OBJECTIVETo investigate the compositions of Th1/Th2/Th3 cells in chronic hepatitis B virus (HBV)-infected individuals by determining the expression of interleukin-4 (IL-4), inetrferon-gamma (IFN-gamma), and transform growth factor-beta (TGF-beta) in single CD4(+) T cells isolated from peripheral blood mononuclear cells (PBMCs) and the role of polarized Th cell populations in chronic HBV-infection was discussed.

METHODSPBMCs from chronically infected HBV individuals were isolated, stimulated by PMA/Ionomycin/Monensin, and IL-4, IFN-gamma and TGF-beta production by CD4(+) T cells was determined by using fluorescence activated cell sorter (FACS) analysis.

RESULTSThe percentage of IFN-gamma-producing T cells, IL-4-producing T cells and TGF-beta-producing T cells ranged from 2.3% - 18.6%, 1.1% - 8.7% and 0.7% - 7.1% respectively in CD4(+) T cells from non-infected individuals. Most of CD4(+) T cells from PBMCs in chronically infected HBV individuals were Th0 cells. The proportion of Th1 cells increased significantly with hepatic inflammatory activity, and in the active period of chronic hepatitis B infection were higher than those in the non-active period (P < 0.05). Th2 cell percentage in CD4(+) T cells from HBV-infected individuals did not differ significantly (P > 0.05), but were higher than that from controls (P < 0.05). Th3 cell percentage in CD4(+) T cells from asymptomatic carrier (AsC) group was higher than that in the chronic hepatitis B (CHB) and control groups (P < 0.05).

CONCLUSIONSTh1 phenotype cytokines were positively correlated with hepatic inflammatory activity in chronic hepatitis B and Th2 cells may be associated with the persistence of HBV infection. Th3 cells cooperating with Th2 cells can negatively regulate immune responses and may be associated with the immune tolerant state of chronic HBV infection.