| [ Summary ] |
In primary HBV adult infection, almost all cases eventually clear the virus. However, patients with chronic HBV infection rarely attain clearance under current anti‒HBV treatment. New therapies for chronic HBV infection are urgently needed. Extensive efforts have been made to understand the mechanisms necessary for mounting anti‒HBV immunity and to identidfy failed immune responses in chronic HBV infection. Restoring dysfunctional HBV‒specific immunity might be a potential therapeutic approach for resolving chronic HBV infection. It is generally accepted that HBV‒specific adaptive immune response, especially HBV‒specific CD8+T cells, is required for HBV clearance. There is growing evidence of the importance of metabolic factors such as indoleamine‒2,3‒dioxygenase (IDO), NK cells, macrophages, and CD4+follicular helper T cells (Tfh cells) and B cells in HBV control and clearance. Activation of CXCL9, CXCL10, CXCL11, CXCL13 and IL‒21 response is a signature pattern in attaining functional HBV cure in acute or chronic hepatitis B patients. We review the innate and adaptive immune responses to primary HBV infection and mechanisms of immune dysfunction in chronic HBV infection, by focusing on recent studies. |