Fig 5.

Perforin and IFN-γ expressed in CD8⁺ T cells are dispensable for sterile immunity at the liver stage of infection. Activated CD8⁺ T cells from perforin^−/− IFN-γ^−/− OT-I, IFN-γ^−/− OT-I, perforin^−/− OT-I, or wild-type OT-I mice or no cells [(−)] were adoptively transferred into B6 mice, which were then infected with sporozoites (300/mouse) of PbA-hsOVA (A) or PbA-gfpOVA (B), and the levels of parasitemia were monitored. Values significantly different (P < 0.05) from those for mice not receiving OT-I cells are indicated (*). In each graph, the number in parentheses indicates the proportion of OT-I cells in the total CD8⁺ T cell population in PBLs at the time of infection. The experiments were performed 3 times; representative data are shown.