title: Partial characterization and immunostimulatory effect of a novel polysaccharide-protein complex extracted from Phellinus linteus.
abstract: Many polysaccharides isolated from mushroom are considered to be biological response modifiers and have been shown to enhance various immune responses in vivo and in vitro. We demonstrate that a novel polysaccharide-protein complex (PPC) extracted from Phellinus linteus was a potent immunomodulator. PPC had a molecular weight of approximately 73 kDa. It was composed of five different monosaccharides, predominantly D-glucose and D-mannose, in the molar ratio of 3:2, the main amino acid being aspartic acid. PPC had a unique mode of immunostimulation with regard to its cell-type specificity. PPC was found to markedly increase the proliferation of B cells, but not T cells. Although PPC and lipopolysaccharide (LPS) had a similar mode of action in B cells, they were differentiated by the fact that PPC-induced cellular activation was not inhibited by polymyxin B (PB), a specific inhibitor of LPS. PPC increased the cytokine production and nitric oxide (NO) from macrophages. PPC also enhanced the lytic death of NO-sensitive tumor cells, B16 melanoma, through the production of NO. In addition, PPC up-regulated the natural killer (NK) cell-mediated killing of tumor cells, YAC-1 lymphoma in vitro. These results suggest that PPC stimulated the tumoricidal activities of macrophages and NK cells, and induced the proliferation of B cells in vitro. This process may be the mechanism by which PPC produced its therapeutic effects.
authors.affiliation: Faculty of Applied Marine Science, Cheju National University, Jeju, South Korea. immunkim@cheju.a.kr
authors.forename: Gi-Young
authors.initials: GY
authors.lastname: Kim
authors.forename: Jae-Yoon
authors.initials: JY
authors.lastname: Lee
authors.forename: Jeong-Ok
authors.initials: JO
authors.lastname: Lee
authors.forename: Chung-Ho
authors.initials: CH
authors.lastname: Ryu
authors.forename: Byung Tae
authors.initials: BT
authors.lastname: Choi
authors.forename: Yong-Ki
authors.initials: YK
authors.lastname: Jeong
authors.forename: Ki-Wan
authors.initials: KW
authors.lastname: Lee
authors.forename: Sang-Chul
authors.initials: SC
authors.lastname: Jeong
authors.forename: Yung Hyun
authors.initials: YH
authors.lastname: Choi
mesh_terms: D000276:Adjuvants, Immunologic / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D001487:Basidiomycota / Q000737:chemistry*; D016207:Cytokines / Q000378:metabolism; D006023:Glycoproteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D007694:Killer Cells, Natural / Q000187:drug effects; D008213:Lymphocyte Activation; D008223:Lymphoma / Q000276:immunology; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000276:immunology; D008546:Melanoma, Experimental / Q000276:immunology; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D016207:Cytokines; D006023:Glycoproteins; D009569:Nitric Oxide