A novel LNP/mRNA-based STING immunotherapy approach for chronic HBV infection 2334947

Introduction Chronic hepatitis B virus (HBV) infection remains a major global health burden. Current antiviral therapies suppress viral replication but fail to eliminate cccDNA or substantially reduce HBsAg, making functional cure rare. Innate immune control of HBV is limited by poor engagement of the STING pathway in hepatocytes due to low endogenous expression and inefficient agonist delivery. We developed a universal STING mimic (uniSTING) delivered via lipid nanoparticles encoding uniSTING mRNA, which drives formation of endomembrane-independent STING polymers and preferential activation of the IRF3/type I interferon axis while minimizing NF-κB signaling. Methods HBV-positive cells were treated with LNP/uniSTING, followed by assessment of type I interferon and interferon-stimulated genes (ISG) induction. In vivo, HBV carrier mice were administered LNP/uniSTING, and serum HBV viremia were monitored alongside HBV-specific innate and adaptive immune responses. Results uniSTING elicited strong IFN-I responses in HBV negative cells. In the HepAD38 cell line where HBV transcription from the integrated HBV genome is suppressed by doxycycline to produce HBV predominantly from HBV cccDNA, uniSTING induced robust IFN-β and ISGs expression, whereas in the Dox- condition, characterized by high-level HBV replication, uniSTING-induced IFN-β and ISG responses were attenuated. In vivo, administration of LNP/uniSTING to naive mice induced robust IFN-β production and ISG expression. In chronic HBV carrier mice, repeated administration of LNP/uniSTING resulted in sustained reductions in serum HBV DNA and HBsAg levels, accompanied by induction of anti-HBs IgG responses. Conclusion These findings demonstrate that uniSTING can break HBV immune tolerance and elicit a functional anti-HBs antibody response in vivo. Collectively, this work highlights uniSTING as a promising immunotherapeutic strategy for chronic HBV infection by simultaneously activating innate antiviral pathways and promoting protective humoral immunity.