Aim: 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.
Methods: 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.
Results: 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.
Conclusion: 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.