OBJECTIVETo investigate the effect of synthetic non-methylated CpG-ODN combined with recombined HBsAg on the phenotype, function and the expression level of nucleic transcription factor NF-kappa B (NF-kB) and AP-1 of monocyte-derived dendritic cells (DC) in patients with chronic hepatitis B (CHB).

METHODSPurified monocytes were isolated from the peripheral blood of CHB patients and healthy volunteers and cultured with human granulocyte-monocyte colony stimulating factor added together with interleukin-4. On the fifth day of culture, CpG-ODN, HBsAg and other reagents, such as TNF alpha and PBS, were added to the medium, and 18 hours later cells were collected for the detection of surface molecules (HLA-DR/CD86/CD1a). IL-12p70 levels in the supernatant and stimulating capacity to allogenic T lymphocytes were detected. The nucleic proteins of NF-kB and AP-1 in DC were extracted and purified for the gel shift assay.

RESULTSCompared with those of the PBS group, the expression rates of HLA-DR of DC treated with CpG-ODN and/or HBsAg were obviously increased. Both the IL-12p70 level and the stimulating capacity of DC to allogenic T lymphocytes in mixed lymphocyte reaction increased significantly in the CpG-ODN group and in the CpG-ODN/HBsAg combination group (P less than 0.01 and 0.05, respectively). The expression rates of CD1a were raised only in the CpG-ODN/HBsAg combination group. Three kinds of immunological adjuvants, TNF alpha, CpG-ODN and CpG-ODN/HBsAg enhanced the expression of nucleic NF-kB and inhibited the expression of AP-1 in DC.

CONCLUSIONCpG-ODN, like TNF alpha, has remarkable stimulatory effect on the impaired phenotype and function of monocyte-derived DC in patients with CHB; CpG-ODN and HBsAg have a synergetic effect in increasing the antigen presenting function. The regulating ability of CpG-ODN and TNF alpha on the expression levels of NF-kB and AP-1 might be one of the mechanisms of their immunostimulatory effects on DC of the CHB patients.