Dysfunction of peripheral blood dendritic cells from patients with chronichepatitis B virus infection

AIM To Identify the property of dendritic cells (DCs) of peripheral blood m onocytes ( PBMC) In patients with chronic HEV Infection. METHODS Twenty patients with persistent HBV Infection were Included In this study, 10 healthy subjects being used as a control group. The peripheral b lood mononuclear cells (PBMC) of T cell-depleted populations were Incubated and Induced into mature dendritic cells in the RPMI-1640 medium in the pre sence of cytokines GMCSF, IL-4, FLt-3, TNF-alpha and 100 mL.L-1 of fetal ca lf serum for a total of 10 - 12 days. The expressions of surface markers on DCs were evaluated using flow cytometric analysis. ELISA method was used t o determine the cytokine levels of interleukin-12 ( IL-12) and IL-10 in the supernatant produced by DCs. For detection of the stimulatory capacity of DCs to T cell proliferation, mytomycin C-treated DC were incubated with all ogenic T cells. RESULTS A typical morphology of mature DCs from healthy subjects and HBV-in fected patients was induced in in vitro incubation, but the proliferation a bility and cellular number of DCs from HBV-infected patients significantly decreased compared with healthy individuals. In particular, the expression levels of HLA-DR, CD80 (B7-1) and CD86 (B7-2) on DC surface from patients w ere also lower than that from healthy individuals (0.46 vs 0.92 for HLA-DR, 0.44 vs 0.88 for CD80 and 0.44 vs 0. 84 for CD86, P < 0.05). The stimulato ry capacity and production of IL-12 of DCs from patients in allogenic mixed lymphocyte reaction (AMLR) significantly decreased, but the production lev el of nitric oxide (NO) by DCs simultaneously increased compared with healt hy subjects (86 +/- 15 vs 170 +/- 22 mu mol.L-1, P <0. 05). CONCLUSION The patients with chronic HBV infection have the defective funct ion and immature phenotype of dendritic cells, which may be associated with the inability of efficient presentation of HBV antigens to host immune sys tem for the clearance of HBV.