Vγ9Vδ2 T cells degranulate in the presence of trophozoites and merozoites in a TCR-dependent mechanism. The S1 and JT Vγ9Vδ2 T-cell lines were incubated for 6 hours with uiRBCs, purified schizonts (Schiz), or merozoites (Mero), and CD107a surface expression was detected as described in “Methods.” (A) Representative flow cytometry dot-plot showing the gating strategy for Vδ2⁺ T cells and for detection of CD107a surface expression on gated cells after incubation with uiRBCs or schizonts. (B) Percentage of CD107a⁺ cells from S1 and JT cell lines incubated in CM or with uiRBCs, purified schizonts, or merozoites at decreasing E/T ratios (1/10, 1/5, and 1/2.5). Data represent mean ± SD of 4 independent experiments (n = 4) and were obtained by collecting of 10 000 Vδ2⁺ events (*P ≤ .05 by Mann-Whitney rank sum test comparing cells incubated with uiRBCs, schizonts, or merozoites with cells incubated in CM). (C) Percentage of CD107a⁺ cells among S1 and JT cells, or among control T cells (a Vγ4Vδ5 T-cell line, a Vδ3VγI T-cell line, and an αβ T4A.5 T-cell clone) incubated in uiRBCs, purified schizonts, or merozoites at 1/10 E/T ratio. The figure is representative of 3 independent experiments (n = 3). (D) Percentage of CD107a⁺ cells among S1 (top) and JT cells (bottom) preincubated for 1 hour with 1, 0.5, 0.1, and 0.01 μg/mL of anti-Vδ2 (IgG1, clone immu389) or anti-NKG2D (IgG1, clone 149810) blocking antibodies and then incubated with uiRBCs, purified schizonts, or merozoites at 1/10 E/T ratio. Data represent mean ± SD of 4 independent experiments (n = 4) and were obtained by collecting 10 000 Vδ2⁺ events (*P ≤ .05 by Mann-Whitney rank sum test comparing cells incubated with different concentrations of anti-Vδ2 or anti-NKG2D blocking antibodies with untreated cells on schizont or merozoite stimulation).