[The cytotoxic effect of CD8+ T subsets plays an important role in the chronic hepatitis B].

Objective: The aim of this study is to explore the cytotoxic effect of CD8+ T subsets in peripheral blood with chronic hepatitis B subjects who are at immune tolerance phase and immune clearance phase (before and after three months' treatment with interferon-alpha), further to investigate their impact in the pathogenesis of chronic hepatitis B and antiviral therapy.
Methods: The subjects of chronic hepatitis B, including 20 subjects of immune tolerance phase and 20 subjects of immune clearance phase, are enrolled in the study. And we use flow cytometry to detect Lysosome-associated membrane protein-1 (LAMP-1, CD107a) and Granzyme B (GrB) expression of CD8(high) and CD8(low) T cells in peripheral blood with chronic hepatitis B subjects.
Results: (1) At immune clearance phase, the CD8+ T subsets expressing GrB and CD107a are higher than counterpart of immune tolerance phase. (2) At immune tolerance phase and immune clearance phase in HBV infection, the CD8(low) T cells expressing GrB and CD107a are higher than that of CD8(high) T cells. (3) After three months' treatment with interferon-a, except for GrB+ CD107a+ CD8(high) T cells, CD8(high) T cells expressing GrB and CD107a present a tendency of ascensus at the same time with that of CD8(low) T cells a tendency of descensus except for GrB(-)CD107a+ CD8(low) T cells. (4) The CD8+ T cell expressing GrB and CD107a, correlate positively with HBV DNA load at immune tolerance phase, but correlated negatively at immune clearance phase.
Conclusions: (1) GrB and CD107a molecule expressed by different CD8+ T cell subsets play an important role in disease evolution and antivirus therapy of chronic hepatitis B, the cytotoxic effect of CD8(high) T cell subset became more and more stronger during the treatment of IFN-alpha, and the cytotoxic effect of CD8(low) T cell subset couldn't be neglected before antivirus therapy. (2) To some degree, the correlation between HBV-DNA load and the expression of GrB and CD107a at different CD8+ T cell subsets, could hint the relationship between virus and immune response.