OBJECTIVERegarding the strong antigen-presenting abilities of dendritic cells (DC), this study was carried out based on the induction and proliferation of DC derived from human umbilical cord blood; the anti-HBV effect of cytotoxicity T lymphocytes (CTL) activated by those DC pulsed with HBsAg was also carried out to explore a new way to activate the HBsAg-specific CTL.

METHODSCord blood was collected from the cord veins of normal placentae after Cesarean sections, from which cord blood mononuclear cells (CBMC) were separated through density gradient centrifugation. The CBMC were cultured in RPMI 1640 with a cytokine cocktail. Pulsed with HBsAg, the DC were prepared to activate the HBsAg-specific CTL among the CBMC. The cytotoxic effect of CBMCs activated by the DC primed with HBsAg was assayed through the killing of those HepG2-S target cells.

RESULTSTypical DC could be induced from CMBC cultured with a cytokine cocktail. DC pulsed by HBsAg activated HBsAg-specific CTL, which killed the target HepG2-S cells to some extent.

CONCLUSIONDC can be induced from CMBC with the cytokine cocktail and they show a strong antigen-presenting ability. DC produced in this way and pulsed by HBsAg can activate HBsAg-specific CTL in vitro. This might mean that it could be a new way to break the tolerance to HBV in chronic HBV-infected patients.