Circumsporozoite Protein-Specific K^d-Restricted CD8+ T Cells Mediate Protective Antimalaria Immunity in Sporozoite-Immunized MHC-I-K^d Transgenic Mice

Figure 4

Protection against plasmodium infection in IrPySpz-immunized MHC-I- 𝐾^𝑑-Tg mice and (MHC-I- 𝐾^𝑑-Tg × CS-Tg) F1 mice. (MHC-I-K^d-Tg × CS-Tg) F1 mice were generated by crossing CS-Tg mice to MHC-I-K^d-Tg mice. Groups (4 mice per group) of naive MHC-I-K^d-Tg mice and MHC-I-K^d-Tg × CS-Tg mice were immunized with 5 × 10⁴ IrPySpz via IM injection. Protection assay was performed by challenge with 1 × 10⁴ infectious P. yoelii sporozoites via IV injection 2 weeks after immunization. Naïve MHC-I-K^d-Tg mice and (MHC-I-K^d-Tg × CS-Tg) F1 mice were also challenged as infection controls. The value of parasite burden was described previously.