Inonotus obliquus BELYU1102 was selected from 12 different strains of Inonotus as a producer of immuno-stimulating
polysaccharide. After a batch fermentation of I. obliquus BELYU1102 was carried out in
a 300 l pilot vessel, endo-
polysaccharide and exo-
polysaccharide were both obtained. The proliferation activity of endo-
polysaccharide for splenic cells was much higher than the activity of exo-
polysaccharide. The active endo-
polysaccharide was produced primarily during the late stationary phase. Enhanced proliferation and polyclonal
IgM antibody production were observed in B cells by purified water-soluble endo-
polysaccharide.
Nitrite production and expression of IL-1beta,
IL-6,
TNF-alpha, and iNOS in macrophages were also enhanced. However, the endo-
polysaccharide did not affect the proliferation of T cells, the
IL-2 expression of Th1 cells, or the
IL-4 expression of Th2 cells. The endo-
polysaccharide showed activities similar to
lipopolysaccharide (LPS) for B cells and macrophages, but there was a large difference between the two
polysaccharides because cellular activations induced by endo-
polysaccharide were not affected by
polymyxin B, a specific inhibitor of LPS. The endo-
polysaccharide appeared to have other cellular binding sites with TLR-4 and did not show a direct toxicity against
tumor cells. However, indirect anti-
cancer effects via immuno-stimulation were observed. The mycelial endo-
polysaccharide of I. obliquus is a candidate for use as an immune response modifier. Submerged mycelial cultures are advantageous for industrial production of
polysaccharides.