title: Astragalus polysaccharides enhance the humoral and cellular immune responses of hepatitis B surface antigen vaccination through inhibiting the expression of transforming growth factor β and the frequency of regulatory T cells.
abstract: Astragalus polysaccharides (APS), extracted from the root of Astragalus membranaceus, a traditional Chinese medicinal herb, have extensive pharmacological and strong immunomodulatory effects. In this study, the potential adjuvant effect of APS on humoral and cellular immune responses to hepatitis B subunit vaccine was investigated. Coadministration of APS with recombinant hepatitis B surface antigen significantly increased antigen-specific antibody production, T-cell proliferation and CTL (cytotoxic T lymphocyte) activity. Production of interferon-γ (IFN-γ), interleukin-2 (IL-2) and IL-4 in CD4(+) T cells and of IFN-γ in CD8(+) T cells were dramatically increased. Furthermore, expression of the genes PFP, GraB, Fas L and Fas were up-regulated; interestingly, expression of transforming growth factor β (TGF-β) and the frequency of CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg cells) were down-regulated. Expression of Toll-like receptor 4 (TLR4) was significantly increased by administration of APS. Together, these results suggest that APS is a potent adjuvant for the hepatitis B subunit vaccine and can enhance both humoral and cellular immune responses via activating the TLR4 signaling pathway and inhibit the expression of TGF-β and frequency of Treg cells.
authors.affiliation: Applied Biophysics and Immune Engineering Laboratory, College of Life Science, Sichuan Agriculture University, Ya'an, Sichuan, China.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Du
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Chen
authors.forename: Bing
authors.initials: B
authors.lastname: Zhao
authors.forename: Yao
authors.initials: Y
authors.lastname: Lv
authors.forename: Huaiyu
authors.initials: H
authors.lastname: Zhang
authors.forename: Hanmei
authors.initials: H
authors.lastname: Liu
authors.forename: Zhiyu
authors.initials: Z
authors.lastname: Chen
authors.forename: Yanger
authors.initials: Y
authors.lastname: Chen
authors.forename: Xianyin
authors.initials: X
authors.lastname: Zeng
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000302:isolation & purification; D000818:Animals; D027885:Astragalus propinquus / Q000737:chemistry; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D049109:Cell Proliferation; D005260:Female; D020869:Gene Expression Profiling; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D007371:Interferon-gamma / Q000378:metabolism; D051379:Mice; D011134:Polysaccharides / Q000008:administration & dosage* / Q000302:isolation & purification; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D015291:Transforming Growth Factors / Q000037:antagonists & inhibitors*
chemical_list: D000276:Adjuvants, Immunologic; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D011134:Polysaccharides; D015291:Transforming Growth Factors; D007371:Interferon-gamma