[HBcAg-specific CTL response induced by PTD-HBcAg fusion protein to inhibit HBV replication in vitro]

To investigate the effects of specific cytotoxic T lymphocyte induced by sensitized dendritic cells(DCs)with PTD-HBcAg fusion protein on inhibiting HBV in vitro.

DCs were cultured and induced maturation by different fusion proteins, and cocultured with allogeneic T cells to detect the secretion level of IL-2, IL-4, IL-10 and INF-gamma in the supernatants of T cells by ELISA. Intracellular cytokine of proliferative T cells was analyzed by flow cytometry and the specific CTL activity was measured by a lactate dehydrogenase (LDH) release assay. The levels of HBsAg and HBV DNA in the supernatant of HepG2.2.15 cells were detected.

Sensitized dendritic cells by different fusion proteins could promote cytokine secretion effectively, the levels of IL-2(552.7+/-117.5 ng/L) and INF-gamma(150.6+/-7.945 ng/L)induced by M-PTD-HBcAg were higher than that induced by M-HBcAg (420+/-12.47 ng/L and 107.5+/-12.19 ng/L, respectively).The amount of CTLs induced by PTD-HBcAg fusion protein was more than others by the analysis of intracellular cytokine of proliferative T cells. Specific CTL killing activity could be induced by PTD-HBcAg and HBcAg(P<0.05) and PTD-HBcAg significantly decreased the levels of HBsAg and HBV DNA.

Sensitised DCs by PTD-HBcAg fusion protein can stimulate cytokine secretion and increase cytotoxic T lymphocytes generation effectively, and also enhance the specific CTL activity to decrease the level of HBsAg and HBV DNA in supernatants of HepG2.2.15 cells.