Characterization of blood beta-1,3-glucan and anti-beta-glucan antibody in hemodialysis patients using culinary-medicinal Royal Sun Agaricus, Agaricus brasiliensis S. Wasser et al. (Agaricomycetideae)

Effects of Outdoor-Grown Royal Sun Medicinal Mushroom Agaricus brasiliensis KA21 (Agaricomycetes) Fruiting Body on Canine Malassezia Dermatitis

Brazil-grown outdoor-cultivated Agaricus brasiliensis KA21 fruiting body (KA21) significantly increases the production of serum anti-beta-glucan antibody. Therefore, KA21 ingestion may be useful for the prevention and alleviation of fungal infections. This study aimed to determine the effects of KA21 in fungal infections in animals. KA21 was administered to nine dogs infected with Malassezia. Notably, the anti-beta-glucan antibody titer remained unchanged or tended to decrease in the oral steroid arm, whereas in the non-steroid arm, antibody titer increased in almost all animals after KA21 ingestion. Dogs showing improved clinical symptoms exhibited increased anti-beta-glucan antibody titers. The results of this study suggest that KA21 ingestion may alleviate the symptoms of Malassezia and other fungal infections and that continuous ingestion may help prolong recurrence-free intervals. Additionally, the ingestion of KA21 during oral steroid dosage reduction or discontinuation may enable smoother steroid withdrawal.

[Fungal Beta-glucans: Structure and Effect on Host Immune Responses]

Fungi are eukaryotic microorganisms that show complex life cycles, including both anamorph and teleomorph stages. Beta-1,3-1,6-glucans (BGs) are major cell wall components in fungi. BGs are also found in a soluble form and are secreted by fungal cells. Studies of fungal BGs extensively expanded from 1960 to 1990 due to their applications in cancer immunotherapy. However, progress in this field slowed down due to the low efficacy of such therapies. In the early 21st century, the discovery of C-type lectin receptors significantly enhanced the molecular understanding of innate immunity. Moreover, pathogen-associated molecular patterns (PAMPs) and pattern recognition receptors (PRRs) were also discovered. Soon, dectin-1 was identified as the PRR of BGs, whereas BGs were established as PAMPs. Then, studies on fungal BGs focused on their participation in the development of deep-seated mycoses and on their role as a source of functional foods. Fungal BGs may have numerous and complex linkages, making it difficult to systematize them even at the primary structure level. Moreover, elucidating the structure of BGs is largely hindered by the multiplicity of genes involved in cell wall biosynthesis, including those for BGs, and by fungal diversity. The present review mainly focused on the characteristics of fungal BGs from the viewpoint of structure and immunological activities.

Diagnostic potential of antibody titres against Candida cell wall β-glucan in Kawasaki disease

Kawasaki disease (KD) is an acute vasculitis syndrome of unknown aetiology in children. The administration of Candida cell wall antigens induced KD-like coronary vasculitis in mice. However, the responses of KD patients to Candida cell wall antigen are unknown. In this study, we examined the response of KD patients to β-glucan (BG), one of the major fungal cell wall antigens, by measuring the anti-BG titre. In KD patients, the anti-C. albicans cell wall BG titre was higher than that in normal children. The anti-BG titre was also higher in KD patients compared to children who served as control subjects. The efficacy of intravenous immunoglobulin (IVIG) therapy in KD is well established. We categorized the KD patients into three groups according to the therapeutic efficacy of intravenous immunoglobulin (IVIG) and compared the anti-BG titre among these groups. Anti-BG titres were similar in the control group and the non-responsive group. In the fully responsive group, the anti-BG titre showed higher values than those in the normal children. This study demonstrated clinically that KD patients have high antibody titres to Candida cell wall BG, and suggested the involvement of Candida cell wall BG in the pathogenesis of KD. The relationship between IVIG therapy and anti-BG titre was also shown. These results provide valuable insights into the therapy and diagnosis of KD.