M1 ‐Like Macrophage May Contribute to the Inflammation and Fibrosis Process of Chronic Hepatitis B

Chronic hepatitis B (CHB), driven by persistent hepatitis B virus (HBV) infection, is characterised by unresolved liver inflammation and fibrosis. Despite its clinical burden, the immune mechanisms underpinning CHB progression, particularly the role of macrophage polarisation, remain incompletely defined. We integrated multi-modal approaches to dissect the CHB immune microenvironment: immunohistochemistry (HBsAg/HBcAg quantification), imaging mass cytometry (spatial immune mapping), microfluidic high-throughput qPCR (gene profiling) and MILLIPLEX assays (cytokine quantification). In vitro, HBV-producing HepG2.2.15 cells were cocultured with polarised THP-1 macrophages (M1/M2) and LX-2 hepatic stellate cells (HSCs) to model macrophage-HSCs crosstalk. CHB severity correlated with elevated virologic markers (HBsAg, HBeAg, HBV DNA) and liver injury indices (ALT/AST). The hepatic immune landscape was dominated by M1-like macrophages, which colocalised with activated HSCs and collagenⅠ+ fibrotic niches. Intrahepatic M1 markers (CD86, TNFα, CXCL9 and CXCR3) were upregulated, while the M2 marker IL-10 was suppressed. Serum HBeAg levels positively correlated with intrahepatic CD86 and CXCL9, implicating HBeAg as a key driver of M1 polarisation. Compartment-specific cytokine profiling revealed elevated liver-to-plasma ratios of TGF-α, IFN-γ and IP-10 in advanced CHB, contrasting with reduced IL-10. In vitro, HBV skewed THP-1 macrophages towards an M1 phenotype and HBV-primed M1 macrophages potently activated LX-2 cells. Persistent HBV infection fuels CHB progression by fostering a pro-inflammatory M1 macrophage-dominated microenvironment, which synergises with HSCs activation and fibrogenesis. Our findings nominate M1 polarisation as therapeutic targets to disrupt inflammation-fibrosis crosstalk in CHB.