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

• Published in: FEMS immunology and medical microbiology Vol. 63; no. 2; pp. 228 - 235
• Main Authors: Du, Xiaogang, Chen, Xiaobing, Zhao, Bing, Lv, Yao, Zhang, Huaiyu, Liu, Hanmei, Chen, Zhiyu, Chen, Yanger, Zeng, Xianyin
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.11.2011; Blackwell; Oxford University Press
• Subjects: adjuvant; Adjuvants; Adjuvants, Immunologic - administration & dosage; Adjuvants, Immunologic - isolation & purification; Animals; Antibodies; Antigens; Applied microbiology; Astragalus; Astragalus membranaceus - chemistry; Astragalus polysaccharides; Biological and medical sciences; CD25 antigen; CD4 antigen; CD4-Positive T-Lymphocytes - immunology; CD8 antigen; CD8-Positive T-Lymphocytes - immunology; CD95 antigen; Cell Proliferation; Cytotoxicity; Fas antigen; Female; Foxp3 protein; Fundamental and applied biological sciences. Psychology; gamma -Interferon; Gene expression; Gene Expression Profiling; Growth factors; Hepatitis; Hepatitis B; Hepatitis B Antibodies - blood; Hepatitis B surface antigen; Hepatitis B Surface Antigens - immunology; hepatitis B vaccine; Hepatitis B Vaccines - administration & dosage; Hepatitis B Vaccines - immunology; Herbal medicine; Herbal medicines; Human viral diseases; immune response; Immune response (cell-mediated); Immune response (humoral); Immunomodulation; Immunoregulation; Infectious diseases; Interferon; Interferon-gamma - secretion; Interleukin 2; Interleukin 4; Lymphocytes; Lymphocytes T; Medical sciences; Medicinal plants; Mice; Microbiology; Miscellaneous; Polysaccharides; Polysaccharides - administration & dosage; Polysaccharides - isolation & purification; Roots; Saccharides; Signal transduction; T-Lymphocytes, Cytotoxic - immunology; T-Lymphocytes, Regulatory - immunology; TGF‐β; TLR4 protein; TLR‐4; Toll-like receptors; Transforming growth factor- beta; Transforming growth factor-b; Transforming Growth Factors - antagonists & inhibitors; Treg; Vaccination; Vaccines; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies (general aspects); Viral diseases; Viral hepatitis; Virology; γ-Interferon; TLR-4; Astragalus polysaccharides; hepatitis B vaccine; adjuvant; immune response; Treg; TGF-β; Toll like receptor 4; Transforming growth factor β; Vaccination; Orthohepadnavirus; Hepatic disease; Cellular immunity; Viral hepatitis B; Immunology; Hepadnaviridae; T-Lymphocyte; Hepatitis B virus; Humoral immunity; Hepatitis B surface antigen; Immune response; Vaccine; Infection; Virus; Viral disease; Immunological adjuvant; Digestive diseases; Polysaccharide
• ISSN: 0928-8244; 1574-695X; 2049-632X
• DOI: 10.1111/j.1574-695X.2011.00845.x

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.