FBXO11 and FBXO32 are associated with TRAF3-TBK1-IRF3 signaling components in chronic hepatitis B: evidence from clinical samples and preliminary mechanistic studies.

Abstract

Background: Chronic hepatitis B (CHB) remains a major global health burden despite the availability of effective vaccines and antiviral therapies. F-box proteins have been implicated in diverse biological processes, including immune regulation, but the potential involvement of FBXO11 and FBXO32 in host responses to HBV infection remains poorly understood.

Aim: To investigate the expression patterns of FBXO11 and FBXO32 in CHB patients and explore their potential associations with components of the TRAF3-TBK1-IRF3 signaling pathway.

Methods: We examined the expression levels of FBXO11 and FBXO32 in PBMCs derived from 30 CHB patients and controls. Protein-protein interactions were evaluated using co-immunoprecipitation and immunofluorescence assays in HEK293T cells. The effects of neddylation inhibition on protein expression and complex formation were examined using MLN4921 treatment. CRISPR/Cas9-mediated gene disruption and adeno-associated virus-mediated overexpression approaches were used for exploratory mechanistic studies. An HBV hydrodynamic injection mouse model was utilized to assess in vivo expression patterns.

Results: FBXO11 and FBXO32 expression levels were significantly elevated in PBMCs from CHB patients compared with healthy controls and were accompanied by increased expression of TRAF3-TBK1-IRF3 pathway-related molecules. Co-immunoprecipitation analyses demonstrated associations of FBXO11 and FBXO32 with TRAF3, TBK1, and IRF3 in both clinical samples and HEK293T cells. Reciprocal enhancement of FBXO11 and FBXO32 expression was observed under overexpression conditions. Inhibition of neddylation reduced FBXO11 and FBXO32 protein abundance and weakened their associations with TRAF3-TBK1-IRF3 pathway components. In vivo experiments showed that HBV exposure was accompanied by increased hepatic expression of FBXO11 and FBXO32, and that genetic manipulation effectively altered their expression levels.

Conclusion: FBXO11 and FBXO32 are upregulated in CHB and exhibit associations with components of the TRAF3-TBK1-IRF3 signaling network. These findings provide preliminary evidence supporting potential involvement of FBXO11 and FBXO32 in host immune-related signaling during HBV infection and warrant further investigation in physiologically relevant HBV infection models.