Wenjing Zai, Kongying Hu, Mengying He, Ziyang Song, Pan Gao, Chen Luo, Minxiang Xie, Asha Ashuo, Min Yang, Jieliang Chen, Zhenghong Yuan
Combined RNAi and PEGIFNα therapy exerts synergistic antiviral effects by relieving HBV antigen-induced immune tolerance and orchestrating a functional T cell-B cell crosstalk network centered on MHC-I/II signaling. Enhancing antigen presentation pathways represents a promising adjunctive strategy to improve functional cure rate of CHB.
BACKGROUNDS/AIMS: PEGylated interferon-α (PEGIFNα) shows promise in treating chronic hepatitis B (CHB), yet patient response remains suboptimal. While suppressing hepatitis B virus (HBV) antigens by RNA interference (RNAi) could enhance PEGIFNα efficacy in CHB patients, the underlying immunological mechanisms remain obscure.
METHODS: Using our newly established extracellular humanized IFNAR (IFNAR-hEC) mouse model of chronic HBV infection, we evaluated the efficacy of a GalNac-conjugated siRNA (GalNac-siHBV) alone or in combination with PEGIFNα. Phenotypic and functional characteristics of immune cells were assessed by flow cytometry, ELISpot, and single-cell RNA sequencing (scRNA-seq).
RESULTS: High circulating HBsAg reduced antiviral effects and immune responsiveness of PEGIFNα. Combined PEGIFNα and RNAi therapy synergistically and durably suppressed HBsAg (~4log10 IU/mL, vs PBS) and achieved HBsAg seroconversion in ~30% of mice, outperforming either monotherapy. Mechanistically, PEGIFNα enhanced global T and B cell function, whereas combined therapy further amplified HBV-specific T and B cell responses. scRNA-seq analysis indicated that combined therapy attenuated inhibitory B cell-B cell interactions, strengthened MHC-I-mediated T cell crosstalk, and enhanced MHC-II signaling networks across B cells and hepatocytes/Cd8+ T cells, collectively improving the lymphocyte functionality and facilitating HBsAg seroconversion. Reinforcing MHC-I/II signaling with agonistic antibodies (α4-1BB, αCD40) or IL-2-Fc further potentiated antiviral immune responses of combinational regimen.
CONCLUSIONS: Combined RNAi and PEGIFNα therapy exerts synergistic antiviral effects by relieving HBV antigen-induced immune tolerance and orchestrating a functional T cell-B cell crosstalk network centered on MHC-I/II signaling. Enhancing antigen presentation pathways represents a promising adjunctive strategy to improve functional cure rate of CHB.