Functional change of human peripheral blood monocyte-derived dendritic cells after recombinant adeno-associated virus type 2-mediated HBsAg gene infection.

OBJECTIVE: To observe the changes in the functions of human peripheral blood monocyte-derived dendritic cells (DCs) after hepatitis B virus surface antigen (HBsAg) gene infection mediated by recombinant adeno-associated virus type 2 (rAAV). METHODS: The levels of both interleukin (IL)-12 in the supernatant of in vitro cultured DCs infected with rAAV-HbsAg and interferon gamma (IFN-gamma) in the supernatant of the lymphocyte populations co-cultured with DCs were determined by ELISA. The functions of the rAAV-HbsAg-infected DCs were assessed by mixed leukocyte reaction (MLR), and the changes of the surface markers (including CD80, CD83, CD86 and HLA-DR) in response to the infection were detected by flow cytometry. RESULTS: After rAAV-HBsAg infection, the IL-12 secretion of DCs was significantly enhanced (P <0.05), while IFN-gamma production by the lymphocyte populations co-cultured with rAAV-HbsAg-infected DCs was reduced (P <0.01). rAAV-HBsAg infection of DCs did not affect the surface marker expressions and stimulation ability of the DCs in allogeneic lymphocytes reaction. CONCLUSION: DCs infected by rAAV-HBsAg are more efficient than naive DCs in eliciting the differentiation of the lymphocytes toward T helper type I cells, but the functions and the surface markers of DCs remain unaffected after the infection, suggesting the applicability of rAAV as a potentially useful vector for HBsAg gene transfer into the DCs for HBV immunotherapy.