Influence of dendritic cells on Th1/Th2 differentiation in patients with chronic hepatitis B

To investigate the functions of dendritic cells(DC) and its influences on the Th1/Th2 differentiation in patients with chronic hepatitis B infection(CHB).The peripheral blood mononuclear cells(PBMC) were isolated and then cultured in RPMI 1640 with recombinant GM-CSF(10 ng/ml) and IL-4(50 ng/ml) to obtain DC,which was further matured by stimulation with recombinant TNF-α(100 ng/ml).The functions of DC stimulating proliferation of allogenic T lymphocytes was detected through MTT method,and the phenotypes of DC,including CD1a,CD83,CD80、CD86,HLA-DR,were detected by flow cytometer(FCM).The CD4+ Th cell subpopulation in peripheral blood was separated by immunomagnetic beads,followed by stimulation with PMA+Ionomycin and then,the differentiation of Th1/Th2 cell was detected by flow cytometry using intracellular fluorescent staining of the IFN-γ and IL-4.The levels of IL-6,IL-12,IFN-γ and IL-4 in culture supernatants of DC or Th cell were detected with ELISA.It was found that the expression of CD1a,CD83,CD80,CD86 and HLA-DR in the DC of the patients with CHB was markedly lower than that of health adults(P0.01).On the 7th culture day,the concentration of IL-12 in patients was also lower,while the IL-6 production was higher than that of control group(P0.05).In comparison with health adults,the percentages of Th1 cells in CD4+ T cells in peripheral blood of CHB patients and the contents of IFN-γ in Th1 cell supernatants of them were both lower(P0.01).When co-cultured with Th cells from allogenic health adults,the capability of the CHB patients' DC to make Th1 cells,characterized with IFN-γ secreation,was remarkably weaker than that of health adults' cells(P0.01).It is evident that Th1 cell differentiation is impaired in patients with CHB,which may be correlated with the dysfunctions of DC.