epiglucan and Eosinophilia

Recurrent respiratory tract infections (RRTIs) present a very important problem in paediatric praxis. As true immunodeficiencies are rare, one of the most important factors assumed to contribute to increased respiratory morbidity is atopy. Several preparations of natural origin have been used for the prevention of RRTIs, and some of the most effective immunomodulators are biologically active polysaccharides - e.g. ß-glucans. In our randomised, double-blind, placebo-controlled study, we investigated the prevalence of atopy in a group of children with RRTIs and the potential anti-allergic effect of pleuran (ß-glucan isolated from Pleurotus ostreatus) on basic laboratory markers of allergic inflammation. We confirmed that atopy may be an important factor contributing to the increased respiratory morbidity in children with RRTIs. The active treatment with pleuran resulted in a significant reduction of peripheral blood eosinophilia and stabilised the levels of total IgE in serum. This was more evident in atopic subjects. Pleuran showed a potential anti-allergic effect. This previously non-described effect could expand the application of this natural immunomodulator also as a complementary adjuvant therapy in allergic patients.

Topics: Anti-Allergic Agents; beta-Glucans; Child; Child, Preschool; Double-Blind Method; Eosinophilia; Female; Humans; Hypersensitivity, Immediate; Immunoglobulin E; Male; Pleurotus; Respiratory Tract Infections

A number of studies have suggested a correlation between a decreased incidence in infectious diseases and an increased incidence of allergic diseases, including asthma. Although several pathogen-derived products have been shown to possess therapeutic potential for allergic diseases, it remains largely unknown whether β-glucan, a cell wall component of a variety of fungi, yeasts, and bacteria, has a regulatory potential for allergic diseases. In this study, we examined the effect of curdlan, a linear β-(1-3)-glucan, on the development of allergic airway inflammation. We found that i.p. injection of curdlan significantly inhibited Ag-induced eosinophil recruitment and Th2 cytokine production in the airways. The activation of CD4(+) T cells in the presence of curdlan induced IL-10-producing CD4(+) T cells with high levels of c-Maf expression. Curdlan-induced development of IL-10-producing CD4(+) T cells required the presence of APCs and ICOS/ICOS ligand interaction. Curdlan-induced development of IL-10-producing CD4(+) T cells also required intrinsic expression of STAT6. Furthermore, the transfer of Ag-specific CD4(+) T cells that were stimulated in the presence of curdlan inhibited Ag-induced eosinophil recruitment into the airways. Taken together, these results suggest that curdlan is capable of inducing IL-10-producing CD4(+) T cells and inhibiting the development of eosinohilic airway inflammation, underscoring the therapeutic potential of curdlan for allergic diseases.

Topics: Animals; beta-Glucans; Bronchial Hyperreactivity; CD4-Positive T-Lymphocytes; Cells, Cultured; Eosinophilia; Inflammation Mediators; Injections, Intraperitoneal; Interleukin-10; Mice; Mice, Inbred BALB C; Mice, Transgenic; Respiratory Hypersensitivity