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

FEMS Immunol Med Microbiol. 2011 Nov;63(2):228-35. doi: 10.1111/j.1574-695X.2011.00845.x.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / administration & dosage*
  • Adjuvants, Immunologic / isolation & purification
  • Animals
  • Astragalus propinquus / chemistry
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • Cell Proliferation
  • Female
  • Gene Expression Profiling
  • Hepatitis B Antibodies / blood
  • Hepatitis B Surface Antigens / immunology*
  • Hepatitis B Vaccines / administration & dosage
  • Hepatitis B Vaccines / immunology*
  • Interferon-gamma / metabolism
  • Mice
  • Polysaccharides / administration & dosage*
  • Polysaccharides / isolation & purification
  • T-Lymphocytes, Cytotoxic / immunology*
  • T-Lymphocytes, Regulatory / immunology*
  • Transforming Growth Factors / antagonists & inhibitors*


  • Adjuvants, Immunologic
  • Hepatitis B Antibodies
  • Hepatitis B Surface Antigens
  • Hepatitis B Vaccines
  • Polysaccharides
  • Transforming Growth Factors
  • Interferon-gamma