Telbivudine on IgG-associated hypergammaglobulinemia and TGF-β1 hyperactivity in hepatitis B virus-related liver cirrhosis

Agalactosyl IgG induces liver fibrogenesis via Fc gamma receptor 3a on human hepatic stellate cells

The relevance of aberrant serum IgG N-glycosylation in liver fibrosis has been identified; however, its causal effect remains unclear. Because hepatic stellate cells (HSCs) contribute substantially to liver fibrosis, we investigated whether and through which mechanisms IgG N-glycosylation affects the fibrogenic properties of HSCs. Analysis of serum IgG1 N-glycome from 151 patients with chronic hepatitis B or liver cirrhosis revealed a positive correlation between Ishak fibrosis grading and IgG1 with agalactosyl N-glycoforms on the crystallizable fragment (Fc). Fc gamma receptor (FcγR) IIIa was observed in cultured human HSCs and HSCs in human liver tissues, and levels of FcγRIIIa in HSCs correlated with the severity of liver fibrosis. Additionally, agalactosyl IgG treatment caused HSCs to have a fibroblast-like morphology, enhanced migration and invasion capabilities, and enhanced expression of the FcγRIIIa downstream tyrosine-protein kinase SYK. Furthermore, agalactosyl IgG treatment increased fibrogenic factors in HSCs, including transforming growth factor (TGF)-β1, total collagen, platelet-derived growth factor subunit B and its receptors, pro-collagen I-α1, α-smooth muscle actin, and matrix metalloproteinase 9. These effects were more pronounced in HSCs that stably expressed FCGR3A and were reduced in FCGR3A knockout cells. Agalactosyl IgG and TGF-β1 each increased FCGR3A in HSCs. Furthermore, serum TGF-β1 concentrations in patients were positively correlated with agalactosyl IgG1 levels and liver fibrosis severity, indicating a positive feedback loop involving agalactosyl IgG, HSC-FcγRIIIa, and TGF-β1. In conclusion, agalactosyl IgG promotes fibrogenic characteristics in HSCs through FcγRIIIa. © 2024 The Pathological Society of Great Britain and Ireland.

Infant immune response to hepatitis B vaccine after fetal exposure to telbivudine

Whether telbivudine (LdT) treatment to pregnant women with hepatitis B surface antigen (HBsAg) affects infant immune response to hepatitis B vaccine (HepB) has not been investigated. A total of 127 HBsAg positive mothers and their neonates were enrolled and followed up at 11–13 months. Mothers took LdT (LdT group) or did not receive antiviral therapy (control group). Infant anti-HBs, immune cells and cytokines were measured after HepB was administered according to 0-1-6 procedure. We performed a 1:3 propensity score matching (PSM). Immune indexes in the two groups were compared. Baseline characteristics of mother-baby pairs were comparable in LdT group and control group. Infant anti-HBs geometric mean concentration (GMC) did not differ significantly between the two groups [767.70 (745.35) vs. 711.90 (819.60), P = .599]. There was no difference between the two groups in infant positive rate of anti-HBs [97.8% (91/93) vs. 97.1% (33/34), P = .999] and strong positive rate of anti-HBs [40.9% (38/93) vs. 44.1% (15/34), P = .742]. Infants with negative, low, medium, and high anti-HBs levels were similarly distributed between the two groups (P = .511). No differences in proportion of helper T cells, cytotoxic T cells, B cells, myeloid dendritic cells, and plasmacytoid dendritic cells of infants (P > .05) were detected between the two groups. Children in the LdT and control group had comparable levels of interleukin-2, interleukin-4, interleukin-6, interleukin-10, interleukin-12, interferon-α, interferon-γ and tumor necrosis factor-α (P > .05). Intrauterine exposure to LdT was safe to infant immune response to HepB after birth.

HBV induces liver fibrosis via the TGF-β1/miR-21-5p pathway

MicroRNA (miR)-21-5p is a newly discovered factor that mediates TGF-β1 signaling. The present study was designed to investigate the role of TGF-β1/miR-21-5p in hepatitis B virus (HBV)-induced liver fibrosis. HBV-infected sodium taurocholate co-transporting polypeptide (NTCP)-transfected Huh7.5.1 cells were co-cultured with LX2 cells to simulate HBV infection in the present study. A total of 29 patients with chronic HBV infection were enrolled. Cells were transfected with miR-21-5p mimic or inhibitor with or without TGF-β1 stimulation. The demographic, biochemical and virological data from the 29 patients were analyzed and liver tissues were collected. miR-21-5p levels and the mRNA and protein expression of α-smooth muscle actin (SMA), collagen type 1 α 1 (CoL1A1), tissue inhibitor of metalloproteinase (TIMP)-1 and Smad from liver cells or tissues were detected by quantitative PCR analysis and western blotting, respectively. Cell viability was observed, and the liver fibrosis score was evaluated. The association between miR-21-5p and liver fibrosis was evaluated by correlation analysis. HBV infection upregulated TGF-β1/miR-21-5p mRNA expression in NTCP-Huh7.5.1 cells compared with mock infection (P<0.05). TGF-β1 incubation significantly increased miR-21-5p levels, as well as the mRNA and protein expression of α-SMA, CoL1A1 and TIMP-1, and reduced Smad7 expression in LX2 cells compared with the normal group, and these effects were counteracted by miR-21-5p inhibitor (P<0.05). miR-21-5p overexpression also contributed to TGF-β1-induced α-SMA, CoL1A1 and TIMP-1 expression in LX2 cells (P<0.05). Co-culture with HBV-infected NTCP-Huh7.5.1 cells upregulated TGF-β1/miR-21-5p activity and CoL1A1 expression in LX2 cells compared with normal control, which were significantly reduced by miR-21-5p inhibitor (P<0.05). miR-21-5p levels were significantly correlated with the liver fibrosis score (r=0.888; P<0.05). These data demonstrated that HBV induced liver fibrosis via the TGF-β1/miR-21-5p pathway and suggested that miR-21-5p may be an effective anti-fibrosis target.