Partial characterization and immunostimulatory effect of a novel polysaccharide-protein complex extracted from Phellinus linteus.
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.
Kim
Gi-Young
GY
Faculty of Applied Marine Science, Cheju National University, Jeju, South Korea. immunkim@cheju.a.kr
Lee
Jae-Yoon
JY
Lee
Jeong-Ok
JO
Ryu
Chung-Ho
CH
Choi
Byung Tae
BT
Jeong
Yong-Ki
YK
Lee
Ki-Wan
KW
Jeong
Sang-Chul
SC
Choi
Yung Hyun
YH
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
D000276:Adjuvants, Immunologic; D016207:Cytokines; D006023:Glycoproteins; D009569:Nitric Oxide