Fig. 4.

Drugs containing non-peptidic antigens induce HCV replication inhibition and Vγ9Vδ2 T cell-mediated IFN-γ production. (A) Detection of the presence of HCV replicon in Rep60 cells. Rep60 cells were co-cultured with PBMCs, isolated from healthy donors, either in the absence (Med) or in the presence of IPP, ZOL or Phosphostim (BrHPP). After 4 days of co-culture, the HCV RNA was analyzed by RT–PCR as described in Fig. 1(A). A representative experiment is shown (n = 5). (B) ZOL and BrHPP treatments induce IFN-γ production by Vγ9Vδ2 T cells. PBMCs isolated from healthy donors were treated with either ZOL or BrHPP for 24 h and two-color intracellular flow cytometric analysis was performed as described in Fig. 2(C). The percentage of positive cells is reported. In parentheses the percentage of IFN-γ-producing Vδ2 T cells among total Vδ2 T cells is reported. A representative analysis of one experiment is shown (n = 5). (C) IFN-γ production by Vγ9Vδ2 T cell lines co-cultured with Rep60 and Huh7 cells in a cell–cell contact system. Vγ9Vδ2 T cell lines, >80% pure population obtained as described in Methods, were co-cultured in a cell–cell contact system with Rep60 cells (black circle) or the parental cell line Huh7 (white circle; i.e. not containing the HCV replicon) either untreated (−) or pre-treated for 2 h with ZOL at different doses as indicated. After 16 h of co-culture, the IFN-γ production by Vδ2 T cells was evaluated by two-color intracellular flow cytometric analysis, as described in Fig. 2(C). A representative experiment is shown (n = 3).