title: Cellular immune responses in patients with hepatitis B surface antigen seroclearance induced by antiviral therapy.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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 (P < 0.001) and S peptide pool (P = 0.001) respectively. A higher response frequency to C than S peptide pools was confirmed in the interferon-gamma ICS assays for both CD4+ (P = 0.033) and CD8+ (P = 0.040) T cells in the HBsAg seroclearance group. The responses to C and S antigens in the inactive carriers were similar.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Hepatology Unit and Key Lab for Organ Failure Research, Nanfang Hospital, Southern Medical University, Guangzhou 510515, PR China.
authors.forename: Minfeng
authors.initials: M
authors.lastname: Liang
authors.forename: Shiwu
authors.initials: S
authors.lastname: Ma
authors.forename: Xiaoxiong
authors.initials: X
authors.lastname: Hu
authors.forename: Bin
authors.initials: B
authors.lastname: Zhou
authors.forename: Junchang
authors.initials: J
authors.lastname: Zhang
authors.forename: Jinjun
authors.initials: J
authors.lastname: Chen
authors.forename: Zhanhui
authors.initials: Z
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Zhu
authors.forename: William
authors.initials: W
authors.lastname: Abbott
authors.forename: Jinlin
authors.initials: J
authors.lastname: Hou
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000008:administration & dosage*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D006509:Hepatitis B / Q000188:drug therapy*; D006512:Hepatitis B Core Antigens / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D006515:Hepatitis B virus / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D007376:Interleukin-2 / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D014759:Viral Envelope Proteins / Q000276:immunology
chemical_list: D000998:Antiviral Agents; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D007376:Interleukin-2; D014759:Viral Envelope Proteins; D007371:Interferon-gamma