CD4+ T Cells in Chronic Hepatitis B and T Cell-Directed Immunotherapy.

The impaired T cell responses observed in chronic hepatitis B (HBV) patients are considered to contribute to the chronicity of the infection. Research on this impairment has been focused on CD8+ T cells because of their cytotoxic effector function; however, CD4+ T cells are crucial in the proper development of these long-lasting effector CD8+ T cells. In this review, we summarize what is known about CD4+ T cells in chronic HBV infection and discuss the importance and opportunities of including CD4+ T cells in T cell-directed immunotherapeutic strategies to cure chronic HBV.