Novel sulfated polysaccharide derived from red-tide microalga Gyrodinium impudicum strain KG03 with immunostimulating activity in vivo.
The high-sulfate-containing exopolysaccharide p-KG03 is produced by the red-tide microalga Gyrodinium impudicum strain KG03. The immunostimulatory effects of this sulfated exopolysaccharide were investigated by isolating peritoneal macrophages from mice 10 or 20 days after they had received a single dose of p-KG03 (100 or 200 mg/kg body weight). The cytotoxicity of the isolated macrophages for B16 tumor cells was tested, as B16 tumor cells are sensitive to tumor necrosis factor alpha (TNF-alpha) and nitric oxide. The activities of natural killer cells from the p-KG03-treated mice against YAC-1 mouse lymphoma cells were also tested. The nonspecific immune functions mediated by natural killer cells and macrophages were increased by treatment with p-KG03 in vivo. These results suggest that p-KG03 has immunostimulatory effects and enhances the tumoricidal activities of macrophages and NK cells in vivo. In addition, p-KG03 treatment increased the plaque-forming cell response to sheep red blood cells, as well as the levels of IgM and IgG Exposure to p-KG03 also increased the production by macrophages of cytokines, such as interleukins -1beta and -6, and TNF-alpha. This is the first report of a marine microalgal sulfated polysaccharide having immunostimulatory activities. The p-KG03 polysaccharide may be useful for the development of biotechnological and pharmaceutical products that incorporate bioactive marine exopolysaccharides.
Korea Polar Research Institute, KORDI, Ansan, P.O. Box 29, Seoul, 425-600, Republic of Korea.
Joung Han
JH
Yim
Eunwha
E
Son
Suhkneung
S
Pyo
Hong Kum
HK
Lee
D000818:Animals; D045744:Cell Line, Tumor; D016207:Cytokines / Q000378:metabolism; D004141:Dinoflagellida / Q000737:chemistry*; D004797:Enzyme-Linked Immunosorbent Assay; D006861:Hydrogen Peroxide / Q000378:metabolism; D007114:Immunization; D007074:Immunoglobulin G / Q000378:metabolism; D007075:Immunoglobulin M / Q000378:metabolism; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D051379:Mice; D011134:Polysaccharides / Q000737:chemistry / Q000276:immunology* / Q000494:pharmacology; D013463:Sulfuric Acid Esters / Q000737:chemistry / Q000276:immunology* / Q000494:pharmacology
D016207:Cytokines; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011134:Polysaccharides; D013463:Sulfuric Acid Esters; D006861:Hydrogen Peroxide