Intracellular Zn2+ levels regulate susceptibility to hepatitis B virus infection by modulating NTCP-mediated viral entry.

Hepatitis B virus (HBV) infection remains a significant global health challenge and is a leading cause of chronic liver diseases, including cirrhosis and hepatocellular carcinoma. Although nucleos(t)ide analogs and interferon-based therapies suppress viral replication, they do not eliminate the viral reservoir, highlighting the need for novel therapeutic strategies. HBV utilizes the sodium taurocholate cotransporting polypeptide (NTCP) as a key receptor for hepatocyte entry; however, the underlying mechanisms governing this process remain incompletely understood. In this study, we demonstrate that intracellular Zn2+ levels, regulated by zinc transporter 1 (ZnT1), also known as solute carrier family 30 member 1 (SLC30A1), serve as critical modulators of HBV entry. Zinc supplementation significantly reduced both HBV and hepatitis D virus infection in NTCP-expressing hepatocytes without affecting post-entry replication steps. Knockout or knockdown of SLC30A1 led to intracellular Zn2+ accumulation and impaired HBV infection, effects reversed by re-expression of functional SLC30A1 or treatment with the Zn2+ chelator TPEN. Mechanistically, elevated Zn2+ levels disrupted NTCP-mediated HBV/HDV internalization and bile acid uptake, implicating Zn2+ in the regulation of receptor activity. RNA sequencing analysis further revealed transcriptional reprogramming of metabolic and bile acid-associated pathways in Zn2+-treated cells. Collectively, these findings reveal a role for intracellular zinc homeostasis in regulating HBV entry and implicate the SLC30A1-Zn2+-NTCP axis in this process.