Purification of soluble beta-glucan with immune-enhancing activity from the cell wall of yeast.
Beta-glucan, one of the major cell wall components of Saccharomyces cerevisiae, has been found to enhance immune functions, especially by activating macrophages. However, a major obstacle to the clinical application of beta-(1-->3)-glucan is its low solubility in aqueous media. In this study, soluble beta-glucan, free of mannoprotein, was prepared, and its effects on TNF-alpha secretion and phagocytosis by macrophages were evaluated. Beta-glucan was first rendered soluble from the yeast cell wall by alkaline extraction (glucan-p1). The extract contained 2.8% of protein which was subsequently removed by successive DEAE-cellulose and ConA chromatography. Beta-glucan thus prepared was completely free of mannoprotein and was soluble at neutral pH (glucan-p3). The effects of beta-glucan on phagocytosis and TNF-alpha release activity were investigated. While glucan-p1 moderately induced TNF-alpha secretion at 200 microg/ml (550 pg of TNF-alpha/5 x 10(5) cells), glucan-p3 markedly stimulated macrophages at 200 microg/ml (2,860 pg of TNF-alpha/5 x 10(5) cells). Furthermore, glucan-p3 stimulated phagocytosis about 20% more than glucan-p1 did. In conclusion, we purified water-soluble beta-glucan which was completely devoid of mannoprotein and effectively stimulated the macrophage function, enabling it to be used as an intravenous injection for sepsis.
Lee
J N
JN
Graduate School of Biotechnology, Korea University, Seoul.
Lee
D Y
DY
Ji
I H
IH
Kim
G E
GE
Kim
H N
HN
Sohn
J
J
Kim
S
S
Kim
C W
CW
D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000302:isolation & purification* / Q000494:pharmacology*; D000818:Animals; D002473:Cell Wall / Q000737:chemistry; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D003636:DEAE-Cellulose; D005936:Glucans / Q000008:administration & dosage / Q000302:isolation & purification* / Q000494:pharmacology*; D066298:In Vitro Techniques; D007275:Injections, Intravenous; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D051379:Mice; D010587:Phagocytosis / Q000187:drug effects; D011134:Polysaccharides / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000737:chemistry*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D000276:Adjuvants, Immunologic; D005936:Glucans; D011134:Polysaccharides; D014409:Tumor Necrosis Factor-alpha; D003636:DEAE-Cellulose