Objective: To investigate the characteristics of phenotype and function of myeloid dendritic cells (mDCs) pulsed with HBV antigens derived from HBV-associated hepatocellular carcinoma (HCC) patients.
Methods: Peripheral blood mononuclear cells (PBMCs) were collected, using blood cell separator, from 21 primary HCC patients and 4 healthy donors. mDCs were propagated in serum-free AIM-V medium in the presence of cytokine cocktail, and pulsed with HBcAg or HBsAg. After 9 days' incubation, the phenotypic patterns of mDC were characterized by flow cytometry and the levels of IL-10 and IL-12 produced by mDCs were analyzed by ELISA. Autologous T cells proliferation stimulated by mDC was tested by non-radioactive cell proliferation assay kit.
Results: The expression rates of CD80, CD86, CD40, and HLA-DR in the mDCs pulsed with HBcAg were 55% +/- 26%, 80% +/- 13%, 70% +/- 13% and 73% +/- 24% respectively, significantly higher than those of the control group (29% +/- 25%, 35% +/- 18%, 44% +/- 26% and 45% +/- 23% respectively, all P < 0.05). Among the expression rates of surface molecules of the mDCs pulsed with HBsAg only the expression rate of HLA-DR was significantly higher than that of the un-pulsed mDCs (63% +/- 15% vs 45% +/- 23%, P < 0.05). T cell proliferation assay revealed an impaired allostimulatory capacity of mDCs in HCC and the stimulatory capacity of the mDCs pulsed with HBcAg to induce proliferation of autologous T cells was more powerful than that pulsed with HBsAg (P < 0.05). The levels of IL-10 and IL-12 produced by the mDCs pulsed with HBsAg were (35 pg/ml +/- 9 pg/ml and 135 pg/ml +/- 63 pg/ml respectively, both significantly lower than those pulsed with HBcAg (236 pg/ml +/- 95 pg/ml and 733 pg/ml +/- 212 pg/ml respectively, both P < 0.05).
Conclusion: Pulsation of mDCs in vitro by HBcAg or HBsAg enhance the expression of CD80, CD86, CD40, and HLA-DR, and increase the ability of mDCs to stimulate the proliferation of autologous T lymphocytes.