[A CASE OF HYPERSENSITIVITY REACTION TO ENOKITAKE (FLAMMULINA VELUTIPES) INGESTION].

We experienced a case of 10-year-old girl who developed hypersensitivity reactions after eating enokitake. The patient had food allergy to egg until 5 years old. When she was 4 years old, she ate enokitake with a hot-pot dish. Later, she felt itching in her mouth. Therefore, she never ate enokitake since that time. At the age of 10, she drank only the soup of enokitake with school lunch. After that she felt discomfort and itching in her oral cavity. The result of enokitake and other mushrooms (siitake, simeji, and eringi) skin prick to prick test were all positive. We performed Western blotting with enokitake extracts and the patient's serum. Enokitake protein's band (75kDa) reacted specifically with the patient's IgE. At the same time Western blotting was performed with the patient's serum of previously reported enokitake anaphylaxis, but a 75kDa band showing specific reaction in this case was not observed. This band we identified was a novel enokitake allergen.

[A case of anaphylaxis caused by enokitake (Flammulina velutipes) ingestion].

Enokitake (Flammulina velutipes, winter mushroom) is a common edible mushroom in Japan. We experienced a case of anaphylaxis after enokitake ingestion. There are no reports describing anaphylaxis caused by the ingestion of this mushroom. Enokitake allergen has also not been reported. We thus attempted to identify enokitake allergen using the patient's serum. The patient was a seventeen-year-old woman who had had no episodes of food allergy and experienced anaphylaxis after the ingestion of sukiyaki (beef, pork, tofu, vegetables, enokitake, etc.). She had previously eaten sukiyaki (the same ingredients) without any symptoms. The result of enokitake skin prick to prick test was positive. Oral food challenge was positive, inducing anaphylaxis. We performed western blotting with enokitake extract and the patient's serum. Three enokitake protein bands (18 kDa, 39 kDa, 50 kDa) reacted specifically with the patient's IgE.

Activation effects of polysaccharides of Flammulina velutipes mycorrhizae on the T lymphocyte immune function.

Flammulina velutipes mycorrhizae have increasingly been produced with increasing of F. velutipes production. A mouse model was thus used to examine potential effect of F. velutipes mycorrhizae on the immune function. Fifty female Wistar mice (5-weeks-old) weighed 15-20 g were randomly allocated into five groups. Polysaccharide of F. velutipes mycorrhizae were treated with mice and mice spleen lymphocytes. The levels of CD3(+), CD4(+), and CD8(+) T lymphocyte, interleukin-2 (IL-2), and tumor necrosis factor-a (TNF-α) were determined. The results showed that the proportions of CD3(+), and CD4(+) T lymphocyte, the ratio of CD4(+)/CD8(+), and the levels of IL-2 and TNF-a were significantly increased in polysaccharide of F. velutipes mycorrhizae, while the proportion of CD8(+) T lymphocyte was decreased in polysaccharide of F. velutipes mycorrhizae-dose dependent manner. Our findings indicated that a long term exposure of polysaccharide of F. velutipes mycorrhizae could activate the T lymphocyte immune function. Polysaccharide of F. velutipes mycorrhizae was expected to develop into the immune health products.

In vitro rapid evolution of fungal immunomodulatory proteins by DNA family shuffling.

Fungal immunomodulatory proteins (FIPs) found in a wide variety of mushrooms hold significant therapeutic potential. Despite much research, the structural determinants for their immunomodulatory functions remain unknown. In this study, a DNA shuffling technique was used to create two shuffled FIP protein libraries: an intrageneric group containing products of shuffling between FIP-glu (FIP gene isolated from Ganoderma lucidum) and FIP-gsi (FIP gene isolated from Ganoderma sinense) genes and an intergeneric group containing the products of shuffling between FIP-glu, FIP-fve (FIP gene isolated from Flammulina velutipes), and FIP-vvo (FIP gene isolated from Volvariella volvacea) genes. The gene shuffling generated 426 and 412 recombinant clones, respectively. Using colony blot analysis, we selected clones that expressed relatively high levels of shuffled gene products recognized by specific polyclonal antibodies. We analyzed the DNA sequences of the selected shuffled genes, and testing of their protein products revealed that they maintained functional abilities to agglutinate blood cells and induce cytokine production by splenocytes from Kunming mice in vitro. Meanwhile, the relationships between protein structure and the hemagglutination activity and between the changed nucleotide sites and expression levels were explored by bioinformatic analysis. These combined analyses identified the nucleotide changes involved in regulating the expression levels and hemagglutination activities of the FIPs. Therefore, we were able to generate recombinant FIPs with improved biological activities and expression levels by using DNA shuffling, a powerful tool for the generation of novel therapeutic proteins and for their structural and functional studies.

IFN-γ induction on carbohydrate binding module of fungal immunomodulatory protein in human peripheral mononuclear cells.

FIP-fve is a protein that is isolated from Flammulina velutipes . Its known immunomodulatory activities are elicitation of the production of type II interferon from human peripheral mononuclear cells (hPBMCs) and hemagglutination. How the target receptors mediate activation of FIP-fve-induced immunomodulatory effects remains to be elucidated. This study postulates the three-dimensional structures to determine whether the carbohydrate binding module family 34 (CBM-34) on FIP-fve is conserved to site N of Thermoactinomyces vulgaris R-47 α-amylase I. Experimental site-directed mutagenesis data as well as ligand-specific binding competition assay are adopted to identify the key residues W24, T28, D34, T90, I91, and W111 of FIP-fve that participate in binding to polysaccharides that are linked to the membrane of immune cells. Treatments of hPBMCs with tunicamycin and deglycosylation enzymes that removed the carbohydrate moieties reduced the secretion of IFN-γ induction from hPBMCs. In conclusion, the experiments herein demonstrated the ligand-binding CBM-34 on FIP-fve and ligand-like glycoproteins on the surface of hPBMCs must be required to induce physiological immunomodulatory effects.

Oral administration of an Enoki mushroom protein FVE activates innate and adaptive immunity and induces anti-tumor activity against murine hepatocellular carcinoma.

FVE is a documented immunomodulatory protein purified from Enoki mushroom (Flammulina velutipes) and known as an activator for human T lymphocytes. This present study was aimed to investigate the anti-tumor effect and the related mechanisms of oral administration of FVE using a murine hepatoma model. Oral administration of FVE (10mg/kg) significantly increased the life span and inhibited the tumor size of BNL 1MEA.7R.1 (BNL) hepatoma-bearing mice. Tumor-bearing mice receiving oral FVE treatment had the highest tumoricidal capacity of peritoneal macrophages and tumor-specific splenocytes against BNL hepatoma cells. In addition, in vivo neutralization of interferon-gamma (IFN-gamma) demonstrated a significant decrease of FVE-induced anti-tumor effect (P<0.05). The expression levels of major histocompatibility complex (MHC) class I and II molecules and costimulatory molecule CD80 on peripheral blood mononuclear cells obtained from the FVE-treated mice were upregulated as compared with those of the PBS-treated mice. Furthermore, immunohistochemical staining showed a strong inhibition of tumor growth and angiogenesis in hepatoma tissues after oral administration of FVE. Taken together, oral administration of FVE displayed anti-tumor activity through activating both innate and adaptive immunity of the host to prime a cytotoxic immune response and IFN-gamma played a key role in the anti-tumor efficacy of FVE.

Coadministration of the fungal immunomodulatory protein FIP-Fve and a tumour-associated antigen enhanced antitumour immunity.

Fve is a fungal protein isolated from the golden needle mushroom Flammulina velutipes and has previously been reported to trigger immunological responses in both mouse and human lymphocytes. In this study, we evaluated the potential application of Fve as an adjuvant for tumour immunotherapy and examined the underlying mechanism(s). When the human papillomavirus (HPV)-16 E7 oncoprotein was used as a model antigen, mice coimmunized with HPV-16 E7 and Fve showed enhanced production of HPV-16 E7-specific antibodies as well as expansion of HPV-16 E7-specific interferon (IFN)-gamma-producing CD4(+) and CD8(+) T cells as compared with mice immunized with HPV-16 E7 alone. Tumour protection assays showed that 60% of mice coimmunized with HPV-16 E7 plus Fve, as compared with 20% of those immunized only with HPV-16 E7, remained tumour-free for up to 167 days after challenge with the tumour cells. Tumour therapeutic assays showed that HPV-16 E7 plus Fve treatment significantly prolonged the survival of tumour-bearing mice as compared with those treated only with HPV-16 E7. In vivo cell depletion and adoptive T-cell transfer assays showed that CD4(+) and CD8(+) T cells and IFN-gamma played critical roles in conferring the antitumour effects. Interestingly, Fve could stimulate the maturation of splenic dendritic cells in vivo and induce antigen-specific CD8(+) T-cell immune responses. In summary, Fve has potent adjuvant properties that enhance T helper type 1 antigen-specific humoral and cellular immune responses which confer strong antitumour effects. The use of Fve as an adjuvant could be an attractive alternative to the current vaccination strategy for cancer immunotherapy.