Guanylate-Binding Protein 1 (GBP1) Enhances IFN-α Mediated Antiviral Activity against Hepatitis B Virus Infection.

Interferon-alpha (IFN-α) is a first-line drug for treating chronic hepatitis B (CHB). Guanylate-binding protein 1 (GBP1) is one of the interferon-stimulating factors, which participates in the innate immunity of the host and plays an antiviral and antibacterial role. In this study, we explored how GBP1 is involved in IFN-α antiviral activity against HBV. Before being gathered, HepG2-NTCP and HepG2 2.15 cells were transfected with the wild-type hGBP1 plasmid or si-GBP1, respectively, and followed by stimulation with Peg-IFNα-2b. We systematically explored the role of GBP1 in regulating HBV infection in cell models. Additionally, we also examined GBP1 levels in CHB patients. GBP1 activity increased, and its half-life was prolonged after HBV infection. Overexpression of GBP1 inhibited the production of HBsAg and HBeAg, as well as HBs protein and HBV total RNA levels, whereas silencing of GBP1 inhibited its ability to block viral infections. Interestingly, overexpressing GBP1 co-treatment with Peg-IFNα-2b further increased the antiviral effect of IFN-α, while GBP1 silencing co-treatment with Peg-IFNα-2b partly restored its inhibitory effect on HBV. Mechanistically, GBP1 mediates the anti-HBV response of Peg-IFNα-2b by targeting HBs. Analysis of clinical samples revealed that GBP1 was elevated in CHB patients and increased with Peg-IFNα-2b treatment, while GBP1 showed good stability in the interferon response group. Our study demonstrates that GBP1 inhibits HBV replication and promotes HBsAg clearance. It is possible to achieve antiviral effects through the regulation of IFN-α induced immune responses in response to HBV.

Risk of HBV reactivation in HCC patients undergoing combination therapy of PD-1 inhibitors and angiogenesis inhibitors in the antiviral era.

BACKGROUND: Although routine antiviral therapy has been implemented in HCC patients, the risk of HBV reactivation (HBVr) remains with the use of programmed cell death-1(PD-1) blockade-based combination immunotherapy and the relevant risk factors are also unclear. Therefore, we aimed to identify the incidence and risk factors of HBVr in HCC patients undergoing combination therapy of PD-1 inhibitors and angiogenesis inhibitors and concurrent first-line antivirals. METHODS: We included a total of 218 HBV-related HCC patients with first-line antivirals who received PD-1 inhibitors alone or together with angiogenesis inhibitors. According to the anti-tumor therapy modalities, patients were divided into PD-1 inhibitors monotherapy group (anti-PD-1 group) and combination therapy group (anti-PD-1 plus angiogenesis inhibitors group). The primary study endpoint was the incidence of HBVr. RESULTS: HBVr occurred in 16 (7.3%) of the 218 patients, 2 cases were found in the anti-PD-1 group and the remaining 14 cases were in the combination group. The Cox proportional hazard model identified 2 independent risk factors for HBVr: combination therapy (hazard ratio [HR], 4.608, 95%CI 1.010-21.016, P = 0.048) and hepatitis B e antigen (HBeAg) positive (HR, 3.695, 95%CI 1.246-10.957, P = 0.018). Based on the above results, we developed a simple risk-scoring system and found that the high-risk group (score = 2) developed HBVr more frequently than the low-risk group (score = 0) (Odds ratio [OR], 17.000, 95%CI 1.946-148.526, P = 0.01). The area under the ROC curve (AUC-ROC) was 7.06 (95%CI 0.581-0.831, P = 0.006). CONCLUSION: HBeAg-positive patients receiving combination therapy have a 17-fold higher risk of HBVr than HBeAg-negative patients with PD-1 inhibitors monotherapy.