The CCL2-CCR2-Ly6c + macrophage axis in PegIFNα-2b therapy for chronic hepatitis B

BACKGROUND: Interferon (IFN) is an important treatment for chronic hepatitis B (CHB), with highly variable clinical efficacy, and how IFN-α mediates its therapeutic benefits via innate immunity, particularly macrophages, is not fully understood. OBJECTIVES: To elucidate whether and how the CCL2-CCR2-macrophage signaling axis mediates the antiviral efficacy of interferon-α therapy in chronic hepatitis B. DESIGN: We first analyzed the hepatic immune microenvironment induced by long-term IFN-α treatment using a public single-cell dataset (GSE237519). Next, we utilized an AAV-HBV-infected type I interferon receptor humanized mouse model (huIFNAR mice) and treated the mice with short-term pegylated interferon-α-2b (PegIFNα-2b), combined with either CCR2 antagonism (INCB3344) administration or macrophage depletion via clodronate liposomes. Through single-cell RNA sequencing (scRNA-seq), flow cytometry, immunohistochemistry, and serum HBV biomarker detection, we systematically investigate the role of the CCL2-CCR2-macrophage signaling axis in the anti-HBV effect of interferon. RESULTS: Long-term IFN treatment reshaped the hepatic macrophage landscape and activated CCL signaling. Depletion of macrophages attenuated IFN-mediated suppression of HBV DNA replication and impaired the decline in HBsAg levels. CCR2 antagonism impaired the antiviral efficacy of PegIFNα-2b and inhibited monocyte recruitment to the liver. Single-cell RNA sequencing further revealed that the CCR2 antagonist disrupted the CCL2-CCR2 signaling axis, which in turn arrested Ly6c + macrophage differentiation, disrupted intercellular communication networks, and promoted a more pronounced pro-inflammatory state. CONCLUSIONS: macrophage axis as a critical immunoregulatory pathway in IFN therapy for CHB. This axis coordinates macrophage recruitment, functional differentiation, and cellular crosstalk to mediate the antiviral effects of PegIFNα-2b. These findings may highlight a potential target to refine IFN-driven immunotherapies for CHB treatment.