An α-glucan isolated from root of Isatis Indigotica, its structure and adjuvant activity.
The root of Isatis indigotica is a traditional Chinese herbal medicine. An α-glucan (IIP-A-1) was firstly isolated from the roots. In this study we elucidated the chemical structure of IIP-A-1 and determined its adjuvant activity by co-immunizing mice with H1N1 influenza virus split and recombinant hepatitis B surface antigen (HBsAg), respectively. The polysaccharide was pretreated with periodate oxidation, Smith degradation and methylation in order to analyze its structure using GC, HPGPC, FT-IR, NMR and GC-MS. The adjuvant effect was evaluated by determining the antibody titers of serum against H1N1 influenza and HBsAg using ELISA. The proliferation and TNF-α secretion of macrophages administrated with different dose of IIP-A-1 were measured in vitro. The results of this study revealed that IIP-A-1 was an α-glucan with the molecular weight of 3,600 Da. The backbone was α-(1 → 4)-D-glucan with (1 → 6) branch chain. The α-glucan could significantly enhance the immune response of mice immunized with H1N1 influenza or HBsAg in vivo and exert good dose-dependent effects on the proliferation and the TNF-α secretion of macrophages in vitro. These results supported that IIP-A-1 was expected to be an efficacious adjuvant candidate for prophylactic and therapeutic vaccines.
Beijing Institute of Pharmacology and Toxicology, Beijing, 100850, China, shanjunjie001@126.com.
Junjie
J
Shan
Guohui
G
Sun
Jinwei
J
Ren
Ting
T
Zhu
Peiyuan
P
Jia
Wensheng
W
Qu
Qian
Q
Li
Junhua
J
Wu
Hao
H
Ma
Song
S
Wen
Yuxia
Y
Wang
D000277:Adjuvants, Pharmaceutic / Q000737:chemistry* / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D002240:Carbohydrate Sequence; D049109:Cell Proliferation; D005936:Glucans / Q000737:chemistry* / Q000494:pharmacology / Q000627:therapeutic use; D007114:Immunization; D031219:Isatis / Q000737:chemistry*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009976:Orthomyxoviridae Infections / Q000276:immunology / Q000628:therapy; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology / Q000627:therapeutic use
D000277:Adjuvants, Pharmaceutic; D000914:Antibodies, Viral; D005936:Glucans; D010936:Plant Extracts