Gut microbiota of hepatitis B virus-infected patients in the immunetolerant and immune-active phases and their implications in metabolite changes

BACKGROUND The microbes and metabolomics of microbiota dysbiosis in the gut in the different phases of hepatitis B virus(HBV) infection are not fully understood.AIM To investigate the specific gut microbiota and metabolites of the immune-tolerant(IT) and immune-active(IA) phases of chronic hepatitis B(CHB).METHODS Clinical fecal samples from healthy individuals and patients in the IT and IA phases of HBV infection were collected. Next, non-target metabolomics, bioinformatics, and 16S rDNA sequencing analyses were performed.RESULTS A total of 293 different metabolites in 14 phyla, 22 classes, 29 orders, 51 families, and 190 genera were identified. The four phyla of Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria were the most abundant, accounting for 99.72%, 99.79%, and 99.55% in the healthy controls, IT-phase patients, and IA-phase patients, respectively. We further identified 16 genera with different richness in the IT phase and IA phase of HBV infection. Of the 134 named metabolites, 57 were upregulated and 77 were downregulated. A total of 101 different metabolic functions were predicted in this study, with 6 metabolic pathways having the highest enrichments, namely carbohydrate metabolism(14.85%), amino acid metabolism(12.87%), lipid metabolism(11.88%), metabolism of cofactors and vitamins(11.88%), xenobiotic biodegradation(9.9%), and metabolism of terpenoids and polyketides(7.92%).CONCLUSION These findings provide observational evidence of compositional alterations of the gut microbiome and some related metabolites in patients with IT-phase or IA-phase HBV infection. Further studies should investigate whether microbiota modulation can facilitate the progression of CHB and the cause-effect relationship between the gut microbiota and CHB.

Overcoming HBV immune tolerance to eliminate HBsAg-positive hepatocytes via pre-administration of GM-CSF as a novel adjuvant for a hepatitis B vaccine in HBV transgenic mice

Granulocyte-macrophage colony-stimulating factor （GM-CSF） is known to be a potential vaccine adjuvant despite contradictory results from animal and human studies. The discrepancies may be due to the different doses and regimens of GM-CSF that were used, given that either mature or immature dendritic cells （DCs） could be induced under different conditions. To test the hypothesis that GM-CSF can be used as a novel adjuvant for a hepatitis B virus （HBV） therapeutic vaccine, we administered GM-CSF once per day for three days prior to vaccination with recombinant HBV vaccine （rHBVvac） in mice. We observed greater DC maturation in these pre-treated animals at day 3 as compared to day 1 or day 2 of daily GM-CSF administration. This strategy was further investigated for its ability to break the immune tolerance established in hepatitis B surface antigen-transgenic （HBsAg-Tg） animals. We found that the levels of induced anti-HBsAg antibodies were significantly higher in animals following three days of GM-CSF pre-treatment before rHBV vaccination after the third immunization. In addition to the increase in anti-HBsAg antibody levels, cell-mediated anti-HBsAg responses, including delayed-type hypersensitivity, T-cell proliferation, interferon-y production, and cytotoxic T lymphocytes, were dramatically enhanced in the three-day GM-CSF pre-treated group. After adoptive transfers of CD8＋ T cells from immunized animals, antigen-specific CD8＋ T cells were observed in the livers of recipient HBsAg-Tg animals. Moreover, the three-day pre-treatments with GM-CSF prior to rHBVvac vaccination could significantly eliminate HBsAg-positive hepatocytes, suggesting beneficial therapeutic effects. Therefore, this protocol utilizing GM-CSF as an adjuvant in combination with the rHBVvac vaccine has the potential to become a novel immunotherapy for chronic hepatitis B patients.

Ratios of T-helper 2 Cells to T-helper 1 Cells and Cytokine Levels in Patients with Hepatitis B

Background：Hepatitis B is an immune response-mediated disease.The aim of this study was to explore the differences of ratios of T-helper （Th） 2 cells to Thl cells and cytokine levels in acute hepatitis B （AHB） patients and chronic hepatitis B virus （HBV）-infected patients in immune-tolerance and immune-active phases.Methods：Thirty chronic HBV-infected patients in the immune-tolerant phase （IT group） and 50 chronic hepatitis B patients in the immuneactive （clearance） phase （IC group）,32 AHB patients （AHB group）,and 13 healthy individuals （HI group） were enrolled in the study.Th cell proportions in peripheral blood,cytokine levels in plasma,and serum levels of HBV DNA,hepatitis B surface antigen,and hepatitis B e antigen were detected.Results：The Th1 cell percentage and Th2/Th1 ratio in the HBV infection group （including IT,IC,and AHB groups） were significantly different from those in HI group （24.10% ± 8.66% and 1.72 ± 0.61 vs.15.16% ± 4.34% and 2.40 ± 0.74,respectively;all P 〈 0.001）.However,there were no differences in the Th1 cell percentages and Th2/Th1 ratios among the IT,IC,and AHB groups.In HBV infection group,the median levels of Flt3 ligand （Flt3L）,interferon （IFN）-γ,and interleukin （IL）-17A were significantly lower than those in HI group （29.26 pg/ml,33.72 pg/ml,and 12.27 pg/ml vs.108.54 pg/ml,66.48 pg/ml,and 35.96 pg/ml,respectively;all P 〈 0.05）.IFN-α2,IL-10,and transforming growth factor （TGF）-β2 median levels in hepatitis group （including patients in AHB and IC groups） were significantly higher than those in IT group （40.14 pg/ml,13.58 pg/ml,and 557.41 pg/ml vs.16.74 pg/ml,6.80 pg/ml,and 419.01 pg/ml,respectively;all P 〈 0.05）,while patients in hepatitis group had significant lower Flt3L level than IT patients （30.77 vs.59.96 pg/ml,P =0.021）.Compared with IC group,patients in AHB group had significant higher median level s of IL-1 0,TGF-β 1,and TGF-β2 （22.77 pg/ml,10,447.00 pg/ml,and 782.28 pg/ml vs.8.66 pg/ml,3755.50 pg/ml,and 482.87 pg/ml,respectively;all P 〈 0.05）.Conclusions：Compared with chronic HBV-infected patients in immune-tolerance phase,chronic HBV-infected patients in immune-active phase and AHB patients had similar Th2/Th 1 ratios,significantly higher levels of IFN-α2,IL-10,and TGF-β.AHB patients had significantly higher IL-10 and TGF-β levels than chronic HBV-infected patients in immune-active phase.