Viral (HCV, HBV, HIV) Persistence and Immune Homeostasis

Immune homeostasis is a host characteristic that maintains biological balance within a host. Humans have evolved many host defense mechanisms that ensure the survival of individuals upon encountering a pathogenic infection, with recovery or persistence from a viral infection being determined by both viral factors and host immunity. Chronic viral infections, such as hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV), often result in chronic fluctuating viremia in the face of host cellular and humoral immune responses, which are dysregulated by multi-faceted mechanisms that are incompletely understood. This review attempts to illuminate the mechanisms involved in this process, focusing on immune homeostasis in the setting of persistent viral infection from the aspects of host defense mechanism, including interferon-stimulated genes (ISGs), APOBEC3, autophagy, and interactions of various immune cells, cytokines, and regulatory molecules.