Background and Aims: Cancer stem cells (CSCs) contribute to therapy resistance in HCC. Linear ubiquitin chain assembly complex (LUBAC) has been reported to accelerate the progression of cancers, yet its role in the sorafenib response of HCC is poorly defined. Herein, we investigated the impact of LUBAC on sorafenib resistance and the CSC properties of HCC, and explored the potential targeted drugs. Approach and Results: We found that HOIL-1, but not the other components of LUBAC, played a contributing role in LUBAC-mediated HCC sorafenib resistance, independent of its ubiquitin ligase activity. Both in vitro and in vivo assays revealed that the upregulated HOIL-1 expression enhanced the CSC properties of HCC. Mechanistically, HOIL-1 promoted sorafenib resistance and the CSC properties of HCC through Notch1 signaling. Mass spectrometry, co-immunoprecipitation, western blot, and immunofluorescence were used to determine that the A64/Q65 residues of HOIL-1 bound with the K78 residue of Numb, resulting in impaired Numb-mediated Notch1 lysosomal degradation. Notably, pixantrone was screened out by Autodock Vina, which was validated to disrupt HOIL-1/Numb interaction to inhibit Notch1 signaling and CSC properties by targeting the Q65 residue of HOIL-1. Moreover, pixantrone exerted synergistic effects with sorafenib for the treatment of HCC in different HCC mouse models. Conclusions: HOIL-1 is critical in promoting sorafenib resistance and CSC properties of HCC through Notch1 signaling. Pixantrone targeting HOIL-1 restrains the sorafenib resistance and provides a potential therapeutic intervention for HCC.

BACKGROUND:Hepatitis B core antibody (anti-HBc) is commonly present in patients with chronic hepatitis B virus (HBV) infection and serves as a marker of humoral immunity. Herein, we aim to investigate the correlation between anti-HBc and antiviral immune response and its putative role in HBV control. METHODS:Quantitative anti-HBc and levels of anti-HBc subtypes were measured in chronic hepatitis B (CHB) patients. The effects of anti-HBc on immune cells and HBV replication were evaluated using the HBV mouse models and human hepatoma cell lines. RESULTS:Baseline levels of IgG1 and IgG3 anti-HBc were elevated in CHB patients with favorable treatment response, and correlated with the virological response observed at week 52. Additionally, increased levels of IgM and IgG1 anti-HBc were observed exclusively in CHB patients with liver inflammation. Notably, significant correlations were identified between quantitative levels of anti-HBc and the frequencies of HBcAg-specific CD8+ T cells. Intriguingly, HBcAg efficiently activates T cells aided by B cells in vitro experiments. Moreover, anti-HBc inhibits HBV replication either by a direct effect or through complement-mediated cytotoxicity in HBV-producing cell lines. CONCLUSIONS:Anti-HBc reflects the activation of an HBV-specific CD8+ T cell immune response and may have anti-HBV activity.

Chemodynamic therapy (CDT) has garnered significant attention for treating diverse malignant tumours due to its minimally invasive nature, reduced damage to healthy tissues, and potential mitigation of side effects. However, its application in glioblastoma (GBM) is hindered by the diminished capacity of CDT agents to traverse the blood-brain barrier (BBB), inadequate tumour targeting efficiency, and restricted availability of H2O2 within the tumour microenvironment (TME). To address these challenges, we devised a novel CDT agent (Fe@tFNAs-ANG-3AT) based on a tetrahedral framework nucleic acids (tFNAs). Fe@tFNAs-ANG-3AT was constructed by anchoring iron ions (Fe3+) onto the dual appendages-modified tFNAs. Specifically, one appendage, Angiopep-2 (ANG, a penetrating peptide), facilitates Fe@tFNAs-ANG-3AT penetration across the BBB and selective targeting of tumour cells. Simultaneously, the second appendage, 3-Amino-1,2,4-triazole (3AT, a H2O2 enzyme inhibitor), augments the H2O2 levels required for effective CDT treatment. Upon tumour cell internalization, the loaded Fe3+ in Fe@tFNAs-ANG-3AT is reduced to Fe2+ by the overexpressed glutathione (GSH) in the TME, catalysing the generation of cytotoxic hydroxyl radicals (·OH) and inducing tumour cell death via elevated oxidative stress levels within tumour cells. It is anticipated that Fe@tFNAs-ANG-3AT holds promise as a transformative treatment strategy for GBM.

Individuals with a recent common cold coronavirus infection, which leads to pre‐existing immunity against SARS‐CoV‐2, displayed a less severe course of COVID‐19. However, the relationship between pre‐existing immunity against SARS‐CoV‐2 and the inactivated‐vaccine‐induced immune response is still unknown. Here, 31 healthcare workers who received standard two doses of inactivated COVID‐19 vaccines (Weeks 0 and 4, respectively) were enrolled, vaccine‐induced neutralization and T cell responses were detected, and the correlation between the pre‐existing SARS‐CoV‐2‐specific immunity was analyzed. We found the SARS‐CoV‐2‐specific antibodies, pseudovirus neutralization test (pVNT) titers, and spike‐specific interferon gamma (IFN‐γ) production in CD4 + and CD8 + T cells were significantly elevated after two doses of inactivated vaccines. Interestingly, the pVNT titers after the second dose of vaccination displayed no significant correlation with the pre‐existing SARS‐CoV‐2‐specific antibodies or B cells, nor the pre‐existing spike‐specific CD4 + T cells. Notably, the spike‐specific T cell response after the second dose of vaccination was positively correlated with the pre‐existing receptor binding domain (RBD)‐specific B cells and CD4 + T cells, which were documented by the frequencies of RBD‐binding B cells, the breadth of RBD‐specific B cell epitopes, and the frequency of IFN‐γ‐expressing RBD‐specific CD4 + T cells. Overall, the inactivated‐vaccine‐induced T cell responses, not the inactivated‐vaccine‐induced neutralization, closely correlated with pre‐existing immunity to SARS‐CoV‐2. Our results provide a better understanding of inactivated‐vaccine‐induced immunity and help predict the immunogenicity induced by inactivated vaccines in individuals.

BACKGROUND:Gut microbiota is crucial for immune homeostasis and is associated with the prognosis of chronic hepatitis B infection. Peyer's patches (PPs), characterized by intestinal mucosa localization, are involved in the gut microbiota-mediated immune response. However, whether and how PPs orchestrate gut microbiota-modulated anti-hepatitis B virus (HBV) response remain elusive. This study aims to elucidate the role of PPs in gut microbiota-mediated anti-HBV adaptive immunity.METHODS:We investigated the effects of gut microbiota and PPs on adaptive immune responses by transcriptomic, phenotypic, and functional analyzes from an HBV mouse model with gut commensal microbiota and PP-depleting interventions.RESULTS:Depletion of gut microbiota impaired systemic adaptive immune responses, resulting in a delayed HBV antigen clearance. Differentially expressed genes analysis of PPs revealed that pathways related to adaptive immune responses were significantly downregulated in gut microbiota-deficient mice. Notably, the depletion of PPs could abolish gut microbiota-boosted intrahepatic HBV-specific T cell response, leading to a higher serum hepatitis B surface antigen level in mice.CONCLUSION:PPs orchestrate gut microbiota-mediated intrahepatic anti-HBV cellular immunity, underlining the significance of remote manipulating the "gut microbiota-PPs" axis for achieving optimum anti-HBV response.

Background and Aim: Long-term maintenance of viral control, even HBsAg loss, remains a challenge for chronic hepatitis B (CHB) patients undergoing nucleos(t)ide analogue (NA) discontinuation. This study aimed to investigate the relationship between HBV-specific T-cell responses targeting peptides spanning the whole proteome and clinical outcomes in CHB patients after NA discontinuation. Approach and Results: Eighty-eight CHB patients undergoing NA discontinuation were classified as responders (remained relapse-free up to 96 weeks) or relapsers (relapsed patients who underwent NA retreatment for up to 48 weeks and reachieved stable viral control). HBV-specific T-cell responses were detected at baseline and longitudinally throughout the follow-up. We found responders had a greater magnitude of HBV polymerase (Pol)-specific T-cell responses than relapsers at baseline. After long-term NA discontinuation, simultaneously enhanced HBV Core-induced and Pol-induced responses were observed in responders. Particularly, responders with HBsAg loss possessed enhanced HBV Envelope (Env)-induced responses after short-term and long-term follow-up. Notably, CD4(+)T cells accounted for the predominance of HBV-specific T-cell responses. Correspondingly, CD4-deficient mice showed attenuated HBV-specific CD8(+)T-cell responses, reduced HBsAb-producing B cells, and delayed HBsAg loss; in contrast, in vitro addition of CD4(+)T cells promoted HBsAb production by B cells. Besides, IL-9, rather than PD-1 blockade, enhanced HBV Pol-specific CD4(+)T-cell responses. Conclusion: HBV-specific CD4(+)T-cell responses induced by the targeted peptide possess specificities for long-term viral control and HBsAg loss in CHB patients undergoing NA discontinuation, indicating that CD4(+)T cells specific to distinct HBV antigens may endow with divergent antiviral potential.

The relationship between chronic hepatitis B (CHB) and Coronavirus disease 2019 (COVID-19) has been inconsistent in traditional observational studies. We explored the total causal and direct causal associations between CHB and the three COVID-19 outcomes using univariate and multivariate Mendelian randomization (MR) analyses, respectively. Genome-wide association study datasets for CHB and COVID-19 were obtained from the Japan Biobank and the COVID-19 Host Genetics Initiative, respectively. Univariate MR analysis showed that CHB increased the risk of SARS-CoV-2 infection (OR = 1.04, 95