MHC class I tetramers specific for NP118 and GP283 were prepared using published protocols [[58, 59]]. Significant differences between two groups were evaluated using a two-tailed Student’s t-test. We sincerely thank all members of the Harty laboratory for helpful discussion. Supported by NIH grants AI46653, AI150073, and AI42767. The authors declare no commercial or financial conflicts of interest. “
“Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston,

MA, USA 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. JQ1 mouse Coadministration of APS NVP-AUY922 molecular weight 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. Hepatitis B is a potentially life-threatening liver disease caused by hepatitis B virus (HBV) infection. It is a global health problem and the most serious type of viral hepatitis (Chisari & Ferrari, 1995). More than 350 million people worldwide are chronic HBV carriers, and 1–2 million people die each year due to the consequences of chronic hepatitis B (Rehermann, 2005). To date, the commercial recombinant hepatitis B surface antigen (HBsAg) vaccine has been widely used, and has become an effective strategy for preventing HBV buy HA-1077 infection. However, the vaccine primarily induces the antibody response and Th2-biased immune response, but elicits relatively weak cell-mediated immune responses, particularly the antigen-specific CTL response. Therefore, it is unable to clear the virus in the infected cells (Zhang et al., 2009; Geurtsvan et al., 2008). Astragalus membranaceus (Huangqi) is a well-tolerated and nontoxic traditional medicinal herb that is used as a therapeutic agent to treat many diseases in China (Luo et al., 2009; Cui et al., 2003). Astragalus polysaccharides (APS), the major component in the root of A.