Objective To investigate the functional changes of dendritic cells(DCs)in patients at different stages of hepatitis B virus(HBV)infection and analyze the mechanisms underlying DC dysfunction.Methods Single-cell RNA sequencing dataset GSE182159 was downloaded from the GEO database and classified into healthy control(HC),immune active(IA),and immune tolerant(IT)groups based on infection stage.Peripheral blood samples were collected from 7 IA patients,7 IT patients,and 12 healthy controls.Flow cytometry was used to isolate classical dendritic cells(cDC)and plasmacytoid dendritic cells(pDC).The expression levels of transcription factors in cDC and pDC were measured by quantitative real-time PCR(qRT-PCR).Bioinformatics analyses were per-formed using R and Python package.Results The proportions of DCs in IA and IT groups were higher than that in HC group.Func-tional enrichment analysis revealed that the differentially expressed genes(DEGs)of cDCs in the IA group were primarily enriched for the processes,such as inflammatory response,MHC classⅡantigen processing and presentation,cell migration,signal transduction,metabolism,and immune response.In contrast the IT group exhibited lower enrichment intensity and a significant reduction in interfer-on responses.The DEGs of pDC in the IA group were enriched in the processes of MHC-Ⅱantigen presentation,Fc receptor signal transduction,and metabolism,whereas those in the IT group were showed enrichment only in Fc receptor signal transduction and me-tabolism with a lower intensity.Both groups exhibited reduced synthesis of typesⅠandⅡinterferons in pDC,with the IT group showing a more pronounced downregulation.Cell-cell communication analysis demonstrated enhanced interactions between myeloid cells(except pDC)and T cells in the IA group,whereas the interactions between cDC/pDC and T cells in the IT group were reduced.Transcription factor analysis revealed that STAT2,STAT3,IRF1,and IRF5 were highly expressed in the IA group but their expression exhibited low-er expression levels in the IT group.In contrast,BHLHE40 was broadly upregulated in both cDC and pDC subsets within the IT group.The qRT-PCR results were consistent with the findings from the single-cell transcription factor analysis.Conclusion The IT phase of hepatitis B infection represents a critical period for cDC dysfunction,characterized by significant suppression of MHCⅡantigen presen-tation,metabolism,and interferon responsiveness.The functional impairment of pDC precedes that of cDC,as evidenced by a marked downregulation of interferon synthesis capacity observed during the IA phase.

Objective To investigate the functional changes of dendritic cells(DCs)in patients at different stages of hepatitis B virus(HBV)infection and analyze the mechanisms underlying DC dysfunction.Methods Single-cell RNA sequencing dataset GSE182159 was downloaded from the GEO database and classified into healthy control(HC),immune active(IA),and immune tolerant(IT)groups based on infection stage.Peripheral blood samples were collected from 7 IA patients,7 IT patients,and 12 healthy controls.Flow cytometry was used to isolate classical dendritic cells(cDC)and plasmacytoid dendritic cells(pDC).The expression levels of transcription factors in cDC and pDC were measured by quantitative real-time PCR(qRT-PCR).Bioinformatics analyses were per-formed using R and Python package.Results The proportions of DCs in IA and IT groups were higher than that in HC group.Func-tional enrichment analysis revealed that the differentially expressed genes(DEGs)of cDCs in the IA group were primarily enriched for the processes,such as inflammatory response,MHC classⅡantigen processing and presentation,cell migration,signal transduction,metabolism,and immune response.In contrast the IT group exhibited lower enrichment intensity and a significant reduction in interfer-on responses.The DEGs of pDC in the IA group were enriched in the processes of MHC-Ⅱantigen presentation,Fc receptor signal transduction,and metabolism,whereas those in the IT group were showed enrichment only in Fc receptor signal transduction and me-tabolism with a lower intensity.Both groups exhibited reduced synthesis of typesⅠandⅡinterferons in pDC,with the IT group showing a more pronounced downregulation.Cell-cell communication analysis demonstrated enhanced interactions between myeloid cells(except pDC)and T cells in the IA group,whereas the interactions between cDC/pDC and T cells in the IT group were reduced.Transcription factor analysis revealed that STAT2,STAT3,IRF1,and IRF5 were highly expressed in the IA group but their expression exhibited low-er expression levels in the IT group.In contrast,BHLHE40 was broadly upregulated in both cDC and pDC subsets within the IT group.The qRT-PCR results were consistent with the findings from the single-cell transcription factor analysis.Conclusion The IT phase of hepatitis B infection represents a critical period for cDC dysfunction,characterized by significant suppression of MHCⅡantigen presen-tation,metabolism,and interferon responsiveness.The functional impairment of pDC precedes that of cDC,as evidenced by a marked downregulation of interferon synthesis capacity observed during the IA phase.

Chronic hepatitis B (CHB) virus infection is an important threat to global health despite the administration of vaccines and the use of antiviral treatments. In recent years, as the prevalence of obesity and metabolic syndrome has increased, non-alcoholic fatty liver disease (NAFLD) in patients with CHB has become more common. Both diseases can lead to liver fibrosis and even hepatocellular carcinoma, but the risk of dual etiology, outcome, and CHB combined with NAFLD is not fully elucidated. In this review, we assess the overlapping prevalence of NAFLD and CHB, summarize recent studies of clinical and basic research related to potential interactions, and evaluate the progressive changes of treatments for CHB patients with NAFLD. This review increases the understanding of the relationship and mechanisms of interaction between steatosis and hepatitis B virus infection, and it provides new strategies for the future clinical management and treatment of CHB combined with NAFLD.