Elevated frequency and function of regulatory T cells in patients with active chronic hepatitis C

Department of Internal Medicine, Buddhist Dalin Tzu Chi General Hospital, Chia-Yi, Taiwan.
Journal of Gastroenterology (Impact Factor: 4.52). 02/2012; 47(7):823-33. DOI: 10.1007/s00535-012-0544-9
Source: PubMed


Regulatory T cells (Tregs) play a pivotal role in the persistence of hepatitis C virus infection. The aim of this study was to evaluate the frequency and function of Tregs in patients with chronic hepatitis C (CHC).
We enrolled 44 CHC patients with elevated alanine aminotransferase (ALT) levels (CH group), 13 CHC patients with persistent normal ALT levels (PNALT group), and 14 age-matched healthy subjects (HS group; controls). Tregs were identified as CD4+, CD25+, and forkhead box P3 (Foxp3)+ T lymphocytes, using three-color fluorescence-activated cell sorting (FACS). The frequency of Tregs was determined by calculating the percentage of CD4+CD25(high) T cells among CD4 T cells. CD127 and CD45RA were also analyzed for subsets of Tregs. The levels of serum transforming growth factor (TGF)-β and interleukin (IL)-10 in immunosuppressive assays were detected by enzyme-linked immunosorbent assay (ELISA). The immunosuppressive abilities of Tregs were evaluated by measuring their ability to inhibit the proliferation of effector cells.
Higher proportions of Tregs were found in the CH and PNALT groups compared with the HS group. The populations of CD127 low/negative and CD45RA negative cells were higher in the CH group than in the PNALT group. The expressions of IL-10 and TGF-β in the CH and PNALT groups were significantly higher than those in the HS group. In addition, the immunosuppressive ability of Tregs from the CH group was increased relative to that in the PNALT and the HS group.
CHC patients, irrespective of liver function, had higher frequencies of Tregs than healthy subjects; however, only CHC patients with inflammation showed enhanced immunosuppressive function of Tregs.

Download full-text


Available from: Kuo-Chih Tseng, Jul 30, 2014
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The cellular immunity has a profound impact on the status of hepatitis C virus (HCV) infection. However, the response of cellular immunity on the virological response in patients with antiviral treatment remains largely unclear. We aimed to clarify the response of peripheral T cells and monocytes in chronic hepatitis C patients with antiviral treatment. Patients with chronic hepatitis C were treated either with interferon alpha-2b plus ribavirin (n = 37) or with pegylated interferon alpha-2a plus ribavirin (n = 33) for up to 24 weeks. Frequencies of peripheral regulatory T-cells (Tregs), programmed death-1 (PD-1) expressing CD4+ T-cells or CD8+ T-cells and toll-like receptor (TLR) 3 expressing CD14+ monocytes were evaluated by flow cytometry in patients at baseline, 12 and 24 weeks following treatment and in 20 healthy controls. Frequencies of Tregs, PD-1 and TLR3 expressing cells were higher in patients than those in control subjects (P<0.05). Patients with complete early virological response (cEVR) showed lower Tregs, PD-1 expressing CD4+ or CD8+ T-cells than those without cEVR at 12 weeks (P<0.05). Patients with low TLR3 expressing CD14+ monocytes at baseline had a high rate of cEVR (P<0.05). Low peripheral TLR3 expressing CD14+ monocytes at baseline could serve as a predictor for cEVR of antiviral therapy in chronic HCV-infected patients. The cEVR rates were significantly increased in the patients with reduced circulating Tregs, PD-1 expressing CD4+ or CD8+ T-cells. Chinese Clinical Trial Registry ChiCTR10001090.
    Full-text · Article · Apr 2014 · PLoS ONE
  • Source

    Full-text · Article · Jul 2014