CHARACTERIZATION AND CYTOKINE-STIMULATING ACTIVITIES OF ACIDIC HETEROGLYCANS FROM TREMELLA-FUCIFORMIS

Four acidic heteroglycans, T2a-T2d, were isolated from the body of Tre mella fuciformis Berk. They contained 1.9 %-2.9 % of acetyl groups and were composed of mannose (Man), glucuronic acid (GlcA), and small amo unts of xylose (Xyl), glucose (Glc), and fucose (Fuc). According to me thylation analysis they had a mannan backbone consisting of 3-linked M an, and side chains containing glucosyl, mannosyl, fucosyl, xylosyl, a nd glucuronic acid residues. The side chains were attached through 0-2 , 0-4, or 0-6 in about 40 percent of backbone mannosyl residues. Molec ular masses of the four polysaccharides were 410, 250, 34, and 20 kDa, respectively. T2a-T2d induced human monocytes to produce interleukin- l (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF) in vit ro. The products of Smith degradation (T2a-S) and lithium degradation (T2a-L) of T2a and the product of deacetylation (T2b-D) of T2b also in duced monocytes to secret IL-l as efficiently as the original polysacc harides, indicating that xylosyl and glucuronic acid residues as well as acetyl groups were not important to promote the cytokine-stimulatin g activity.