 production induced by Agaricus blazei fraction H (ABH) involves Toll-like receptor (TLR) Evid Based Complement Alternat Med. 2004;1:259–67. [PMC free article] [PubMed]
21. Hashimoto W, Takeda K, Anzai R, Ogasawara K, Sakihara H, Sugiura K, Seki S, Kumagai K. Cytotoxic NK1.1 Ag+αβ T cells with intermediate TCR induced in the liver of mice by IL-12. J Immunol. 1995;154:4333–40. [PubMed]
22. Yamazaki T, Akiba H, Iwai H, et al. Expression of programmed death 1 ligands by murine T cells and APC. J Immunol. 2002;169:5538–45. [PubMed]
23. Maldonado-Lopez R, De Smedt T, Michel P, et al. CD8α+ and CD8α subclasses of dendritic cells direct the development of distinct T helper cells in vivo. J Exp Med. 1999;189:587–92. [PMC free article] [PubMed]
24. Poltorak A, He X, Smirnova I, et al. Defective LPS signaling in C3H/HeJ and C57BL/10ScCr mice: mutations in Tlr4 gene. Science. 1998;282:2085–8. [PubMed]
25. Jacobs MD, Morrison DC. Dissociation between mitogenicity and immunogenicity of TNP-lipopolysaccharide, a T-independent antigen. J Exp Med. 1975;141:1453–8. [PMC free article] [PubMed]
26. Dunn GP, Bruce AT, Ikeda H, Old LJ, Schreiber RD. Cancer immunoediting: from immunosurveillance to tumor escape. Nat Immunol. 2002;3:991–8. [PubMed]
27. Smyth MJ, Dunn GP, Schreiber RD. Cancer immunosurveillance and immunoediting: the roles of immunity in suppressing tumor development and shaping tumor immunogenicity. Adv Immunol. 2006;90:1–50. [PubMed]
28. Brunda MJ. Interleukin-12. J Leukoc Biol. 1994;55:280–8. [PubMed]
29. Trinchieri G. Interleukin-12. A proinflammatory cytokine with immunoregulatory functions that bridge innate resistance and antigen-specific adaptive immunity. Annu Rev Immunol. 1995;13:251–76. [PubMed]
30. Okamura H, Kashiwamura S, Tsutsui H, Yoshimoto T, Nakanishi K. Regulation of interferon-γ production by IL-12 and IL-18. Curr Opin Immunol. 1998;10:259–64. [PubMed]
31. van den Broek ME, Kagi D, Ossendorp F, et al. Decreased tumor surveillance in perforin-deficient mice. J Exp Med. 1996;184:1781–90. [PMC free article] [PubMed]
32. Smyth MJ, Thia KY, Cretney E, Kelly JM, Snook MB, Forbes CA, Scalzo AA. Perforin is a major contributor to NK cell control of tumor metastasis. J Immunol. 1999;162:6658–62. [PubMed]
33. Nastala CL, Edington HD, McKinney TG, et al. Recombinant IL-12 administration induces tumor regression in association with IFN-γ production. J Immunol. 1994;153:1697–706. [PubMed]
34. Yu WG, Yamamoto N, Takenaka H, et al. Molecular mechanisms underlying IFN-γ-mediated tumor growth inhibition induced during tumor immunotherapy with rIL-12. Int Immunol. 1996;8:855–65. [PubMed]
35. Tannenbaum CS, Tubbs R, Armstrong D, Finke JH, Bukowski RM, Hamilton TA. The CXC chemokines IP-10 and Mig are necessary for IL-12-mediated regression of the mouse RENCA tumor. J Immunol. 1998;161:927–32. [PubMed]
36. Ellertsen LK, Hetland G, Johnson E, Grinde B. Effect of a medicinal extract from Agaricus blazei Murill on gene expression in a human monocyte cell line as examined by microarrays and immuno assays. Int Immunopharmacol. 2006;6:133–43. [PubMed]
37. Kawagishi H, Inagaki R, Kanao T, Mizuno T, Shimura K, Ito H, Hagiwara T, Nakamura T. Fractionation and antitumor activity of the water-insoluble residue of Agaricus blazei fruiting bodies. Carbohydr Res. 1989;186:267–73. [PubMed]
38. Brown GD, Gordon S. Immune recognition. A new receptor for β-glucans. Nature. 2001;413:36–7. [PubMed]
39. Brown GD. Dectin-1: a signalling non-TLR pattern-recognition receptor. Nat Rev Immunol. 2006;6:33–43. [PubMed]
40. Underhill DM, Ozinsky A, Hajjar AM, Stevens A, Wilson CB, Bassetti M, Aderem A. The Toll-like receptor 2 is recruited to macrophage phagosomes and discriminates between pathogens. Nature. 1999;401:811–5. [PubMed]
41. Ozinsky A, Underhill DM, Fontenot JD, Hajjar AM, Smith KD, Wilson CB, Schroeder L, Aderem A. The repertoire for pattern recognition of pathogens by the innate immune system is defined by cooperation between toll-like receptors. Proc Natl Acad Sci U S A. 2000;97:13766–71. [PMC free article] [PubMed]
42. Kodama T, Takeda K, Shimozato O, et al. Perforin-dependent NK cell cytotoxicity is sufficient for anti-metastatic effect of IL-12. Eur J Immunol. 1999;29:1390–6. [PubMed]
43. Ozmen L, Pericin M, Hakimi J, Chizzonite RA, Wysocka M, Trinchieri G, Gately M, Garotta G. Interleukin 12, interferon γ, and tumor necrosis factor α are the key cytokines of the generalized Shwartzman reaction. J Exp Med. 1994;180:907–15. [PMC free article] [PubMed]
44. Tsutsui H, Matsui K, Kawada N, Hyodo Y, Hayashi N, Okamura H, Higashino K, Nakanishi K. IL-18 accounts for both TNF-α- and Fas ligand-mediated hepatotoxic pathways in endotoxin-induced liver injury in mice. J Immunol. 1997;159:3961–7. [PubMed]

Articles from Immunology are provided here courtesy of British Society for Immunology
PubReader format: click here to try

Formats:

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...

Links

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...