Cellular immune responses in patients with hepatitis B surface antigen seroclearance induced by antiviral therapy

• Main Authors: Zhu Xiaolin, Sun Jian, Wang Zhanhui, Chen Jinjun, Zhang Junchang, Zhou Bin, Hu Xiaoxiong, Ma Shiwu, Liang Minfeng, Abbott William, Hou Jinlin
• Format: Article
• Language: English
• Published: BMC 2011-02-01
• Series: Virology Journal
• Online Access: http://www.virologyj.com/content/8/1/69

<p>Abstract</p> <p>Background</p> <p>The mechanisms by which chronic hepatitis B is completely resolved through antiviral therapy are unknown, and the contribution of acquired T cell immunity to hepatitis B surface antigen (HBsAg) seroclearance has not been investigated. Therefore, we measured the T-cell responses to core and envelope antigens in patients with HBsAg seroclearance.</p> <p>Methods</p> <p>Fourteen subjects with HBsAg seroclearance following antiviral treatment for chronic hepatitis B, 7 HBeAg-positive immunotolerant HBV carriers and 9 HBeAg-negative inactive HBsAg carriers were recruited. HBV-specific T-cell responses to recombinant HBV core (rHBcAg) and envelope (rHBsAg) proteins and pools of core and envelope peptides were measured using an ELISPOT assay detecting interferon-gamma and intracellular cytokine staining (ICS) assays detecting interferon-gamma or interleukin 2.</p> <p>Results</p> <p>Interferon-gamma ELISPOT assays showed a low frequency of weak responses to the rHBsAg and S peptide pool in the HBsAg seroclearance group, and the response frequency to the rHBcAg and the C peptide pool was higher than to the rHBsAg (<it>P </it>< 0.001) and S peptide pool (<it>P </it>= 0.001) respectively. A higher response frequency to C than S peptide pools was confirmed in the interferon-gamma ICS assays for both CD4+ (<it>P </it>= 0.033) and CD8+ (<it>P </it>= 0.040) T cells in the HBsAg seroclearance group. The responses to C and S antigens in the inactive carriers were similar.</p> <p>Conclusions</p> <p>There was a low frequency of CD4+ and CD8+ T cell immune responses to envelope antigens in Chinese subjects with HBsAg seroclearance following antiviral therapy. It is unlikely that these immune responses are responsible for HBsAg seroclearance in these subjects.</p>