Effects of ß-glucans on the immune system

Abstract

ß-Glucans are naturally occurring polysaccharides. These glucose polymers are constituents of the cell wall of certain pathogenic bacteria and fungi. The healing and immunostimulating properties of mushrooms have been known for thousands of years in the Eastern countries. These mushrooms contain biologically active polysaccharides that mostly belong to group of ß-glucans. These substances increase host immune defense by activating complement system, enhancing macrophages and natural killer cell function. The induction of cellular responses by mushroom and other ß-glucans is likely to involve their specific interaction with several cell surface receptors, as complement receptor 3 (CR3; CD11b/CD18), lactosylceramide, selected scavenger receptors, and dectin-1 (ßGR). ß-Glucans also show anticarcinogenic activity. They can prevent oncogenesis due to the protective effect against potent genotoxic carcinogens. As immunostimulating agent, which acts through the activation of macrophages and NK cell cytotoxicity, ß-glucan can inhibit tumor growth in promotion stage too. Antiangiogenesis can be one of the pathways through which ß-glucans can reduce tumor proliferation, prevent tumor metastasis. ß-Glucan as adjuvant to cancer chemotherapy and radiotherapy demonstrated the positive role in the restoration of hematopiesis following by bone marrow injury. Immunotherapy using monoclonal antibodies is a novel strategy of cancer treatment. These antibodies activate complement system and opsonize tumor cells with iC3b fragment. In contrast to microorganisms, tumor cells, as well as other host cells, lack ß-glucan as a surface component and cannot trigger complement receptor 3-dependent cellular cytotoxicity and initiate tumor-killing activity. This mechanism could be induced in the presence of ß-glucans.

In Vitro Effects of Candida albicans and Aspergillus fumigatus on Dendritic Cells and the Role of Beta Glucan in this Effect

“…β-glucan has several immunopharmacological effects such as IL-6, TNF and nitrogen oxide secretion from macrophages, the adjuvant effect in the antibody production and antitumor effect [17]. Since it enhances DC maturation, it can be used in DC-based vaccination and in combination therapies to boost DC maturation [15].…”

Dietary Supplement Use in Cancer Care: Help or Harm

“…Medicinal mushrooms and mushroom-derived polysaccharide preparations have been extensively studied as immune modulators and adjuvant agents in cancer treatment using in vitro and animal models with some human clinical trials as well [81][82][83][84]. In addition to improving quality of life or modifying tumor response, medicinal mushroom preparations have been shown to have beneficial effects on immune response, mainly in patients with solid, as opposed to hematologic, malignancies.…”

Phagocytic Effects of β-Glucans from the Mushroom Coriolus versicolor are Related to Dectin-1, NOS, TNF-α Signaling in Macrophages

“…When a pathogen crosses an epithelial barrier, it is affected by phagocytosis and lysosomal enzymes and subsequently cytokines (IL-1, IL-6, TNF-α) and infl ammatory mediators (NO and H 2 O 2 ) are secreted (Akramiene et al, 2007). We used laminarin as a dectin-1 antagonist to investigate whether iNOS, eNOS, and TNF-α protein expression was affected by major β-glucan receptor dectin-1 signaling.…”