Peyer's patch-involved gut microbiota facilitates anti-HBV immunity in mice.

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.

Interferon α facilitates anti-HBV cellular immune response in a B cell-dependent manner.

OBJECTIVES: Dissecting the underlying mechanism of T cells remodeling mediated by interferon α (IFN-α) is indispensable for achieving an optimum therapeutic response in chronic hepatitis B (CHB) patients. However, little is known about B cells in this process. This study aims to elucidate the roles of B cells in IFN-α-mediated anti-hepatitis B virus (HBV) cellular immunity. METHOD: The effects of B cells on IFN-α-mediated T cell response were investigated in B cell-deficient mouse model with HBV and IFN-α plasmid hydrodynamic injection. Single-cell RNA sequencing was performed to dissect the crosstalk among B cell and T cell subsets and the underlying molecule and pathway signatures on longitudinal blood samples from IFN-α-treated CHB patients. RESULTS: B cell depletion impaired the functional T cell subsets, including HBV-specific CD8+ T cells, and engendered a delayed HBV clearance. IFN-α treatment boosted the response of HBV-specific CD8+ T cells, whereas such effects disappeared in B cell-deficient mice. The underlying mechanisms were associated with IFN-α-reinforced connections of B cells toward T cells as mediated by the antigen presentation and costimulatory functions in B cells. CONCLUSION: IFN-α orchestrates protective HBV-specific cellular immunity in a B cell-dependent manner.

Downregulation of GRIM-19 is associated with hyperactivation of p-STAT3 in hepatocellular carcinoma.

Accumulating evidence has implicated that constitutive activation of signal transducer and activator of transcription protein 3 (STAT3) may be a major oncogenic factor involved in hepatocellular carcinoma (HCC) development. Gene associated with retinoid-interferon-induced mortality-19 (GRIM-19) has been shown to be a tumor suppressor associated with growth control and suppression of STAT3 activity. The downregulation of GRIM-19 expression has been shown in a number of human tumor types, and it has been correlated with hyperactivation of STAT3. However, the role of GRIM-19 in the pathogenesis of HCC has not been evaluated. The aim of our study was to evaluate GRIM-19 expression levels and investigate their correlation with phosphorylated STAT3 (p-STAT3) levels in HCC. GRIM-19 and p-STAT3 expression levels were analyzed in HCC and adjacent nontumorous liver tissues (ANLT) by immunohistochemistry, western blot analysis, and RT-PCR. GRIM-19 protein expression was predominantly located in the cytoplasm with weak staining in the nucleus in ANLT, but only located in the cytoplasm in HCC tissues. HCC samples exhibited low levels of GRIM-19 and moderate to high levels of p-STAT3 expression. In contrast, ANLT was characterized by high levels of GRIM-19 and low levels of p-STAT3 expression. Downregulation of GRIM-19 was closely correlated with increased histological grade in HCC. GRIM-19 expression is closely correlated with histological grading and p-STAT3 in HCC. Thus, the potential role of GRIM-19 in HCC development may be through these correlations.