NAFLD indirectly impairs antigen-specific CD8+ T cell immunity against liver cancer in mice.

Non-alcoholic fatty liver disease (NAFLD) has become an important etiology leading to liver cancer. NAFLD alters adaptive T cell immunity and has a profound influence on liver cancer development. However, it is unclear how NAFLD affects tumor antigen-specific T cell response. In this study, we generated a doxycycline-inducible MHC-I and -II antigen-expressing HCC cell line which allowed us to investigate tumor antigen-specific T cell response in two NAFLD mouse models. The system proved to be an effective and efficient way to study tumor antigen-specific T cells. Using this model, it was found that NAFLD impairs antigen-specific CD8+ T cell immunity against HCC. The effect was not due to reduced generation or intrinsic functional changes of tumor antigen-specific CD8+ T cells but caused by accumulated macrophages in the liver environment. The findings suggest that targeting macrophages in NAFLD-driven HCC may improve therapeutic outcomes.