Anti-tumor metastatic activity of beta-glucan purified from mutated Saccharomyces cerevisiae

Therapeutic potential of trained immunity for malignant disease

Trained immunity (TI) is functional memory displayed by innate immune cells (IICs). TI facilitates rapid, non-specific responses to pathogens upon secondary challenge. It is driven by immunological signaling and metabolic rewriting via epigenetic alteration, triggered by recognition of certain stimuli. Recently, immune checkpoint inhibitors have come into common use in clinical oncology settings, and genetically engineered cytotoxic T cells comprise a potent cancer treatment strategy. However, the contributions of TI in the tumor microenvironment (TME) are only beginning to be uncovered. Accumulating evidence that various microorganisms and vaccines convey tumoricidal ability suggest that TI may become a useful anti-cancer tool. The expected roles of TI in tumor therapy are the 1) promotion of proinflammatory cytokine section, 2) enhancement of phagocytosis, 3) quick expansion and recruitment of cancer-specific cytotoxic T cells to the TME through neoantigen presentation, 4) reversal of immunosuppression in the TME, and 5) removal of pathogens associated with carcinogenesis or tumor development. Medium- to long-term TI durability may reduce the risk of tumor development. Recent findings on TI usher in new aspirations for cancer treatment.

Oncolytic Virotherapies and Adjuvant Gut Microbiome Therapeutics to Enhance Efficacy Against Malignant Gliomas

Glioblastoma (GBM) is the most prevalent malignant brain tumor. Current standard-of-care treatments offer limited benefits for patient survival. Virotherapy is emerging as a novel strategy to use oncolytic viruses (OVs) for the treatment of GBM. These engineered and non-engineered viruses infect and lyse cancer cells, causing tumor destruction without harming healthy cells. Recent advances in genetic modifications to OVs have helped improve their targeting capabilities and introduce therapeutic genes, broadening the therapeutic window and minimizing potential side effects. The efficacy of oncolytic virotherapy can be enhanced by combining it with other treatments such as immunotherapy, chemotherapy, or radiation. Recent studies suggest that manipulating the gut microbiome to enhance immune responses helps improve the therapeutic efficacy of the OVs. This narrative review intends to explore OVs and their role against solid tumors, especially GBM while emphasizing the latest technologies used to enhance and improve its therapeutic and clinical responses.

Effect of combination of Beta Glucan and Lactobacillus rhamnosus HerizI on white blood cell counts and serum levels of IL-4 and IL-12 in women with breast cancer undergoing chemotherapy: A randomized double-blind placebo-controlled clinical trial

BACKGROUND

Aim of this study was the isolation of native probiotic and determine the effect of combination of Beta Glucan and Lactobacillus rhamnosus Heriz I on White Blood Cell Counts and serum levels of IL-4and IL-12 in breast cancer women receiving Chemotherapy.

METHODS

This study was randomized double-blind placebo-controlled clinical trial in 30 women with breast cancer. Women in the intervention group received two 10-mg capsules of soluble 1-3,1-6, D-beta glucan and one capsule of Lactobacillus rhamnosus strain Heriz I (2 × 107 CFU) daily and placebo group received placebo during 21days, interval between two courses of chemotherapy. White blood cells, neuthrophil, lymphocyte and monocyte counts, serum levels of IL-4 and IL-12 were measured before and after the study.

RESULTS

We isolated Lactobacillus rhamnosus Heriz I from conventional yogurt of Heriz region and registered in NCBI GeneBank. After administration, in both groups white blood cells counts decreased. At the end of study, serum level of IL-4 was decreased in combination group compared to placebo (P = 0.005). Also, serum level of IL-12 in combination group increased non-significantly (P = 0.066).

CONCLUSION

The findings suggest that combination of Beta Glucan and Lactobacillus rhamnosus Heriz I may be useful as immunomodulary supplements in chemotherapy patients however further studies were needed.

Fungi in cancer

Both the gut and the tumour microbiome are now established as crucial regulators of cancer phenotypes and have been implicated in cancer initiation, progression and therapy response. Although the role of bacteria in these processes is beginning to be unravelled, the relevance of fungi is only just emerging. In this Viewpoint, we asked experts to discuss the current knowledge on the mycobiome–cancer connection and share their opinion on how to best solve open questions.

Gut Mycobiota Dysbiosis Is Associated with Melanoma and Response to Anti-PD-1 Therapy

Recent research indicates that gut microbiota may be vital in the advancement of melanoma. In this study, we found that melanoma patients exhibited a distinct gut mycobiota structure compared with healthy participants. Candida albicans, Candida dubliniensis, and Neurospora crassa were more abundant in samples from patients with melanoma, whereas Saccharomyces cerevisiae and Debaryomyces hansenii were less abundant. During anti-PD-1 treatment, the relative amount of Malassezia restricta and C. albicans increased. A higher level of Saccharomyces paradoxus was associated with a positive response to anti-PD-1 treatment, whereas a higher level of Tetrapisispora blattae was associated with a lack of clinical benefits. High levels of M. restricta and C. albicans, elevated serum lactate dehydrogenase, and being overweight were linked to increased risk of melanoma progression and poorer response to anti-PD-1 treatment. Thus, this study has revealed melanoma-associated mycobiome dysbiosis, characterized by altered fungal composition and fungi species associated with a higher risk of melanoma progression, identifying a role for the gut mycobiome in melanoma progression.

Potential promising anticancer applications of β-glucans: a review

β-Glucans are valuable functional polysaccharides distributed in nature, especially in the cell walls of fungi, yeasts, bacteria, and cereals. The unique features of β-glucans, such as water solubility, viscosity, molecular weight, and so on, have rendered them to be broadly applied in various food systems as well as in medicine to improve human health. Moreover, inhibition of cancer development could be achieved by an increase in immune system activity via β-glucans. β-glucans, which are part of a class of naturally occurring substances known as biological response modifiers (BRMs), have also shown evidence of being anti-tumorogenic, anti-cytotoxic, and anti-mutagenic. These properties make them attractive candidates for use as pharmaceutical health promoters. Along these lines, they could activate particular proteins or receptors, like lactosylceramide (LacCer), Dickin-1, complement receptor 3 (CR3), scavenge receptors (SR), and the toll-like receptor (TLR). This would cause the release of cytokines, which would then activate other antitumor immune cells, like macrophages stimulating neutrophils and monocytes. These cells are biased toward pro-inflammatory cytokine synthesis and phagocytosis enhancing the elicited immunological responses. So, to consider the importance of β-glucans, the present review introduces the structure characteristics, biological activity, and antitumor functions of fungal β-glucans, as well as their application.

GCMS characterization and biological potential of the seeds and aerial part of Galium tricorne Stokes

Abstract Natural products have long been proven very effective against various challenging diseases including cancer and bacterial infections. Galium tricorne is one of the important source of natural products, which has not been explored till date in spite of its profound ethnomedicinal prominence. The current study has been designed to explore the biological potential of G. tricorne and to extract and isolate chemical constituents from its aerial part and seeds respectively along with identification of their chemical constituents. Phytochemical screening was performed to figure out the presence of secondary metabolite in G. tricorne. Crude Methanolic extract (Gt.Crd), which was obtained from the aerial part while the fatty acids were extracted from the seeds, which were later on analyzed by GCMS. Similarly, Well Diffusion and MTT method were used for antibacterial activity and cancer cell line assay respectively. To evaluate the cytotoxic potential, brine shrimps were used. Likewise, in Gas Chromatography-Mass Spectroscopy (GC-MS) analysis a total number of 23 compounds were identified in Gt.Crd extract out of which 7 compounds were sorted out to have some sort of toxicity profile. In the same fashion, 5 fatty acids were identified in the seeds of G. tricorne. Moreover, among the fractions, chloroform fraction (Gt.Chf) exhibited greater zone of inhibition (ZOI) 20.37 mm followed by Gt.Crd 18.40 mm against S. aureus and S. pyogenes respectively. In cytotoxicity Gt.Chf was more active followed by ethyl acetate fraction (Gt.Eta) by exhibiting 88.32±0.62% (LC50=60 µg/mL) and 73.95±2.25% (LC50=80 µg/mL) respectively at 1000 µg/mL concentration of the tested sample. Gt.Chf exhibited greater cell line inhibitory activity (IC50=61 µg/mL) against HeLa cell line. Similarly, Gt.Crd displayed IC50 values of 167.84 µg/mL and 175.46 µg/mL against HeLa and NIH/3T3 cell line respectively. Based on the literature review and screenings, it may be concluded that the aerial part and seeds of G. tricorne are the rich sources of bioactive compounds. The results of the current study also authenticate the scientific background for the ethnomedicinal uses of G. tricorne.

Unveiling the hidden players: exploring the role of gut mycobiome in cancer development and treatment dynamics

The role of gut fungal species in tumor-related processes remains largely unexplored, with most studies still focusing on fungal infections. This review examines the accumulating evidence suggesting the involvement of commensal and pathogenic fungi in cancer biological process, including oncogenesis, progression, and treatment response. Mechanisms explored include fungal influence on host immunity, secretion of bioactive toxins/metabolites, interaction with bacterial commensals, and migration to other tissues in certain types of cancers. Attempts to utilize fungal molecular signatures for cancer diagnosis and fungal-derived products for treatment are discussed. A few studies highlight fungi's impact on the responsiveness and sensitivity to chemotherapy, radiotherapy, immunotherapy, and fecal microbiota transplant. Given the limited understanding and techniques in fungal research, the studies on gut fungi are still facing great challenges, despite having great potentials.

Emerging relevance of cell wall components from non-conventional yeasts as functional ingredients for the food and feed industry

Non-conventional yeast species, or non-Saccharomyces yeasts, are increasingly recognized for their involvement in fermented foods. Many of them exhibit probiotic characteristics that are mainly due to direct contacts with other cell types through various molecular components of their cell wall. The biochemical composition and/or the molecular structure of the cell wall components are currently considered the primary determinant of their probiotic properties. Here we first present the techniques that are used to extract and analyze the cell wall components of food industry-related non-Saccharomyces yeasts. We then review the current understanding of the cell wall composition and structure of each polysaccharide from these yeasts. Finally, the data exploring the potential beneficial role of their cell wall components, which could be a source of innovative functional ingredients, are discussed. Such research would allow the development of high value-added products and provide the food industry with novel inputs beyond the well-established S. cerevisiae.

Fungi and cancer

The microbiome may impact cancer development, progression and treatment responsiveness, but its fungal components remain insufficiently studied in this context. In this review, we highlight accumulating evidence suggesting a possible involvement of commensal and pathogenic fungi in modulation of cancer-related processes. We discuss the mechanisms by which fungi can influence tumour biology, locally by activity exerted within the tumour microenvironment, or remotely through secretion of bioactive metabolites, modulation of host immunity and communications with neighbouring bacterial commensals. We examine prospects of utilising fungi-related molecular signatures in cancer diagnosis, patient stratification and assessment of treatment responsiveness, while highlighting challenges and limitations faced in performing such research. In all, we demonstrate that fungi likely constitute important members of mucosal and tumour-residing microbiomes. Exploration of fungal inter-kingdom interactions with the bacterial microbiome and the host and decoding of their causal impacts on tumour biology may enable their harnessing into cancer diagnosis and treatment.

β-Glucan produced by Lentinus edodes suppresses breast cancer progression via the inhibition of macrophage M2 polarization by integrating autophagy and inflammatory signals

BACKGROUND

β-Glucan from Lentinus edodes (LNT), an edible mushroom, possesses strong anticancer activity. However, the therapeutic effects of LNT during the occurrence and progression of breast cancer and their underlying molecular mechanisms have not been elucidated.

METHODS

Mouse mammary tumor virus-polyoma middle tumor-antigen (MMTV-PyMT) transgenic mice were used as a breast cancer mouse model. Hematoxylin and eosin, immunohistochemical, and immunofluorescence staining were performed for histopathological analysis. Moreover, we developed an inflammatory cell model using tumor necrosis factor-α (TNF-α). Macrophage polarization was assessed using western blot analysis and immunofluorescence.

RESULTS

Orphan nuclear receptor 77 (Nur77) and sequestosome-1 (p62) were highly expressed and positively correlated with each other in breast cancer tissues. LNT significantly inhibited tumor growth, ameliorated inflammatory cell infiltration, and induced tumor cell apoptosis in PyMT transgenic mice. Moreover, LNT attenuated the ability of tumors to metastasize to lung tissue. Mechanistically, LNT treatment restrained macrophage polarization from M1 to M2 phenotype and promoted autophagic cell death by inhibiting Nur77 expression, AKT/mTOR signaling, and inflammatory signals in breast tumor cells. However, LNT did not exhibit a direct pro-autophagic effect on tumor cell death, except for its inhibitory effect on Nur77 expression. LNT-mediated autophagic tumor cell death depends on M1 macrophage polarization. In in vitro experiments, LNT inhibited the upregulation of p62, autophagy activation, and inflammatory signaling pathways in Nur77 cells.

CONCLUSION

LNT inhibited macrophage M2 polarization and subsequently blocked the AKT/mTOR and inflammatory signaling axes in breast cancer cells, thereby promoting autophagic tumor cell death. Thus, LNT may be a promising therapeutic strategy for breast cancer.

The Mycobiome: Cancer Pathogenesis, Diagnosis, and Therapy

Cancer is among the leading causes of death globally. Despite advances in cancer research, a full understanding of the exact cause has not been established. Recent data have shown that the microbiome has an important relationship with cancer on various levels, including cancer pathogenesis, diagnosis and prognosis, and treatment. Since most studies have focused only on the role of bacteria in this process, in this article we review the role of fungi-another important group of the microbiome, the totality of which is referred to as the "mycobiome"-in the development of cancer and how it can impact responses to anticancer medications. Furthermore, we provide recent evidence that shows how the different microbial communities interact and affect each other at gastrointestinal and non-gastrointestinal sites, including the skin, thereby emphasizing the importance of investigating the microbiome beyond bacteria.

β-glucan from Lentinus edodes inhibits breast cancer progression via the Nur77/HIF-1α axis

Background: β-glucan from Lentinus edodes (LNT) is a plant-derived medicinal fungus possessing significant bioactivities on anti-tumor. Both hypoxia-induced factor-1α (HIF)-1α and Nur77 have been shown to be involved in the development of breast cancer. However, there is yet no proof of Nur77/HIF-1α involvement in the process of LNT-mediated tumor-inhibition effect.

Methods: Immunohistochemistry, immunofluorescence and Hematoxylin–Eosin staining were used to investigate tumor growth and metastasis in MMTV-PyMT transgenic mice. Proliferation and metastasis-associated molecules were determined by Western blotting and reverse transcription-quantitative PCR. Hypoxic cellular model was established under the exposure of CoCl₂. Small interference RNA was transfected using Lipofectamine reagent. The ubiquitin proteasome pathway was blunted by adding the proteasome inhibitor MG132.

Results: LNT inhibited the growth of breast tumors and the development of lung metastases from breast cancer, accompanied by a decreased expression of HIF-1α in the tumor tissues. In in vitro experiments, hypoxia induced the expression of HIF-1α and Nur77 in breast cancer cells, while LNT addition down-regulated HIF-1α expression in an oxygen-free environment, and this process was in a manner of Nur77 dependent. Mechanistically, LNT evoked the down-regulation of HIF-1α involved the Nur77-mediated ubiquitin proteasome pathway. A strong positive correlation between Nur77 and HIF-1α expression in human breast cancer specimens was also confirmed.

Conclusion: Therefore, LNT appears to inhibit the progression of breast cancer partly through the Nur77/HIF-1α signaling axis. The findings of the present study may provide a theoretical basis for targeting HIFs in the treatment of breast cancer.

Recent advances in the application of probiotic yeasts, particularly Saccharomyces, as an adjuvant therapy in the management of cancer with focus on colorectal cancer

Today, the increasing rate of cancer-related mortality, has rendered cancer a major global challenge, and the second leading cause of death worldwide. Conventional approaches in the treatment of cancer mainly include chemotherapy, surgery, immunotherapy, and radiotherapy. However, these approaches still come with certain disadvantages, including drug resistance, and different side effects such as gastrointestinal (GI) irritation (e.g., diarrhea, mucositis). This has encouraged scientists to look for alternative therapeutic methods and adjuvant therapies for a more proper treatment of malignancies. Application of probiotics as an adjuvant therapy in the clinical management of cancer appears to be a promising strategy, with several notable advantages, e.g., increased safety, higher tolerance, and negligible GI side effects. Both in vivo and in vitro analyses have indicated the active role of yeast probiotics in mitigating the rate of cancer cell proliferation, and the induction of apoptosis through regulating the expression of cancer-related genes and cellular pathways. Strain-specific anti-cancer activities of yeast probiotics strongly suggest that their administration along with the current cancer therapies may be an efficient method to reduce the side effects of these approaches. The main purpose of this article is to evaluate the efficacy of yeast probiotics in alleviating the adverse effects associated with cancer therapies.

Degradation mechanism of Saccharomyces cerevisiae β-D-glucan by ionic liquid and dynamic high pressure microfluidization

The insolubility of Saccharomyces cerevisiae β-D-glucan in most common solvents seriously restricts its applications and recovery. In this work, ionic liquids (ILs) were used for dissolution and modification under high pressure microfluidization (HPM). ILs 1-ethyl-3-methylimidazolium acetate (EmimAc) showed good β-D-glucan dissolving capacities, which can facilitate its structural modifications to recycle under environmentally friendly conditions. However, the synergistic effect of ionic liquid and high pressure microfluidization on physiochemical properties and structure of S. cerevisiae β-D-glucan were unclearly. The objectives of this study were: 1) to study the physiochemical properties of β-D-glucan after treating by ILs and HPM; 2) to compare the essential structure and conformation of β-D-glucan after treating by ILs and HPM; 3) to provide theoretical basis for precise regulation and green manufacturing of soluble S. cerevisiae β-D-glucan.

The effect of Candida cell wall beta-glucan on treatment-resistant LL/2 cancer cell line: in vitro evaluation

Candida albicans (C. albicans) cell wall beta-glucan has been considered as a potential agent in the treatment of cancers due to its anti-tumor properties. Therefore, in the present study, we investigated the anti-cancer effects of Candida cell wall beta-glucan on Lewis lung carcinoma cell line (LL/2) cells. Beta-glucan of C. albicans cell wall was extracted. LL/2 cell line was cultured, then sphere cells and parental cells were exposed to the different concentrations of beta-glucan extracted from C. albicans (10-6000 μg/ml), for 24, 48 and 72 h. Cytotoxicity of beta-glucan was assayed by MTT test, then RNA extracted from cells population (treated and untreated cells), cDNA synthetized and expression level of Sox2, Oct4, C-myc, Nanog genes were also investigated using Real-time methods. At optimal concentrations of 800 and 1000 μg/ml, the extracted beta-glucan showed a significant cytotoxic effect on both parental and sphere cell populations (p < 0.05). Real-time PCR analysis revealed a decreased expression of Oct4 and Sox2 genes in treatment of cells with beta-glucan compared with control group. Since the extracted beta-glucan showed an inhibitory effect on the expression of Oct4 and Sox2 genes involved in LL/2 metastasis, therefore, beta-glucan can be considered as an anti-tumor agent because of its anti-metastatic properties, however, more in vitro and in vivo studies are needed to provide further evidence on this topic in the future.

Yeast β-D-glucan exerts antitumour activity in liver cancer through impairing autophagy and lysosomal function, promoting reactive oxygen species production and apoptosis

Autophagy is an evolutionarily conserved catabolic process that recycles proteins and organelles in a lysosome-dependent manner and is induced as an alternative source of energy and metabolites in response to diverse stresses. Inhibition of autophagy has emerged as an appealing therapeutic strategy in cancer. However, it remains to be explored whether autophagy inhibition is a viable approach for the treatment of hepatocellular carcinoma (HCC). Here, we identify that water-soluble yeast β-D-glucan (WSG) is a novel autophagy inhibitor and exerts significant antitumour efficacy on the inhibition of HCC cells proliferation and metabolism as well as the tumour growth in vivo. We further reveal that WSG inhibits autophagic degradation by increasing lysosomal pH and inhibiting lysosome cathepsins (cathepsin B and cathepsin D) activities, which results in the accumulation of damaged mitochondria and reactive oxygen species (ROS) production. Furthermore, WSG sensitizes HCC cells to apoptosis via the activation of caspase 8 and the transfer of truncated BID (tBID) into mitochondria under nutrient deprivation condition. Of note, administration of WSG as a single agent achieves a significant antitumour effect in xenograft mouse model and DEN/CCl₄ (diethylnitrosamine/carbon tetrachloride)-induced primary HCC model without apparent toxicity. Our studies reveal, for the first time, that WSG is a novel autophagy inhibitor with significant antitumour efficacy as a single agent, which has great potential in clinical application for liver cancer therapy.

•

Water-soluble yeast β-D-glucan (WSG) exerts direct antitumour activity in HCC

•

WSG inhibits autophagic degradation by increasing lysosomal pH

•

WSG causes accumulation of damaged mitochondria and ROS production

•

WSG sensitizes HCC cells to apoptosis via the activation of caspase 8

An overview of yeast probiotics as cancer biotherapeutics: possible clinical application in colorectal cancer

The previous reports have established a strong link between diet, lifestyle, and gut microbiota population with the onset of the colorectal cancer (CRC). Administration of probiotics has become a particular interest in prevention and treatment of CRC. As potential dietary complements, probiotics might be able to lower the risk of CRC and manage the safety of traditional cancer therapies such as surgery, radiation therapy, and chemotherapy. This review investigates the promising effects of probiotics as biotherapeutics, with due attention to possible clinical application of yeast probiotics in prevention and treatment of CRC. In addition, various underlying anti-cancer mechanisms are covered here based on scientific evidence and findings from numerous experimental studies. Application of probiotics as biotherapeutics in CRC, however, needs to be approved by human clinical trials. It is of prime concern, to find potential probiotic strains, effective doses for administrations and regimes, and molecular mechanisms involved in prevention and treatment.

Yeast-based vaccines: New perspective in vaccine development and application

In presently licensed vaccines, killed or attenuated organisms act as a source of immunogens except for peptide-based vaccines. These conventional vaccines required a mass culture of associated or related organisms and long incubation periods. Special requirements during storage and transportation further adds to the cost of vaccine preparations. Availability of complete genome sequence, well-established genetic, inherent natural adjuvant and non-pathogenic nature of yeast species viz. Saccharomyces cerevisiae, Pichia pastoris makes them an ideal model system for the development of vaccines both for public health and for on-farm consumption. In this review, we compile the work in this emerging field during last two decades with major emphases on S. cerevisiae and P. pastoris which are routinely used worldwide for expression of heterologous proteins with therapeutic value against infectious diseases along with possible use in cancer therapy. We also pointed towards the developments in use of whole recombinant yeast, yeast surface display and virus-like particles as a novel strategy in the fight against infectious diseases and cancer along with other aspects including suitability of yeast in vaccines preparations, yeast cell wall component as an immune stimulator or modulator and present status of yeast-based vaccines in clinical trials.

Immunostimulating and Antimetastatic Effects of Polysaccharides Purified from Ginseng Berry

Ginseng root has been used in traditional oriental medicine for the enhancement of immune system function. The immunostimulatory effects of ginseng berry polysaccharides, however, remain unclear. Effects of polysaccharides from ginseng berry on the activation of natural killer (NK) cells and inhibition of tumors are reported. A crude polysaccharide was isolated from ginseng berry as a ginseng berry polysaccharide portion (GBPP) and was further fractionated using gel filtration chromatography to obtain the three polysaccharide fractions GBPP-I, -II and -III. GBPP-I consisted of mainly galactose (46.9%) and arabinose (27.5%). GBPP-I showed a high dose-dependent anticomplementary activity. Stimulation of murine peritoneal macrophages by GBPP-I showed the greatest enhancement of interleukin (IL)-6 and IL-12 and tumor necrosis factor (TNF)- α production. In addition, an ex vivo assay of natural killer (NK) cell activity showed that oral ( p.o.) administration of GBPP-I significantly increased NK cell cytotoxicity in YAC-1 tumor cells and production of granzyme B. Prophylactic intravenous ( i.v.) and p.o. administration of GBPP-I significantly and dose-dependently inhibited lung metastatic activity in B16BL6 melanoma cells. Depletion of NK cells after injection of rabbit anti-asialo GM1 partially abolished the inhibitory effect of GBPP-I on lung metastasis, indicating that NK cells play an important role in anticancer effects. GBPP-I exerts a strong immune-enhancing activity and can prevent cancer metastasis through activation of NK cells and other immune-related cells.

Beta-glucan-induced inflammatory monocytes mediate antitumor efficacy in the murine lung

β-Glucan is a naturally occurring glucose polysaccharide with immunostimulatory activity in both infection and malignancy. β-Glucan's antitumor effects have been attributed to the enhancement of complement receptor 3-dependent cellular cytotoxicity, as well as modulation of suppressive and stimulatory myeloid subsets, which in turn enhances antitumor T cell immunity. In the present study, we demonstrate antitumor efficacy of yeast-derived β-glucan particles (YGP) in a model of metastatic-like melanoma in the lung, through a mechanism that is independent of previously reported β-glucan-mediated antitumor pathways. Notably, efficacy is independent of adaptive immunity, but requires inflammatory monocytes. YGP-activated monocytes mediated direct cytotoxicity against tumor cells in vitro, and systemic YGP treatment upregulated inflammatory mediators, including TNFα, M-CSF, and CCL2, in the lungs. Collectively, these studies identify a novel role for inflammatory monocytes in β-glucan-mediated antitumor efficacy, and expand the understanding of how this immunomodulator can be used to generate beneficial immune responses against metastatic disease.

Fungal mediated innate immune memory, what have we learned?

The binary classification of mammalian immune memory is now obsolete. Innate immune cells carry memory characteristics. The overall capacity of innate immune cells to remember and alter their responses is referred as innate immune memory and the induction of a non-specific memory resulting in an enhanced immune status is termed "trained immunity". Historically, trained immunity was first described as triggered by the human fungal pathogen Candida albicans. Since, numerous studies have accumulated and deciphered the main characteristics of trained immunity mediated by fungi and fungal components. This review aims at presenting the newly described aspect of memory in innate immunity with an emphasis on the historically fungal mediated one, covering the known molecular mechanisms associated with training. In addition, the review uncovers the numerous non-specific effect that β-glucans trigger in the context of infectious diseases and septicaemia, inflammatory diseases and cancer.

The Complexity of Fungal β-Glucan in Health and Disease: Effects on the Mononuclear Phagocyte System

β-glucan, the most abundant fungal cell wall polysaccharide, has gained much attention from the scientific community in the last few decades for its fascinating but not yet fully understood immunobiology. Study of this molecule has been motivated by its importance as a pathogen-associated molecular pattern upon fungal infection as well as by its promising clinical utility as biological response modifier for the treatment of cancer and infectious diseases. Its immune effect is attributed to the ability to bind to different receptors expressed on the cell surface of phagocytic and cytotoxic innate immune cells, including monocytes, macrophages, neutrophils, and natural killer cells. The characteristics of the immune responses generated depend on the cell types and receptors involved. Size and biochemical composition of β-glucans isolated from different sources affect their immunomodulatory properties. The variety of studies using crude extracts of fungal cell wall rather than purified β-glucans renders data difficult to interpret. A better understanding of the mechanisms of purified fungal β-glucan recognition, downstream signaling pathways, and subsequent immune regulation activated, is, therefore, essential not only to develop new antifungal therapy but also to evaluate β-glucan as a putative anti-infective and antitumor mediator. Here, we briefly review the complexity of interactions between fungal β-glucans and mononuclear phagocytes during fungal infections. Furthermore, we discuss and present available studies suggesting how different fungal β-glucans exhibit antitumor and antimicrobial activities by modulating the biologic responses of mononuclear phagocytes, which make them potential candidates as therapeutic agents.

The effects of gene disruption of Kre6-like proteins on the phenotype of β-glucan-producing Aureobasidium pullulans

Killer toxin resistant 6 (Kre6) and its paralog, suppressor of Kre null 1 (Skn1), are thought to be involved in the biosynthesis of cell wall β-(1 → 6)-D-glucan in baker's yeast, Saccharomyces cerevisiae. The Δkre6Δskn1 mutant of S. cerevisiae and other fungi shows severe growth defects due to the failure to synthesize normal cell walls. In this study, two homologs of Kre6, namely, K6LP1 (Kre6-like protein 1) and K6LP2 (Kre6-like protein 2), were identified in Aureobasidium pullulans M-2 by draft genome analysis. The Δk6lp1, Δk6lp2, and Δk6lp1Δk6lp2 mutants were generated in order to confirm the functions of the Kre6-like proteins in A. pullulans M-2. The cell morphologies of Δk6lp1 and Δk6lp1Δk6lp2 appeared to be different from those of wild type and Δk6lp2 in both their yeast and hyphal forms. The productivity of the extracellular polysaccharides, mainly composed of β-(1 → 3),(1 → 6)-D-glucan (β-glucan), of the mutants was 5.1-17.3% less than that of wild type, and the degree of branching in the extracellular β-glucan of mutants was 14.5-16.8% lower than that of wild type. This study showed that the gene disruption of Kre6-like proteins affected the cell morphology, the productivity of extracellular polysaccharides, and the structure of extracellular β-glucan, but it did not have a definite effect on the cell viability even in Δk6lp1Δk6lp2, unlike in the Δkre6Δskn1 of S. cerevisiae.

Use of transfer factor in immunosuppressed surgical patients

ABSTRACT Objective : to evaluate the action of Transfer Factor on the immune response of patients with malignant neoplasm submitted to surgery, chemotherapy and radiotherapy. Method: we analyzed the variations of leukocytes, total lymphocytes, T-lymphocytes and CD4 counts in 60 patients submitted to immunostimulation with a single, daily dose of 0.5mg sublingual Transfer Factor, started simultaneously with chemotherapy and/or radiotherapy. Results: there were statistically significant increases in the counts of all cell lines studied, more pronounced after 12 months of use of the medication. Conclusion: the Transfer Factor restored immune response and showed no side effects.

Clinical and Physiological Perspectives of β-Glucans: The Past, Present, and Future

β-Glucans are a group of biologically-active fibers or polysaccharides from natural sources with proven medical significance. β-Glucans are known to have antitumor, anti-inflammatory, anti-obesity, anti-allergic, anti-osteoporotic, and immunomodulating activities. β-Glucans are natural bioactive compounds and can be taken orally, as a food supplement, or as part of a daily diet, and are considered safe to use. The medical significance and efficiency of β-glucans are confirmed in vitro, as well as using animal- and human-based clinical studies. However, systematic study on the clinical and physiological significance of β-glucans is scarce. In this review, we not only discuss the clinical and physiological importance of β-glucans, we also compare their biological activities through the existing in vitro and animal-based in vivo studies. This review provides extensive data on the clinical study of β-glucans.

Gamma-irradiated β-glucan modulates signaling molecular targets of hepatocellular carcinoma in rats

β-glucans are one of the most abundant forms of polysaccharides known as biological response modifiers which influence host's biological response and stimulate immune system. Accordingly, this study was initiated to evaluate irradiated β-glucan as a modulator for cellular signaling growth factors involved in the pathogenesis of hepatocellular carcinoma in rats. Hepatocellular carcinoma was induced with 20 mg diethylnitrosamine/kg BW. Rats received daily by gastric gavage 65 mg irradiated β-glucan/kg BW. It was found that treatment of rats with diethylnitrosamine induced hepatic injury and caused significant increase in liver injury markers with a concomitant significant increase in both hepatic oxidative and inflammatory indices: alpha-fetoprotein, interferon gamma, and interleukin 6 in comparison with normal and irradiated β-glucan-treated groups. Western immunoblotting showed a significant increase in the signaling growth factors: extracellular signal-regulated kinase 1 and phosphoinositide 3-kinase proteins in a diethylnitrosamine-treated group while both preventive and therapeutic irradiated β-glucan treatments recorded significant improvement versus diethylnitrosamine group via the modulation of growth factors that encounters hepatic toxicity. The transcript levels of vascular endothelial growth factor A and inducible nitric oxide synthase genes were significantly higher in the diethylnitrosamine-treated group in comparison with controls. Preventive and therapeutic treatments with irradiated β-glucan demonstrated that the transcript level of these genes was significantly decreased which demonstrates the protective effect of β-glucan. Histological investigations revealed that diethylnitrosamine treatment affects the hepatic architecture throughout the significant severe appearance of inflammatory cell infiltration in the portal area and congestion in the portal vein in association with severe degeneration and dysplasia in hepatocytes all over hepatic parenchyma. The severity of hepatic architecture changes was significantly decreased with both β-glucan therapeutic and preventive treatments. In conclusion, irradiated β-glucan modulated signal growth factors, vascular endothelial growth factor A, extracellular signal-regulated kinase 1, and phosphatidylinositol-3-kinase, which contributed to experimental hepatocarcinogenesis.

Lung cancer and β-glucans: review of potential therapeutic applications

The potential of natural substances with immunotherapeutic properties has long been studied. β-glucans, a cell wall component of certain bacteria and fungi, potentiate the immune system against microbes and toxic substances. Moreover, β-glucans are known to exhibit direct anticancer effects and can suppress cancer proliferation through immunomodulatory pathways. Mortality of lung cancer has been alarmingly increasingly worldwide; therefore, treatment of lung cancer is an urgent necessity. Numerous researchers are now dedicated to using β-glucans as a therapy for lung cancer. In the present attempt, we have reviewed the studies addressing therapeutic effects of β-glucans in primary and metastatic lung cancer published in the time period of 1991-2016.

Uptake of intraperitoneally administrated triple helical β-glucan for antitumor activity in murine tumor models

Triple helical β-glucan (THG) was captured by macrophages and degraded into small fragments to activate neutrophils, leading to apoptosis of tumor cells.

Anti-tumor effects of (1→3)-β-d-glucan from Saccharomyces cerevisiae in S180 tumor-bearing mice

(1→3)-β-d-Glucan from Saccharomyces cerevisiae is a typical polysaccharide with various biological effects and is considered a candidate for the prevention and treatment of cancer in vitro. Research into the function of (1→3)-β-d-glucan in tumor-bearing animals in vivo, however, is limited. Here, we investigated the effects of (1→3)-β-d-glucan from S. cerevisiae on S180 tumor-bearing mice and on the immunity of the tumor-bearing host. The molecular mechanisms underlying the observed effects were investigated. (1→3)-β-d-Glucan was shown to exert anti-tumor effects without toxicity in normal mouse cells. The volume and weight of S180 tumors decreased dramatically following treatment with (1→3)-β-d-glucan, and treatment with the polysaccharide was furthermore shown to increase the tumor inhibition rate in a dose-dependent manner. Spleen index, T lymphocyte subsets (CD₄ and CD₈), as well as interleukins (IL)-2, (IL-2, IL-6), and tumor necrosis factor-α were assayed to detect the immunoregulatory and anti-tumor effects after (1→3)-β-d-glucan intragastrical administration. (1→3)-β-d-Glucan was shown to significantly potentiate the mouse immune responses by, among other effects, decreasing the ratio of CD₄ to CD₈. The expression levels of IL-2, IL-6, and TNF-α were also significantly increased by (1→3)-β-d-glucan. These results suggest that (1→3)-β-d-glucan enhances the host's immune function during the tumor inhibition process. S180 tumor cells treated with (1→3)-β-d-glucan also exhibited significant apoptotic characteristics. (1→3)-β-d-glucan increased the ratio of Bax to Bcl-2 at the translation level by up-regulating Bax expression and down-regulating Bcl-2 expression, resulting in the initiation of cell apoptosis in S180 tumor-bearing mice. Taken together, these results indicate that the anti-tumor effects exerted by (1→3)-β-d-glucan may be attributed to the polysaccharide's immunostimulating properties and apoptosis-inducing features. Further investigation into these properties and their associated mechanisms will contribute to the development of potent polysaccharide-based anti-tumor agents.

Beta-glucan contamination of pharmaceutical products: How much should we accept?

Beta-glucans are large polysaccharides produced by a range of prokaryotic and eukaryotic organisms. They have potential immunostimulatory properties and have been used with therapeutic intent as anti-microbial and anti-tumour agents. A range of other potentially beneficial effects have been described, and oral forms of beta-glucans are widely available over-the-counter and online. Parenteral formulations are popular in parts of Asia and are the subject of ongoing trials, worldwide. Beta-glucans are also potential contaminants of pharmaceutical products, and high levels have been described in some blood products. However, little is known about the clinical effects of such contamination, considerable uncertainty exists over the level at which immunostimulation may occur, and there are no guidelines available on acceptable levels. We encountered beta-glucan contamination of one of our products, and we suspect that others may encounter similar issues since the origin of beta-glucan contamination includes commonly used filters and solutions applied in the manufacture of biotherapeutic agents. It is likely that regulators will increasingly enquire about beta-glucan levels in pharmaceutical products, especially those with an immunomodulatory mechanism of action. Here, we review the literature on beta-glucans in pharmaceutical products and propose an acceptable level for therapeutic agents for parenteral use.

Gamma-irradiated β-glucan induces immunomodulation and anticancer activity through MAPK and NF-κB pathways

BACKGROUND

This study was designed to evaluate the antitumor activity of low-molecular-weight β-glucan (LMBG) produced by gamma irradiation (50 kGy), using in vivo and in vitro models.

RESULTS

The results indicate that treatment with LMBG increased the proliferation of murine peritoneal macrophages, and their production of tumor necrosis factor α and nitric oxide, to a greater extent than treatment with high-molecular-weight β-glucan (HMBG). The activation of peritoneal macrophages by LMBG was mediated by both mitogen-activated protein kinases and nuclear factor-κB signaling. Interestingly, when administered prophylactically, LMBG significantly inhibited tumor growth and lung metastasis in mice injected with B16BL6 melanoma cells compared with the HMBG-treated group. In comparison with HMBG treatment, LMBG treatment also elevated cell proliferation, cytokine (interferon-γ and interleukin-2) production, and CD8(+) T cell populations in splenocytes from tumor-bearing mice.

CONCLUSION

These data indicate that LMBG is important in eliciting antitumor activity through a non-specific immune response and may play a major role as a value-added product in the medical industry.

Effect of beta glucan on white blood cell counts and serum levels of IL-4 and IL-12 in women with breast cancer undergoing chemotherapy: a randomized double-blind placebo-controlled clinical trial

BACKGROUND

Breast cancer is the most common female malignancy in the world. Beta glucan can be a hematopoietic and an immune modulator agent in cancer patients. The aim of this trial was to determine the effect of beta glucan on white blood cell counts and serum levels of IL-4 and IL-12 in women with breast cancer undergoing chemotherapy.

MATERIALS AND METHODS

This randomized double-blind placebo-controlled clinical trial was conducted on 30 women with breast carcinoma aged 28-65 years. The eligible participants were randomly assigned to intervention (n=15) or placebo (n=15) groups using a block randomization procedure with matching based on age, course of chemotherapy and menopause status. Patients in the intervention group received two 10-mg capsules of soluble 1-3, 1-6, D-beta glucan daily and the control group receiving placebo during 21 days, the interval between two courses of chemotherapy. White blood cells, neuthrophil, lymphocyte and monocyte counts as well as serum levels of IL-4 and IL-12 were measured at baseline and at the end of the study as primary outcomes of the study.

RESULTS

In both groups white blood cell counts decreased after 21 days of the intervention, however in the beta glucan group, WBC was less decreased non significantly than the placebo group. At the end of the study, the change in the serum level of IL-4 in the beta glucan group in comparison with the placebo group was statistically significant (p=0.001). The serum level of IL-12 in the beta glucan group statistically increased (p=0.03) and comparison between two groups at the end of the study was significant after adjusting for baseline values and covariates (p=0.007).

CONCLUSIONS

The findings suggest that beta glucan can be useful as a complementary or adjuvant therapy and immunomodulary agent in breast cancer patients in combination with cancer therapies, but further studies are needed for confirmation.

Anticancer properties of low molecular weight oat beta-glucan – An in vitro study

Anticancer properties of 1-3, 1-4 oat beta glucan are under intensive investigation now. Antitumor characteristic of fungi and yeast beta-glucans have been widely recognized, but those polysaccharides are mostly insoluble which creates several problems especially in topical formulation. Also high molecular weight oat beta-glucans reveal high viscosity which restricts its application. According to those problems in the current study the antitumor activities of low molecular weight beta-glucan derived from oats were investigated in cancer cells: Me45, A431 and normal HaCaT and murine macrophages P388/D1. The low molecular weight beta-glucan from oat significantly deceased cancer cells viability, while for the normal cells it was non-toxic. It was observed that with the increasing incubation time and the beta-glucan concentration the cancer cells viability significantly deceased. Furthermore for the normal cells the low molecular weight beta-glucan from oat was non-toxic. Immunocytochemical ABC analysis showed that beta-glucan induced strong expression of caspase-12 in both cancer cell lines, while in HaCaT cells ABC reaction was significantly lower and in P388/D1 cell line ABC reaction was negative. Our preliminary studies show strong anti-tumor properties of new low molecular weight beta-glucan from oat and at the same time no toxicity for normal cells.

Effect of Beta glucan on quality of life in women with breast cancer undergoing chemotherapy: a randomized double-blind placebo-controlled clinical trial

PURPOSE

Breast cancer is the most common female malignancy in the world. Beta glucan may improve quality of life in cancer patients receiving chemotherapy. The aim of this trial was to determine the effect of Beta glucan on quality of life in women with breast cancer undergoing chemotherapy.

METHODS

This study was conducted on 30 women with breast carcinoma. The eligible participants were randomly assigned to intervention (n=15) or placebo (n=15) groups using a block randomization procedure. Patients in the intervention group received two 10-mg capsules of soluble 1-3, 1-6, D-beta glucan daily and the placebo group received placebo for 21 days, in an interval between two courses of chemotherapy. Health - related quality of life (HRQL) was evaluated using the EORTC Quality of Life Questionnaire version.3.0 (EORTC QLQ-C30) at the beginning and end of the study.

RESULTS

At the end of the study, the Global health status /QoL score for the Beta glucan group was significantly increased (P=0.023), but the difference between the two groups was not significant. After intervention, the Functional scales score showed no significant change (P=0.099) between the two groups or within the groups. At the end of the study, the Symptom scales\items score was decreased significantly in Beta glucan group comparing the placebo group (P=0.048), as well as after adjusting for baseline score. The Symptom scales\items score's change was significant (P=0.012) within the Beta glucan group, compared with the baseline score.

CONCLUSION

The findings suggest that Beta glucan may be useful as a complementary or adjuvant therapy for improving quality of life in breast cancer patients in combination with cancer therapies.

β-Glucan supplementation, allergy symptoms, and quality of life in self-described ragweed allergy sufferers

This randomized, placebo-controlled, double-blind study compared the effects of daily supplementation for 4 week with 250 mg Wellmune WGP® β-1,3/1,6-Glucan (WGP) with placebo 250 mg/day (rice flour) on physical and psychological health attributes of self-described “moderate” ragweed allergy sufferers. Study participants (mean age = 36 ± 9 year; range 18–53 year) were recruited before the beginning of ragweed season (September) in Northeastern Ohio. Serum IgE concentration, allergy symptoms [via self-report, Visual Analog Scale (VAS), and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ)], psychological well-being [Profile of Mood States (POMS)], and physical function (RAND SF-36 Medical Outcomes Study) were measured immediately prior to and after supplementation with WGP (n = 24) or placebo (n = 24) for 4 weeks. Data were analyzed using repeated measures analyses of variance (ANOVA). Compared with placebo, WGP reduced total allergy symptoms (28%), symptom severity (52%), and symptom rating on the VAS (37%) (P < 0.05), but had no effect on serum IgE levels. As measured by the POMS, WGP increased participants' rating of vigor (10%), but reduced tension (34%), depression (45%), anger (41%), fatigue (38%), and confusion (34%) (P < 0.05). Study participants given WGP reported increased physical health (11%), energy (19%), and emotional well-being (7%) compared with study participants given the placebo (RAND SF-36 Medical Outcomes Study). The WGP group also reported decreased sleep problems (53%), reduced nasal symptoms (59%), eye symptoms (57%), non-nasal symptoms (50%), activities (53%), emotions (57%), and improved quality of life (QOL) (56%), as well as improved global mood state (13%). Supplementation with WGP for 4 weeks improved allergy symptoms, overall physical health, and emotional well-being compared with placebo in self-described “moderate” ragweed allergy sufferers during ragweed allergy season.

Immunosuppression of the trimellitic anhydride-induced th2 response by novel nonanatural products mixture in mice

Many natural dietary products prevent or cure allergic inflammation; however, the ability of mixtures of these natural medicinals to suppress allergic skin inflammation is unknown. We examined the inhibitory effects of nonanatural products mixture (NPM-9), which provides immunoregulatory activation, on Th2-mediated skin allergic inflammation. Oral administration of NPM-9 in mice reduced ear thickness and specific IgE production in trimellitic anhydride- (TMA-)induced contact hypersensitivity (CHS). NPM-9 also suppressed IL-4 and IL-1β production in splenocytes but prevented only TMA-induced IL-1β production in inflamed ears. To characterize the mechanism of this effect, we examined NPM-9 immunosuppression on an OVA-induced Th2 allergic state. Oral administration of NPM-9 inhibited Th2-mediated serum IgE overproduction. NPM-9 also downregulated the polarized Th2 response, whereas it upregulated Th1 response in splenocytes. These data suggest that NPM-9 may be a useful therapeutic agent for allergic inflammatory diseases through its suppression of the Th2-mediated allergic response.

Immunostimulatory properties and antitumor activities of glucans (Review)

New foods and natural biological modulators have recently become of scientific interest in the investigation of the value of traditional medical therapeutics. Glucans have an important part in this renewed interest. These fungal wall components are claimed to be useful for various medical purposes and they are obtained from medicinal mushrooms commonly used in traditional Oriental medicine. The immunotherapeutic properties of fungi extracts have been reported, including the enhancement of anticancer immunity responses. These properties are principally related to the stimulation of cells of the innate immune system. The discovery of specific receptors for glucans on dendritic cells (dectin-1), as well as interactions with other receptors, mainly expressed by innate immune cells (e.g., Toll-like receptors, complement receptor-3), have raised new attention toward these products as suitable therapeutic agents. We briefly review the characteristics of the glucans from mycelial walls as modulators of the immunity and their possible use as antitumor treatments.

Antiallergic effect of Trigonella foenum-graecum L. extracts on allergic skin inflammation induced by trimellitic anhydride in BALB/c mice

ETHNOPHARMACOLOGICAL RELEVANCE

Fenugreek (Trigonella foenum-graecum L.) has a wide variety of therapeutic properties for allergic and inflammatory diseases and is used as a traditional functional food, but its antiallergenic mechanism in these diseases is yet to be clearly elucidated.

AIM

In the present study, we investigated the antiallergic activity of fenugreek extract using trimellitic anhydride (TMA)-induced contact hypersensitivity (CHS) mice in vivo and ovalbumin (OVA)-immunized BALB/c mice ex vivo as represented model of T-helper (Th) 2-induced allergy.

MATERIALS AND METHODS

BALB/c mice were administered 250 mg/kg body weight (BW) of fenugreek extract for 7 days after sensitization and challenge treatment with 2-5% TMA. Ear thickness were noted, and the infiltration of eosinophils and mast cells was investigated by hematoxylin and eosin (H&E) and toluidine blue (TB) staining. The supernatants from homogenized ear and splenocytes were used for cytokine determination using ELISA. In addition, splenocytes from OVA-immunized BALB/c mice were treated with fenugreek extract ex vivo. The levels of cytokines present in the supernatants were determined by ELISA. The mRNA expression of T-box transcription factor 21 gene (T-bet), GATA-binding protein 3 (GATA-3), interferon (IFN)-γ, and interleukin (IL)-4 were evaluated by real-time RT-PCR.

RESULTS

Fenugreek extract was found to reduce ear thickness as well as the infiltration of eosinophils and mast cells. In homogenized ear, the production of IL-4, IL-5, IL-13, and IL-1β was suppressed. To determine the mechanism by which fenugreek extract inhibits allergic skin inflammation, detailed studies were conducted revealing that fenugreek extract prevented differentiation into Th2 cells in the splenocytes of OVA-induced allergic mice, resulting from suppressing the secretion of IL-4 and mRNA expression of GATA-3, an IL-4 transcription factor. In earlier phase, these extracts enhanced the secretion of IFN-γ, the mRNA expression of T-bet, an IFN-γ transcription factor, and the number of IFN-γ-producing CD4(+) T cells.

CONCLUSIONS

These results indicate that fenugreek extract cures Th2-induced allergic skin inflammation by enhancing Th1 differentiation. These data suggest that fenugreek extracts may prove to be an useful therapeutic agent on allergic inflammatory diseases as traditional use as well as Th2-mediated allergic response.

The mechanism of the anticancer function of M1 macrophages and their use in the clinic

M1-type macrophages are capable of inducing lysis in various types of cancer cells, but the mechanism of action is unclear. It has been noted that an "unknown protein" produced together with protease by activated macrophages is responsible for this action. Activated M1 macrophages have been recently reported to produce family 18 chitinases, all of which have been named chitotriosidase. Our experiments have demonstrated that family 18 chitinases work together with proteases and can damage various cancer cells both in vitro and in vivo. Thus, in this article, we suggest that the 50-kDa chitotriosidase is the reported "unknown protein". In addition, we discuss how to properly stimulate activated M1 macrophages to produce 50-kDa chitotriosidases and proteases for destroying cancer cells. Because family 19 chitinase has recently been reported to kill cancer cells, we also discuss the possibility of directly using human family 18 chitotriosidase and the humanized plant family 19 chitinase for cancer treatment.

The involvement of NK cell activation following intranasal administration of CpG DNA lipoplex in the prevention of pulmonary metastasis and peritoneal dissemination in mice

Synthetic oligodeoxynucleotides containing CpG motifs (CpG DNA) can activate immunocompetent cells, which may possess antitumor activity. Previously, we found that when the cationic liposomes complexes formed with CpG DNA (CpG DNA lipoplex) were administered intranasally, they could prevent pulmonary metastasis in mice. However, the mechanisms underlying this process are unknown. In the present study, we show that natural killer (NK) cells play an important role in preventing pulmonary metastasis and peritoneal dissemination in a mouse model of metastatic disease. Further, in vitro, the NK cells obtained from mice treated with CpG DNA lipoplex showed higher cytotoxicity compared with untreated mice and in vivo, depletion of NK cells (achieved through injection of rabbit anti-asialo GM1 serum), abolished the inhibitory effect of CpG DNA lipoplex on pulmonary metastasis and peritoneal dissemination. In contrast, macrophage elimination did not disrupt the effects of the CpG DNA lipoplex. These results suggest that intranasal administration of CpG DNA lipoplex could prevent pulmonary metastasis and peritoneal dissemination by activating NK cells.