cqvip:Dendritic cells (DC) play an important role in the induction of T-cell respon ses. We hypothesize that the hampered antiviral T-cell response in chronic hepa titis B patients is a result of impaired dendritic cell function. In this study, we compared the number, phenotype and functionality of two important blood prec ursor DC, myeloid DC (mDC) and plasmacytoid DC (pDC), of chronic hepatitis B pat ients with healthy volunteers. No differences in percentages of mDC and pDC in p eripheral blood mononuclear cells were observed between chronic hepatitis B pati ents and healthy controls. The allostimulatory capacity of isolated and in vitro matured mDC, but not of pDC, was significantly decreased in patients compared t o controls. Accordingly, a decreased percentage of mDC expressing CD80 and CD86 was observed after maturation, compared to controls. In addition, mDC of patient s showed a reduced capacity to produce tumor necrosis factor αafter a stimulus with synthetic double-stranded RNA and interferon γ. Purified pDC from patient s produced less interferon α, an important antiviral cytokine, in response to s timulation with Stapfylococcus aureus Cowan strain I than pDC isolated from cont rols. In conclusion, mDC and pDC are functionally impaired in patients with chro nic hepatitis B. This might be an important way by which hepatitis B virus evade s an adequate immune response, leading to viral persistence and disease chronici ty.
展开▼
