Induction of DTH was mediated by CD8⁺ T cells in pcD-S2 and PZQ immunized group.

<p>A: Twelve days after the second immunization with indicated the combinations, all groups were challenged with the rHBsAg in the right foot pad as test and with a saline solution in the left foot pad as control. The thickness of footpads was measured at 24, 48 and 72 h. B, Mice were depleted of CD4⁺ (CD4del) or CD8⁺ (CD8del) T cells by in vivo injection of specific mAbs. The efficiency of depletion was determined by flow cytometry of splenocytes. The numbers indicate the percentages of CD4⁺ or CD8⁺ T cells. C: Ten days after the second immunization of pcD-S2 plus PZQ, mice were injected i.p. with anti-CD4 mAb, anti-CD8 mAb, or rat IgG and challenged 2 days later with rHBsAg. DTH was measured at 24 h. D: The immunization schedule is shown. The data shown summarizes one of three experiments, all of which demonstrated similar results (* p<0.05; ** p<0.01).