Blockade of Tim-3 Pathway Ameliorates Interferon-_γ Production from Hepatic CD8⁺ T Cells in a Mouse Model of Hepatitis B Virus Infection

Abstract

T cell immunoglobulin- and mucin-domain-containing molecule-3 (Tim-3) has been reported to participate in the pathogenesis of inflammatory diseases. However, whether Tim-3 is involved in hepatitis B virus (HBV) infection remains unknown. Here, we studied the expression and function of Tim-3 in a hydrodynamics-based mouse model of HBV infection. A significant increase of Tim-3 expression on hepatic T lymphocytes, especially on CD8⁺ T cells, was demonstrated in HBV model mice from day 7 to day 18. After Tim-3 knockdown by specific shRNAs, significantly increased IFN-_γ production from hepatic CD8⁺ T cells in HBV model mice was observed. Very interestingly, we found Tim-3 expression on CD8⁺ T cells was higher in HBV model mice with higher serum anti-HBs production. Moreover, Tim-3 knockdown influenced anti-HBs production in vivo. Collectively, our data suggested that Tim-3 might act as a potent regulator of antiviral T-cell responses in HBV infection.