Branched chitins as nonnatural immunomodulatory biopolymers: secretions of TNF-alpha and NO by direct stimulation of macrophages.
In view of the interesting properties of branched polysaccharides occurring in nature, biological activities of nonnatural branched chitins having beta-1,6-N-acetyl-D-glucosamine branches on the poly(beta-1,4-N-acetyl-D-glucosamine) backbone have been studied. The immunostimulatory activities of the branched chitins were determined and compared with those of lentinan, a beta-1,3-D-glucan having beta-1,6-D-glucose branches, using the mouse macrophagelike cell line RAW264.7 in vitro. The secretions of the tumor necrosis factor and nitric oxide proved to be significantly higher with the branched chitins than with lentinan. Moreover, when interferon-gamma was used in conjunction with the branched chitins on macrophage treatment, a marked augmentation of nitric oxide production was observed. These results are interpreted as the direct stimulation of macrophages by the branched chitins, and the distinctive activities suggest the possibility of developing new types of polysaccharide antitumor agents.
Shimojoh
Manabu
M
Research and Development Department, Toyo Suisan Kaisha, Ltd., Kohnan, Minato-ku, Tokyo 108-8501, Japan. shimojohm@maruchan.co.jp
Kojima
Taku
T
Nakajima
Kohji
K
Hatta
Kiyoshige
K
Katoh
Akira
A
Kurita
Keisuke
K
D000276:Adjuvants, Immunologic / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D001704:Biopolymers / Q000737:chemistry / Q000494:pharmacology*; D002240:Carbohydrate Sequence; D002686:Chitin / Q000737:chemistry / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D000276:Adjuvants, Immunologic; D001704:Biopolymers; D014409:Tumor Necrosis Factor-alpha; D002686:Chitin; D009569:Nitric Oxide